8008378: FJP.commonPool support parallelism 0, add awaitQuiescence

Reviewed-by: chegar
Contributed-by: NDoug Lea &lt;dl@cs.oswego.edu&gt;, Chris Hegarty <chris.hegarty@oracle.com>

src/share/classes/java/util/concurrent/ForkJoinTask.java

@@ -464,7 +464,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
     }
 
     /**
-     * Records exception and possibly propagates
+     * Records exception and possibly propagates.
      *
      * @return status on exit
      */
@@ -497,7 +497,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
     }
 
     /**
-     * Removes exception node and clears status
+     * Removes exception node and clears status.
      */
     private void clearExceptionalCompletion() {
         int h = System.identityHashCode(this);
@@ -635,7 +635,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
                 throw (Error)ex;
             if (ex instanceof RuntimeException)
                 throw (RuntimeException)ex;
-            throw uncheckedThrowable(ex, RuntimeException.class);
+            ForkJoinTask.<RuntimeException>uncheckedThrow(ex);
         }
     }
 
@@ -645,8 +645,9 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
      * unchecked exceptions
      */
     @SuppressWarnings("unchecked") static <T extends Throwable>
-        T uncheckedThrowable(final Throwable t, final Class<T> c) {
-        return (T)t; // rely on vacuous cast
+        void uncheckedThrow(Throwable t) throws T {
+        if (t != null)
+            throw (T)t; // rely on vacuous cast
     }
 
     /**
@@ -681,7 +682,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
         if ((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)
             ((ForkJoinWorkerThread)t).workQueue.push(this);
         else
-            ForkJoinPool.commonPool.externalPush(this);
+            ForkJoinPool.common.externalPush(this);
         return this;
     }
 
@@ -857,7 +858,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
      * <p>This method is designed to be invoked by <em>other</em>
      * tasks. To terminate the current task, you can just return or
      * throw an unchecked exception from its computation method, or
-     * invoke {@link #completeExceptionally}.
+     * invoke {@link #completeExceptionally(Throwable)}.
      *
      * @param mayInterruptIfRunning this value has no effect in the
      * default implementation because interrupts are not used to
@@ -1007,8 +1008,9 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
         if (Thread.interrupted())
             throw new InterruptedException();
         // Messy in part because we measure in nanosecs, but wait in millisecs
-        int s; long ns, ms;
-        if ((s = status) >= 0 && (ns = unit.toNanos(timeout)) > 0L) {
+        int s; long ms;
+        long ns = unit.toNanos(timeout);
+        if ((s = status) >= 0 && ns > 0L) {
             long deadline = System.nanoTime() + ns;
             ForkJoinPool p = null;
             ForkJoinPool.WorkQueue w = null;
@@ -1104,7 +1106,7 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
             wt.pool.helpQuiescePool(wt.workQueue);
         }
         else
-            ForkJoinPool.externalHelpQuiescePool();
+            ForkJoinPool.quiesceCommonPool();
     }
 
     /**
@@ -1390,6 +1392,24 @@ public abstract class ForkJoinTask<V> implements Future<V>, Serializable {
         private static final long serialVersionUID = 5232453952276885070L;
     }
 
+    /**
+     * Adaptor for Runnables in which failure forces worker exception
+     */
+    static final class RunnableExecuteAction extends ForkJoinTask<Void> {
+        final Runnable runnable;
+        RunnableExecuteAction(Runnable runnable) {
+            if (runnable == null) throw new NullPointerException();
+            this.runnable = runnable;
+        }
+        public final Void getRawResult() { return null; }
+        public final void setRawResult(Void v) { }
+        public final boolean exec() { runnable.run(); return true; }
+        void internalPropagateException(Throwable ex) {
+            rethrow(ex); // rethrow outside exec() catches.
+        }
+        private static final long serialVersionUID = 5232453952276885070L;
+    }
+
     /**
      * Adaptor for Callables
      */

