gc notifications

substratevm/mx.substratevm/suite.py

@@ -356,6 +356,9 @@
                 "java.management": [
                     "sun.management",
                 ],
+                "jdk.management": [
+                    "com.sun.management.internal"
+                ],
                 "jdk.internal.vm.ci" : [
                     "jdk.vm.ci.code",
                 ],
@@ -994,6 +997,9 @@
                     "jdk.internal.misc",
                     "sun.security.jca",
                 ],
+                "java.management": [
+                    "sun.management",
+                ],
             },
             "checkstyle": "com.oracle.svm.test",
             "checkstyleVersion" : "10.7.0",

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/AbstractGarbageCollectorMXBean.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2024, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2024, Red Hat Inc. 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 com.oracle.svm.core.genscavenge;
+
+import com.oracle.svm.core.util.BasedOnJDKFile;
+
+import com.oracle.svm.core.SubstrateUtil;
+import com.oracle.svm.core.genscavenge.service.GcNotificationRequest;
+import com.oracle.svm.core.genscavenge.service.PoolMemoryUsage;
+import com.oracle.svm.core.genscavenge.service.Target_com_sun_management_GcInfo;
+import com.oracle.svm.core.genscavenge.service.Target_java_lang_management_internal_GcInfoBuilder;
+
+import com.sun.management.GarbageCollectionNotificationInfo;
+import com.sun.management.GcInfo;
+import com.sun.management.internal.GarbageCollectionNotifInfoCompositeData;
+import com.sun.management.internal.GcInfoBuilder;
+import sun.management.NotificationEmitterSupport;
+
+import javax.management.MBeanNotificationInfo;
+import javax.management.Notification;
+import javax.management.NotificationEmitter;
+import javax.management.openmbean.CompositeData;
+import java.lang.management.MemoryUsage;
+
+public abstract class AbstractGarbageCollectorMXBean extends NotificationEmitterSupport
+                implements com.sun.management.GarbageCollectorMXBean, NotificationEmitter {
+    @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-24+14/src/hotspot/share/gc/serial/serialHeap.cpp#L451") //
+
+    private static final String ACTION_MINOR = "end of minor GC";
+    @BasedOnJDKFile("https://github.com/openjdk/jdk/blob/jdk-24+14/src/hotspot/share/gc/serial/serialHeap.cpp#L718") //
+    private static final String ACTION_MAJOR = "end of major GC";
+    private GcInfoBuilder gcInfoBuilder;
+    private volatile GcInfo gcInfo;
+    private long seqNumber = 0;
+
+    private synchronized GcInfoBuilder getGcInfoBuilder() {
+        if (gcInfoBuilder == null) {
+            Target_java_lang_management_internal_GcInfoBuilder gib = new Target_java_lang_management_internal_GcInfoBuilder(this, getMemoryPoolNames());
+            gcInfoBuilder = SubstrateUtil.cast(gib, GcInfoBuilder.class);
+        }
+        return gcInfoBuilder;
+    }
+
+    /**
+     * Use the data taken from the request queue to populate MemoryUsage. The service thread calls
+     * this method.
+     */
+    public void createNotification(GcNotificationRequest request) {
+        AbstractMemoryPoolMXBean[] beans = GenScavengeMemoryPoolMXBeans.singleton().getMXBeans();
+
+        String[] poolNames = getMemoryPoolNames();
+        MemoryUsage[] before = new MemoryUsage[poolNames.length];
+        MemoryUsage[] after = new MemoryUsage[poolNames.length];
+
+        // Pools must be in the order of getMemoryPoolNames() to match GcInfoBuilder
+        for (int i = 0; i < poolNames.length; i++) {
+            for (int j = 0; j < beans.length; j++) {
+                PoolMemoryUsage pmu = request.getPoolBefore(j);
+                if (pmu.name != null && pmu.name.equals(poolNames[i])) {
+                    before[i] = beans[j].memoryUsage(pmu.used, pmu.committed);
+                    pmu = request.getPoolAfter(j);
+                    after[i] = beans[j].memoryUsage(pmu.used, pmu.committed);
+                }
+            }
+        }
+
+        // Number of GC threads.
+        Object[] extAttribute = new Object[]{Integer.valueOf(1)};
+
+        Target_com_sun_management_GcInfo targetGcInfo = new Target_com_sun_management_GcInfo(getGcInfoBuilder(), request.epoch, request.startTime, request.endTime, before, after, extAttribute);
+        gcInfo = SubstrateUtil.cast(targetGcInfo, GcInfo.class);
+
+        GarbageCollectionNotificationInfo info = new GarbageCollectionNotificationInfo(
+                        getName(),
+                        request.isIncremental ? ACTION_MINOR : ACTION_MAJOR,
+                        request.cause.getName(),
+                        gcInfo);
+
+        CompositeData cd = GarbageCollectionNotifInfoCompositeData.toCompositeData(info);
+
+        Notification notif = new Notification(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION,
+                        getObjectName(),
+                        getNextSeqNumber(),
+                        request.timestamp,
+                        getName());
+        notif.setUserData(cd);
+
+        sendNotification(notif);
+    }
+
+    private long getNextSeqNumber() {
+        return ++seqNumber;
+    }
+
+    @Override
+    public MBeanNotificationInfo[] getNotificationInfo() {
+        return new MBeanNotificationInfo[]{
+                        new MBeanNotificationInfo(
+                                        new String[]{GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION},
+                                        "javax.management.Notification",
+                                        "GC Notification")
+        };
+    }
+
+    /** OpenJDK calls to native code to obtain this. */
+    @Override
+    public GcInfo getLastGcInfo() {
+        return gcInfo;
+    }
+}

