From 0d8fd571458be8799e9a62940e0f458250752cf3 Mon Sep 17 00:00:00 2001
From: Thomas Stuefe <stuefe@openjdk.org>
Date: Wed, 21 Jun 2023 04:55:43 +0000
Subject: [PATCH 01/19] 8310265: (process) jspawnhelper should not use argv[0]

Reviewed-by: simonis, rriggs
---
 .../unix/native/jspawnhelper/jspawnhelper.c          |  4 ++--
 src/java.base/unix/native/libjava/ProcessImpl_md.c   | 12 ++++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/java.base/unix/native/jspawnhelper/jspawnhelper.c b/src/java.base/unix/native/jspawnhelper/jspawnhelper.c
index 16845901589..5a583fda61f 100644
--- a/src/java.base/unix/native/jspawnhelper/jspawnhelper.c
+++ b/src/java.base/unix/native/jspawnhelper/jspawnhelper.c
@@ -136,14 +136,14 @@ void initChildStuff (int fdin, int fdout, ChildStuff *c) {
 int main(int argc, char *argv[]) {
     ChildStuff c;
     struct stat buf;
-    /* argv[0] contains the fd number to read all the child info */
+    /* argv[1] contains the fd number to read all the child info */
     int r, fdinr, fdinw, fdout;
     sigset_t unblock_signals;
 
 #ifdef DEBUG
     jtregSimulateCrash(0, 4);
 #endif
-    r = sscanf (argv[argc-1], "%d:%d:%d", &fdinr, &fdinw, &fdout);
+    r = sscanf (argv[1], "%d:%d:%d", &fdinr, &fdinw, &fdout);
     if (r == 3 && fcntl(fdinr, F_GETFD) != -1 && fcntl(fdinw, F_GETFD) != -1) {
         fstat(fdinr, &buf);
         if (!S_ISFIFO(buf.st_mode))
diff --git a/src/java.base/unix/native/libjava/ProcessImpl_md.c b/src/java.base/unix/native/libjava/ProcessImpl_md.c
index 66c44956b21..04a1e5cf6b5 100644
--- a/src/java.base/unix/native/libjava/ProcessImpl_md.c
+++ b/src/java.base/unix/native/libjava/ProcessImpl_md.c
@@ -488,16 +488,20 @@ spawnChild(JNIEnv *env, jobject process, ChildStuff *c, const char *helperpath)
     pid_t resultPid;
     int i, offset, rval, bufsize, magic;
     char *buf, buf1[(3 * 11) + 3]; // "%d:%d:%d\0"
-    char *hlpargs[2];
+    char *hlpargs[3];
     SpawnInfo sp;
 
     /* need to tell helper which fd is for receiving the childstuff
      * and which fd to send response back on
      */
     snprintf(buf1, sizeof(buf1), "%d:%d:%d", c->childenv[0], c->childenv[1], c->fail[1]);
-    /* put the fd string as argument to the helper cmd */
-    hlpargs[0] = buf1;
-    hlpargs[1] = 0;
+    /* NULL-terminated argv array.
+     * argv[0] contains path to jspawnhelper, to follow conventions.
+     * argv[1] contains the fd string as argument to jspawnhelper
+     */
+    hlpargs[0] = (char*)helperpath;
+    hlpargs[1] = buf1;
+    hlpargs[2] = NULL;
 
     /* Following items are sent down the pipe to the helper
      * after it is spawned.

From b8f5e3d93280bf99c6e7a3a9ddb34d84c1d2e32f Mon Sep 17 00:00:00 2001
From: Emanuel Peter <epeter@openjdk.org>
Date: Wed, 21 Jun 2023 06:40:50 +0000
Subject: [PATCH 02/19] 8308606: C2 SuperWord: remove alignment checks when not
 required

Reviewed-by: fgao, kvn, pli
---
 .../superword/TestDependencyOffsets.java      |  76 ++---
 .../runner/LoopArrayIndexComputeTest.java     |  89 ++++-
 .../bench/vm/compiler/VectorAlignment.java    | 315 ++++++++++++++++++
 3 files changed, 432 insertions(+), 48 deletions(-)
 create mode 100644 test/micro/org/openjdk/bench/vm/compiler/VectorAlignment.java

diff --git a/test/hotspot/jtreg/compiler/loopopts/superword/TestDependencyOffsets.java b/test/hotspot/jtreg/compiler/loopopts/superword/TestDependencyOffsets.java
index 9130571a406..14033f9712a 100644
--- a/test/hotspot/jtreg/compiler/loopopts/superword/TestDependencyOffsets.java
+++ b/test/hotspot/jtreg/compiler/loopopts/superword/TestDependencyOffsets.java
@@ -25,10 +25,9 @@
  * Summary:
  *   Test SuperWord vectorization with different access offsets
  *   and various MaxVectorSize values, and +- AlignVector.
- *   Note: CompileCommand Option Vectorize is enabled.
  *
  * Note: this test is auto-generated. Please modify / generate with script:
- *       https://bugs.openjdk.org/browse/JDK-8298935
+ *       https://bugs.openjdk.org/browse/JDK-8308606
  *
  * Types: int, long, short, char, byte, float, double
  * Offsets: 0, -1, 1, -2, 2, -3, 3, -4, 4, -7, 7, -8, 8, -14, 14, -16, 16, -18, 18, -20, 20, -31, 31, -32, 32, -63, 63, -64, 64, -65, 65, -128, 128, -129, 129, -192, 192
@@ -91,7 +90,7 @@
 
 /*
  * @test id=vanilla-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @library /test/lib /
@@ -100,7 +99,7 @@
 
 /*
  * @test id=vanilla-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @library /test/lib /
@@ -109,7 +108,7 @@
 
 /*
  * @test id=sse4-v016-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -120,7 +119,7 @@
 
 /*
  * @test id=sse4-v016-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -131,7 +130,7 @@
 
 /*
  * @test id=sse4-v008-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -142,7 +141,7 @@
 
 /*
  * @test id=sse4-v008-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -153,7 +152,7 @@
 
 /*
  * @test id=sse4-v004-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -164,7 +163,7 @@
 
 /*
  * @test id=sse4-v004-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -175,7 +174,7 @@
 
 /*
  * @test id=sse4-v002-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -186,7 +185,7 @@
 
 /*
  * @test id=sse4-v002-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -197,7 +196,7 @@
 
 /*
  * @test id=avx1-v032-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -208,7 +207,7 @@
 
 /*
  * @test id=avx1-v032-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -219,7 +218,7 @@
 
 /*
  * @test id=avx1-v016-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -230,7 +229,7 @@
 
 /*
  * @test id=avx1-v016-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -241,7 +240,7 @@
 
 /*
  * @test id=avx2-v032-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -252,7 +251,7 @@
 
 /*
  * @test id=avx2-v032-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -263,7 +262,7 @@
 
 /*
  * @test id=avx2-v016-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -274,7 +273,7 @@
 
 /*
  * @test id=avx2-v016-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -285,7 +284,7 @@
 
 /*
  * @test id=avx512-v064-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -296,7 +295,7 @@
 
 /*
  * @test id=avx512-v064-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -307,7 +306,7 @@
 
 /*
  * @test id=avx512-v032-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -318,7 +317,7 @@
 
 /*
  * @test id=avx512-v032-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -329,7 +328,7 @@
 
 /*
  * @test id=avx512bw-v064-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -340,7 +339,7 @@
 
 /*
  * @test id=avx512bw-v064-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -351,7 +350,7 @@
 
 /*
  * @test id=avx512bw-v032-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -362,7 +361,7 @@
 
 /*
  * @test id=avx512bw-v032-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64")
@@ -373,7 +372,7 @@
 
 /*
  * @test id=vec-v064-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -383,7 +382,7 @@
 
 /*
  * @test id=vec-v064-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -393,7 +392,7 @@
 
 /*
  * @test id=vec-v032-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -403,7 +402,7 @@
 
 /*
  * @test id=vec-v032-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -413,7 +412,7 @@
 
 /*
  * @test id=vec-v016-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -423,7 +422,7 @@
 
 /*
  * @test id=vec-v016-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -433,7 +432,7 @@
 
 /*
  * @test id=vec-v008-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -443,7 +442,7 @@
 
 /*
  * @test id=vec-v008-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -453,7 +452,7 @@
 
 /*
  * @test id=vec-v004-A
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -463,7 +462,7 @@
 
 /*
  * @test id=vec-v004-U
- * @bug 8298935
+ * @bug 8298935 8308606
  * @summary Test SuperWord: vector size, offsets, dependencies, alignment.
  * @requires vm.compiler2.enabled
  * @requires (os.arch!="x86" & os.arch!="i386" & os.arch!="amd64" & os.arch!="x86_64")
@@ -1262,7 +1261,6 @@ public class TestDependencyOffsets {
     public static void main(String args[]) {
         TestFramework framework = new TestFramework(TestDependencyOffsets.class);
         framework.addFlags("-XX:-TieredCompilation",
-                           "-XX:CompileCommand=option,compiler.loopopts.superword.TestDependencyOffsets::test*,Vectorize",
                            "-XX:CompileCommand=compileonly,compiler.loopopts.superword.TestDependencyOffsets::init",
                            "-XX:CompileCommand=compileonly,compiler.loopopts.superword.TestDependencyOffsets::test*",
                            "-XX:CompileCommand=compileonly,compiler.loopopts.superword.TestDependencyOffsets::verify",
diff --git a/test/hotspot/jtreg/compiler/vectorization/runner/LoopArrayIndexComputeTest.java b/test/hotspot/jtreg/compiler/vectorization/runner/LoopArrayIndexComputeTest.java
index e09c58d8dbd..cc35213e5db 100644
--- a/test/hotspot/jtreg/compiler/vectorization/runner/LoopArrayIndexComputeTest.java
+++ b/test/hotspot/jtreg/compiler/vectorization/runner/LoopArrayIndexComputeTest.java
@@ -161,9 +161,11 @@ public int[] indexWithTwoInvariants() {
     }
 
     @Test
-    // Note that this case cannot be vectorized due to data dependence.
-    @IR(failOn = {IRNode.STORE_VECTOR})
-    public int[] indexWithDifferentConstants() {
+    // No true dependency in read-forward case.
+    @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
+        applyIf = {"AlignVector", "false"},
+        counts = {IRNode.STORE_VECTOR, ">0"})
+    public int[] indexWithDifferentConstantsPos() {
         int[] res = new int[SIZE];
         for (int i = 0; i < SIZE / 4; i++) {
             res[i] = ints[i + 1];
@@ -171,6 +173,17 @@ public int[] indexWithDifferentConstants() {
         return res;
     }
 
+    @Test
+    // Note that this case cannot be vectorized due to data dependence.
+    @IR(failOn = {IRNode.STORE_VECTOR})
+    public int[] indexWithDifferentConstantsNeg() {
+        int[] res = new int[SIZE];
+        for (int i = 1; i < SIZE / 4; i++) {
+            res[i] = ints[i - 1];
+        }
+        return res;
+    }
+
     @Test
     // Note that this case cannot be vectorized due to data dependence.
     @IR(failOn = {IRNode.STORE_VECTOR})
@@ -246,10 +259,13 @@ public int[] sameArrayWithDifferentIndex() {
     }
 
     // ---------------- Subword Type Arrays ----------------
+
     @Test
-    // Note that this case cannot be vectorized due to data dependence.
-    @IR(failOn = {IRNode.STORE_VECTOR})
-    public short[] shortArrayWithDependence() {
+    // No true dependency in read-forward case.
+    @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
+        applyIf = {"AlignVector", "false"},
+        counts = {IRNode.STORE_VECTOR, ">0"})
+    public short[] shortArrayWithDependencePos() {
         short[] res = new short[SIZE];
         System.arraycopy(shorts, 0, res, 0, SIZE);
         for (int i = 0; i < SIZE / 2; i++) {
@@ -261,7 +277,21 @@ public short[] shortArrayWithDependence() {
     @Test
     // Note that this case cannot be vectorized due to data dependence.
     @IR(failOn = {IRNode.STORE_VECTOR})
-    public char[] charArrayWithDependence() {
+    public short[] shortArrayWithDependenceNeg() {
+        short[] res = new short[SIZE];
+        System.arraycopy(shorts, 0, res, 0, SIZE);
+        for (int i = 1; i < SIZE / 2; i++) {
+            res[i] *= shorts[i - 1];
+        }
+        return res;
+    }
+
+    @Test
+    // No true dependency in read-forward case.
+    @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
+        applyIf = {"AlignVector", "false"},
+        counts = {IRNode.STORE_VECTOR, ">0"})
+    public char[] charArrayWithDependencePos() {
         char[] res = new char[SIZE];
         System.arraycopy(chars, 0, res, 0, SIZE);
         for (int i = 0; i < SIZE / 2; i++) {
@@ -273,7 +303,21 @@ public char[] charArrayWithDependence() {
     @Test
     // Note that this case cannot be vectorized due to data dependence.
     @IR(failOn = {IRNode.STORE_VECTOR})
-    public byte[] byteArrayWithDependence() {
+    public char[] charArrayWithDependenceNeg() {
+        char[] res = new char[SIZE];
+        System.arraycopy(chars, 0, res, 0, SIZE);
+        for (int i = 2; i < SIZE / 2; i++) {
+            res[i] *= chars[i - 2];
+        }
+        return res;
+    }
+
+    @Test
+    // No true dependency in read-forward case.
+    @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
+        applyIf = {"AlignVector", "false"},
+        counts = {IRNode.STORE_VECTOR, ">0"})
+    public byte[] byteArrayWithDependencePos() {
         byte[] res = new byte[SIZE];
         System.arraycopy(bytes, 0, res, 0, SIZE);
         for (int i = 0; i < SIZE / 2; i++) {
@@ -282,10 +326,25 @@ public byte[] byteArrayWithDependence() {
         return res;
     }
 
+
     @Test
     // Note that this case cannot be vectorized due to data dependence.
     @IR(failOn = {IRNode.STORE_VECTOR})
-    public boolean[] booleanArrayWithDependence() {
+    public byte[] byteArrayWithDependenceNeg() {
+        byte[] res = new byte[SIZE];
+        System.arraycopy(bytes, 0, res, 0, SIZE);
+        for (int i = 3; i < SIZE / 2; i++) {
+            res[i] *= bytes[i - 3];
+        }
+        return res;
+    }
+
+    @Test
+    // No true dependency in read-forward case.
+    @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
+        applyIf = {"AlignVector", "false"},
+        counts = {IRNode.STORE_VECTOR, ">0"})
+    public boolean[] booleanArrayWithDependencePos() {
         boolean[] res = new boolean[SIZE];
         System.arraycopy(booleans, 0, res, 0, SIZE);
         for (int i = 0; i < SIZE / 2; i++) {
@@ -294,6 +353,18 @@ public boolean[] booleanArrayWithDependence() {
         return res;
     }
 
+    @Test
+    // Note that this case cannot be vectorized due to data dependence.
+    @IR(failOn = {IRNode.STORE_VECTOR})
+    public boolean[] booleanArrayWithDependenceNeg() {
+        boolean[] res = new boolean[SIZE];
+        System.arraycopy(booleans, 0, res, 0, SIZE);
+        for (int i = 4; i < SIZE / 2; i++) {
+            res[i] |= booleans[i - 4];
+        }
+        return res;
+    }
+
     // ---------------- Multiple Operations ----------------
     @Test
     @IR(applyIfCPUFeatureOr = {"asimd", "true", "sse2", "true"},
diff --git a/test/micro/org/openjdk/bench/vm/compiler/VectorAlignment.java b/test/micro/org/openjdk/bench/vm/compiler/VectorAlignment.java
new file mode 100644
index 00000000000..7fff4952c8e
--- /dev/null
+++ b/test/micro/org/openjdk/bench/vm/compiler/VectorAlignment.java
@@ -0,0 +1,315 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.openjdk.bench.vm.compiler;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.*;
+
+import java.util.concurrent.TimeUnit;
+import java.util.Random;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Thread)
+@Warmup(iterations = 1, time = 1, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 1, time = 1, timeUnit = TimeUnit.SECONDS)
+@Fork(value = 1)
+public abstract class VectorAlignment {
+    @Param({/*"512",  "1024", */  "2048"})
+    public int COUNT;
+
+    private int[] aI;
+    private int[] bI;
+    private int[] rI;
+
+    private long[] aL;
+    private long[] bL;
+    private long[] rL;
+
+    private short[] aS;
+    private short[] bS;
+    private short[] rS;
+
+    private char[] aC;
+    private char[] bC;
+    private char[] rC;
+
+    private byte[] aB;
+    private byte[] bB;
+    private byte[] rB;
+
+    private float[] aF;
+    private float[] bF;
+    private float[] rF;
+
+    private double[] aD;
+    private double[] bD;
+    private double[] rD;
+
+
+    @Param("0")
+    private int seed;
+    private Random r = new Random(seed);
+
+    @Setup
+    public void init() {
+        aI = new int[COUNT];
+        bI = new int[COUNT];
+        rI = new int[COUNT];
+
+        aL = new long[COUNT];
+        bL = new long[COUNT];
+        rL = new long[COUNT];
+
+        aS = new short[COUNT];
+        bS = new short[COUNT];
+        rS = new short[COUNT];
+
+        aC = new char[COUNT];
+        bC = new char[COUNT];
+        rC = new char[COUNT];
+
+        aB = new byte[COUNT];
+        bB = new byte[COUNT];
+        rB = new byte[COUNT];
+
+        aF = new float[COUNT];
+        bF = new float[COUNT];
+        rF = new float[COUNT];
+
+        aD = new double[COUNT];
+        bD = new double[COUNT];
+        rD = new double[COUNT];
+
+
+        for (int i = 0; i < COUNT; i++) {
+            aI[i] = r.nextInt();
+            bI[i] = r.nextInt();
+
+            aL[i] = r.nextLong();
+            bL[i] = r.nextLong();
+
+            aS[i] = (short) r.nextInt();
+            bS[i] = (short) r.nextInt();
+
+            aC[i] = (char) r.nextInt();
+            bC[i] = (char) r.nextInt();
+
+            aB[i] = (byte) r.nextInt();
+            bB[i] = (byte) r.nextInt();
+
+            aF[i] = r.nextFloat();
+            bF[i] = r.nextFloat();
+
+            aD[i] = r.nextDouble();
+            bD[i] = r.nextDouble();
+        }
+    }
+
+    @Benchmark
+    // Control: should always vectorize with SuperWord
+    public void bench000I_control() {
+        for (int i = 0; i < COUNT; i++) {
+            // Have multiple MUL operations to make loop compute bound (more compute than load/store)
+            rI[i] = aI[i] * aI[i] * aI[i] * aI[i];
+        }
+    }
+
+    @Benchmark
+    public void bench000L_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rL[i] = aL[i] * aL[i] * aL[i] * aL[i];
+        }
+    }
+
+    @Benchmark
+    public void bench000S_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rS[i] = (short)(aS[i] * aS[i] * aS[i] * aS[i]);
+        }
+    }
+
+    @Benchmark
+    public void bench000C_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rC[i] = (char)(aC[i] * aC[i] * aC[i] * aC[i]);
+        }
+    }
+
+    @Benchmark
+    public void bench000B_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rB[i] = (byte)(aB[i] * aB[i] * aB[i] * aB[i]);
+        }
+    }
+
+    @Benchmark
+    public void bench000F_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rF[i] = aF[i] * aF[i] * aF[i] * aF[i];
+        }
+    }
+
+    @Benchmark
+    public void bench000D_control() {
+        for (int i = 0; i < COUNT; i++) {
+            rD[i] = aD[i] * aD[i] * aD[i] * aD[i];
+        }
+    }
+
+    @Benchmark
+    // Control: should always vectorize with SuperWord
+    public void bench001_control() {
+        for (int i = 0; i < COUNT; i++) {
+            // Have multiple MUL operations to make loop compute bound (more compute than load/store)
+            rI[i] = aI[i] * aI[i] * aI[i] * aI[i] + bI[i];
+        }
+    }
+
+    @Benchmark
+    // Vectorizes without AlignVector
+    public void bench100I_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rI[i] = aI[i+1] * aI[i+1] * aI[i+1] * aI[i+1];
+        }
+    }
+
+    @Benchmark
+    public void bench100L_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rL[i] = aL[i+1] * aL[i+1] * aL[i+1] * aL[i+1];
+        }
+    }
+
+    @Benchmark
+    public void bench100S_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rS[i] = (short)(aS[i+1] * aS[i+1] * aS[i+1] * aS[i+1]);
+        }
+    }
+
+    @Benchmark
+    public void bench100C_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rC[i] = (char)(aC[i+1] * aC[i+1] * aC[i+1] * aC[i+1]);
+        }
+    }
+
+
+    @Benchmark
+    public void bench100B_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rB[i] = (byte)(aB[i+1] * aB[i+1] * aB[i+1] * aB[i+1]);
+        }
+    }
+
+    @Benchmark
+    public void bench100F_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rF[i] = aF[i+1] * aF[i+1] * aF[i+1] * aF[i+1];
+        }
+    }
+
+    @Benchmark
+    public void bench100D_misaligned_load() {
+        for (int i = 0; i < COUNT-1; i++) {
+            rD[i] = aD[i+1] * aD[i+1] * aD[i+1] * aD[i+1];
+        }
+    }
+
+    @Benchmark
+    // Only without "Vectorize" (confused by hand-unrolling)
+    public void bench200_hand_unrolled_aligned() {
+        for (int i = 0; i < COUNT-10; i+=2) {
+            rI[i+0] = aI[i+0] * aI[i+0] * aI[i+0] * aI[i+0];
+            rI[i+1] = aI[i+1] * aI[i+1] * aI[i+1] * aI[i+1];
+        }
+    }
+
+    @Benchmark
+    // Only with "Vectorize", without we get issues with modulo computation of alignment for bI
+    public void bench300_multiple_misaligned_loads() {
+        for (int i = 0; i < COUNT-10; i++) {
+            rI[i] = aI[i] * aI[i] * aI[i] * aI[i] + bI[i+1];
+        }
+    }
+
+    @Benchmark
+    // Only with "Vectorize", without we may confuse aI[5] with aI[4+1] and pack loads in wrong pack
+    public void bench301_multiple_misaligned_loads() {
+        for (int i = 0; i < COUNT-10; i++) {
+            rI[i] = aI[i] * aI[i] * aI[i] * aI[i] + aI[i+1];
+        }
+    }
+
+    @Benchmark
+    // Only with "Vectorize", without we get mix of aI[i] and a[i-2]
+    public void bench302_multiple_misaligned_loads_and_stores() {
+        for (int i = 2; i < COUNT; i++) {
+            rI[i - 2] = aI[i-2] * aI[i-2] * aI[i-2] * aI[i-2]; // can do this for all iterations
+            rI[i] = aI[i] + 3;                                 // before doing this second line
+        }
+    }
+
+    @Benchmark
+    // Currently does not vectorize:
+    //   hand-unrolled confuses Vectorize -> adjacent loads not from same original node (not even same line)
+    //   multiple unaligned loads confuses non-Vectorize: aI[5+1] confused with aI[4+2] (plus modulo alignment issue)
+    public void bench400_hand_unrolled_misaligned() {
+        for (int i = 0; i < COUNT-10; i+=2) {
+            rI[i+0] = aI[i+1] * aI[i+1] * aI[i+1] * aI[i+1] + aI[i];
+            rI[i+1] = aI[i+2] * aI[i+2] * aI[i+2] * aI[i+2] + aI[i+1];
+        }
+    }
+
+    @Benchmark
+    // Currently does not vectorize:
+    //   hand-unrolled confuses Vectorize -> adjacent loads not from same original node (not even same line)
+    //   non-Vectorize: plus modulo alignment issue
+    public void bench401_hand_unrolled_misaligned() {
+        for (int i = 0; i < COUNT-10; i+=2) {
+            rI[i+0] = aI[i+1] * aI[i+1] * aI[i+1] * aI[i+1] + bI[i];
+            rI[i+1] = aI[i+2] * aI[i+2] * aI[i+2] * aI[i+2] + bI[i+1];
+        }
+    }
+
+    @Fork(value = 1, jvmArgsPrepend = {
+        "-XX:+UseSuperWord", "-XX:CompileCommand=Option,*::*,Vectorize"
+    })
+    public static class VectorAlignmentSuperWordWithVectorize extends VectorAlignment {}
+
+    @Fork(value = 1, jvmArgsPrepend = {
+        "-XX:+UseSuperWord", "-XX:+AlignVector"
+    })
+    public static class VectorAlignmentSuperWordAlignVector extends VectorAlignment {}
+
+    @Fork(value = 1, jvmArgsPrepend = {
+        "-XX:+UseSuperWord"
+    })
+    public static class VectorAlignmentSuperWord extends VectorAlignment {}
+
+    @Fork(value = 1, jvmArgsPrepend = {
+        "-XX:-UseSuperWord"
+    })
+    public static class VectorAlignmentNoSuperWord extends VectorAlignment {}
+}