test/java/util/concurrent/forkjoin/ThreadLessCommon.java

+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/*
+ * @test
+ * @bug 8008378
+ * @summary Basic checks for parallelism 0, and null returning factory
+ * @run main/othervm -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 ThreadLessCommon
+ * @run main/othervm -Djava.util.concurrent.ForkJoinPool.common.threadFactory=ThreadLessCommon$NullForkJoinWorkerThreadFactory ThreadLessCommon
+ * @author Chris Hegarty
+ */
+
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ForkJoinPool.ForkJoinWorkerThreadFactory;
+import java.util.concurrent.ForkJoinWorkerThread;
+import java.util.concurrent.RecursiveTask;
+
+public class ThreadLessCommon {
+
+    static final int THRESHOLD = 1000;
+    static final boolean debug = true;
+
+    private static void realMain(String[] args) throws Throwable {
+        if (debug) {
+            String pp = System.getProperty(
+                    "java.util.concurrent.ForkJoinPool.common.parallelism");
+            System.out.println(
+                    "java.util.concurrent.ForkJoinPool.common.parallelism:" + pp);
+            String tf = System.getProperty(
+                    "java.util.concurrent.ForkJoinPool.common.threadFactory");
+            System.out.println(
+                    "java.util.concurrent.ForkJoinPool.common.threadFactory:" + tf);
+        }
+
+        long from = 0, to = 50000;
+        RecursiveTask<Long> task = new SumTask(from, to, Thread.currentThread());
+        long sum = task.invoke();
+        System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum);
+
+        task.fork();
+        sum = task.join();
+        System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum);
+
+        sum = ForkJoinPool.commonPool().invoke(task.fork());
+        System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum);
+    }
+
+    static class SumTask extends RecursiveTask<Long> {
+        final Thread expectedThread;
+        final long from;
+        final long to;
+        SumTask(long from, long to, Thread thread) {
+            this.from = from; this.to = to; expectedThread = thread;
+        }
+
+        @Override
+        public Long compute() {
+            check(Thread.currentThread() == expectedThread,
+                  "Expected " + expectedThread + ", got " + Thread.currentThread());
+            long range = to - from;
+            if (range < THRESHOLD) {
+                long acc = 0;
+                for (long i = from; i <= to; i++)
+                    acc = acc + i;
+                return acc;
+            } else {
+                long half = from + range / 2;
+                SumTask t1 = new SumTask(from, half ,expectedThread);
+                SumTask t2 = new SumTask(half+1, to ,expectedThread);
+                if (half % 2 == 0) {
+                    t1.fork();
+                    return t2.compute() + t1.join();
+                } else {
+                    invokeAll(t1, t2);
+                    try { return t1.get() + t2.get(); }
+                    catch (Exception x) { unexpected(x); return 0L;}
+                }
+            }
+        }
+    }
+
+    public static class NullForkJoinWorkerThreadFactory
+        implements ForkJoinWorkerThreadFactory
+    {
+        @Override
+        public ForkJoinWorkerThread newThread(ForkJoinPool pool) {
+            return null;
+        }
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    static volatile int passed = 0, failed = 0;
+    static void pass() {passed++;}
+    static void fail() {failed++; /*Thread.dumpStack();*/}
+    static void fail(String msg) {System.out.println(msg); fail();}
+    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    static void check(boolean cond, String msg) {if (cond) pass(); else fail(msg);}
+    static 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 {
+        try {realMain(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");}
+}

test/java/util/concurrent/forkjoin/ThrowingRunnable.java

+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/*
+ * @test
+ * @bug 8008378
+ * @run main/othervm -Djava.util.concurrent.ForkJoinPool.common.exceptionHandler=ThrowingRunnable
+ *                   ThrowingRunnable
+ * @summary FJP.execute(Runnable), uncaught exception should cause worker thread
+ *          to die.
+ * @author Chris Hegarty
+ */
+
+import java.lang.Thread.UncaughtExceptionHandler;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.TimeUnit;
+
+public class ThrowingRunnable implements Runnable, UncaughtExceptionHandler {
+
+    static final Phaser phaser = new Phaser(2);
+
+    private static void realMain(String[] args) throws Throwable {
+        ThrowingRunnable r = new ThrowingRunnable();
+        ForkJoinPool.commonPool().execute(r);
+        phaser.awaitAdvanceInterruptibly(phaser.arrive(), 10, TimeUnit.SECONDS);
+        pass();
+    }
+
+    @Override
+    public void run() {
+        throw new RuntimeException("This is an exception.");
+    }
+
+    @Override
+    public void uncaughtException(Thread t, Throwable e) {
+        pass();
+        phaser.arrive();
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    static volatile int passed = 0, failed = 0;
+    static void pass() {passed++;}
+    static void fail() {failed++; /*Thread.dumpStack();*/}
+    static void fail(String msg) {System.out.println(msg); fail();}
+    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    static void check(boolean cond, String msg) {if (cond) pass(); else fail(msg);}
+    static 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 {
+        try {realMain(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");}
+}