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/AbstractMemoryPoolMXBean.java

@@ -66,6 +66,12 @@ UnsignedWord getInitialValue() {
         return initialValue;
     }
 
+    public abstract long getUsedBytes();
+
+    public long getCommittedBytes() {
+        return getUsedBytes();
+    }
+
     abstract UnsignedWord computeInitialValue();
 
     abstract void beforeCollection();
@@ -77,7 +83,11 @@ MemoryUsage memoryUsage(UnsignedWord usedAndCommitted) {
     }
 
     MemoryUsage memoryUsage(UnsignedWord used, UnsignedWord committed) {
-        return new MemoryUsage(getInitialValue().rawValue(), used.rawValue(), committed.rawValue(), getMaximumValue().rawValue());
+        return memoryUsage(used.rawValue(), committed.rawValue());
+    }
+
+    public MemoryUsage memoryUsage(long usedAndCommitted, long committed) {
+        return new MemoryUsage(getInitialValue().rawValue(), usedAndCommitted, committed, getMaximumValue().rawValue());
     }
 
     @Override

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/CompleteGarbageCollectorMXBean.java

@@ -26,21 +26,16 @@
 
 import java.lang.management.ManagementFactory;
 
-import javax.management.MBeanNotificationInfo;
-import javax.management.NotificationEmitter;
-import javax.management.NotificationFilter;
-import javax.management.NotificationListener;
 import javax.management.ObjectName;
 
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.Platforms;
 
 import com.oracle.svm.core.util.TimeUtils;
-import com.sun.management.GcInfo;
 
 import sun.management.Util;
 
-public final class CompleteGarbageCollectorMXBean implements com.sun.management.GarbageCollectorMXBean, NotificationEmitter {
+public final class CompleteGarbageCollectorMXBean extends AbstractGarbageCollectorMXBean {
 
     @Platforms(Platform.HOSTED_ONLY.class)
     public CompleteGarbageCollectorMXBean() {
@@ -81,26 +76,4 @@ public boolean isValid() {
     public ObjectName getObjectName() {
         return Util.newObjectName(ManagementFactory.GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE, getName());
     }
-
-    @Override
-    public void removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) {
-    }
-
-    @Override
-    public void addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) {
-    }
-
-    @Override
-    public void removeNotificationListener(NotificationListener listener) {
-    }
-
-    @Override
-    public MBeanNotificationInfo[] getNotificationInfo() {
-        return new MBeanNotificationInfo[0];
-    }
-
-    @Override
-    public GcInfo getLastGcInfo() {
-        return null;
-    }
 }

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/GCImpl.java

@@ -66,6 +66,7 @@
 import com.oracle.svm.core.genscavenge.HeapChunk.Header;
 import com.oracle.svm.core.genscavenge.UnalignedHeapChunk.UnalignedHeader;
 import com.oracle.svm.core.genscavenge.remset.RememberedSet;
+import com.oracle.svm.core.genscavenge.service.ServiceSupport;
 import com.oracle.svm.core.graal.RuntimeCompilation;
 import com.oracle.svm.core.heap.CodeReferenceMapDecoder;
 import com.oracle.svm.core.heap.GC;
@@ -103,6 +104,7 @@
 import com.oracle.svm.core.threadlocal.VMThreadLocalSupport;
 import com.oracle.svm.core.util.TimeUtils;
 import com.oracle.svm.core.util.VMError;
+import com.oracle.svm.core.VMInspectionOptions;
 
 import jdk.graal.compiler.api.replacements.Fold;
 