From 5e53bb4c165ec3e80af4ee93f0ba1b3cbafb25af Mon Sep 17 00:00:00 2001
From: Julian Waters <jwaters@openjdk.org>
Date: Wed, 21 Jun 2023 06:43:03 +0000
Subject: [PATCH 03/19] 8307145: windowsaccessbridge.dll erroneously includes
 private methods in its C API

Reviewed-by: djelinski
---
 .../native/libwindowsaccessbridge/WinAccessBridge.DEF        | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/src/jdk.accessibility/windows/native/libwindowsaccessbridge/WinAccessBridge.DEF b/src/jdk.accessibility/windows/native/libwindowsaccessbridge/WinAccessBridge.DEF
index 659a5882c7c..d9dafebb635 100644
--- a/src/jdk.accessibility/windows/native/libwindowsaccessbridge/WinAccessBridge.DEF
+++ b/src/jdk.accessibility/windows/native/libwindowsaccessbridge/WinAccessBridge.DEF
@@ -28,11 +28,6 @@
 ;DESCRIPTION 'WINDOWSACCESSBRIDGE.DLL'
 EXPORTS
 
-    addJavaEventNotification
-    removeJavaEventNotification
-    addAccessibilityEventNotification
-    removeAccessibilityEventNotification
-
     Windows_run
 
     getAccessibleTableInfo

From 9f7ec13417a99bfa391e0489983cd5a04103d40e Mon Sep 17 00:00:00 2001
From: Matthias Baesken <mbaesken@openjdk.org>
Date: Wed, 21 Jun 2023 06:49:24 +0000
Subject: [PATCH 04/19] 8310321: make JDKOPT_CHECK_CODESIGN_PARAMS more verbose

Reviewed-by: erikj
---
 make/autoconf/jdk-options.m4 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/make/autoconf/jdk-options.m4 b/make/autoconf/jdk-options.m4
index f08cc6ddd41..f56081223a6 100644
--- a/make/autoconf/jdk-options.m4
+++ b/make/autoconf/jdk-options.m4
@@ -822,6 +822,9 @@ AC_DEFUN([JDKOPT_CHECK_CODESIGN_PARAMS],
   $RM "$CODESIGN_TESTFILE"
   $TOUCH "$CODESIGN_TESTFILE"
   CODESIGN_SUCCESS=false
+
+  $ECHO "check codesign, calling $CODESIGN $PARAMS $CODESIGN_TESTFILE" >&AS_MESSAGE_LOG_FD
+
   eval \"$CODESIGN\" $PARAMS \"$CODESIGN_TESTFILE\" 2>&AS_MESSAGE_LOG_FD \
       >&AS_MESSAGE_LOG_FD && CODESIGN_SUCCESS=true
   $RM "$CODESIGN_TESTFILE"

From bc9a172d7931ab2a55f9d009134dbc35b922ab82 Mon Sep 17 00:00:00 2001
From: Tobias Hartmann <thartmann@openjdk.org>
Date: Wed, 21 Jun 2023 07:05:41 +0000
Subject: [PATCH 05/19] 8310143: RandomCommandsTest fails due to unexpected VM
 exit code after JDK-8282797

Reviewed-by: rcastanedalo, chagedorn
---
 .../compilercontrol/jcmd/StressAddJcmdBase.java      |  2 +-
 .../compiler/compilercontrol/share/MultiCommand.java |  7 +++++--
 .../compilercontrol/share/scenario/Executor.java     | 12 ++++--------
 .../compilercontrol/share/scenario/Scenario.java     |  2 +-
 4 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/test/hotspot/jtreg/compiler/compilercontrol/jcmd/StressAddJcmdBase.java b/test/hotspot/jtreg/compiler/compilercontrol/jcmd/StressAddJcmdBase.java
index cfd9e1c4bb0..a8c57bc408a 100644
--- a/test/hotspot/jtreg/compiler/compilercontrol/jcmd/StressAddJcmdBase.java
+++ b/test/hotspot/jtreg/compiler/compilercontrol/jcmd/StressAddJcmdBase.java
@@ -116,7 +116,7 @@ private enum JcmdCommand {
     private class TimeLimitedExecutor extends Executor {
         public TimeLimitedExecutor() {
             /* There are no need to check the state */
-            super(true, VM_OPTIONS, null, null);
+            super(VM_OPTIONS, null, null);
         }
 
         @Override
diff --git a/test/hotspot/jtreg/compiler/compilercontrol/share/MultiCommand.java b/test/hotspot/jtreg/compiler/compilercontrol/share/MultiCommand.java
index b043414b76a..3fceae41146 100644
--- a/test/hotspot/jtreg/compiler/compilercontrol/share/MultiCommand.java
+++ b/test/hotspot/jtreg/compiler/compilercontrol/share/MultiCommand.java
@@ -56,6 +56,7 @@ public static AbstractTestBase generateRandomTest(boolean validOnly) {
         List<CompileCommand> testCases = new ArrayList<>();
 
         for (Command cmd : commands) {
+            boolean isValid = true;
             String argument = null;
 
             if (validOnly && cmd == Command.NONEXISTENT) {
@@ -67,6 +68,7 @@ public static AbstractTestBase generateRandomTest(boolean validOnly) {
                     argument = Utils.getRandomElement(VALID_INTRINSIC_SAMPLES);
                 } else {
                     argument = Utils.getRandomElement(INVALID_INTRINSIC_SAMPLES);
+                    isValid = false;
                 }
             }
 
@@ -78,12 +80,13 @@ public static AbstractTestBase generateRandomTest(boolean validOnly) {
                 md = AbstractTestBase.getValidMethodDescriptor(exec);
             } else {
                 md = AbstractTestBase.METHOD_GEN.generateRandomDescriptor(exec);
+                isValid &= md.isValid();
             }
             CompileCommand cc;
             if (cmd == Command.INTRINSIC) {
-                cc = cmdGen.generateCompileCommand(cmd, true, md, null, argument);
+                cc = cmdGen.generateCompileCommand(cmd, isValid, md, null, argument);
             } else {
-                cc = cmdGen.generateCompileCommand(cmd, true, md, null);
+                cc = cmdGen.generateCompileCommand(cmd, isValid, md, null);
             }
             testCases.add(cc);
         }
diff --git a/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Executor.java b/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Executor.java
index 8a868e89ee6..0111d1e90a1 100644
--- a/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Executor.java
+++ b/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Executor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,6 @@
 import java.util.Map;
 
 public class Executor {
-    private final boolean isValid;
     private final List<String> vmOptions;
     private final Map<Executable, State> states;
     private final List<String> jcmdCommands;
@@ -57,16 +56,13 @@ public class Executor {
     /**
      * Constructor
      *
-     * @param isValid      shows that the input given to the VM is valid and
-     *                     VM shouldn't fail
      * @param vmOptions    a list of VM input options
      * @param states       a state map, or null for the non-checking execution
      * @param jcmdCommands a list of diagnostic commands to be preformed
      *                     on test VM
      */
-    public Executor(boolean isValid, List<String> vmOptions,
-            Map<Executable, State> states, List<String> jcmdCommands) {
-        this.isValid = isValid;
+    public Executor(List<String> vmOptions, Map<Executable, State> states,
+                    List<String> jcmdCommands) {
         if (vmOptions == null) {
             this.vmOptions = new ArrayList<>();
         } else {
@@ -77,7 +73,7 @@ public Executor(boolean isValid, List<String> vmOptions,
     }
 
     /**
-     * Executes separate VM a gets an OutputAnalyzer instance with the results
+     * Executes separate VM and gets an OutputAnalyzer instance with the results
      * of execution
      */
     public List<OutputAnalyzer> execute() {
diff --git a/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Scenario.java b/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Scenario.java
index b277ae888b2..ad168f62eda 100644
--- a/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Scenario.java
+++ b/test/hotspot/jtreg/compiler/compilercontrol/share/scenario/Scenario.java
@@ -104,7 +104,7 @@ private Scenario(boolean isValid,
             jcmdExecCommands.add(JcmdType.PRINT.command);
         }
         jcmdProcessor = new PrintDirectivesProcessor(directives);
-        executor = new Executor(isValid, vmopts, states, jcmdExecCommands);
+        executor = new Executor(vmopts, states, jcmdExecCommands);
     }
 
     /**

From 1634cb554d052ff4bfa5cf9794b4cd5834e7fc8b Mon Sep 17 00:00:00 2001
From: Jan Lahoda <jlahoda@openjdk.org>
Date: Wed, 21 Jun 2023 09:15:48 +0000
Subject: [PATCH 06/19] 8302865: Illegal bytecode for break from if with
 instanceof pattern matching condition

Reviewed-by: vromero
---
 .../com/sun/tools/javac/comp/Attr.java        | 68 +++++++++++++------
 .../com/sun/tools/javac/comp/Flow.java        | 53 +++------------
 .../tools/javac/patterns/BindingsTest1.java   | 61 +++++++++++++++++
 .../tools/javac/patterns/BindingsTest2.java   | 57 ++++++++++++++++
 .../tools/javac/patterns/BindingsTest2.out    | 13 ++--
 .../tools/javac/patterns/BreakAndLoops.java   | 11 +++
 6 files changed, 195 insertions(+), 68 deletions(-)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
index fc646cc746e..1412c3644dd 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
@@ -1447,12 +1447,7 @@ public void visitBlock(JCBlock tree) {
     public void visitDoLoop(JCDoWhileLoop tree) {
         attribStat(tree.body, env.dup(tree));
         attribExpr(tree.cond, env, syms.booleanType);
-        if (!breaksOutOf(tree, tree.body)) {
-            //include condition's body when false after the while, if cannot get out of the loop
-            MatchBindings condBindings = matchBindings;
-            condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
-            condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
-        }
+        handleLoopConditionBindings(matchBindings, tree, tree.body);
         result = null;
     }
 
@@ -1466,19 +1461,10 @@ public void visitWhileLoop(JCWhileLoop tree) {
         } finally {
             whileEnv.info.scope.leave();
         }
-        if (!breaksOutOf(tree, tree.body)) {
-            //include condition's bindings when false after the while, if cannot get out of the loop
-            condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
-            condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
-        }
+        handleLoopConditionBindings(condBindings, tree, tree.body);
         result = null;
     }
 
-    private boolean breaksOutOf(JCTree loop, JCTree body) {
-        preFlow(body);
-        return flow.breaksOutOf(env, loop, body, make);
-    }
-
     public void visitForLoop(JCForLoop tree) {
         Env<AttrContext> loopEnv =
             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
@@ -1503,11 +1489,50 @@ public void visitForLoop(JCForLoop tree) {
         finally {
             loopEnv.info.scope.leave();
         }
-        if (!breaksOutOf(tree, tree.body)) {
-            //include condition's body when false after the while, if cannot get out of the loop
-            condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
-            condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
+        handleLoopConditionBindings(condBindings, tree, tree.body);
+    }
+
+    /**
+     * Include condition's bindings when false after the loop, if cannot get out of the loop
+     */
+    private void handleLoopConditionBindings(MatchBindings condBindings,
+                                             JCStatement loop,
+                                             JCStatement loopBody) {
+        if (condBindings.bindingsWhenFalse.nonEmpty() &&
+            !breaksTo(env, loop, loopBody)) {
+            addBindings2Scope(loop, condBindings.bindingsWhenFalse);
+        }
+    }
+
+    private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
+        preFlow(body);
+        return flow.breaksToTree(env, loop, body, make);
+    }
+
+    /**
+     * Add given bindings to the current scope, unless there's a break to
+     * an immediately enclosing labeled statement.
+     */
+    private void addBindings2Scope(JCStatement introducingStatement,
+                                   List<BindingSymbol> bindings) {
+        if (bindings.isEmpty()) {
+            return ;
+        }
+
+        var searchEnv = env;
+        while (searchEnv.tree instanceof JCLabeledStatement labeled &&
+               labeled.body == introducingStatement) {
+            if (breaksTo(env, labeled, labeled.body)) {
+                //breaking to an immediately enclosing labeled statement
+                return ;
+            }
+            searchEnv = searchEnv.next;
+            introducingStatement = labeled;
         }
+
+        //include condition's body when false after the while, if cannot get out of the loop
+        bindings.forEach(env.info.scope::enter);
+        bindings.forEach(BindingSymbol::preserveBinding);
     }
 
     public void visitForeachLoop(JCEnhancedForLoop tree) {
@@ -2242,8 +2267,7 @@ public void visitIf(JCIf tree) {
             afterIfBindings = condBindings.bindingsWhenFalse;
         }
 
-        afterIfBindings.forEach(env.info.scope::enter);
-        afterIfBindings.forEach(BindingSymbol::preserveBinding);
+        addBindings2Scope(tree, afterIfBindings);
 
         result = null;
     }
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
index 6651e961985..c2b02650693 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
@@ -287,7 +287,7 @@ public boolean aliveAfter(Env<AttrContext> env, JCTree that, TreeMaker make) {
         }
     }
 
-    public boolean breaksOutOf(Env<AttrContext> env, JCTree loop, JCTree body, TreeMaker make) {
+    public boolean breaksToTree(Env<AttrContext> env, JCTree breakTo, JCTree body, TreeMaker make) {
         //we need to disable diagnostics temporarily; the problem is that if
         //"that" contains e.g. an unreachable statement, an error
         //message will be reported and will cause compilation to skip the flow analysis
@@ -295,10 +295,10 @@ public boolean breaksOutOf(Env<AttrContext> env, JCTree loop, JCTree body, TreeM
         //related errors, which will allow for more errors to be detected
         Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log);
         try {
-            SnippetBreakAnalyzer analyzer = new SnippetBreakAnalyzer();
+            SnippetBreakToAnalyzer analyzer = new SnippetBreakToAnalyzer(breakTo);
 
             analyzer.analyzeTree(env, body, make);
-            return analyzer.breaksOut();
+            return analyzer.breaksTo();
         } finally {
             log.popDiagnosticHandler(diagHandler);
         }
@@ -1909,52 +1909,21 @@ public boolean isAlive() {
         }
     }
 
-    class SnippetBreakAnalyzer extends AliveAnalyzer {
-        private final Set<JCTree> seenTrees = new HashSet<>();
-        private boolean breaksOut;
+    class SnippetBreakToAnalyzer extends AliveAnalyzer {
+        private final JCTree breakTo;
+        private boolean breaksTo;
 
-        public SnippetBreakAnalyzer() {
-        }
-
-        @Override
-        public void visitLabelled(JCTree.JCLabeledStatement tree) {
-            seenTrees.add(tree);
-            super.visitLabelled(tree);
-        }
-
-        @Override
-        public void visitWhileLoop(JCTree.JCWhileLoop tree) {
-            seenTrees.add(tree);
-            super.visitWhileLoop(tree);
-        }
-
-        @Override
-        public void visitForLoop(JCTree.JCForLoop tree) {
-            seenTrees.add(tree);
-            super.visitForLoop(tree);
-        }
-
-        @Override
-        public void visitForeachLoop(JCTree.JCEnhancedForLoop tree) {
-            seenTrees.add(tree);
-            super.visitForeachLoop(tree);
-        }
-
-        @Override
-        public void visitDoLoop(JCTree.JCDoWhileLoop tree) {
-            seenTrees.add(tree);
-            super.visitDoLoop(tree);
+        public SnippetBreakToAnalyzer(JCTree breakTo) {
+            this.breakTo = breakTo;
         }
 
         @Override
         public void visitBreak(JCBreak tree) {
-            breaksOut |= (super.alive == Liveness.ALIVE &&
-                          !seenTrees.contains(tree.target));
-            super.visitBreak(tree);
+            breaksTo |= breakTo == tree.target && super.alive == Liveness.ALIVE;
         }
 
-        public boolean breaksOut() {
-            return breaksOut;
+        public boolean breaksTo() {
+            return breaksTo;
         }
     }
 
diff --git a/test/langtools/tools/javac/patterns/BindingsTest1.java b/test/langtools/tools/javac/patterns/BindingsTest1.java
index 1c6df9de87f..d9693fc4c67 100644
--- a/test/langtools/tools/javac/patterns/BindingsTest1.java
+++ b/test/langtools/tools/javac/patterns/BindingsTest1.java
@@ -231,6 +231,67 @@ public void run() {
             throw new AssertionError();
         }
 
