Merge pull request #164 from shintaro-iwasaki/FixExamples

Fix examples

examples/.gitignore

@@ -1,7 +1,6 @@
 # examples
 fibonacci_future
-fibonacci_task
-fibonacci_thread_task
+fibonacci_recursive
 hello_world
 hello_world_thread
 sched_predef

examples/Makefile.am

@@ -7,8 +7,7 @@ TESTS = \
 	hello_world \
 	hello_world_thread \
 	fibonacci_future \
-	fibonacci_task \
-	fibonacci_thread_task \
+	fibonacci_recursive \
 	sched_predef \
 	sched_shared_pool \
 	sched_stack \
@@ -26,8 +25,7 @@ include $(top_srcdir)/test/Makefile.mk
 hello_world_SOURCES = hello_world.c
 hello_world_thread_SOURCES = hello_world_thread.c
 fibonacci_future_SOURCES = fibonacci_future.c
-fibonacci_task_SOURCES = fibonacci_task.c
-fibonacci_thread_task_SOURCES = fibonacci_thread_task.c
+fibonacci_recursive_SOURCES = fibonacci_recursive.c
 sched_predef_SOURCES = sched_predef.c
 sched_shared_pool_SOURCES = sched_shared_pool.c
 sched_stack_SOURCES = sched_stack.c
@@ -41,8 +39,7 @@ testing:
 	./hello_world
 	./hello_world_thread
 	./fibonacci_future
-	./fibonacci_task
-	./fibonacci_thread_task
+	./fibonacci_recursive
 	./sched_predef
 	./sched_shared_pool
 	./sched_stack

examples/fibonacci_future.c

@@ -120,7 +120,6 @@ int main(int argc, char *argv[])
     for (i = 1; i < num_xstreams; i++) {
         ABT_xstream_create_basic(ABT_SCHED_DEFAULT, 1, &g_pool,
                                  ABT_SCHED_CONFIG_NULL, &xstreams[i]);
-        ABT_xstream_start(xstreams[i]);
     }
 
     args.n = n;

examples/fibonacci_recursive.c

@@ -0,0 +1,122 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
+/*
+ * See COPYRIGHT in top-level directory.
+ */
+
+/**
+ * This Fibonacci example showcases recursive parallelism.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <abt.h>
+
+#define N 10
+#define NUM_XSTREAMS 4
+
+/* global variables */
+ABT_pool g_pool = ABT_POOL_NULL;
+
+/* structure to pass arguments to threads */
+typedef struct {
+    int n;
+    int result;
+} thread_args;
+
+/* Function to compute Fibonacci numbers */
+void fibonacci(void *arguments)
+{
+    thread_args *args = (thread_args *)arguments;
+    int n = args->n;
+
+    /* checking for base cases */
+    if (n <= 2)
+        args->result = 1;
+    else {
+        thread_args a1, a2;
+        ABT_thread thread1;
+
+        a1.n = n - 1;
+        ABT_thread_create(g_pool, fibonacci, &a1, ABT_THREAD_ATTR_NULL,
+                          &thread1);
+        a2.n = n - 2;
+        fibonacci(&a2);
+
+        ABT_thread_free(&thread1);
+        args->result = a1.result + a2.result;
+    }
+}
+
+/* Verification function */
+int verify(int n)
+{
+    int i;
+    int old[2], val;
+
+    if (n <= 2)
+        return 1;
+
+    old[0] = old[1] = 1;
+    for (i = 3; i <= n; i++) {
+        val = old[0] + old[1];
+        old[i % 2] = val;
+    }
+    return val;
+}
+
+/* Main function */
+int main(int argc, char *argv[])
+{
+    int n, i, expected;
+    int num_xstreams;
+    ABT_xstream *xstreams;
+    thread_args args;
+
+    if (argc > 1 && strcmp(argv[1], "-h") == 0) {
+        printf("Usage: %s [N=10] [num_ES=4]\n", argv[0]);
+        return EXIT_SUCCESS;
+    }
+    n = argc > 1 ? atoi(argv[1]) : N;
+    num_xstreams = argc > 2 ? atoi(argv[2]) : NUM_XSTREAMS;
+    printf("# of ESs: %d\n", num_xstreams);
+
+    /* initialization */
+    ABT_init(argc, argv);
+
+    /* shared pool creation */
+    ABT_pool_create_basic(ABT_POOL_FIFO, ABT_POOL_ACCESS_MPMC, ABT_TRUE,
+                          &g_pool);
+
+    /* ES creation */
+    xstreams = (ABT_xstream *)malloc(sizeof(ABT_xstream) * num_xstreams);
+    ABT_xstream_self(&xstreams[0]);
+    ABT_xstream_set_main_sched_basic(xstreams[0], ABT_SCHED_DEFAULT, 1,
+                                     &g_pool);
+    for (i = 1; i < num_xstreams; i++) {
+        ABT_xstream_create_basic(ABT_SCHED_DEFAULT, 1, &g_pool,
+                                 ABT_SCHED_CONFIG_NULL, &xstreams[i]);
+    }
+
+    args.n = n;
+    fibonacci(&args);
+
+    /* join ESs */
+    for (i = 1; i < num_xstreams; i++) {
+        ABT_xstream_join(xstreams[i]);
+        ABT_xstream_free(&xstreams[i]);
+    }
+
+    ABT_finalize();
+
+    free(xstreams);
+
+    printf("Fib(%d): %d\n", n, args.result);
+    expected = verify(n);
+    if (args.result != expected) {
+        fprintf(stderr, "ERROR: expected=%d\n", expected);
+        exit(EXIT_FAILURE);
+    }
+
+    return EXIT_SUCCESS;
+}