@@ -240,6 +242,9 @@ assert getCollectionEpoch().equal(data.getRequestingEpoch()) ||
         try {
             ThreadLocalAllocation.disableAndFlushForAllThreads();
             GenScavengeMemoryPoolMXBeans.singleton().notifyBeforeCollection();
+            if (VMInspectionOptions.hasGcNotificationSupport()) {
+                ServiceSupport.singleton().beforeCollection(Isolates.getCurrentUptimeMillis());
+            }
             HeapImpl.getAccounting().notifyBeforeCollection();
 
             verifyHeap(Before);
@@ -257,6 +262,10 @@ assert getCollectionEpoch().equal(data.getRequestingEpoch()) ||
         GenScavengeMemoryPoolMXBeans.singleton().notifyAfterCollection();
         ChunkBasedCommittedMemoryProvider.get().afterGarbageCollection();
 
+        if (VMInspectionOptions.hasGcNotificationSupport()) {
+            ServiceSupport.singleton().afterCollection(!isCompleteCollection(), cause, getCollectionEpoch(), Isolates.getCurrentUptimeMillis());
+        }
+
         printGCAfter(cause);
         JfrGCHeapSummaryEvent.emit(JfrGCWhen.AFTER_GC);
 

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/GenScavengeMemoryPoolMXBeans.java

@@ -39,13 +39,13 @@
 import jdk.graal.compiler.api.replacements.Fold;
 
 public class GenScavengeMemoryPoolMXBeans {
-    static final String YOUNG_GEN_SCAVENGER = "young generation scavenger";
-    static final String COMPLETE_SCAVENGER = "complete scavenger";
+    public static final String YOUNG_GEN_SCAVENGER = "young generation scavenger";
+    public static final String COMPLETE_SCAVENGER = "complete scavenger";
     static final String EPSILON_SCAVENGER = "epsilon scavenger";
 
     static final String EDEN_SPACE = "eden space";
     static final String SURVIVOR_SPACE = "survivor space";
-    static final String OLD_GEN_SPACE = "old generation space";
+    public static final String OLD_GEN_SPACE = "old generation space";
     static final String EPSILON_HEAP = "epsilon heap";
 
     private final AbstractMemoryPoolMXBean[] mxBeans;
@@ -125,9 +125,16 @@ public MemoryUsage getCollectionUsage() {
             return memoryUsage(WordFactory.zero());
         }
 
+        @Override
+        public long getUsedBytes() {
+            return getCurrentUsage().rawValue();
+        }
+
         private static UnsignedWord getCurrentUsage() {
             return HeapImpl.getAccounting().getEdenUsedBytes();
         }
+
+
     }
 
     static final class SurvivorMemoryPoolMXBean extends AbstractMemoryPoolMXBean {
@@ -166,6 +173,11 @@ public MemoryUsage getPeakUsage() {
         public MemoryUsage getCollectionUsage() {
             return memoryUsage(HeapImpl.getAccounting().getSurvivorUsedBytes());
         }
+
+        @Override
+        public long getUsedBytes() {
+            return HeapImpl.getAccounting().getSurvivorUsedBytes().rawValue();
+        }
     }
 
     static final class OldGenerationMemoryPoolMXBean extends AbstractMemoryPoolMXBean {
@@ -204,6 +216,11 @@ public MemoryUsage getPeakUsage() {
         public MemoryUsage getCollectionUsage() {
             return memoryUsage(HeapImpl.getAccounting().getOldUsedBytes());
         }
+
+        @Override
+        public long getUsedBytes() {
+            return HeapImpl.getAccounting().getOldUsedBytes().rawValue();
+        }
     }
 
     static final class EpsilonMemoryPoolMXBean extends AbstractMemoryPoolMXBean {
@@ -243,5 +260,15 @@ public MemoryUsage getPeakUsage() {
         public MemoryUsage getCollectionUsage() {
             return memoryUsage(WordFactory.zero());
         }
+
+        @Override
+        public long getUsedBytes() {
+            return HeapImpl.getAccounting().getUsedBytes().rawValue();
+        }
+
+        @Override
+        public long getCommittedBytes() {
+            return HeapImpl.getAccounting().getCommittedBytes().rawValue();
+        }
     }
 }

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/HeapAccounting.java

@@ -79,7 +79,7 @@ public void notifyAfterCollection() {
         invalidData = false;
     }
 
-    HeapSizes getHeapSizesBeforeGc() {
+    public HeapSizes getHeapSizesBeforeGc() {
         return beforeGc;
     }
 
@@ -136,11 +136,11 @@ public UnsignedWord getCommittedBytes() {
         return getUsedBytes().add(getBytesInUnusedChunks());
     }
 
-    static class HeapSizes {
-        UnsignedWord eden;
-        UnsignedWord survivor;
-        UnsignedWord old;
-        UnsignedWord free;
+    public static class HeapSizes {
+        public UnsignedWord eden;
+        public UnsignedWord survivor;
+        public UnsignedWord old;
+        public UnsignedWord free;
 
         @Platforms(Platform.HOSTED_ONLY.class)
         HeapSizes() {