+        {
+            L: {
+                while (!(o1 instanceof String s)) {
+                    break L;
+                }
+
+                s.length();
+            }
+        }
+
+        {
+            L: {
+                for (; !(o1 instanceof String s); ) {
+                    break L;
+                }
+
+                s.length();
+            }
+        }
+
+        {
+            int j = 0;
+            L: while (j++ < 2)
+                   if (!(o1 instanceof String s)) {
+                       break L;
+                   }
+        }
+
+        {
+            int j = 0;
+            L: for (; j++ < 2; )
+                   if (!(o1 instanceof String s)) {
+                       break L;
+                   }
+        }
+
+        {
+            //"s" in the outter scope does not flow out of the if, but
+            //variables inside a lambda or anonymous or local class may:
+            L: if (!(o1 instanceof String s)) {
+                Runnable r = () -> {
+                    NESTED: {
+                        if (!(o1 instanceof String n)) {
+                            break NESTED;
+                        }
+
+                        n.length();
+                    }
+                };
+                break L;
+            }
+        }
+
+        switch (0) {
+            case 0:
+                if (!(o1 instanceof String s)) {
+                    break;
+                }
+                s.length();
+        }
+
         //binding in an anonymous class:
         if (!(invokeOnce("") instanceof String s)) {
             throw new AssertionError();
diff --git a/test/langtools/tools/javac/patterns/BindingsTest2.java b/test/langtools/tools/javac/patterns/BindingsTest2.java
index b9bd372ddc8..c4b1f4d958c 100644
--- a/test/langtools/tools/javac/patterns/BindingsTest2.java
+++ b/test/langtools/tools/javac/patterns/BindingsTest2.java
@@ -247,5 +247,62 @@ public static void meth() {
                 s = "";
             }
         }
+        {
+            LBL1: LBL2: if (!(o1 instanceof String s)) {
+                break LBL1;
+            }
+
+            System.err.println(s);
+        }
+        {
+            LBL1: LBL2: if (!(o1 instanceof String s)) {
+                break LBL2;
+            }
+
+            System.err.println(s);
+        }
+        {
+            LBL1: LBL2: if (o1 instanceof String s) {
+            } else {
+                break LBL1;
+            }
+
+            System.err.println(s);
+        }
+        {
+            LBL1: LBL2: if (o1 instanceof String s) {
+            } else {
+                break LBL2;
+            }
+
+            System.err.println(s);
+        }
+        {
+            switch (0) {
+                case 0:
+                    if (!(o1 instanceof String s)) {
+                        break;
+                    }
+            }
+            s.length();
+        }
+
+        {
+            int j = 0;
+            L: while (j++ < 2)
+                   if (!(o1 instanceof String s)) {
+                       break L;
+                   }
+            s.length();
+        }
+
+        {
+            int j = 0;
+            L: for (; j++ < 2; )
+                   if (!(o1 instanceof String s)) {
+                       break L;
+                   }
+            s.length();
+        }
     }
 }
diff --git a/test/langtools/tools/javac/patterns/BindingsTest2.out b/test/langtools/tools/javac/patterns/BindingsTest2.out
index b42dededfdf..0695c3c9b41 100644
--- a/test/langtools/tools/javac/patterns/BindingsTest2.out
+++ b/test/langtools/tools/javac/patterns/BindingsTest2.out
@@ -43,11 +43,16 @@ BindingsTest2.java:179:13: compiler.err.cant.resolve.location: kindname.variable
 BindingsTest2.java:196:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
 BindingsTest2.java:204:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
 BindingsTest2.java:212:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
-BindingsTest2.java:221:17: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
-BindingsTest2.java:231:17: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
-BindingsTest2.java:241:17: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
 BindingsTest2.java:247:17: compiler.err.cant.assign.val.to.var: final, s
+BindingsTest2.java:255:32: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:262:32: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:270:32: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:278:32: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:287:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:296:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
+BindingsTest2.java:305:13: compiler.err.cant.resolve.location: kindname.variable, s, , , (compiler.misc.location: kindname.class, BindingsTest2, null)
 BindingsTest2.java:135:17: compiler.err.unreachable.stmt
 BindingsTest2.java:160:17: compiler.err.unreachable.stmt
 BindingsTest2.java:185:17: compiler.err.unreachable.stmt
-52 errors
+BindingsTest2.java:241:17: compiler.err.unreachable.stmt
+57 errors
\ No newline at end of file
diff --git a/test/langtools/tools/javac/patterns/BreakAndLoops.java b/test/langtools/tools/javac/patterns/BreakAndLoops.java
index 0c19fcbf35d..31ad8908f53 100644
--- a/test/langtools/tools/javac/patterns/BreakAndLoops.java
+++ b/test/langtools/tools/javac/patterns/BreakAndLoops.java
@@ -104,6 +104,17 @@ protected void doWork() throws Throwable {
                 shouldPass = true;
             } else if (innerLoop.supportsAnonymousBreak && brk == Break.BREAK) {
                 shouldPass = true;
+             } else if (outterLabel == OutterLabel.LABEL && brk == Break.BREAK_LABEL && outterLoop != OutterLoop.NONE) {
+                 shouldPass = switch(mainLoop) {
+                     case WHILE, FOR -> true;
+                     case DO_WHILE -> switch (innerLoop) {
+                         case WHILE, FOR, FOR_EACH -> true;
+                         //the statement following the do-while is unreachable:
+                         case BLOCK, DO_WHILE, NONE -> {
+                             yield false;
+                         }
+                     };
+                 };
             } else {
                 shouldPass = false;
             }

From 41b14abc8ce0915bf9a65808adddf7059e680948 Mon Sep 17 00:00:00 2001
From: Jan Lahoda <jlahoda@openjdk.org>
Date: Wed, 21 Jun 2023 09:16:12 +0000
Subject: [PATCH 07/19] 8310133: Effectivelly final condition not enforced in
 guards for binding variables from the same case

Reviewed-by: vromero
---
 .../share/classes/com/sun/tools/javac/comp/Flow.java       | 7 ++++++-
 test/langtools/tools/javac/patterns/GuardsErrors.java      | 5 ++++-
 test/langtools/tools/javac/patterns/GuardsErrors.out       | 5 +++--
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
index c2b02650693..ff77c9cdf18 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
@@ -3202,7 +3202,7 @@ void markDead() {
         void checkEffectivelyFinal(DiagnosticPosition pos, VarSymbol sym) {
             if (currentTree != null &&
                     sym.owner.kind == MTH &&
-                    sym.pos < currentTree.getStartPosition()) {
+                    sym.pos < getCurrentTreeStartPosition()) {
                 switch (currentTree.getTag()) {
                     case CLASSDEF:
                     case CASE:
@@ -3214,6 +3214,11 @@ void checkEffectivelyFinal(DiagnosticPosition pos, VarSymbol sym) {
             }
         }
 
+        int getCurrentTreeStartPosition() {
+            return currentTree instanceof JCCase cse ? cse.guard.getStartPosition()
+                                                     : currentTree.getStartPosition();
+        }
+
         @SuppressWarnings("fallthrough")
         void letInit(JCTree tree) {
             tree = TreeInfo.skipParens(tree);
diff --git a/test/langtools/tools/javac/patterns/GuardsErrors.java b/test/langtools/tools/javac/patterns/GuardsErrors.java
index 788c46e4e14..3beb9d5741f 100644
--- a/test/langtools/tools/javac/patterns/GuardsErrors.java
+++ b/test/langtools/tools/javac/patterns/GuardsErrors.java
@@ -23,7 +23,7 @@
 
 /*
  * @test
- * @bug 8262891
+ * @bug 8262891 8310133
  * @summary Check errors reported for guarded patterns.
  * @compile/fail/ref=GuardsErrors.out -XDrawDiagnostics GuardsErrors.java
  */
@@ -54,6 +54,9 @@ public boolean test() {
                     return i == 2;
                 }
             }.test() -> {}
+            case Integer v when v != null -> {
+                v = null;
+            }
             case Number v1 when v1 instanceof Integer v2 && (v2 = 0) == 0 -> {}
             default -> {}
         }
diff --git a/test/langtools/tools/javac/patterns/GuardsErrors.out b/test/langtools/tools/javac/patterns/GuardsErrors.out
index a87e4f1867c..2e42efc412f 100644
--- a/test/langtools/tools/javac/patterns/GuardsErrors.out
+++ b/test/langtools/tools/javac/patterns/GuardsErrors.out
@@ -2,5 +2,6 @@ GuardsErrors.java:36:38: compiler.err.cant.ref.non.effectively.final.var: check,
 GuardsErrors.java:47:34: compiler.err.cannot.assign.not.declared.guard: i1
 GuardsErrors.java:48:33: compiler.err.cant.ref.non.effectively.final.var: i2, (compiler.misc.guard)
 GuardsErrors.java:49:35: compiler.err.cant.ref.non.effectively.final.var: i2, (compiler.misc.guard)
-GuardsErrors.java:64:34: compiler.err.cannot.assign.not.declared.guard: f
-5 errors
+GuardsErrors.java:57:33: compiler.err.cant.ref.non.effectively.final.var: v, (compiler.misc.guard)
+GuardsErrors.java:67:34: compiler.err.cannot.assign.not.declared.guard: f
+6 errors

From a19176d2d35833452623f7a4fb0a039f0b4b7804 Mon Sep 17 00:00:00 2001
From: Erik Joelsson <erikj@openjdk.org>
Date: Wed, 21 Jun 2023 09:57:26 +0000
Subject: [PATCH 08/19] 8310369: UTIL_ARG_WITH fails when arg is disabled

Reviewed-by: mikael
---
 make/autoconf/util.m4 | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/make/autoconf/util.m4 b/make/autoconf/util.m4
index 83349aea99d..349a04a089e 100644
--- a/make/autoconf/util.m4
+++ b/make/autoconf/util.m4
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2022, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -509,7 +509,7 @@ AC_DEFUN([UTIL_CHECK_TYPE_directory],
     FAILURE="Directory $1 does not exist or is not readable"
   fi
 
-  if test "[x]ARG_CHECK_FOR_FILES" != x; then
+  if test "[x]ARG_CHECK_FOR_FILES" != "x:"; then
     for file in ARG_CHECK_FOR_FILES; do
       found_files=$($ECHO $(ls $1/$file 2> /dev/null))
       if test "x$found_files" = x; then
@@ -781,25 +781,25 @@ UTIL_DEFUN_NAMED([UTIL_ARG_WITH],
     else
       AC_MSG_RESULT([$ARG_RESULT, $REASON])
     fi
-  fi
 
-  # Verify value
-  # First use our dispatcher to verify that type requirements are satisfied
-  UTIL_CHECK_TYPE(ARG_TYPE, $ARG_RESULT)
+    # Verify value
+    # First use our dispatcher to verify that type requirements are satisfied
+    UTIL_CHECK_TYPE(ARG_TYPE, $ARG_RESULT)
 
-  if test "x$FAILURE" = x; then
-    # Execute custom verification payload, if present
-    RESULT="$ARG_RESULT"
+    if test "x$FAILURE" = x; then
+      # Execute custom verification payload, if present
+      RESULT="$ARG_RESULT"
 
-    ARG_CHECK_VALUE
+      ARG_CHECK_VALUE
 
-    ARG_RESULT="$RESULT"
-  fi
+      ARG_RESULT="$RESULT"
+    fi
 
-  if test "x$FAILURE" != x; then
-    AC_MSG_NOTICE([Invalid value for [--with-]ARG_NAME: "$ARG_RESULT"])
-    AC_MSG_NOTICE([$FAILURE])
-    AC_MSG_ERROR([Cannot continue])
+    if test "x$FAILURE" != x; then
+      AC_MSG_NOTICE([Invalid value for [--with-]ARG_NAME: "$ARG_RESULT"])
+      AC_MSG_NOTICE([$FAILURE])
+      AC_MSG_ERROR([Cannot continue])
+    fi
   fi
 
   # Execute result payloads, if present

From 26a722661ba240320808e6f98b418f6bee2fc58b Mon Sep 17 00:00:00 2001
From: Erik Joelsson <erikj@openjdk.org>
Date: Wed, 21 Jun 2023 09:57:49 +0000
Subject: [PATCH 09/19] 8310376: Extend SetupTarget macro with DIR parameter

Reviewed-by: mikael
---
 make/MainSupport.gmk | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/make/MainSupport.gmk b/make/MainSupport.gmk
index 34137c502d4..8c575423005 100644
--- a/make/MainSupport.gmk
+++ b/make/MainSupport.gmk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -38,11 +38,16 @@ _MAINSUPPORT_GMK := 1
 #   TARGET the makefile target
 #   ARGS arguments to the makefile
 #   DEPS the target(s) this new rule depends on
+#   DIR the directory of the makefile (defaults to $(TOPDIR)/make)
 #
 SetupTarget = $(NamedParamsMacroTemplate)
 define SetupTargetBody
+  ifeq ($$($1_DIR), )
+    $1_DIR := $(TOPDIR)/make
+  endif
+
   $1:
-	+($(CD) $(TOPDIR)/make && $(MAKE) $(MAKE_ARGS) -f $$($1_MAKEFILE).gmk $$($1_TARGET) $$($1_ARGS))
+	+($(CD) $$($1_DIR) && $(MAKE) $(MAKE_ARGS) -f $$($1_MAKEFILE).gmk $$($1_TARGET) $$($1_ARGS))
 
   ALL_TARGETS += $1
 

From 4543fbb6f4841f5ec50908ec4bf6c9d651e8362b Mon Sep 17 00:00:00 2001
From: Coleen Phillimore <coleenp@openjdk.org>
Date: Wed, 21 Jun 2023 11:45:37 +0000
Subject: [PATCH 10/19] 8310297: assert(static_cast<T1>(result) == thing) with
 ctw

Reviewed-by: iklam, dholmes
---
 .../ConstantPool/ByteFieldInitTest.java       | 55 +++++++++++++++++++
 .../ConstantPool/CompatByteFieldInit.jasm     | 38 +++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 test/hotspot/jtreg/runtime/ConstantPool/ByteFieldInitTest.java
 create mode 100644 test/hotspot/jtreg/runtime/ConstantPool/CompatByteFieldInit.jasm

diff --git a/test/hotspot/jtreg/runtime/ConstantPool/ByteFieldInitTest.java b/test/hotspot/jtreg/runtime/ConstantPool/ByteFieldInitTest.java
new file mode 100644
index 00000000000..59f48342213
--- /dev/null
+++ b/test/hotspot/jtreg/runtime/ConstantPool/ByteFieldInitTest.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8310297
+ * @summary Negative fields shorter than an int may not be sign extended in cpool
+ *          but should in static field initializers. javac gives an error for this but
+ *          not other sources of bytecodes.  With checked_cast<> this crashes.
+ * @compile CompatByteFieldInit.jasm
+ * @run main ByteFieldInitTest
+ */
+
+import java.lang.reflect.Field;
+
+public class ByteFieldInitTest {
+
+    final static byte b = -128;     // compare with 0x80
+    final static short s = -32768;  // compare with 0x8000
+
+    public static void main(java.lang.String[] unused) throws Exception {
+        // javac is smart enough to complain about the other class's byte and short values when referred
+        // to directly.  With checked_cast<> loading this class should fail.
+        Class<?> c = Class.forName("CompatByteFieldInit");
+        Field cb = c.getDeclaredField("b");
+        Field cs = c.getDeclaredField("s");
+        if (b != cb.getByte(null) || s != cs.getShort(null)) {
+            throw new RuntimeException("constant pool init not compatible " + cb.getByte(null) + " " + cs.getShort(null));
+        } else {
+            System.out.println("Fields are same test passed");
+        }
+    }
+}
+
+
diff --git a/test/hotspot/jtreg/runtime/ConstantPool/CompatByteFieldInit.jasm b/test/hotspot/jtreg/runtime/ConstantPool/CompatByteFieldInit.jasm
new file mode 100644
index 00000000000..b2420a9ecc3
--- /dev/null
+++ b/test/hotspot/jtreg/runtime/ConstantPool/CompatByteFieldInit.jasm
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+
+super class CompatByteFieldInit
+	version 65:0
+{
+  public static final Field b:B	= int 0x80;
+  public static final Field s:S	= int 0x8000;
+
+  Method "<init>":"()V"
+	stack 1 locals 1
+  {
+		aload_0;
+		invokespecial	Method java/lang/Object."<init>":"()V";
+		return;
+  }
+} // end Class CompatByteFieldInit

From 7856c967166d21aad8f4a8fe5379a12a73300ebc Mon Sep 17 00:00:00 2001
From: Erik Gahlin <egahlin@openjdk.org>
Date: Wed, 21 Jun 2023 11:47:25 +0000
Subject: [PATCH 11/19] 8309296: jdk/jfr/event/runtime/TestAgentEvent.java
 fails due to "missing" dynamic JavaAgent

Reviewed-by: mgronlun
---
 .../jdk/jfr/event/runtime/TestAgentEvent.java | 55 +++++++++++++------
 1 file changed, 38 insertions(+), 17 deletions(-)

diff --git a/test/jdk/jdk/jfr/event/runtime/TestAgentEvent.java b/test/jdk/jdk/jfr/event/runtime/TestAgentEvent.java
index a457b417a90..3bba83ffbe4 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestAgentEvent.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestAgentEvent.java
@@ -27,6 +27,7 @@
 import java.security.Timestamp;
 import java.time.Duration;
 import java.time.Instant;
+import java.util.Comparator;
 import java.util.List;
 import com.sun.tools.attach.VirtualMachine;
 
@@ -35,6 +36,7 @@
 import jdk.jfr.consumer.RecordedClassLoader;
 import jdk.jfr.consumer.RecordedEvent;
 import jdk.jfr.Event;
+import jdk.jfr.StackTrace;
 import jdk.test.lib.Asserts;
 import jdk.test.lib.jfr.EventNames;
 import jdk.test.lib.jfr.Events;
@@ -55,19 +57,22 @@
  *      jdk.jfr.event.runtime.JavaAgent
  *      JavaAgent.jar
  *
- * @run main/othervm -javaagent:JavaAgent.jar=foo=bar
+ * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -javaagent:JavaAgent.jar=foo=bar
  *      jdk.jfr.event.runtime.TestAgentEvent
  *      testJavaStatic
  *
- * @run main/othervm -Djdk.attach.allowAttachSelf=true
+ * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -Djdk.attach.allowAttachSelf=true
  *      jdk.jfr.event.runtime.TestAgentEvent
  *      testJavaDynamic
  *
- * @run main/othervm -agentlib:jdwp=transport=dt_socket,server=y,address=any,onjcmd=y
+ * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -agentlib:jdwp=transport=dt_socket,server=y,address=any,onjcmd=y
  *      jdk.jfr.event.runtime.TestAgentEvent
  *      testNativeStatic
  */
 public final class TestAgentEvent {
+    @StackTrace(false)
+    static class RecordingInterval extends Event {
+    }
     private static final String JAVA_AGENT_JAR = "JavaAgent.jar";
 
     public static void main(String[] args) throws Throwable {
@@ -81,17 +86,22 @@ public static void main(String[] args) throws Throwable {
 
     private static void testJavaStatic() throws Throwable {
         try (Recording r = new Recording()) {
-            r.enable(EventNames.JavaAgent);
+            r.enable(EventNames.JavaAgent).with("period", "endChunk");
             r.start();
+            RecordingInterval intervalEvent = new RecordingInterval();
+            intervalEvent.commit();
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
-            RecordedEvent e = events.get(0);
+            events.sort(Comparator.comparing(RecordedEvent::getEndTime));
+            RecordedEvent interval = events.getFirst();
+            System.out.println(interval);
+            RecordedEvent e = events.get(1);
             System.out.println(e);
             Events.assertField(e, "name").equal(JAVA_AGENT_JAR);
             Events.assertField(e, "options").equal("foo=bar");
             Events.assertField(e, "dynamic").equal(false);
             Instant initializationTime = e.getInstant("initializationTime");
-            if (initializationTime.isAfter(r.getStartTime())) {
+            if (initializationTime.isAfter(interval.getStartTime())) {
                 throw new Exception("Expected a static JavaAgent to be initialized before recording start");
             }
             Events.assertField(e, "initializationDuration").atLeast(0L);
@@ -100,17 +110,22 @@ private static void testJavaStatic() throws Throwable {
 
     private static void testNativeStatic() throws Throwable {
         try (Recording r = new Recording()) {
-            r.enable(EventNames.NativeAgent);
+            r.enable(EventNames.NativeAgent).with("period", "endChunk");
             r.start();
+            RecordingInterval intervalEvent = new RecordingInterval();
+            intervalEvent.commit();
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
-            RecordedEvent e = events.get(0);
+            events.sort(Comparator.comparing(RecordedEvent::getEndTime));
+            RecordedEvent interval = events.getFirst();
+            System.out.println(interval);
+            RecordedEvent e = events.get(1);
             System.out.println(e);
             Events.assertField(e, "name").equal("jdwp");
             Events.assertField(e, "options").equal("transport=dt_socket,server=y,address=any,onjcmd=y");
             Events.assertField(e, "dynamic").equal(false);
             Instant initializationTime = e.getInstant("initializationTime");
-            if (initializationTime.isAfter(r.getStartTime())) {
+            if (initializationTime.isAfter(interval.getStartTime())) {
                 throw new Exception("Expected a static NativeAgent to be initialized before recording start");
             }
             Events.assertField(e, "initializationDuration").atLeast(0L);
@@ -119,8 +134,10 @@ private static void testNativeStatic() throws Throwable {
 
     private static void testJavaDynamic() throws Throwable {
         try (Recording r = new Recording()) {
-            r.enable(EventNames.JavaAgent);
+            r.enable(EventNames.JavaAgent).with("period", "endChunk");
             r.start();
+            RecordingInterval intervalEvent = new RecordingInterval();
+            intervalEvent.begin();
             long pid = ProcessHandle.current().pid();
             VirtualMachine vm = VirtualMachine.attach(Long.toString(pid));
             vm.loadAgent(JAVA_AGENT_JAR, "bar=baz");
@@ -132,15 +149,19 @@ private static void testJavaDynamic() throws Throwable {
             vm.loadAgent(JAVA_AGENT_JAR, "");
             vm.loadAgent(JAVA_AGENT_JAR, "=");
             vm.detach();
+            intervalEvent.commit();
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
-            for (RecordedEvent e : events) {
+            events.sort(Comparator.comparing(RecordedEvent::getEndTime));
+            RecordedEvent interval = events.getFirst();
+            System.out.println(interval);
+            for (RecordedEvent e : events.subList(1, events.size())) {
                 System.out.println(e);
                 Instant initializationTime = e.getInstant("initializationTime");
-                if (initializationTime.isBefore(r.getStartTime())) {
+                if (initializationTime.isBefore(interval.getStartTime())) {
                     throw new Exception("Expected a dynamic JavaAgent to be initialized after recording start");
                 }
-                if (initializationTime.isAfter(r.getStopTime())) {
+                if (initializationTime.isAfter(interval.getEndTime())) {
                     throw new Exception("Expected a dynamic JavaAgent to be initialized before recording stop");
                 }
                 Duration initializationDuration = e.getDuration("initializationDuration");
@@ -152,10 +173,10 @@ private static void testJavaDynamic() throws Throwable {
                 }
                 Events.assertField(e, "name").equal(JAVA_AGENT_JAR);
             }
-            Events.assertField(events.get(0), "options").equal("bar=baz");
-            Events.assertField(events.get(1), "options").equal(null);
-            Events.assertField(events.get(2), "options").equal("");
-            Events.assertField(events.get(3), "options").equal("=");
+            Events.assertField(events.get(1), "options").equal("bar=baz");
+            Events.assertField(events.get(2), "options").equal(null);
+            Events.assertField(events.get(3), "options").equal("");
+            Events.assertField(events.get(4), "options").equal("=");
         }
     }
 }

