/*
* 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.
*
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*/
/*
* 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.
* @library /lib/testlibrary/
*/
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.lang.ref.WeakReference;
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;
import jdk.testlibrary.Utils;
public class GCRetention {
static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
/**
* 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); }
};
}
}
int countRefsCleared(WeakReference<?>[] refs) {
int count = 0;
for (WeakReference<?> ref : refs)
if (ref.get() == null)
count++;
return count;
}
void test(String[] args) throws Throwable {
CustomPool pool = new CustomPool(10);
final int size = 100;
WeakReference<?>[] refs = new WeakReference<?>[size];
Future<?>[] futures = new Future<?>[size];
for (int i = 0; i < size; i++) {
final Object x = new Object();
refs[i] = new WeakReference<Object>(x);
// Create a Runnable with a strong ref to x.
Runnable r = new Runnable() {
public void run() { System.out.println(x); }
};
// Schedule a custom task with a strong reference to r.
// Later tasks have earlier expiration, to ensure multiple
// residents of queue head.
futures[i] = pool.schedule(r, size*2-i, TimeUnit.MINUTES);
}
Thread.sleep(10);
for (int i = 0; i < size; i++) {
if (futures[i] != null) {
futures[i].cancel(false);
futures[i] = null;
}
}
pool.purge();
int cleared = 0;
for (int i = 0;
i < 10 && (cleared = countRefsCleared(refs)) < size;
i++) {
System.gc();
System.runFinalization();
Thread.sleep(10);
}
pool.shutdown();
pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS);
if (cleared < size)
throw new Error(String.format
("references to %d/%d tasks retained (\"leaked\")",
size - cleared, size));
}
//--------------------- 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");}
}