6602600: Fast removal of cancelled scheduled thread pool tasks

Reviewed-by: alanb

jdk/test/java/util/concurrent/ScheduledThreadPoolExecutor/BasicCancelTest.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2008 Sun Microsystems, 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.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 6602600
+ * @run main/othervm -Xmx8m BasicCancelTest
+ * @summary Check effectiveness of RemoveOnCancelPolicy
+ */
+
+import java.util.concurrent.*;
+import java.util.Random;
+
+/**
+ * Simple timer cancellation test. Submits tasks to a scheduled executor
+ * service and immediately cancels them.
+ */
+public class BasicCancelTest {
+
+    void checkShutdown(final ExecutorService es) {
+        final Runnable nop = new Runnable() {public void run() {}};
+        try {
+            if (new Random().nextBoolean()) {
+                check(es.isShutdown());
+                if (es instanceof ThreadPoolExecutor)
+                    check(((ThreadPoolExecutor) es).isTerminating()
+                          || es.isTerminated());
+                THROWS(RejectedExecutionException.class,
+                       new F(){void f(){es.execute(nop);}});
+            }
+        } catch (Throwable t) { unexpected(t); }
+    }
+
+    void checkTerminated(final ThreadPoolExecutor tpe) {
+        try {
+            checkShutdown(tpe);
+            check(tpe.getQueue().isEmpty());
+            check(tpe.isTerminated());
+            check(! tpe.isTerminating());
+            equal(tpe.getActiveCount(), 0);
+            equal(tpe.getPoolSize(), 0);
+            equal(tpe.getTaskCount(), tpe.getCompletedTaskCount());
+            check(tpe.awaitTermination(0, TimeUnit.SECONDS));
+        } catch (Throwable t) { unexpected(t); }
+    }
+
+    void test(String[] args) throws Throwable {
+
+        final ScheduledThreadPoolExecutor pool =
+            new ScheduledThreadPoolExecutor(1);
+
+        // Needed to avoid OOME
+        pool.setRemoveOnCancelPolicy(true);
+
+        final long moreThanYouCanChew = Runtime.getRuntime().freeMemory() / 4;
+        System.out.printf("moreThanYouCanChew=%d%n", moreThanYouCanChew);
+
+        Runnable noopTask = new Runnable() { public void run() {}};
+
+        for (long i = 0; i < moreThanYouCanChew; i++)
+            pool.schedule(noopTask, 10, TimeUnit.MINUTES).cancel(true);
+
+        pool.shutdown();
+        check(pool.awaitTermination(1L, TimeUnit.DAYS));
+        checkTerminated(pool);
+        equal(pool.getTaskCount(), 0L);
+        equal(pool.getCompletedTaskCount(), 0L);
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    volatile int passed = 0, failed = 0;
+    void pass() {passed++;}
+    void fail() {failed++; Thread.dumpStack();}
+    void fail(String msg) {System.err.println(msg); fail();}
+    void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    void check(boolean cond) {if (cond) pass(); else fail();}
+    void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        new BasicCancelTest().instanceMain(args);}
+    void instanceMain(String[] args) throws Throwable {
+        try {test(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+    abstract class F {abstract void f() throws Throwable;}
+    void THROWS(Class<? extends Throwable> k, F... fs) {
+        for (F f : fs)
+            try {f.f(); fail("Expected " + k.getName() + " not thrown");}
+            catch (Throwable t) {
+                if (k.isAssignableFrom(t.getClass())) pass();
+                else unexpected(t);}}
+}

jdk/test/java/util/concurrent/ScheduledThreadPoolExecutor/Stress.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2008 Sun Microsystems, 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.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+import java.util.concurrent.*;
+
+/**
+ * This is not a regression test, but a stress benchmark test for
+ * 6602600: Fast removal of cancelled scheduled thread pool tasks
+ *
+ * This runs in the same wall clock time, but much reduced cpu time,
+ * with the changes for 6602600.
+ */
+public class Stress {
+
+    public static void main(String[] args) throws Throwable {
+
+        final CountDownLatch count = new CountDownLatch(1000);
+
+        final ScheduledThreadPoolExecutor pool =
+            new ScheduledThreadPoolExecutor(100);
+        pool.prestartAllCoreThreads();
+
+        final Runnable incTask = new Runnable() { public void run() {
+            count.countDown();
+        }};
+
+        pool.scheduleAtFixedRate(incTask, 0, 10, TimeUnit.MILLISECONDS);
+
+        count.await();
+
+        pool.shutdown();
+        pool.awaitTermination(1L, TimeUnit.DAYS);
+    }
+}