From 7d094c78a8dd5cb46763391bb68e9c876d9f93c3 Mon Sep 17 00:00:00 2001
From: Damon Fenacci <dfenacci@openjdk.org>
Date: Wed, 21 Jun 2023 12:27:02 +0000
Subject: [PATCH 12/19] 8264899: C1: -XX:AbortVMOnException does not work if
 all methods in the call stack are compiled with C1 and there are no exception
 handlers

Reviewed-by: thartmann, amitkumar, fyang, mdoerr
---
 .../ErrorHandling/TestAbortVmOnException.java | 89 +++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 test/hotspot/jtreg/runtime/ErrorHandling/TestAbortVmOnException.java

diff --git a/test/hotspot/jtreg/runtime/ErrorHandling/TestAbortVmOnException.java b/test/hotspot/jtreg/runtime/ErrorHandling/TestAbortVmOnException.java
new file mode 100644
index 00000000000..447b690fa02
--- /dev/null
+++ b/test/hotspot/jtreg/runtime/ErrorHandling/TestAbortVmOnException.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestAbortVmOnException
+ * @summary Test -XX:AbortVMOnException=MyAbortException with C1 compilation
+ * @library /test/lib
+ * @run driver TestAbortVmOnException
+ * @bug 8264899
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+import java.io.IOException;
+
+
+public class TestAbortVmOnException {
+
+    public static void main(String[] args) throws Exception {
+        if (args.length == 1) {
+            if (args[0].equals("throwExceptionWithMessage")) {
+                throw new MyAbortException("MyExceptionMessage");
+            } else {
+                throw new MyAbortException();
+            }
+        }
+        // Run process throwing MyException
+        Process myExceptionThrowingProcess = runProcess( "MyAbortException", false, null);
+        parseOutput(myExceptionThrowingProcess, "fatal error: Saw MyAbortException, aborting");
+        // Run process throwing MyException with message
+        Process myExceptionThrowingWithMessageProcess = runProcess( "MyAbortException", true, null);
+        parseOutput(myExceptionThrowingWithMessageProcess, "fatal error: Saw MyAbortException: MyExceptionMessage, aborting");
+        // Run process throwing MyException with message and check message
+        Process myExceptionThrowingWithMessageCheckProcess = runProcess( "MyAbortException", true, "MyExceptionMessage");
+        parseOutput(myExceptionThrowingWithMessageCheckProcess, "fatal error: Saw MyAbortException: MyExceptionMessage, aborting");
+        System.out.println("PASSED");
+    }
+
+    private static Process runProcess(String exceptionName, boolean withMessage, String exceptionMessage) throws IOException {
+        if (exceptionMessage == null) {
+            return ProcessTools.createJavaProcessBuilder("-XX:+UnlockDiagnosticVMOptions",
+                "-XX:AbortVMOnException=" + exceptionName, "-Xcomp", "-Xbatch", "-XX:TieredStopAtLevel=3", TestAbortVmOnException.class.getName(),
+                withMessage ? "throwExceptionWithMessage" : "throwException").start();
+        } else {
+            return ProcessTools.createJavaProcessBuilder("-XX:+UnlockDiagnosticVMOptions",
+                "-XX:AbortVMOnException=" + exceptionName, "-XX:AbortVMOnExceptionMessage=" + exceptionMessage,
+                "-Xcomp", "-Xbatch", "-XX:TieredStopAtLevel=3", TestAbortVmOnException.class.getName(),
+                withMessage ? "throwExceptionWithMessage" : "throwException").start();
+        }
+    }
+
+    private static void parseOutput(Process process, String expectedString) throws IOException {
+        OutputAnalyzer output = new OutputAnalyzer(process);
+        output.stdoutShouldNotBeEmpty();
+        output.shouldContain(expectedString);
+    }
+
+}
+
+class MyAbortException extends RuntimeException {
+    public MyAbortException() {
+        super();
+    }
+
+    public MyAbortException(String message) {
+        super(message);
+    }
+}

From 1a58ac88cf5e688e53dcd0ac552f0ae5ceef02e7 Mon Sep 17 00:00:00 2001
From: Erik Gahlin <egahlin@openjdk.org>
Date: Wed, 21 Jun 2023 15:07:42 +0000
Subject: [PATCH 13/19] 8310335: JFR: Modernize collections and switch
 statements

Reviewed-by: mgronlun
---
 .../classes/jdk/jfr/ValueDescriptor.java      |   2 +-
 .../jdk/jfr/consumer/RecordedObject.java      | 276 ++++++------------
 .../jfr/consumer/snippet-files/Snippets.java  |   4 +-
 .../jfr/internal/EventInstrumentation.java    |   2 +-
 .../classes/jdk/jfr/internal/FilePurger.java  |   9 +-
 .../jdk/jfr/internal/MetadataReader.java      |   4 +-
 .../jdk/jfr/internal/PlatformRecorder.java    |   2 +-
 .../jdk/jfr/internal/PlatformRecording.java   |   2 +-
 .../internal/consumer/CompositeParser.java    |   4 +-
 .../jdk/jfr/internal/dcmd/ArgumentParser.java |   4 +-
 .../classes/jdk/jfr/internal/jfc/JFC.java     |  23 +-
 .../jfr/internal/jfc/model/XmlElement.java    |   4 +-
 .../jdk/jfr/internal/jfc/model/XmlNot.java    |   4 +-
 .../jfr/internal/jfc/model/XmlSelection.java  |   4 +-
 .../jdk/jfr/internal/jfc/model/XmlTest.java   |   4 +-
 .../jdk/jfr/internal/query/FieldBuilder.java  |   8 +-
 .../jdk/jfr/internal/query/TableRenderer.java |   2 +-
 .../jdk/jfr/internal/query/ViewFile.java      |   3 +-
 .../jdk/jfr/internal/tool/Command.java        |   2 +-
 .../jdk/jfr/internal/tool/Disassemble.java    |   2 +-
 .../jdk/jfr/internal/tool/Filters.java        |   2 +-
 .../jdk/jfr/internal/tool/PrettyWriter.java   |   4 +-
 .../jdk/jfr/api/consumer/TestFieldAccess.java |   4 +-
 .../api/consumer/TestMethodGetModifiers.java  |   4 +-
 .../jfr/api/consumer/TestRecordedEvent.java   |   4 +-
 .../consumer/TestRecordedEventGetThread.java  |   4 +-
 .../TestRecordedEventGetThreadOther.java      |   4 +-
 .../jfr/api/consumer/TestRecordedFrame.java   |   4 +-
 .../consumer/TestRecordedFullStackTrace.java  |   4 +-
 .../TestRecordedInstantEventTimestamp.java    |   4 +-
 .../TestRecordedMethodDescriptor.java         |   4 +-
 .../jfr/api/consumer/TestRecordedObject.java  |   4 +-
 .../api/consumer/TestSingleRecordedEvent.java |   4 +-
 .../jdk/jfr/api/consumer/TestToString.java    |   4 +-
 .../consumer/TestValueDescriptorRecorded.java |   4 +-
 .../recordingstream/TestOnMetadata.java       |   4 +-
 .../recordingstream/TestStoppedRecording.java |   4 +-
 .../jdk/jfr/api/event/TestEventDuration.java  |   4 +-
 .../event/dynamic/TestDynamicAnnotations.java |   6 +-
 .../jfr/api/flightrecorder/TestSnapshot.java  |   8 +-
 .../api/metadata/annotations/TestName.java    |   4 +-
 .../eventtype/TestGetAnnotationElements.java  |   6 +-
 .../metadata/eventtype/TestGetCategory.java   |   4 +-
 .../metadata/eventtype/TestGetSettings.java   |   4 +-
 .../valuedescriptor/TestConstructor.java      |   4 +-
 .../test.jfr.main/test/jfr/main/MainTest.java |   4 +-
 .../destination/TestDestFileExist.java        |   4 +-
 .../destination/TestDestInvalid.java          |   4 +-
 .../destination/TestDestLongPath.java         |   4 +-
 .../destination/TestDestReadOnly.java         |   4 +-
 .../recording/destination/TestDestState.java  |   4 +-
 .../destination/TestDestToDiskFalse.java      |   4 +-
 .../destination/TestDestToDiskTrue.java       |   4 +-
 .../destination/TestDestWithDuration.java     |   4 +-
 .../api/recording/dump/TestDumpLongPath.java  |   4 +-
 .../api/recording/event/TestChunkPeriod.java  |   6 +-
 .../api/recording/misc/TestRecordingCopy.java |   4 +-
 .../event/compiler/TestCodeCacheConfig.java   |   4 +-
 .../jfr/event/compiler/TestCodeCacheFull.java |   4 +-
 .../jfr/event/diagnostics/TestHeapDump.java   |   2 +-
 .../jfr/event/gc/collection/TestSystemGC.java |   4 +-
 .../GCHeapConfigurationEventTester.java       |   4 +-
 ...ungGenerationConfigurationEventTester.java |   4 +-
 .../TestGCConfigurationEvent.java             |   4 +-
 ...figurationEventWithDefaultPauseTarget.java |   4 +-
 .../TestGCSurvivorConfigurationEvent.java     |   4 +-
 .../TestGCTLABConfigurationEvent.java         |   4 +-
 .../gc/detailed/StressAllocationGCEvents.java |   4 +-
 .../TestGCHeapMemoryPoolUsageEvent.java       |   2 +-
 .../detailed/TestGCHeapMemoryUsageEvent.java  |   2 +-
 .../event/gc/detailed/TestGCLockerEvent.java  |   2 +-
 .../event/io/TestDeserializationEvent.java    |  26 +-
 .../event/profiling/TestFullStackTrace.java   |   6 +-
 .../runtime/TestActiveRecordingEvent.java     |   2 +-
 .../TestClassLoadingStatisticsEvent.java      |   4 +-
 .../event/runtime/TestClassRedefinition.java  |   4 +-
 .../event/runtime/TestExceptionEvents.java    |   4 +-
 .../runtime/TestNativeMemoryUsageEvents.java  |   6 +-
 .../event/runtime/TestRedefineClasses.java    |   4 +-
 .../event/runtime/TestRetransformClasses.java |   4 +-
 .../jfr/event/runtime/TestShutdownEvent.java  |   4 +-
 test/jdk/jdk/jfr/jcmd/TestJcmdConfigure.java  |   4 +-
 .../jdk/jdk/jfr/jcmd/TestJcmdDumpLimited.java |   6 +-
 .../jfr/jcmd/TestJcmdStartPathToGCRoots.java  |   4 +-
 .../TestPredefinedConfigurationInvalid.java   |   4 +-
 test/jdk/jdk/jfr/jmx/TestSnapshot.java        |   6 +-
 test/jdk/jdk/jfr/jvm/TestDumpOnCrash.java     |   4 +-
 .../jdk/jdk/jfr/jvm/TestPrimitiveClasses.java |   2 +-
 .../jdk/jfr/startupargs/StartupHelper.java    |   4 +-
 .../jfr/startupargs/TestEventSettings.java    |   4 +-
 .../threading/TestNestedVirtualThreads.java   |   4 +-
 91 files changed, 275 insertions(+), 400 deletions(-)

diff --git a/src/jdk.jfr/share/classes/jdk/jfr/ValueDescriptor.java b/src/jdk.jfr/share/classes/jdk/jfr/ValueDescriptor.java
index aeff81e41f5..b3c52d078e5 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/ValueDescriptor.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/ValueDescriptor.java
@@ -251,7 +251,7 @@ public String getContentType() {
      */
     public String getTypeName() {
         if (type.isSimpleType()) {
-            return type.getFields().get(0).getTypeName();
+            return type.getFields().getFirst().getTypeName();
         }
         return type.getName();
     }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java
index bc9f443b5c3..7fa2250b77f 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java
@@ -464,7 +464,6 @@ public final char getChar(String name) {
         if (o instanceof Character c) {
             return c;
         }
-
         throw newIllegalArgumentException(name, "char");
     }
 
@@ -495,23 +494,13 @@ public final char getChar(String name) {
      * @see #getValue(String)
      */
     public final short getShort(String name) {
-        Object o = getValue(name, true);
-        if (o instanceof Short s) {
-            return s;
-        }
-        if (o instanceof Byte b) {
-            return b;
-        }
-        if (o instanceof UnsignedValue unsigned) {
-            Object u = unsigned.value();
-            if (u instanceof Short s) {
-                return s;
-            }
-            if (u instanceof Byte b) {
-                return (short) Byte.toUnsignedInt(b);
-            }
-        }
-        throw newIllegalArgumentException(name, "short");
+        return switch (getValue(name, true)) {
+            case Short s -> s;
+            case Byte b -> b;
+            case UnsignedValue(Short s) -> s;
+            case UnsignedValue(Byte b) -> (short) Byte.toUnsignedInt(b);
+            case null, default -> throw newIllegalArgumentException(name, "short");
+        };
     }
 
     /**
@@ -542,32 +531,16 @@ public final short getShort(String name) {
      * @see #getValue(String)
      */
     public final int getInt(String name) {
-        Object o = getValue(name, true);
-        if (o instanceof Integer i) {
-            return i;
-        }
-        if (o instanceof Short s) {
-            return s;
-        }
-        if (o instanceof Character c) {
-            return c;
-        }
-        if (o instanceof Byte b) {
-            return b;
-        }
-        if (o instanceof UnsignedValue unsigned) {
-            Object u = unsigned.value();
-            if (u instanceof Integer i) {
-                return i;
-            }
-            if (u instanceof Short s) {
-                return Short.toUnsignedInt(s);
-            }
-            if (u instanceof Byte b) {
-                return Byte.toUnsignedInt(b);
-            }
-        }
-        throw newIllegalArgumentException(name, "int");
+        return switch(getValue(name, true)) {
+            case Integer i -> i;
+            case Short s -> s;
+            case Character c -> c;
+            case Byte b -> b;
+            case UnsignedValue(Integer i) -> i;
+            case UnsignedValue(Short s) -> Short.toUnsignedInt(s);
+            case UnsignedValue(Byte b) -> Byte.toUnsignedInt(b);
+            case null, default -> throw newIllegalArgumentException(name, "short");
+        };
     }
 
     /**
@@ -595,26 +568,15 @@ public final int getInt(String name) {
      * @see #getValue(String)
      */
     public final float getFloat(String name) {
-        Object o = getValue(name);
-        if (o instanceof Float f) {
-            return f;
-        }
-        if (o instanceof Long l) {
-            return l;
-        }
-        if (o instanceof Integer i) {
-            return i;
-        }
-        if (o instanceof Short s) {
-            return s;
-        }
-        if (o instanceof Byte b) {
-            return b;
-        }
-        if (o instanceof Character c) {
-            return c;
-        }
-        throw newIllegalArgumentException(name, "float");
+        return switch(getValue(name)) {
+            case Float f -> f;
+            case Long l -> l;
+            case Integer i -> i;
+            case Short s -> s;
+            case Character c -> c;
+            case Byte b -> b;
+            case null, default -> throw newIllegalArgumentException(name, "float");
+        };
     }
 
     /**
@@ -645,35 +607,17 @@ public final float getFloat(String name) {
      * @see #getValue(String)
      */
     public final long getLong(String name) {
-        Object o = getValue(name, true);
-        if (o instanceof Long l) {
-            return l;
-        }
-        if (o instanceof Integer i) {
-            return i;
-        }
-        if (o instanceof Short s) {
-            return s;
-        }
-        if (o instanceof Character c) {
-            return c;
-        }
-        if (o instanceof Byte b) {
-            return b.longValue();
-        }
-        if (o instanceof UnsignedValue unsigned) {
-            Object u = unsigned.value();
-            if (u instanceof Integer i) {
-                return Integer.toUnsignedLong(i);
-            }
-            if (u instanceof Short s) {
-                return Short.toUnsignedLong(s);
-            }
-            if (u instanceof Byte b) {
-                return Byte.toUnsignedLong(b);
-            }
-        }
-        throw newIllegalArgumentException(name, "long");
+        return switch(getValue(name, true)) {
+            case Long l -> l;
+            case Integer i -> i;
+            case Short s -> s;
+            case Character c -> c;
+            case Byte b -> b;
+            case UnsignedValue(Integer i) -> Integer.toUnsignedLong(i);
+            case UnsignedValue(Short s) -> Short.toUnsignedLong(s);
+            case UnsignedValue(Byte b) -> Byte.toUnsignedLong(b);
+            case null, default -> throw newIllegalArgumentException(name, "long");
+        };
     }
 
     /**
@@ -701,29 +645,16 @@ public final long getLong(String name) {
      * @see #getValue(String)
      */
     public final double getDouble(String name) {
-        Object o = getValue(name);
-        if (o instanceof Double d) {
-            return d.doubleValue();
-        }
-        if (o instanceof Float f) {
-            return f.doubleValue();
-        }
-        if (o instanceof Long l) {
-            return l.doubleValue();
-        }
-        if (o instanceof Integer i) {
-            return i.doubleValue();
-        }
-        if (o instanceof Short s) {
-            return s.doubleValue();
-        }
-        if (o instanceof Byte b) {
-            return b.doubleValue();
-        }
-        if (o instanceof Character c) {
-            return c;
-        }
-        throw newIllegalArgumentException(name, "double");
+        return switch(getValue(name)) {
+            case Double d -> d;
+            case Float f -> f;
+            case Long l -> l.doubleValue();
+            case Integer i -> i.doubleValue();
+            case Short s -> s.doubleValue();
+            case Character c -> c;
+            case Byte b -> b.doubleValue();
+            case null, default -> throw newIllegalArgumentException(name, "double");
+        };
     }
 
