| /* |
| * 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 and Martin Buchholz 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 |
| * @summary Ensure that waiting pool threads don't retain refs to tasks. |
| */ |
| |
| import java.lang.ref.ReferenceQueue; |
| import java.lang.ref.WeakReference; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.Delayed; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.RunnableScheduledFuture; |
| import java.util.concurrent.ScheduledThreadPoolExecutor; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.TimeoutException; |
| |
| public class GCRetention { |
| |
| /** |
| * A custom thread pool with a custom RunnableScheduledFuture, for the |
| * sole purpose of ensuring that the task retains a strong reference to |
| * the Runnable even after cancellation. |
| */ |
| static class CustomPool extends ScheduledThreadPoolExecutor { |
| CustomPool(int n) { super(n); } |
| protected <V> RunnableScheduledFuture<V> decorateTask( |
| final Runnable r, |
| final RunnableScheduledFuture<V> task) { |
| return new RunnableScheduledFuture<V>() { |
| public void run() { System.err.println(r); task.run(); } |
| public boolean isPeriodic() { return task.isPeriodic(); } |
| public V get() |
| throws InterruptedException,ExecutionException |
| { return task.get(); } |
| public V get(long x, TimeUnit y) |
| throws InterruptedException,ExecutionException,TimeoutException |
| { return task.get(x, y); } |
| public boolean isDone() { return task.isDone(); } |
| public boolean isCancelled() { return task.isCancelled(); } |
| public boolean cancel(boolean x) { return task.cancel(x); } |
| public long getDelay(TimeUnit x) { return task.getDelay(x); } |
| public int compareTo(Delayed x) { return task.compareTo(x); } |
| }; |
| } |
| } |
| |
| void removeAll(ReferenceQueue<?> q, int n) throws InterruptedException { |
| for (int j = n; j--> 0; ) { |
| if (q.poll() == null) { |
| for (;;) { |
| System.gc(); |
| if (q.remove(1000) != null) |
| break; |
| System.out.printf( |
| "%d/%d unqueued references remaining%n", j, n); |
| } |
| } |
| } |
| check(q.poll() == null); |
| } |
| |
| void test(String[] args) throws Throwable { |
| final CustomPool pool = new CustomPool(10); |
| final int size = 100; |
| final ReferenceQueue<Object> q = new ReferenceQueue<>(); |
| final List<WeakReference<?>> refs = new ArrayList<>(size); |
| final List<Future<?>> futures = new ArrayList<>(size); |
| |
| // Schedule custom tasks with strong references. |
| class Task implements Runnable { |
| final Object x; |
| Task() { refs.add(new WeakReference<>(x = new Object(), q)); } |
| public void run() { System.out.println(x); } |
| } |
| // Give tasks added later earlier expiration, to ensure |
| // multiple residents of queue head. |
| for (int i = size; i--> 0; ) |
| futures.add(pool.schedule(new Task(), i + 1, TimeUnit.MINUTES)); |
| futures.forEach(future -> future.cancel(false)); |
| futures.clear(); |
| |
| pool.purge(); |
| removeAll(q, size); |
| for (WeakReference<?> ref : refs) check(ref.get() == null); |
| |
| pool.shutdown(); |
| // rely on test harness to handle timeout |
| pool.awaitTermination(1L, TimeUnit.DAYS); |
| } |
| |
| //--------------------- 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 GCRetention().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");} |
| } |