     /**
@@ -777,35 +708,17 @@ public final String getString(String name) {
      * @see #getValue(String)
      */
     public final Duration getDuration(String name) {
-        Object o = getValue(name);
-        if (o instanceof Long l) {
-            return getDuration(l, name);
-        }
-        if (o instanceof Integer i) {
-            return getDuration(i, name);
-        }
-        if (o instanceof Short s) {
-            return getDuration(s, name);
-        }
-        if (o instanceof Character c) {
-            return getDuration(c, name);
-        }
-        if (o instanceof Byte b) {
-            return getDuration(b, name);
-        }
-        if (o instanceof UnsignedValue unsigned) {
-            Object u = unsigned.value();
-            if (u instanceof Integer i) {
-                return getDuration(Integer.toUnsignedLong(i), name);
-            }
-            if (u instanceof Short s) {
-                return getDuration(Short.toUnsignedLong(s), name);
-            }
-            if (u instanceof Byte b) {
-                return getDuration(Short.toUnsignedLong(b), name);
-            }
-        }
-        throw newIllegalArgumentException(name, "java.time.Duration");
+        return switch (getValue(name, true)) {
+            case Long l -> getDuration(l, name);
+            case Integer i -> getDuration(i,name);
+            case Short s -> getDuration(s, name);
+            case Character c -> getDuration(c, name);
+            case Byte b -> getDuration(b, name);
+            case UnsignedValue(Integer i) -> getDuration(Integer.toUnsignedLong(i), name);
+            case UnsignedValue(Short s) -> getDuration(Short.toUnsignedLong(s), name);
+            case UnsignedValue(Byte b) -> getDuration(Short.toUnsignedLong(b), name);
+            case null, default ->  throw newIllegalArgumentException(name, "java.time.Duration");
+        };
     }
 
     private Duration getDuration(long timespan, String name) {
@@ -821,19 +734,14 @@ private Duration getDuration(long timespan, String name) {
         }
         Timespan ts = v.getAnnotation(Timespan.class);
         if (ts != null) {
-            switch (ts.value()) {
-            case Timespan.MICROSECONDS:
-                return Duration.ofNanos(1000 * timespan);
-            case Timespan.SECONDS:
-                return Duration.ofSeconds(timespan);
-            case Timespan.MILLISECONDS:
-                return Duration.ofMillis(timespan);
-            case Timespan.NANOSECONDS:
-                return Duration.ofNanos(timespan);
-            case Timespan.TICKS:
-                return Duration.ofNanos(objectContext.convertTimespan(timespan));
-            }
-            throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timespan unit " + ts.value());
+            return switch (ts.value()) {
+                case Timespan.MICROSECONDS -> Duration.ofNanos(1000 * timespan);
+                case Timespan.SECONDS -> Duration.ofSeconds(timespan);
+                case Timespan.MILLISECONDS -> Duration.ofMillis(timespan);
+                case Timespan.NANOSECONDS -> Duration.ofNanos(timespan);
+                case Timespan.TICKS -> Duration.ofNanos(objectContext.convertTimespan(timespan));
+                default ->  throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timespan unit " + ts.value());
+            };
         }
         throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with missing @Timespan");
     }
@@ -862,35 +770,17 @@ private Duration getDuration(long timespan, String name) {
      * @see #getValue(String)
      */
     public final Instant getInstant(String name) {
-        Object o = getValue(name, true);
-        if (o instanceof Long l) {
-            return getInstant(l, name);
-        }
-        if (o instanceof Integer i) {
-            return getInstant(i, name);
-        }
-        if (o instanceof Short s) {
-            return getInstant(s, name);
-        }
-        if (o instanceof Character c) {
-            return getInstant(c, name);
-        }
-        if (o instanceof Byte b) {
-            return getInstant(b, name);
-        }
-        if (o instanceof UnsignedValue unsigned) {
-            Object u = unsigned.value();
-            if (u instanceof Integer i) {
-                return getInstant(Integer.toUnsignedLong(i), name);
-            }
-            if (u instanceof Short s) {
-                return getInstant(Short.toUnsignedLong(s), name);
-            }
-            if (u instanceof Byte b) {
-                return getInstant(Short.toUnsignedLong(b), name);
-            }
-        }
-        throw newIllegalArgumentException(name, "java.time.Instant");
+        return switch (getValue(name, true)) {
+            case Long l -> getInstant(l, name);
+            case Integer i -> getInstant(i, name);
+            case Short s -> getInstant(s, name);
+            case Character c -> getInstant(c, name);
+            case Byte b -> getInstant(b, name);
+            case UnsignedValue(Integer i) -> getInstant(Integer.toUnsignedLong(i), name);
+            case UnsignedValue(Short s) -> getInstant(Short.toUnsignedLong(s), name);
+            case UnsignedValue(Byte b) -> getInstant(Short.toUnsignedLong(b), name);
+            case null, default -> throw newIllegalArgumentException(name, "java.time.Instant");
+        };
     }
 
     private Instant getInstant(long timestamp, String name) {
@@ -900,13 +790,11 @@ private Instant getInstant(long timestamp, String name) {
             if (timestamp == Long.MIN_VALUE) {
                 return Instant.MIN;
             }
-            switch (ts.value()) {
-            case Timestamp.MILLISECONDS_SINCE_EPOCH:
-                return Instant.ofEpochMilli(timestamp);
-            case Timestamp.TICKS:
-                return Instant.ofEpochSecond(0, objectContext.convertTimestamp(timestamp));
-            }
-            throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timestamp unit " + ts.value());
+            return switch (ts.value()) {
+                case Timestamp.MILLISECONDS_SINCE_EPOCH -> Instant.ofEpochMilli(timestamp);
+                case Timestamp.TICKS -> Instant.ofEpochSecond(0, objectContext.convertTimestamp(timestamp));
+                default -> throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timestamp unit " + ts.value());
+            };
         }
         throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with missing @Timestamp");
     }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/consumer/snippet-files/Snippets.java b/src/jdk.jfr/share/classes/jdk/jfr/consumer/snippet-files/Snippets.java
index 0b0ff55e65e..1aa45fa52c6 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/snippet-files/Snippets.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/snippet-files/Snippets.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -54,7 +54,7 @@ public static void main(String[] args) throws IOException {
                 .filter(e -> e.getEventType().getName().equals("jdk.ExecutionSample"))
                 .map(e -> e.getStackTrace())
                 .filter(s -> s != null)
-                .map(s -> s.getFrames().get(0))
+                .map(s -> s.getFrames().getFirst())
                 .filter(f -> f.isJavaFrame())
                 .map(f -> f.getMethod())
                 .collect(
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java
index 5bc25bb744e..9c3770c8fad 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java
@@ -227,7 +227,7 @@ private static List<SettingInfo> buildSettingInfos(Class<?> superClass, ClassNod
                         for (AnnotationNode nameCandidate : m.visibleAnnotations) {
                             if (ANNOTATION_NAME_DESCRIPTOR.equals(nameCandidate.desc)) {
                                 List<Object> values = nameCandidate.values;
-                                if (values.size() == 1 && values.get(0)instanceof String s) {
+                                if (values.size() == 1 && values.getFirst() instanceof String s) {
                                     name = Utils.validJavaIdentifier(s, name);
                                 }
                             }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java
index 1e9f68c47ca..ca5bfed73f1 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,7 +28,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.LinkedHashSet;
-import java.util.Set;
+import java.util.SequencedSet;
 
 import jdk.jfr.internal.SecuritySupport.SafePath;
 
@@ -36,7 +36,7 @@
 // so they can a later staged be removed.
 final class FilePurger {
 
-    private static final Set<SafePath> paths = new LinkedHashSet<>();
+    private static final SequencedSet<SafePath> paths = new LinkedHashSet<>();
 
     public static synchronized void add(SafePath p) {
         paths.add(p);
@@ -58,8 +58,7 @@ public static synchronized void purge() {
     }
 
     private static void removeOldest() {
-        SafePath oldest = paths.iterator().next();
-        paths.remove(oldest);
+        paths.removeFirst();
     }
 
     private static boolean delete(SafePath p) {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataReader.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataReader.java
index 13b81ca85d6..81f4c79fba4 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataReader.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataReader.java
@@ -75,12 +75,12 @@ public MetadataReader(RecordingInput input) throws IOException {
         }
         descriptor = new MetadataDescriptor();
         Element root = createElement();
-        Element metadata = root.elements("metadata").get(0);
+        Element metadata = root.elements("metadata").getFirst();
         declareTypes(metadata);
         defineTypes(metadata);
         annotateTypes(metadata);
         buildEvenTypes();
-        Element time = root.elements("region").get(0);
+        Element time = root.elements("region").getFirst();
         descriptor.gmtOffset = time.attribute(MetadataDescriptor.ATTRIBUTE_GMT_OFFSET, 1);
         descriptor.dst = time.attribute(MetadataDescriptor.ATTRIBUTE_DST, 0L);
         descriptor.locale = time.attribute(MetadataDescriptor.ATTRIBUTE_LOCALE, "");
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java
index 891b6e72ac3..2ce2bd8d722 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java
@@ -100,7 +100,7 @@ private static Timer createTimer() {
             jvm.exclude(t);
             t.start();
             t.join();
-            return result.get(0);
+            return result.getFirst();
         } catch (InterruptedException e) {
             throw new IllegalStateException("Not able to create timer task. " + e.getMessage(), e);
         }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java
index 6e5f461320a..9b31a9006e0 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java
@@ -797,7 +797,7 @@ private static List<RepositoryChunk> reduceFromBeginning(Long maxSize, List<Repo
         }
         // always keep at least one chunk
         if (result.isEmpty()) {
-            result.add(input.get(0));
+            result.add(input.getFirst());
         }
         return result;
     }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/CompositeParser.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/CompositeParser.java
index 72a9bf0ec66..0d3f4beb387 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/CompositeParser.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/CompositeParser.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -67,7 +67,7 @@ static Object parseReferences(RecordingInput input, Parser[] parsers) throws IOE
             return null;
         }
         if (refs.size() == 1) {
-            return refs.get(0);
+            return refs.getFirst();
         }
         return refs.toArray();
     }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/ArgumentParser.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/ArgumentParser.java
index 531ab867825..a614516d295 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/ArgumentParser.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/ArgumentParser.java
@@ -110,14 +110,14 @@ protected void checkConflict() {
             sb.append("s ");
             StringJoiner sj = new StringJoiner(", ");
             while (conflictedOptions.size() > 1) {
-                sj.add(conflictedOptions.remove(0));
+                sj.add(conflictedOptions.removeFirst());
             }
             sb.append(sj);
             sb.append(" and");
         }
 
         sb.append(" ");
-        sb.append(conflictedOptions.remove(0));
+        sb.append(conflictedOptions.removeFirst());
         sb.append(" can only be specified once.");
         throw new IllegalArgumentException(sb.toString());
     }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/JFC.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/JFC.java
index 213fe6c4c25..6d7cccfb2a6 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/JFC.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/JFC.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -303,18 +303,13 @@ public static String formatException(String prefix, Exception e, String input) {
     }
 
     private static String exceptionToVerb(Exception e) {
-        if (e instanceof FileNotFoundException || e instanceof NoSuchFileException) {
-            return "find";
-        }
-        if (e instanceof ParseException) {
-            return "parse";
-        }
-        if (e instanceof JFCModelException) {
-            return "use";
-        }
-        if (e instanceof AccessDeniedException) {
-            return "access";
-        }
-        return "open";  // InvalidPath, IOException
+        return switch (e) {
+            case FileNotFoundException f -> "find";
+            case NoSuchFileException n -> "find";
+            case ParseException p -> "parse";
+            case JFCModelException j -> "use";
+            case AccessDeniedException a -> "access";
+            default -> "open"; // InvalidPath, IOException
+        };
     }
 }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlElement.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlElement.java
index 90d5101d032..d05516ed229 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlElement.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlElement.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -175,7 +175,7 @@ protected Result evaluate() {
         if (producers.size() != 1) {
             throw new Error("Unsure how to evaluate multiple producers " + getClass());
         }
-        return producers.get(0).evaluate();
+        return producers.getFirst().evaluate();
     }
 
     protected void validateAttributes() throws JFCModelException {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlNot.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlNot.java
index b375bfcf838..3e0bef58e42 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlNot.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlNot.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,7 @@ protected void validateChildConstraints() throws JFCModelException {
     protected Result evaluate() {
         List<XmlElement> producers = getProducers();
         if (!producers.isEmpty()) {
-            Result r = producers.get(0).evaluate();
+            Result r = producers.getFirst().evaluate();
             if (!r.isNull()) {
                 return r.isTrue() ? Result.FALSE : Result.TRUE;
             }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlSelection.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlSelection.java
index c451119fb1a..32a4eca60c5 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlSelection.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlSelection.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -121,6 +121,6 @@ private XmlOption getSelected() {
                 return optionElement;
             }
         }
-        return options.isEmpty() ? null : options.get(0);
+        return options.isEmpty() ? null : options.getFirst();
     }
 }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlTest.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlTest.java
index 7da80dc1d60..ed17e00e307 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlTest.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/jfc/model/XmlTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -71,7 +71,7 @@ protected Result evaluate() {
         Result ret = Result.NULL;
         List<XmlElement> producers = getProducers();
         if (!producers.isEmpty()) {
-            XmlElement producer = producers.get(0);
+            XmlElement producer = producers.getFirst();
             Result r = producer.evaluate();
             if (!r.isNull()) {
                 ret = getValue().equals(r.value()) ? Result.TRUE : Result.FALSE;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/FieldBuilder.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/FieldBuilder.java
index 2105936b6cf..454ec180530 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/FieldBuilder.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/FieldBuilder.java
@@ -254,15 +254,11 @@ private void configureTime() {
 
     private void configureNumericTypes() {
         switch (descriptor.getTypeName()) {
-        case "int":
-        case "long":
-        case "short":
-        case "byte":
+        case "int", "long", "short", "byte":
             field.integralType = true;
             field.alignLeft = false;
             break;
-        case "float":
-        case "double":
+        case "float", "double":
             field.fractionalType = true;
             field.alignLeft = false;
             break;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/TableRenderer.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/TableRenderer.java
index b494d6b6dc8..dd9497d344f 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/TableRenderer.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/TableRenderer.java
@@ -331,7 +331,7 @@ private void printRow() {
         for (TableCell cell : tableCells) {
             maxHeight = Math.max(cell.getHeight(), maxHeight);
         }
-        TableCell lastCell = tableCells.get(tableCells.size() - 1);
+        TableCell lastCell = tableCells.getLast();
         for (int rowIndex = 0; rowIndex < maxHeight; rowIndex++) {
             for (TableCell cell : tableCells) {
                 if (rowIndex < cell.getHeight()) {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/ViewFile.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/ViewFile.java
index dc8aa75e490..96eb1fbdea8 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/query/ViewFile.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/query/ViewFile.java
@@ -110,8 +110,7 @@ private List<ViewConfiguration> parse(String text) throws ParseException {
                 String key = tokenizer.next();
                 tokenizer.expect("=");
                 String value = tokenizer.next();
-                ViewConfiguration view = views.get(views.size() - 1);
-                view.properties().put(key, value);
+                views.getLast().properties().put(key, value);
             }
         }
         return views;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Command.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Command.java
index 032e4d1982b..974e8846aa4 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Command.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Command.java
@@ -122,7 +122,7 @@ private static String buildAlias(Command c) {
         StringBuilder sb = new StringBuilder();
         if (aliases.size() == 1) {
             sb.append(" (alias ");
-            sb.append(aliases.get(0));
+            sb.append(aliases.getFirst());
             sb.append(")");
             return sb.toString();
          }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Disassemble.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Disassemble.java
index edcaf228d78..06616771cf9 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Disassemble.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Disassemble.java
@@ -181,7 +181,7 @@ private List<Long> findChunkSizes(Path p) throws IOException {
     private List<Long> combineChunkSizes(List<Long> sizes, int maxChunks, long maxSize) {
         List<Long> reduced = new ArrayList<Long>();
         int chunks = 1;
-        long fileSize = sizes.get(0);
+        long fileSize = sizes.getFirst();
         for (int i = 1; i < sizes.size(); i++) {
             long size = sizes.get(i);
             if (fileSize + size > maxSize || chunks == maxChunks) {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Filters.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Filters.java
index 7020e0daaa0..e63fd34f8b8 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Filters.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Filters.java
@@ -96,7 +96,7 @@ public static <T> Predicate<T> matchAny(List<Predicate<T>> filters) {
             return t -> true;
         }
         if (filters.size() == 1) {
-            return filters.get(0);
+            return filters.getFirst();
         }
         return t -> {
             for (Predicate<T> p : filters) {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java
index 26cf7f66ce0..89a8faba686 100644
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java
@@ -418,7 +418,7 @@ void printObject(RecordedObject object, long arraySize) {
         if (clazz != null) {
             String className = clazz.getName();
             if (className!= null && className.startsWith("[")) {
-                className = decodeDescriptors(className, arraySize > 0 ? Long.toString(arraySize) : "").get(0);
+                className = decodeDescriptors(className, arraySize > 0 ? Long.toString(arraySize) : "").getFirst();
             }
             print(className);
             String description = object.getString("description");
@@ -484,7 +484,7 @@ private void printClass(RecordedClass clazz, String postFix) {
         }
         String className = clazz.getName();
         if (className.startsWith("[")) {
-            className = decodeDescriptors(className, "").get(0);
+            className = decodeDescriptors(className, "").getFirst();
         }
         println(className + " (classLoader = " + classLoaderName + ")" + postFix);
     }
diff --git a/test/jdk/jdk/jfr/api/consumer/TestFieldAccess.java b/test/jdk/jdk/jfr/api/consumer/TestFieldAccess.java
index fa3e8e028cc..3a35ca6d751 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestFieldAccess.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestFieldAccess.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -65,7 +65,7 @@ public static void main(String[] args) throws Throwable {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             testHasField(event);
             testGetField(event, myEvent);
         }
diff --git a/test/jdk/jdk/jfr/api/consumer/TestMethodGetModifiers.java b/test/jdk/jdk/jfr/api/consumer/TestMethodGetModifiers.java
index 2b6e50c51e5..9b5505c55de 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestMethodGetModifiers.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestMethodGetModifiers.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,7 +57,7 @@ public static void main(String[] args) throws Throwable {
 
             List<RecordedEvent> recordedEvents = Events.fromRecording(recording);
             Events.hasEvents(recordedEvents);
-            RecordedEvent recordedEvent = recordedEvents.get(0);
+            RecordedEvent recordedEvent = recordedEvents.getFirst();
 
             System.out.println(recordedEvent);
 
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedEvent.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedEvent.java
index 6f23845f161..9223d2ef5ad 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedEvent.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -66,7 +66,7 @@ public static void main(String[] args) throws Throwable {
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
             Asserts.assertEquals(events.size(), 1);
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
 
             List<ValueDescriptor> descriptors = event.getFields();
 
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThread.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThread.java
index 657170cacfe..d3d581bc374 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThread.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThread.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -56,7 +56,7 @@ public static void main(String[] args) throws Throwable {
 
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             RecordedThread recordedThread = event.getThread();
             Asserts.assertNotNull(recordedThread);
 
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThreadOther.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThreadOther.java
index 29e925ba07d..daaec8c0557 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThreadOther.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedEventGetThreadOther.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -85,7 +85,7 @@ public static void main(String[] args) throws Exception  {
         List<RecordedEvent> events = RecordingFile.readAllEvents(dumpFilePath);
         Asserts.assertEquals(events.size(), 1);
 
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
         RecordedThread recordedThread = event.getThread();
 
         Asserts.assertNotNull(recordedThread);
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedFrame.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedFrame.java
index a543c2560aa..611ed0e688f 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedFrame.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedFrame.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -68,7 +68,7 @@ static void test() throws IOException {
 
             List<RecordedEvent> recordedEvents = Events.fromRecording(recording);
             Events.hasEvents(recordedEvents);
-            RecordedEvent recordedEvent = recordedEvents.get(0);
+            RecordedEvent recordedEvent = recordedEvents.getFirst();
 
             RecordedStackTrace stacktrace = recordedEvent.getStackTrace();
             List<RecordedFrame> frames = stacktrace.getFrames();
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedFullStackTrace.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedFullStackTrace.java
index 6993fe31001..18fcb300382 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedFullStackTrace.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedFullStackTrace.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -151,7 +151,7 @@ private static void checkEvent(RecordedEvent event, int expectedDepth) throws Th
             boolean isTruncateExpected = expectedDepth > MAX_DEPTH;
             Asserts.assertEquals(isTruncated, isTruncateExpected, "Wrong value for isTruncated. Expected:" + isTruncateExpected);
 
-            String firstMethod = frames.get(frames.size() - 1).getMethod().getName();
+            String firstMethod = frames.getLast().getMethod().getName();
             boolean isFullTrace = "run".equals(firstMethod);
             String msg = String.format("Wrong values for isTruncated=%b, isFullTrace=%b", isTruncated, isFullTrace);
             Asserts.assertTrue(isTruncated != isFullTrace, msg);
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedInstantEventTimestamp.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedInstantEventTimestamp.java
index ae2162c2466..8c37fe8743b 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedInstantEventTimestamp.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedInstantEventTimestamp.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -50,7 +50,7 @@ public static void main(String[] args) throws Throwable {
 
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             Asserts.assertEquals(event.getStartTime(), event.getEndTime());
         }
     }
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedMethodDescriptor.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedMethodDescriptor.java
index 47b8831d2e4..884697c26a5 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedMethodDescriptor.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedMethodDescriptor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -65,7 +65,7 @@ public static void main(String[] args) throws Exception  {
 
             List<RecordedEvent> recordedEvents = Events.fromRecording(recording);
             assertEquals(1, recordedEvents.size(), "Expected one event");
-            RecordedEvent recordedEvent = recordedEvents.get(0);
+            RecordedEvent recordedEvent = recordedEvents.getFirst();
 
             RecordedStackTrace stacktrace = recordedEvent.getStackTrace();
             List<RecordedFrame> frames = stacktrace.getFrames();
diff --git a/test/jdk/jdk/jfr/api/consumer/TestRecordedObject.java b/test/jdk/jdk/jfr/api/consumer/TestRecordedObject.java
index af7b5dfbf90..17878ff7e6c 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestRecordedObject.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestRecordedObject.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -392,7 +392,7 @@ private static RecordedObject makeRecordedObject() throws IOException {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            return events.get(0);
+            return events.getFirst();
         }
     }
 
diff --git a/test/jdk/jdk/jfr/api/consumer/TestSingleRecordedEvent.java b/test/jdk/jdk/jfr/api/consumer/TestSingleRecordedEvent.java
index 34572e09ad5..f8bd63b915a 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestSingleRecordedEvent.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestSingleRecordedEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,7 +58,7 @@ public static void main(String[] args) throws Throwable {
 
             // Should be 1 event only
             Asserts.assertEquals(events.size(), 1);
-            RecordedEvent recordedEvent = events.get(0);
+            RecordedEvent recordedEvent = events.getFirst();
             Asserts.assertEquals(recordedEvent.getEventType().getDescription(), "MyDescription");
         }
     }
diff --git a/test/jdk/jdk/jfr/api/consumer/TestToString.java b/test/jdk/jdk/jfr/api/consumer/TestToString.java
index 309d9d8ecf7..3c363176624 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestToString.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestToString.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,7 @@ public static void main(String[] args) throws Throwable {
             recording.stop();
             List<RecordedEvent> events = Events.fromRecording(recording);
             Events.hasEvents(events);
-            RecordedEvent e = events.get(0);
+            RecordedEvent e = events.getFirst();
             String toString = e.toString();
             System.out.println(toString);
             Asserts.assertTrue(toString.contains("hello, world"), "Missing String field value in RecordedEvent#toString()");
diff --git a/test/jdk/jdk/jfr/api/consumer/TestValueDescriptorRecorded.java b/test/jdk/jdk/jfr/api/consumer/TestValueDescriptorRecorded.java
index 1569fac7a8d..4fc90c10cf1 100644
--- a/test/jdk/jdk/jfr/api/consumer/TestValueDescriptorRecorded.java
+++ b/test/jdk/jdk/jfr/api/consumer/TestValueDescriptorRecorded.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,7 @@ public static void main(String[] args) throws Throwable {
 
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent recordedEvent = events.get(0);
+            RecordedEvent recordedEvent = events.getFirst();
             for (ValueDescriptor desc : recordedEvent.getFields()) {
                 if ("myValue".equals(desc.getName())) {
                     Asserts.assertEquals(desc.getLabel(), "myLabel");
diff --git a/test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnMetadata.java b/test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnMetadata.java
index fe4637144f4..79ca6634454 100644
--- a/test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnMetadata.java
+++ b/test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnMetadata.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -67,7 +67,7 @@ private static void testUnmodifiable() throws Exception {
         AtomicBoolean fail = new AtomicBoolean();
         try (RecordingStream r = new RecordingStream()) {
             r.onMetadata(m -> {
-                EventType t = FlightRecorder.getFlightRecorder().getEventTypes().get(0);
+                EventType t = FlightRecorder.getFlightRecorder().getEventTypes().getFirst();
                 try {
                     m.getEventTypes().add(t);
                     System.out.println("Should not be able to modify getEventTypes()");
diff --git a/test/jdk/jdk/jfr/api/consumer/recordingstream/TestStoppedRecording.java b/test/jdk/jdk/jfr/api/consumer/recordingstream/TestStoppedRecording.java
index 6daff7b339b..c0593f4d97b 100644
--- a/test/jdk/jdk/jfr/api/consumer/recordingstream/TestStoppedRecording.java
+++ b/test/jdk/jdk/jfr/api/consumer/recordingstream/TestStoppedRecording.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,7 +47,7 @@ public static void main(String... args) throws Exception {
         CountDownLatch latch = new CountDownLatch(1);
         try (RecordingStream rs = new RecordingStream()) {
             rs.onEvent(e -> {
-                FlightRecorder.getFlightRecorder().getRecordings().get(0).stop();
+                FlightRecorder.getFlightRecorder().getRecordings().getFirst().stop();
             });
             rs.onClose(() -> {
                 latch.countDown();
diff --git a/test/jdk/jdk/jfr/api/event/TestEventDuration.java b/test/jdk/jdk/jfr/api/event/TestEventDuration.java
index 15633bbf23a..f043ee26c53 100644
--- a/test/jdk/jdk/jfr/api/event/TestEventDuration.java
+++ b/test/jdk/jdk/jfr/api/event/TestEventDuration.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,7 +55,7 @@ public static void main(String[] args) throws Exception {
 
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
-            if (events.get(0).getDuration().toNanos() < 1) {
+            if (events.getFirst().getDuration().toNanos() < 1) {
                 throw new AssertionError("Expected a duration");
             }
         }
diff --git a/test/jdk/jdk/jfr/api/event/dynamic/TestDynamicAnnotations.java b/test/jdk/jdk/jfr/api/event/dynamic/TestDynamicAnnotations.java
index 4d5290a2e5a..18fb3cc5865 100644
--- a/test/jdk/jdk/jfr/api/event/dynamic/TestDynamicAnnotations.java
+++ b/test/jdk/jdk/jfr/api/event/dynamic/TestDynamicAnnotations.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -138,7 +138,7 @@ public static void testECID() throws Exception {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            Events.assertField(events.get(0), "ecid").equal(ecidValue);
+            Events.assertField(events.getFirst(), "ecid").equal(ecidValue);
         }
         EventType type = f.getEventType();
         ECID e = type.getAnnotation(ECID.class);
@@ -175,7 +175,7 @@ public static void testArray() throws Exception {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent re = events.get(0);
+            RecordedEvent re = events.getFirst();
             Array arrayAnnotation = re.getEventType().getAnnotation(Array.class);
             if (arrayAnnotation== null) {
                 throw new Exception("Missing array annotation");
diff --git a/test/jdk/jdk/jfr/api/flightrecorder/TestSnapshot.java b/test/jdk/jdk/jfr/api/flightrecorder/TestSnapshot.java
index cdf582cfbe9..fbb41b7f157 100644
--- a/test/jdk/jdk/jfr/api/flightrecorder/TestSnapshot.java
+++ b/test/jdk/jdk/jfr/api/flightrecorder/TestSnapshot.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -72,7 +72,7 @@ private static void testMultiple() throws IOException {
         }
         try (Recording snapshot = recorder.takeSnapshot()) {
             Asserts.assertEquals(snapshot.getSize(), size);
-            Asserts.assertGreaterThanOrEqual(snapshot.getStartTime(), recordings.get(0).getStartTime());
+            Asserts.assertGreaterThanOrEqual(snapshot.getStartTime(), recordings.getFirst().getStartTime());
             Asserts.assertLessThanOrEqual(snapshot.getStopTime(), recordings.get(RECORDING_COUNT - 1).getStopTime());
             Asserts.assertGreaterThanOrEqual(snapshot.getDuration(), Duration.ZERO);
             assertStaticOptions(snapshot);
@@ -122,7 +122,7 @@ private static void testOngoing(boolean disk) throws IOException {
                 List<RecordedEvent> events = Events.fromRecording(snapshot);
                 Events.hasEvents(events);
                 Asserts.assertEquals(events.size(), 1);
-                Asserts.assertEquals(events.get(0).getEventType().getName(), SimpleEvent.class.getName());
+                Asserts.assertEquals(events.getFirst().getEventType().getName(), SimpleEvent.class.getName());
             }
 
             r.stop();
@@ -162,7 +162,7 @@ private static void testStopped() throws IOException {
                 List<RecordedEvent> events = Events.fromRecording(snapshot);
                 Events.hasEvents(events);
                 Asserts.assertEquals(events.size(), 1);
-                Asserts.assertEquals(events.get(0).getEventType().getName(), SimpleEvent.class.getName());
+                Asserts.assertEquals(events.getFirst().getEventType().getName(), SimpleEvent.class.getName());
             }
         }
     }
diff --git a/test/jdk/jdk/jfr/api/metadata/annotations/TestName.java b/test/jdk/jdk/jfr/api/metadata/annotations/TestName.java
index ee0d38a58e1..411f5da67e1 100644
--- a/test/jdk/jdk/jfr/api/metadata/annotations/TestName.java
+++ b/test/jdk/jdk/jfr/api/metadata/annotations/TestName.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -269,7 +269,7 @@ private static void assertIllegalSettingName(Class<? extends Event> eventClass)
     private static void assertIllegalFieldName(Class<? extends Event> eventClass) throws Exception {
         EventType type = EventType.getEventType(eventClass);
         if (type.getField("field") == null) {
-            String illegal = type.getFields().get(type.getFields().size() - 1).getName();
+            String illegal = type.getFields().getLast().getName();
             throw new Exception("Expected default field name 'field' for event " + type.getName() + ", not illegal name " + illegal);
         }
     }
diff --git a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetAnnotationElements.java b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetAnnotationElements.java
index 213246a8486..34b84779d3e 100644
--- a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetAnnotationElements.java
+++ b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetAnnotationElements.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -98,12 +98,12 @@ public static void main(String[] args) throws Throwable {
 
         EventFactory f = EventFactory.create(eventAnnotations, fields);
         EventType type = f.getEventType();
-        List<AnnotationElement> aes = type.getAnnotationElements().get(0).getAnnotationElements();
+        List<AnnotationElement> aes = type.getAnnotationElements().getFirst().getAnnotationElements();
         Asserts.assertEquals(0, aes.size());
 
         EventType et = EventType.getEventType(MyEvent.class);
         ValueDescriptor field = et.getField("transactionRate");
-        aes = field.getAnnotationElements().get(0).getAnnotationElements();
+        aes = field.getAnnotationElements().getFirst().getAnnotationElements();
         Asserts.assertEquals(3, aes.size());
         assertContainsAnnotation(aes, Description.class);
         assertContainsAnnotation(aes, Label.class);
diff --git a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetCategory.java b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetCategory.java
index 5a9dbd809e1..ec92be1eb4e 100644
--- a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetCategory.java
+++ b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetCategory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,7 @@ public static void main(String[] args) throws Throwable {
         List<String> noCategory = EventType.getEventType(NoCategory.class).getCategoryNames();
         System.out.println("noCategory=" + noCategory);
         Asserts.assertEquals(noCategory.size(), 1, "Wrong default category");
-        Asserts.assertEquals(noCategory.get(0), "Uncategorized", "Wrong default category");
+        Asserts.assertEquals(noCategory.getFirst(), "Uncategorized", "Wrong default category");
 
         List<String>  withCategory = EventType.getEventType(WithCategory.class).getCategoryNames();
         Asserts.assertEquals(withCategory.size(), 4, "Wrong category");
diff --git a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetSettings.java b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetSettings.java
index faca325c810..f47d451edfb 100644
--- a/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetSettings.java
+++ b/test/jdk/jdk/jfr/api/metadata/eventtype/TestGetSettings.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,7 +46,7 @@ public static void main(String[] args) throws Throwable {
 
         // test immutability
         try {
-            settings.add(settings.get(0));
+            settings.add(settings.getFirst());
             Asserts.fail("Should not be able to modify list returned by getSettings()");
         } catch (UnsupportedOperationException uoe) {
             // OK, as expected
diff --git a/test/jdk/jdk/jfr/api/metadata/valuedescriptor/TestConstructor.java b/test/jdk/jdk/jfr/api/metadata/valuedescriptor/TestConstructor.java
index a3add739be0..056f216d677 100644
--- a/test/jdk/jdk/jfr/api/metadata/valuedescriptor/TestConstructor.java
+++ b/test/jdk/jdk/jfr/api/metadata/valuedescriptor/TestConstructor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -59,7 +59,7 @@ public static void main(String[] args) throws Throwable {
 
         // Get labelA from getAnnotations() list
         Asserts.assertEquals(1, vdComplex.getAnnotationElements().size(), "Expected getAnnotations().size() == 1");
-        final AnnotationElement outAnnotation = vdComplex.getAnnotationElements().get(0);
+        final AnnotationElement outAnnotation = vdComplex.getAnnotationElements().getFirst();
         Asserts.assertNotNull(outAnnotation, "outAnnotation was null");
         System.out.printf("Annotation: %s = %s%n", outAnnotation.getTypeName(), outAnnotation.getValue("value"));
         Asserts.assertEquals(outAnnotation, labelA, "Expected firstAnnotation == labelA");
diff --git a/test/jdk/jdk/jfr/api/modules/src_mods/test.jfr.main/test/jfr/main/MainTest.java b/test/jdk/jdk/jfr/api/modules/src_mods/test.jfr.main/test/jfr/main/MainTest.java
index ff063856f0c..b850807875d 100644
--- a/test/jdk/jdk/jfr/api/modules/src_mods/test.jfr.main/test/jfr/main/MainTest.java
+++ b/test/jdk/jdk/jfr/api/modules/src_mods/test.jfr.main/test/jfr/main/MainTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -94,7 +94,7 @@ private static void assertMetadata(List<RecordedEvent> events) {
 
     private static void assertMetaAnnotation(List<AnnotationElement> aes) {
         assertEquals(aes.size(), 1, "@ModularizedAnnotation should only have one meta-annotation");
-        AnnotationElement ae = aes.get(0);
+        AnnotationElement ae = aes.getFirst();
         assertEquals(ae.getTypeName(), ModularizedAnnotation.class.getName(), "Incorrect meta-annotation");
     }
 
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestFileExist.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestFileExist.java
index 944653bf124..42f5e277ced 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestFileExist.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestFileExist.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -59,7 +59,7 @@ public static void main(String[] args) throws Throwable {
         r.stop();
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No events found");
-        System.out.println(events.iterator().next());
+        System.out.println(events.getFirst());
         r.close();
     }
 
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestInvalid.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestInvalid.java
index 13a700fe95f..93e2709c222 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestInvalid.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestInvalid.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -92,7 +92,7 @@ public static void main(String[] args) throws Throwable {
         Asserts.assertTrue(Files.exists(dest), "No recording file: " + dest);
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s in %s%n", events.get(0).getEventType().getName(), dest.toString());
+        System.out.printf("Found event %s in %s%n", events.getFirst().getEventType().getName(), dest.toString());
     }
 
     private static void verifyException(VoidFunction f, String msg, Class<?> exceptionClass) throws Throwable {
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestLongPath.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestLongPath.java
index f5eb200b1ed..9ab67cfc02e 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestLongPath.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestLongPath.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,7 +58,7 @@ public static void main(String[] args) throws Throwable {
         Asserts.assertTrue(Files.exists(dest), "No recording file: " + dest);
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+        System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
     }
 
 }
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestReadOnly.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestReadOnly.java
index 464c089cb6e..8c4a132cb71 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestReadOnly.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestReadOnly.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -72,7 +72,7 @@ public static void main(String[] args) throws Throwable {
         Asserts.assertTrue(Files.exists(dest), "No recording file: " + dest);
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s in %s%n", events.get(0).getEventType().getName(), dest.toString());
+        System.out.printf("Found event %s in %s%n", events.getFirst().getEventType().getName(), dest.toString());
     }
 
     private static void verifyException(VoidFunction f, String msg) throws Throwable {
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestState.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestState.java
index 8d0ac868e6a..99ded47f5ea 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestState.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestState.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,7 +70,7 @@ public static void main(String[] args) throws Throwable {
         Asserts.assertTrue(Files.exists(runningDest), "No recording file: " + runningDest);
         List<RecordedEvent> events = RecordingFile.readAllEvents(runningDest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+        System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
         r.close();
     }
 
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskFalse.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskFalse.java
index cf6de33aa97..4930916a1d9 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskFalse.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskFalse.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -66,7 +66,7 @@ public static void main(String[] args) throws Throwable {
 
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+        System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
 
         assertEquals(r.getSize(), 0L, "getSize() should return 0, chunks should have been released at stop");
         // getDestination() should return null after recording have been written to file.
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskTrue.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskTrue.java
index b4b5f6b560e..3684c6e65e8 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskTrue.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestToDiskTrue.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,7 @@ public static void main(String[] args) throws Throwable {
         Asserts.assertTrue(Files.exists(dest), "No recording file: " + dest);
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+        System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
         System.out.printf("File size=%d, getSize()=%d%n", Files.size(dest), r.getSize());
         assertEquals(r.getSize(), 0L, "getSize() should return 0, chunks should have be released at stop");
         Asserts.assertNotEquals(Files.size(dest), 0L, "File length 0. Should at least be some bytes");
diff --git a/test/jdk/jdk/jfr/api/recording/destination/TestDestWithDuration.java b/test/jdk/jdk/jfr/api/recording/destination/TestDestWithDuration.java
index d51060c959d..ba305a18c2a 100644
--- a/test/jdk/jdk/jfr/api/recording/destination/TestDestWithDuration.java
+++ b/test/jdk/jdk/jfr/api/recording/destination/TestDestWithDuration.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -68,7 +68,7 @@ public static void main(String[] args) throws Throwable {
 
         List<RecordedEvent> events = RecordingFile.readAllEvents(dest);
         Asserts.assertFalse(events.isEmpty(), "No event found");
-        System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+        System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
     }
 
 }
diff --git a/test/jdk/jdk/jfr/api/recording/dump/TestDumpLongPath.java b/test/jdk/jdk/jfr/api/recording/dump/TestDumpLongPath.java
index 2c73aee18f3..a1d2f714f4e 100644
--- a/test/jdk/jdk/jfr/api/recording/dump/TestDumpLongPath.java
+++ b/test/jdk/jdk/jfr/api/recording/dump/TestDumpLongPath.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,7 +60,7 @@ public static void main(String[] args) throws Exception {
         Asserts.assertTrue(Files.exists(path), "Recording file does not exist: " + path);
         List<RecordedEvent> events = RecordingFile.readAllEvents(path);
         Asserts.assertFalse(events.isEmpty(), "No events found");
-        String foundEventPath = events.get(0).getEventType().getName();
+        String foundEventPath = events.getFirst().getEventType().getName();
         System.out.printf("Found event: %s%n", foundEventPath);
         Asserts.assertEquals(foundEventPath, eventPath, "Wrong event");
     }
diff --git a/test/jdk/jdk/jfr/api/recording/event/TestChunkPeriod.java b/test/jdk/jdk/jfr/api/recording/event/TestChunkPeriod.java
index 64c024cfa4f..71ffa1f3a9f 100644
--- a/test/jdk/jdk/jfr/api/recording/event/TestChunkPeriod.java
+++ b/test/jdk/jdk/jfr/api/recording/event/TestChunkPeriod.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -68,7 +68,7 @@ private static void testBeginChunk() throws IOException {
         r.stop();
         List<RecordedEvent> events = Events.fromRecording(r);
         Asserts.assertEquals(events.size(), 1, "Expected one event with beginChunk");
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
         Asserts.assertGreaterThanOrEqual(event.getStartTime(), beforeStart);
         Asserts.assertGreaterThanOrEqual(afterStart, event.getStartTime());
         r.close();
@@ -83,7 +83,7 @@ private static void testEndChunk() throws IOException {
         Instant afterStop =  Instant.now().plus(MARGIN_OF_ERROR);
         List<RecordedEvent> events = Events.fromRecording(r);
         Asserts.assertEquals(events.size(), 1, "Expected one event with endChunk");
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
         Asserts.assertGreaterThanOrEqual(event.getStartTime(), beforeStop);
         Asserts.assertGreaterThanOrEqual(afterStop, event.getStartTime());
         r.close();
diff --git a/test/jdk/jdk/jfr/api/recording/misc/TestRecordingCopy.java b/test/jdk/jdk/jfr/api/recording/misc/TestRecordingCopy.java
index dd11040b30a..8d539ed68c4 100644
--- a/test/jdk/jdk/jfr/api/recording/misc/TestRecordingCopy.java
+++ b/test/jdk/jdk/jfr/api/recording/misc/TestRecordingCopy.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -126,7 +126,7 @@ private static void assertCopy(Recording recording, Recording original) throws E
         Events.hasEvents(recordedEvents);
         Asserts.assertEquals(1, recordedEvents.size(), "Expected exactly one event");
 
-        RecordedEvent re = recordedEvents.get(0);
+        RecordedEvent re = recordedEvents.getFirst();
         Asserts.assertEquals(EVENT_ID, re.getValue("id"));
     }
 
diff --git a/test/jdk/jdk/jfr/event/compiler/TestCodeCacheConfig.java b/test/jdk/jdk/jfr/event/compiler/TestCodeCacheConfig.java
index 99431ed8248..cfc2115d68b 100644
--- a/test/jdk/jdk/jfr/event/compiler/TestCodeCacheConfig.java
+++ b/test/jdk/jdk/jfr/event/compiler/TestCodeCacheConfig.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,7 +60,7 @@ public static void main(String[] args) throws Exception {
 
         List<RecordedEvent> events = Events.fromRecording(recording);
         Events.hasEvents(events);
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
         long initialSize = (long) event.getValue("initialSize");
         long reservedSize = (long) event.getValue("reservedSize");
         long nonNMethodSize = (long) event.getValue("nonNMethodSize");
diff --git a/test/jdk/jdk/jfr/event/compiler/TestCodeCacheFull.java b/test/jdk/jdk/jfr/event/compiler/TestCodeCacheFull.java
index 70cdb7c31da..ba72d251372 100644
--- a/test/jdk/jdk/jfr/event/compiler/TestCodeCacheFull.java
+++ b/test/jdk/jdk/jfr/event/compiler/TestCodeCacheFull.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -67,7 +67,7 @@ private static void testWithBlobType(BlobType btype, long availableSize) throws
 
         List<RecordedEvent> events = Events.fromRecording(r);
         Events.hasEvents(events);
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
 
         String codeBlobType = Events.assertField(event, "codeBlobType").notNull().getValue();
         BlobType blobType = blobTypeFromName(codeBlobType);
diff --git a/test/jdk/jdk/jfr/event/diagnostics/TestHeapDump.java b/test/jdk/jdk/jfr/event/diagnostics/TestHeapDump.java
index 4cbb0826fa0..20577d8257d 100644
--- a/test/jdk/jdk/jfr/event/diagnostics/TestHeapDump.java
+++ b/test/jdk/jdk/jfr/event/diagnostics/TestHeapDump.java
@@ -60,7 +60,7 @@ public static void main(String[] args) throws Exception {
             if (events.size() != 1) {
                 throw new Exception("Expected one event, got " + events.size());
             }
-            RecordedEvent e = events.get(0);
+            RecordedEvent e = events.getFirst();
             Events.assertField(e, "destination").equal(path.toString());
             Events.assertField(e, "gcBeforeDump").equal(true);
             Events.assertField(e, "onOutOfMemoryError").equal(false);
diff --git a/test/jdk/jdk/jfr/event/gc/collection/TestSystemGC.java b/test/jdk/jdk/jfr/event/gc/collection/TestSystemGC.java
index 05b6aa45b8c..81c5be964fc 100644
--- a/test/jdk/jdk/jfr/event/gc/collection/TestSystemGC.java
+++ b/test/jdk/jdk/jfr/event/gc/collection/TestSystemGC.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,7 +60,7 @@ public static void main(String[] args) throws Exception {
 
             Asserts.assertEquals(3, events.size(), "Expected 3 SystemGC events");
 
-            RecordedEvent event1 = events.get(0);
+            RecordedEvent event1 = events.getFirst();
             Events.assertFrame(event1, System.class, "gc");
             Events.assertEventThread(event1, Thread.currentThread());
             Events.assertField(event1, "invokedConcurrent").isEqual(concurrent);
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/GCHeapConfigurationEventTester.java b/test/jdk/jdk/jfr/event/gc/configuration/GCHeapConfigurationEventTester.java
index ff554d659b4..1bbd8fcfa38 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/GCHeapConfigurationEventTester.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/GCHeapConfigurationEventTester.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,7 +42,7 @@ public void run() throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        EventVerifier v = createVerifier(events.get(0));
+        EventVerifier v = createVerifier(events.getFirst());
         v.verify();
     }
 
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/GCYoungGenerationConfigurationEventTester.java b/test/jdk/jdk/jfr/event/gc/configuration/GCYoungGenerationConfigurationEventTester.java
index 780b9094153..83dd9d735ac 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/GCYoungGenerationConfigurationEventTester.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/GCYoungGenerationConfigurationEventTester.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -41,7 +41,7 @@ public void run() throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        EventVerifier v = createVerifier(events.get(0));
+        EventVerifier v = createVerifier(events.getFirst());
         v.verify();
     }
 
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEvent.java b/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEvent.java
index c134c21ffdc..e459b0f2e7b 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -50,7 +50,7 @@ public static void main(String[] args) throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        GCConfigurationEventVerifier verifier = new GCConfigurationEventVerifier(events.get(0));
+        GCConfigurationEventVerifier verifier = new GCConfigurationEventVerifier(events.getFirst());
         verifier.verify();
     }
 }
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEventWithDefaultPauseTarget.java b/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEventWithDefaultPauseTarget.java
index 868065791f2..c3a28030338 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEventWithDefaultPauseTarget.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/TestGCConfigurationEventWithDefaultPauseTarget.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -48,7 +48,7 @@ public static void main(String[] args) throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        DefaultGCConfigurationVerifier verifier = new DefaultGCConfigurationVerifier(events.get(0));
+        DefaultGCConfigurationVerifier verifier = new DefaultGCConfigurationVerifier(events.getFirst());
         verifier.verify();
     }
 }
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/TestGCSurvivorConfigurationEvent.java b/test/jdk/jdk/jfr/event/gc/configuration/TestGCSurvivorConfigurationEvent.java
index 89dcd97cd4e..fde69412a7a 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/TestGCSurvivorConfigurationEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/TestGCSurvivorConfigurationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,7 +49,7 @@ public static void main(String[] args) throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        GCSurvivorConfigurationEventVerifier verifier = new GCSurvivorConfigurationEventVerifier(events.get(0));
+        GCSurvivorConfigurationEventVerifier verifier = new GCSurvivorConfigurationEventVerifier(events.getFirst());
         verifier.verify();
     }
 }
diff --git a/test/jdk/jdk/jfr/event/gc/configuration/TestGCTLABConfigurationEvent.java b/test/jdk/jdk/jfr/event/gc/configuration/TestGCTLABConfigurationEvent.java
index e67897199a5..b69e4fb8490 100644
--- a/test/jdk/jdk/jfr/event/gc/configuration/TestGCTLABConfigurationEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/configuration/TestGCTLABConfigurationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,7 +49,7 @@ public static void main(String[] args) throws Exception {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         assertGreaterThanOrEqual(events.size(), 1, "Expected at least 1 event");
-        GCTLABConfigurationEventVerifier verifier = new GCTLABConfigurationEventVerifier(events.get(0));
+        GCTLABConfigurationEventVerifier verifier = new GCTLABConfigurationEventVerifier(events.getFirst());
         verifier.verify();
     }
 }
diff --git a/test/jdk/jdk/jfr/event/gc/detailed/StressAllocationGCEvents.java b/test/jdk/jdk/jfr/event/gc/detailed/StressAllocationGCEvents.java
index 257d35bd389..779ed704ea7 100644
--- a/test/jdk/jdk/jfr/event/gc/detailed/StressAllocationGCEvents.java
+++ b/test/jdk/jdk/jfr/event/gc/detailed/StressAllocationGCEvents.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -157,7 +157,7 @@ private void checkEvent(RecordedEvent event) throws Exception {
         List<RecordedFrame> frames = stackTrace.getFrames();
         //String[] stacktrace = StackTraceHelper.buildStackTraceFromFrames(frames);
 
-        if (!(frames.get(0).getMethod().getName().equals(DIVER_FRAME_NAME))) {
+        if (!(frames.getFirst().getMethod().getName().equals(DIVER_FRAME_NAME))) {
             System.out.println("Skip stacktrace check for: \n"
                     + String.join("\n", threadName));
             return;
diff --git a/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryPoolUsageEvent.java b/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryPoolUsageEvent.java
index 33c1b04dbca..6d5308408d6 100644
--- a/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryPoolUsageEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryPoolUsageEvent.java
@@ -50,7 +50,7 @@ public static void main(String[] args) throws Exception {
             System.out.println(events);
             assertFalse(events.isEmpty());
 
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             Events.assertField(event, "name").notNull();
             Events.assertField(event, "used").atLeast(0L);
             Events.assertField(event, "committed").atLeast(0L);
diff --git a/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryUsageEvent.java b/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryUsageEvent.java
index 61aa079ca23..7f1d96a3993 100644
--- a/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryUsageEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/detailed/TestGCHeapMemoryUsageEvent.java
@@ -49,7 +49,7 @@ public static void main(String[] args) throws Exception {
             List<RecordedEvent> events = Events.fromRecording(recording);
             System.out.println(events);
             assertFalse(events.isEmpty());
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             Events.assertField(event, "used").above(0L);
             Events.assertField(event, "committed").above(0L);
             Events.assertField(event, "max").above(0L);
diff --git a/test/jdk/jdk/jfr/event/gc/detailed/TestGCLockerEvent.java b/test/jdk/jdk/jfr/event/gc/detailed/TestGCLockerEvent.java
index d35309c1883..f0d9fa3f35a 100644
--- a/test/jdk/jdk/jfr/event/gc/detailed/TestGCLockerEvent.java
+++ b/test/jdk/jdk/jfr/event/gc/detailed/TestGCLockerEvent.java
@@ -88,7 +88,7 @@ public static void main(String[] args) throws Exception {
         // Verify recording
         var all = Events.fromRecording(recording);
         Events.hasEvents(all);
-        var event = all.get(0);
+        var event = all.getFirst();
 
         assertTrue(Events.isEventType(event, EVENT_NAME));
         Events.assertField(event, "lockCount").equal(CRITICAL_THREAD_COUNT);
diff --git a/test/jdk/jdk/jfr/event/io/TestDeserializationEvent.java b/test/jdk/jdk/jfr/event/io/TestDeserializationEvent.java
index c2b250c3e00..28b26165e2f 100644
--- a/test/jdk/jdk/jfr/event/io/TestDeserializationEvent.java
+++ b/test/jdk/jdk/jfr/event/io/TestDeserializationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -175,9 +175,9 @@ public void testFilterDisallow(Status filterStatus,
             recording.stop();
             List<RecordedEvent> events = Events.fromRecording(recording);
             assertEquals(events.size(), 1);
-            assertEquals(events.get(0).getEventType().getName(), "jdk.Deserialization");
-            assertFilterConfigured(true).accept(events.get(0));
-            assertFilterStatus(expectedValue).accept(events.get(0));
+            assertEquals(events.getFirst().getEventType().getName(), "jdk.Deserialization");
+            assertFilterConfigured(true).accept(events.getFirst());
+            assertFilterStatus(expectedValue).accept(events.getFirst());
         }
     }
 
@@ -202,9 +202,9 @@ public void testFilterAllowed(Status filterStatus,
             recording.stop();
             List<RecordedEvent> events = Events.fromRecording(recording);
             assertEquals(events.size(), 1);
-            assertEquals(events.get(0).getEventType().getName(), "jdk.Deserialization");
-            assertFilterConfigured(true).accept(events.get(0));
-            assertFilterStatus(expectedValue).accept(events.get(0));
+            assertEquals(events.getFirst().getEventType().getName(), "jdk.Deserialization");
+            assertFilterConfigured(true).accept(events.getFirst());
+            assertFilterStatus(expectedValue).accept(events.getFirst());
         }
     }
 
@@ -224,10 +224,10 @@ public void testException() throws Exception {
             recording.stop();
             List<RecordedEvent> events = Events.fromRecording(recording);
             assertEquals(events.size(), 1);
-            assertEquals(events.get(0).getEventType().getName(), "jdk.Deserialization");
-            assertFilterConfigured(true).accept(events.get(0));
-            assertExceptionType(XYZException.class).accept(events.get(0));
-            assertExceptionMessage("I am a bad filter!!!").accept(events.get(0));
+            assertEquals(events.getFirst().getEventType().getName(), "jdk.Deserialization");
+            assertFilterConfigured(true).accept(events.getFirst());
+            assertExceptionType(XYZException.class).accept(events.getFirst());
+            assertExceptionMessage("I am a bad filter!!!").accept(events.getFirst());
         }
     }
 
@@ -428,8 +428,8 @@ public void testRejectedClassNotInitialized() throws Exception {
             List<RecordedEvent> events = Events.fromRecording(recording);
             assertEquals(events.size(), 1);
             assertEquals(events.get(0).getEventType().getName(), "jdk.Deserialization");
-            assertFilterConfigured(true).accept(events.get(0));
-            assertFilterStatus("REJECTED").accept(events.get(0));
+            assertFilterConfigured(true).accept(events.getFirst());
+            assertFilterStatus("REJECTED").accept(events.getFirst());
             assertFalse(initializedFoo);
             assertType(Foo.class);
         }
diff --git a/test/jdk/jdk/jfr/event/profiling/TestFullStackTrace.java b/test/jdk/jdk/jfr/event/profiling/TestFullStackTrace.java
index b9f23ebed86..b7abbc0a587 100644
--- a/test/jdk/jdk/jfr/event/profiling/TestFullStackTrace.java
+++ b/test/jdk/jdk/jfr/event/profiling/TestFullStackTrace.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -121,7 +121,7 @@ private static boolean hasValidStackTraces(Recording recording, RecurseThread[]
     public static String getTopMethodName(RecordedEvent event) {
         List<RecordedFrame> frames = event.getStackTrace().getFrames();
         Asserts.assertFalse(frames.isEmpty(), "JavaFrames was empty");
-        return frames.get(0).getMethod().getName();
+        return frames.getFirst().getMethod().getName();
     }
 
     private static void checkEvent(RecordedEvent event, int expectedDepth) throws Throwable {
@@ -144,7 +144,7 @@ private static void checkEvent(RecordedEvent event, int expectedDepth) throws Th
             boolean isTruncateExpected = expectedDepth > MAX_DEPTH;
             Asserts.assertEquals(isTruncated, isTruncateExpected, "Wrong value for isTruncated. Expected:" + isTruncateExpected);
 
-            String firstMethod = frames.get(frames.size() - 1).getMethod().getName();
+            String firstMethod = frames.getLast().getMethod().getName();
             boolean isFullTrace = "run".equals(firstMethod);
             String msg = String.format("Wrong values for isTruncated=%b, isFullTrace=%b", isTruncated, isFullTrace);
             Asserts.assertTrue(isTruncated != isFullTrace, msg);
diff --git a/test/jdk/jdk/jfr/event/runtime/TestActiveRecordingEvent.java b/test/jdk/jdk/jfr/event/runtime/TestActiveRecordingEvent.java
index c929ff1d5e8..e786e8c933d 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestActiveRecordingEvent.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestActiveRecordingEvent.java
@@ -89,7 +89,7 @@ private static void testWithPath(Path path) throws Throwable {
         List<RecordedEvent> events = Events.fromRecording(recording);
 
         Events.hasEvents(events);
-        RecordedEvent ev = events.get(0);
+        RecordedEvent ev = events.getFirst();
 
         // Duration must be kept in milliseconds
         assertEquals(REC_DURATION.toMillis(), ev.getValue("recordingDuration"));
diff --git a/test/jdk/jdk/jfr/event/runtime/TestClassLoadingStatisticsEvent.java b/test/jdk/jdk/jfr/event/runtime/TestClassLoadingStatisticsEvent.java
index 31760614019..8bbbdcbc447 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestClassLoadingStatisticsEvent.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestClassLoadingStatisticsEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -116,7 +116,7 @@ private static RecordedEvent getCurrentEvent() throws Throwable {
         recording.stop();
         List<RecordedEvent> events = Events.fromRecording(recording);
         Asserts.assertFalse(events.isEmpty(), "No events in recording");
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
         return event;
     }
 
diff --git a/test/jdk/jdk/jfr/event/runtime/TestClassRedefinition.java b/test/jdk/jdk/jfr/event/runtime/TestClassRedefinition.java
index f3e24581b23..23c2f2cbc3a 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestClassRedefinition.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestClassRedefinition.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -81,7 +81,7 @@ public static void main(String[] args) throws Throwable {
         List<RecordedEvent> events = RecordingFile.readAllEvents(DUMP_PATH);
 
         Asserts.assertEquals(events.size(), 2, "Expected exactly two ClassRedefinition event");
-        RecordedEvent e1 = events.get(0);
+        RecordedEvent e1 = events.getFirst();
         System.out.println(e1);
         RecordedEvent e2 = events.get(1);
         System.out.println(e2);
diff --git a/test/jdk/jdk/jfr/event/runtime/TestExceptionEvents.java b/test/jdk/jdk/jfr/event/runtime/TestExceptionEvents.java
index 5176e0e44db..46488f0221a 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestExceptionEvents.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestExceptionEvents.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -102,7 +102,7 @@ class TestException extends Exception {
                 RecordedStackTrace rs = e.getStackTrace();
                 RecordedClass rc = e.getValue("thrownClass");
                 List<RecordedFrame> frames = rs.getFrames();
-                RecordedFrame topFrame = frames.get(0);
+                RecordedFrame topFrame = frames.getFirst();
                 System.out.println(rc.getName() + " Top frame: " + topFrame.getMethod().getName());
                 if (!topFrame.getMethod().getName().equals("<init>")) {
                     throw new Exception("Expected name of top frame to be <init>");
diff --git a/test/jdk/jdk/jfr/event/runtime/TestNativeMemoryUsageEvents.java b/test/jdk/jdk/jfr/event/runtime/TestNativeMemoryUsageEvents.java
index 14165afb31e..179d0f50810 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestNativeMemoryUsageEvents.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestNativeMemoryUsageEvents.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -150,8 +150,8 @@ private static void verifyHeapGrowth(List<RecordedEvent> events) throws Exceptio
                 .toList();
 
         // Verify that the heap has grown between the first and last sample.
-        long firstSample = javaHeapCommitted.get(0);
-        long lastSample = javaHeapCommitted.get(javaHeapCommitted.size() - 1);
+        long firstSample = javaHeapCommitted.getFirst();
+        long lastSample = javaHeapCommitted.getLast();
         assertGreaterThan(lastSample, firstSample, "heap should have grown and NMT should show that");
     }
 
diff --git a/test/jdk/jdk/jfr/event/runtime/TestRedefineClasses.java b/test/jdk/jdk/jfr/event/runtime/TestRedefineClasses.java
index 4331bae0d98..40fc583872f 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestRedefineClasses.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestRedefineClasses.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -79,7 +79,7 @@ public static void premain(String agentArgs, Instrumentation instrumentation) th
     public static void main(String[] args) throws Throwable {
         List<RecordedEvent> events = RecordingFile.readAllEvents(DUMP_PATH);
         Asserts.assertEquals(events.size(), 1, "Expected one RedefineClasses event");
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
 
         System.out.println(event);
 
diff --git a/test/jdk/jdk/jfr/event/runtime/TestRetransformClasses.java b/test/jdk/jdk/jfr/event/runtime/TestRetransformClasses.java
index 00242de5b2a..a02f97366c3 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestRetransformClasses.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestRetransformClasses.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -84,7 +84,7 @@ public static void premain(String agentArgs, Instrumentation instrumentation) th
     public static void main(String[] args) throws Throwable {
         List<RecordedEvent> events = RecordingFile.readAllEvents(DUMP_PATH);
         Asserts.assertEquals(events.size(), 1, "Expected one RetransformClasses event");
-        RecordedEvent event = events.get(0);
+        RecordedEvent event = events.getFirst();
 
         System.out.println(event);
 
diff --git a/test/jdk/jdk/jfr/event/runtime/TestShutdownEvent.java b/test/jdk/jdk/jfr/event/runtime/TestShutdownEvent.java
index 71b617ecd79..26d72578170 100644
--- a/test/jdk/jdk/jfr/event/runtime/TestShutdownEvent.java
+++ b/test/jdk/jdk/jfr/event/runtime/TestShutdownEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -114,7 +114,7 @@ private static void runSubtest(int subTestIndex) throws Exception {
             .collect(Collectors.toList());
 
         Asserts.assertEquals(filteredEvents.size(), 1);
-        RecordedEvent event = filteredEvents.get(0);
+        RecordedEvent event = filteredEvents.getFirst();
         subTests[subTestIndex].verifyEvents(event, exitCode);
     }
 
diff --git a/test/jdk/jdk/jfr/jcmd/TestJcmdConfigure.java b/test/jdk/jdk/jfr/jcmd/TestJcmdConfigure.java
index aa76f501483..2780f396f05 100644
--- a/test/jdk/jdk/jfr/jcmd/TestJcmdConfigure.java
+++ b/test/jdk/jdk/jfr/jcmd/TestJcmdConfigure.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -88,7 +88,7 @@ public static void main(String[] args) throws Exception {
             for (Exception e : testExceptions) {
                 System.out.println("Error: " + e.getMessage());
             }
-            throw testExceptions.get(0);
+            throw testExceptions.getFirst();
         }
     }
 
diff --git a/test/jdk/jdk/jfr/jcmd/TestJcmdDumpLimited.java b/test/jdk/jdk/jfr/jcmd/TestJcmdDumpLimited.java
index cb05f49950a..ce4b11937c6 100644
--- a/test/jdk/jdk/jfr/jcmd/TestJcmdDumpLimited.java
+++ b/test/jdk/jdk/jfr/jcmd/TestJcmdDumpLimited.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -110,9 +110,7 @@ public static void main(String[] args) throws Exception {
             recs.add(new TestRecording(i, 100));
         }
         int last = 0;
-        List<TestRecording> reversed = new ArrayList<>(recs);
-        Collections.reverse(reversed);
-        for (TestRecording r : reversed) {
+        for (TestRecording r : recs.reversed()) {
             r.total = r.size + last;
             last += r.size;
         }
diff --git a/test/jdk/jdk/jfr/jcmd/TestJcmdStartPathToGCRoots.java b/test/jdk/jdk/jfr/jcmd/TestJcmdStartPathToGCRoots.java
index 31a458c2f8f..ff87d2b68a1 100644
--- a/test/jdk/jdk/jfr/jcmd/TestJcmdStartPathToGCRoots.java
+++ b/test/jdk/jdk/jfr/jcmd/TestJcmdStartPathToGCRoots.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -66,7 +66,7 @@ private static void assertCutoff(String expected, String errorMessage) throws Ex
         }
 
         String settingName = EventNames.OldObjectSample + "#" + "cutoff";
-        Recording r = recordings.get(0);
+        Recording r = recordings.getFirst();
         String cutoff = r.getSettings().get(settingName);
         System.out.println(settingName + "=" + cutoff);
         if (!expected.equals(cutoff)) {
diff --git a/test/jdk/jdk/jfr/jmx/TestPredefinedConfigurationInvalid.java b/test/jdk/jdk/jfr/jmx/TestPredefinedConfigurationInvalid.java
index f5a2651ebed..d68bacbcbd0 100644
--- a/test/jdk/jdk/jfr/jmx/TestPredefinedConfigurationInvalid.java
+++ b/test/jdk/jdk/jfr/jmx/TestPredefinedConfigurationInvalid.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -48,7 +48,7 @@ public static void main(String[] args) throws Throwable {
         setInvalidConfigName(recId, "invalidname");
 
         // Verify we can set named config after failed attempts.
-        Configuration config = Configuration.getConfigurations().get(0);
+        Configuration config = Configuration.getConfigurations().getFirst();
         bean.setPredefinedConfiguration(recId, config.getName());
         JmxHelper.verifyMapEquals(bean.getRecordingSettings(recId), config.getSettings());
     }
diff --git a/test/jdk/jdk/jfr/jmx/TestSnapshot.java b/test/jdk/jdk/jfr/jmx/TestSnapshot.java
index c6ca923d635..b4eb13216b5 100644
--- a/test/jdk/jdk/jfr/jmx/TestSnapshot.java
+++ b/test/jdk/jdk/jfr/jmx/TestSnapshot.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,7 +58,7 @@ private static void testStopped() throws IOException {
                 r.close();
                 FlightRecorderMXBean mxBean = JmxHelper.getFlighteRecorderMXBean();
                 List<RecordingInfo> recs = mxBean.getRecordings();
-                JmxHelper.verifyEquals(recs.get(0), snapshot);
+                JmxHelper.verifyEquals(recs.getFirst(), snapshot);
             }
         }
     }
@@ -67,7 +67,7 @@ private static void testEmpty() throws IOException {
         try (Recording snapshot = FlightRecorder.getFlightRecorder().takeSnapshot()) {
             FlightRecorderMXBean mxBean = JmxHelper.getFlighteRecorderMXBean();
             List<RecordingInfo> recs = mxBean.getRecordings();
-            JmxHelper.verifyEquals(recs.get(0), snapshot);
+            JmxHelper.verifyEquals(recs.getFirst(), snapshot);
         }
     }
 }
diff --git a/test/jdk/jdk/jfr/jvm/TestDumpOnCrash.java b/test/jdk/jdk/jfr/jvm/TestDumpOnCrash.java
index f318961b57a..374e23ecb48 100644
--- a/test/jdk/jdk/jfr/jvm/TestDumpOnCrash.java
+++ b/test/jdk/jdk/jfr/jvm/TestDumpOnCrash.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -153,7 +153,7 @@ private static void verify(long pid, String dumppath, boolean expectDump) throws
 
             List<RecordedEvent> events = RecordingFile.readAllEvents(file);
             Asserts.assertFalse(events.isEmpty(), "No event found");
-            System.out.printf("Found event %s%n", events.get(0).getEventType().getName());
+            System.out.printf("Found event %s%n", events.getFirst().getEventType().getName());
 
             Files.delete(file);
         } else {
diff --git a/test/jdk/jdk/jfr/jvm/TestPrimitiveClasses.java b/test/jdk/jdk/jfr/jvm/TestPrimitiveClasses.java
index 54c20f5bea8..bb0163bc925 100644
--- a/test/jdk/jdk/jfr/jvm/TestPrimitiveClasses.java
+++ b/test/jdk/jdk/jfr/jvm/TestPrimitiveClasses.java
@@ -62,7 +62,7 @@ public static void main(String[] args) throws Exception {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            RecordedEvent event = events.get(0);
+            RecordedEvent event = events.getFirst();
             System.out.println(event);
             testField(event, "booleanClass", boolean.class);
             testField(event, "charClass", char.class);
diff --git a/test/jdk/jdk/jfr/startupargs/StartupHelper.java b/test/jdk/jdk/jfr/startupargs/StartupHelper.java
index c1ddcdce85f..01911cd8cc1 100644
--- a/test/jdk/jdk/jfr/startupargs/StartupHelper.java
+++ b/test/jdk/jdk/jfr/startupargs/StartupHelper.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,7 +60,7 @@ public static List<Path> listFilesInDir(Path root) throws IOException {
         searchPaths.add(root);
 
         while (!searchPaths.isEmpty()) {
-            Path currRoot = searchPaths.remove(searchPaths.size() - 1);
+            Path currRoot = searchPaths.removeLast();
             DirectoryStream<Path> contents = Files.newDirectoryStream(currRoot);
             for (Path path : contents) {
                 paths.add(path);
diff --git a/test/jdk/jdk/jfr/startupargs/TestEventSettings.java b/test/jdk/jdk/jfr/startupargs/TestEventSettings.java
index 0961e472e3d..41e59523339 100644
--- a/test/jdk/jdk/jfr/startupargs/TestEventSettings.java
+++ b/test/jdk/jdk/jfr/startupargs/TestEventSettings.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -84,7 +84,7 @@ private static void assertSetting(String key, String value) throws Exception {
         if (rs.size() != 1) {
             throw new Exception("Expected only one recording");
         }
-        Map<String, String> currentSettings = rs.get(0).getSettings();
+        Map<String, String> currentSettings = rs.getFirst().getSettings();
         String s = currentSettings.get(key);
         if (!Objects.equals(s, value)) {
             System.out.println("Key:" + key);
diff --git a/test/jdk/jdk/jfr/threading/TestNestedVirtualThreads.java b/test/jdk/jdk/jfr/threading/TestNestedVirtualThreads.java
index 6d4dbb766e1..04799748159 100644
--- a/test/jdk/jdk/jfr/threading/TestNestedVirtualThreads.java
+++ b/test/jdk/jdk/jfr/threading/TestNestedVirtualThreads.java
@@ -70,8 +70,8 @@ public static void main(String... args) throws Exception {
             r.stop();
             List<RecordedEvent> events = Events.fromRecording(r);
             Events.hasEvents(events);
-            System.out.println(events.get(0));
-            RecordedEvent e = events.get(0);
+            System.out.println(events.getFirst());
+            RecordedEvent e = events.getFirst();
             RecordedThread t = e.getThread();
             Asserts.assertTrue(t.isVirtual());
             Asserts.assertEquals(t.getJavaName(), ""); // vthreads default name is the empty string.

From d31412bf57f70ecaa466c40647dde55f5d360d33 Mon Sep 17 00:00:00 2001
From: Erik Joelsson <erikj@openjdk.org>
Date: Wed, 21 Jun 2023 17:18:15 +0000
Subject: [PATCH 14/19] 8310379: Relax prerequisites for java.base-jmod target

Reviewed-by: mikael
---
 make/Main.gmk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/make/Main.gmk b/make/Main.gmk
index e13e6f47386..6753b7dc558 100644
--- a/make/Main.gmk
+++ b/make/Main.gmk
@@ -971,7 +971,8 @@ else
   # When creating the BUILDJDK, we don't need to add hashes to java.base, thus
   # we don't need to depend on all other jmods
   ifneq ($(CREATING_BUILDJDK), true)
-    java.base-jmod: jrtfs-jar $(filter-out java.base-jmod, $(JMOD_TARGETS))
+    java.base-jmod: jrtfs-jar $(filter-out java.base-jmod \
+        $(addsuffix -jmod, $(call FindAllUpgradeableModules)), $(JMOD_TARGETS))
   endif
 
   # If not already set, set the JVM target so that the JVM will be built.

From 39b4c99eeae9042a0464e3164d3788b143847822 Mon Sep 17 00:00:00 2001
From: Jonathan Gibbons <jjg@openjdk.org>
Date: Wed, 21 Jun 2023 18:00:14 +0000
Subject: [PATCH 15/19] 8309883: no `@since` info in com.sun.tools.javac
 package-info.java, Main.java

Reviewed-by: iris, darcy
---
 src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java    | 2 ++
 .../share/classes/com/sun/tools/javac/package-info.java         | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java
index 07cae101a64..7e785322eb3 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java
@@ -32,6 +32,8 @@
  * compiler, javac.
  * See the <a href="{@docRoot}/jdk.compiler/module-summary.html">{@code jdk.compiler}</a>
  * module for details on replacement APIs.
+ *
+ * @since 1.5
  */
 public class Main {
     /**
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/package-info.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/package-info.java
index fb2483cd726..c40577aa624 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/package-info.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/package-info.java
@@ -27,5 +27,7 @@
  * This package provides a legacy entry point for the <em>javac</em> tool.
  * See the <a href="{@docRoot}/jdk.compiler/module-summary.html">{@code jdk.compiler}</a>
  * module for details on replacement APIs.
+ *
+ * @since 1.5
  */
 package com.sun.tools.javac;

From 58ec27ddb9fc40da0e84e812e472c80e65e2b7b3 Mon Sep 17 00:00:00 2001
From: Erik Joelsson <erikj@openjdk.org>
Date: Wed, 21 Jun 2023 18:28:19 +0000
Subject: [PATCH 16/19] 8310384: Add hooks for custom image creation

Reviewed-by: mikael, alanb
---
 make/Images.gmk | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/make/Images.gmk b/make/Images.gmk
index 5b2f776155f..aeda1e2f0d6 100644
--- a/make/Images.gmk
+++ b/make/Images.gmk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2014, 2022, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2014, 2023, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,7 @@ include $(SPEC)
 include MakeBase.gmk
 include Execute.gmk
 include Modules.gmk
+include Utils.gmk
 
 JDK_TARGETS :=
 JRE_TARGETS :=
@@ -39,7 +40,7 @@ $(eval $(call IncludeCustomExtension, Images-pre.gmk))
 ################################################################################
 
 # All modules for the current target platform.
-ALL_MODULES := $(call FindAllModules)
+ALL_MODULES := $(call FindAllModules) $(EXTRA_MODULES)
 
 $(eval $(call ReadImportMetaData))
 
@@ -54,7 +55,10 @@ JDK_MODULES_LIST := $(call CommaList, $(JDK_MODULES))
 
 BASE_RELEASE_FILE := $(JDK_OUTPUTDIR)/release
 
-JMODS := $(wildcard $(IMAGES_OUTPUTDIR)/jmods/*.jmod)
+JMODS_DIRS := $(EXTRA_JMODS_DIR) $(IMAGES_OUTPUTDIR)/jmods
+
+JDK_JMODS := $(foreach m, $(JDK_MODULES), $(firstword $(wildcard $(addsuffix /$m.jmod, $(JMODS_DIRS)))))
+JRE_JMODS := $(foreach m, $(JRE_MODULES), $(firstword $(wildcard $(addsuffix /$m.jmod, $(JMODS_DIRS)))))
 
 JLINK_ORDER_RESOURCES := **module-info.class
 JLINK_JLI_CLASSES :=
@@ -71,7 +75,7 @@ JLINK_ORDER_RESOURCES += \
     #
 
 JLINK_TOOL := $(JLINK) -J-Djlink.debug=true \
-    --module-path $(IMAGES_OUTPUTDIR)/jmods \
+    --module-path $(call PathList, $(JMODS_DIRS)) \
     --endian $(OPENJDK_TARGET_CPU_ENDIAN) \
     --release-info $(BASE_RELEASE_FILE) \
     --order-resources=$(call CommaList, $(JLINK_ORDER_RESOURCES)) \
@@ -87,12 +91,15 @@ endif
 
 JLINK_DISABLE_WARNINGS := | ( $(GREP) -v -e "WARNING: Using incubator module" || test "$$?" = "1" )
 
+JDK_IMAGE_SUPPORT_DIR := $(SUPPORT_OUTPUTDIR)/images/jdk
+JRE_IMAGE_SUPPORT_DIR := $(SUPPORT_OUTPUTDIR)/images/jre
+
 $(eval $(call SetupExecute, jlink_jdk, \
     WARN := Creating jdk image, \
-    DEPS := $(JMODS) $(BASE_RELEASE_FILE) \
-        $(call DependOnVariable, JDK_MODULES_LIST), \
+    DEPS := $(JDK_JMODS) $(BASE_RELEASE_FILE) \
+        $(call DependOnVariable, JDK_MODULES_LIST, $(JDK_IMAGE_SUPPORT_DIR)/_jlink_jdk.vardeps), \
     OUTPUT_DIR := $(JDK_IMAGE_DIR), \
-    SUPPORT_DIR := $(SUPPORT_OUTPUTDIR)/images/jdk, \
+    SUPPORT_DIR := $(JDK_IMAGE_SUPPORT_DIR), \
     PRE_COMMAND := $(RM) -r $(JDK_IMAGE_DIR), \
     COMMAND := $(JLINK_TOOL) --add-modules $(JDK_MODULES_LIST) \
         $(JLINK_JDK_EXTRA_OPTS) --output $(JDK_IMAGE_DIR) \
@@ -103,10 +110,10 @@ JLINK_JDK_TARGETS := $(jlink_jdk)
 
 $(eval $(call SetupExecute, jlink_jre, \
     WARN := Creating legacy jre image, \
-    DEPS := $(JMODS) $(BASE_RELEASE_FILE) \
-        $(call DependOnVariable, JDK_MODULES_LIST), \
+    DEPS := $(JRE_JMODS) $(BASE_RELEASE_FILE) \
+        $(call DependOnVariable, JRE_MODULES_LIST, $(JRE_IMAGE_SUPPORT_DIR)/_jlink_jre.vardeps), \
     OUTPUT_DIR := $(JRE_IMAGE_DIR), \
-    SUPPORT_DIR := $(SUPPORT_OUTPUTDIR)/images/jre, \
+    SUPPORT_DIR := $(JRE_IMAGE_SUPPORT_DIR), \
     PRE_COMMAND := $(RM) -r $(JRE_IMAGE_DIR), \
     COMMAND := $(JLINK_TOOL) --add-modules $(JRE_MODULES_LIST) \
         $(JLINK_JRE_EXTRA_OPTS) --output $(JRE_IMAGE_DIR), \
@@ -142,7 +149,7 @@ define CreateCDSArchive
       INFO := Using CDS flags for $1: $$($1_$2_CDS_DUMP_FLAGS), \
       DEPS := $$(jlink_jdk), \
       OUTPUT_FILE := $$(JDK_IMAGE_DIR)/$$($1_$2_CDS_ARCHIVE), \
-      SUPPORT_DIR := $$(SUPPORT_OUTPUTDIR)/images/jdk, \
+      SUPPORT_DIR := $$(JDK_IMAGE_SUPPORT_DIR), \
       COMMAND := $$(FIXPATH) $$(JDK_IMAGE_DIR)/bin/java -Xshare:dump \
           -XX:SharedArchiveFile=$$(JDK_IMAGE_DIR)/$$($1_$2_CDS_ARCHIVE) \
           -$1 $$($1_$2_DUMP_EXTRA_ARG) $$($1_$2_CDS_DUMP_FLAGS) $$(LOG_INFO), \
@@ -155,7 +162,7 @@ define CreateCDSArchive
       INFO := Using CDS flags for $1: $$($1_$2_CDS_DUMP_FLAGS), \
       DEPS := $$(jlink_jre), \
       OUTPUT_FILE := $$(JRE_IMAGE_DIR)/$$($1_$2_CDS_ARCHIVE), \
-      SUPPORT_DIR := $$(SUPPORT_OUTPUTDIR)/images/jre, \
+      SUPPORT_DIR := $$(JRE_IMAGE_SUPPORT_DIR), \
       COMMAND := $$(FIXPATH) $$(JRE_IMAGE_DIR)/bin/java -Xshare:dump \
           -XX:SharedArchiveFile=$$(JRE_IMAGE_DIR)/$$($1_$2_CDS_ARCHIVE) \
           -$1 $$($1_$2_DUMP_EXTRA_ARG) $$($1_$2_CDS_DUMP_FLAGS) $$(LOG_INFO), \

From 1a122701c4ea139eecd3b1ae0d1c26ce16764bef Mon Sep 17 00:00:00 2001
From: Jonathan Gibbons <jjg@openjdk.org>
Date: Wed, 21 Jun 2023 19:56:51 +0000
Subject: [PATCH 17/19] 8310575: no `@since` for StandardDoclet

Reviewed-by: darcy
---
 .../share/classes/jdk/javadoc/doclet/StandardDoclet.java        | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java b/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java
index dff6f3e34bd..82cac37012b 100644
--- a/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java
@@ -65,6 +65,8 @@
  *
  * @spec javadoc/doc-comment-spec.html Documentation Comment Specification for the Standard Doclet
  * @spec https://www.w3.org/TR/html52 HTML Standard
+ *
+ * @since 9
  */
 public class StandardDoclet implements Doclet {
 

From f61b606bdc4dd39321b162dc18805507cf810b21 Mon Sep 17 00:00:00 2001
From: Christoph Langer <clanger@openjdk.org>
Date: Wed, 21 Jun 2023 20:04:03 +0000
Subject: [PATCH 18/19] 8310512: Cleanup indentation in jfc files

Reviewed-by: egahlin
---
 src/jdk.jfr/share/conf/jfr/default.jfc | 27 +++++++++++-------------
 src/jdk.jfr/share/conf/jfr/profile.jfc | 29 +++++++++++++-------------
 2 files changed, 26 insertions(+), 30 deletions(-)

diff --git a/src/jdk.jfr/share/conf/jfr/default.jfc b/src/jdk.jfr/share/conf/jfr/default.jfc
index 0ed815f2611..5743b64285b 100644
--- a/src/jdk.jfr/share/conf/jfr/default.jfc
+++ b/src/jdk.jfr/share/conf/jfr/default.jfc
@@ -735,8 +735,8 @@
     </event>
 
     <event name="jdk.Deserialization">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.InitialSecurityProperty">
@@ -745,13 +745,13 @@
     </event>
 
     <event name="jdk.SecurityPropertyModification">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.SecurityProviderService">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.TLSHandshake">
@@ -760,13 +760,13 @@
     </event>
 
     <event name="jdk.X509Validation">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.X509Certificate">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.JavaExceptionThrow">
@@ -918,8 +918,6 @@
 
 
 
-
-
 
 
 
@@ -929,7 +927,7 @@
   carry the control attribute.
   -->
     <control>
-     <selection name="gc" default="normal" label="Garbage Collector">
+      <selection name="gc" default="normal" label="Garbage Collector">
         <option label="Off" name="off">off</option>
         <option label="Normal" name="normal">normal</option>
         <option label="Detailed" name="detailed">detailed</option>
@@ -974,7 +972,7 @@
       </selection>
 
       <condition name="object-allocation-enabled" true="true" false="false">
-	 <not>
+        <not>
           <test name="allocation-profiling" operator="equal" value="off"/>
         </not>
       </condition>
@@ -1122,7 +1120,6 @@
       <text name="socket-threshold" label="Socket I/O Threshold" contentType="timespan" minimum="0 s">20 ms</text>
 
       <flag name="class-loading" label="Class Loading">false</flag>
-
     </control>
 
 </configuration>
diff --git a/src/jdk.jfr/share/conf/jfr/profile.jfc b/src/jdk.jfr/share/conf/jfr/profile.jfc
index ca24acb809c..816408a4baf 100644
--- a/src/jdk.jfr/share/conf/jfr/profile.jfc
+++ b/src/jdk.jfr/share/conf/jfr/profile.jfc
@@ -735,8 +735,8 @@
     </event>
 
     <event name="jdk.Deserialization">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.InitialSecurityProperty">
@@ -745,13 +745,13 @@
     </event>
 
     <event name="jdk.SecurityPropertyModification">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.SecurityProviderService">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.TLSHandshake">
@@ -760,13 +760,13 @@
     </event>
 
     <event name="jdk.X509Validation">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.X509Certificate">
-       <setting name="enabled">false</setting>
-       <setting name="stackTrace">true</setting>
+      <setting name="enabled">false</setting>
+      <setting name="stackTrace">true</setting>
     </event>
 
     <event name="jdk.JavaExceptionThrow">
@@ -927,7 +927,7 @@
   carry the control attribute.
   -->
     <control>
-        <selection name="gc" default="detailed" label="Garbage Collector">
+      <selection name="gc" default="detailed" label="Garbage Collector">
         <option label="Off" name="off">off</option>
         <option label="Normal" name="normal">normal</option>
         <option label="Detailed" name="detailed">detailed</option>
@@ -945,11 +945,11 @@
       </condition>
 
       <condition name="gc-enabled-detailed" true="true" false="false">
-       <or>
+        <or>
           <test name="gc" operator="equal" value="detailed"/>
           <test name="gc" operator="equal" value="high"/>
           <test name="gc" operator="equal" value="all"/>
-       </or>
+        </or>
       </condition>
 
       <condition name="gc-enabled-high" true="true" false="false">
@@ -967,7 +967,7 @@
         <option label="Off" name="off">0/s</option>
         <option label="Low" name="low">150/s</option>
         <option label="Medium" name="medium">300/s</option>
-	    <option label="High" name="high">1000/s</option>
+        <option label="High" name="high">1000/s</option>
         <option label="Maximum" name="maximum">1000000000/s</option>
       </selection>
 
@@ -1120,7 +1120,6 @@
       <text name="socket-threshold" label="Socket I/O Threshold" contentType="timespan" minimum="0 s">10 ms</text>
 
       <flag name="class-loading" label="Class Loading">false</flag>
-
     </control>
 
 </configuration>

From ebc1aaa12603f13075329a735017226edc7e0c26 Mon Sep 17 00:00:00 2001
From: "Daniel D. Daugherty" <dcubed@openjdk.org>
Date: Wed, 21 Jun 2023 21:07:04 +0000
Subject: [PATCH 19/19] 8310586: ProblemList
 java/lang/ScopedValue/StressStackOverflow.java#default with virtual threads
 on linux-all

Reviewed-by: dholmes, mikael
---
 test/jdk/ProblemList-Virtual.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/jdk/ProblemList-Virtual.txt b/test/jdk/ProblemList-Virtual.txt
index 428a8854cab..5765cc8c3a0 100644
--- a/test/jdk/ProblemList-Virtual.txt
+++ b/test/jdk/ProblemList-Virtual.txt
@@ -44,6 +44,8 @@ javax/management/remote/mandatory/loading/RMIDownloadTest.java 8308366 windows-x
 
 java/lang/instrument/NativeMethodPrefixAgent.java 8307169 generic-all
 
+java/lang/ScopedValue/StressStackOverflow.java#default 8309646 linux-all
+
 ##########
 ## Tests incompatible with virtual test thread factory.
 ## There is no goal to run all test with virtual test thread factory.