openjdk/test/jdk/java/util/concurrent/tck/ForkJoinPool20Test.java
2025-06-02 09:22:37 +00:00

668 lines
26 KiB
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/
*/
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.ForkJoinWorkerThread;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.LockSupport;
import java.util.stream.Stream;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
import junit.framework.Test;
import junit.framework.TestSuite;
/**
* Tests for ForkJoinPool and ForkJoinWorkerThread additions in JDK 20.
*/
public class ForkJoinPool20Test extends JSR166TestCase {
public static void main(String[] args) {
main(suite(), args);
}
public static Test suite() {
return new TestSuite(ForkJoinPool20Test.class);
}
/**
* Test that tasks submitted with externalSubmit execute.
*/
public void testExternalSubmit1() throws Exception {
try (var pool = new ForkJoinPool()) {
// submit from external client
var task1 = ForkJoinTask.adapt(() -> "foo");
pool.externalSubmit(task1);
assertEquals(task1.get(), "foo");
// submit from worker thread
Future<Future<String>> task2 = pool.submit(() -> {
return pool.externalSubmit(ForkJoinTask.adapt(() -> "foo"));
});
assertEquals(task2.get().get(), "foo");
}
}
/**
* Test that tasks submitted with externalSubmit are pushed to a submission queue.
*/
public void testExternalSubmit2() throws Exception {
try (var pool = new ForkJoinPool(1)) {
pool.submit(() -> {
assertTrue(pool.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedSubmissionCount() == 0);
for (int count = 1; count <= 3; count++) {
var task = ForkJoinTask.adapt(() -> { });
pool.externalSubmit(task);
assertTrue(pool.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedSubmissionCount() == count);
}
}).get();
}
}
/**
* Test externalSubmit return value.
*/
public void testExternalSubmitReturnsTask() {
try (var pool = new ForkJoinPool()) {
var task = ForkJoinTask.adapt(() -> "foo");
assertTrue(pool.externalSubmit(task) == task);
}
}
/**
* Test externalSubmit(null) throws NullPointerException.
*/
public void testExternalSubmitWithNull() {
try (var pool = new ForkJoinPool()) {
assertThrows(NullPointerException.class, () -> pool.externalSubmit(null));
}
}
/**
* Test externalSubmit throws RejectedExecutionException when pool is shutdown.
*/
public void testExternalSubmitWhenShutdown() {
try (var pool = new ForkJoinPool()) {
pool.shutdown();
var task = ForkJoinTask.adapt(() -> { });
assertThrows(RejectedExecutionException.class, () -> pool.externalSubmit(task));
}
}
/**
* Test that tasks submitted with submit(ForkJoinTask) are pushed to a
* submission queue.
*/
public void testSubmit() throws Exception {
try (var pool = new ForkJoinPool(1)) {
ForkJoinWorkerThread worker = submitBusyTask(pool);
try {
assertTrue(worker.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedSubmissionCount() == 0);
for (int count = 1; count <= 3; count++) {
var task = ForkJoinTask.adapt(() -> { });
pool.submit(task);
// task should be in submission queue
assertTrue(worker.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedTaskCount() == 0);
assertTrue(pool.getQueuedSubmissionCount() == count);
}
} finally {
LockSupport.unpark(worker);
}
}
}
/**
* Test ForkJoinWorkerThread::getQueuedTaskCount returns the number of tasks in the
* current thread's queue. This test runs with parallelism of 1 to ensure that tasks
* aren't stolen.
*/
public void testGetQueuedTaskCount1() throws Exception {
try (var pool = new ForkJoinPool(1)) {
pool.submit(() -> {
var worker = (ForkJoinWorkerThread) Thread.currentThread();
assertTrue(worker.getQueuedTaskCount() == 0);
for (int count = 1; count <= 3; count++) {
pool.submit(() -> { });
// task should be in this thread's task queue
assertTrue(worker.getQueuedTaskCount() == count);
assertTrue(pool.getQueuedTaskCount() == count);
assertTrue(pool.getQueuedSubmissionCount() == 0);
}
}).get();
}
}
/**
* Test ForkJoinWorkerThread::getQueuedTaskCount returns the number of tasks in the
* thread's queue. This test runs with parallelism of 2 and one worker active running
* a task. This gives the test two task queues to sample.
*/
public void testGetQueuedTaskCount2() throws Exception {
try (var pool = new ForkJoinPool(2)) {
// keep one worker thread active
ForkJoinWorkerThread worker1 = submitBusyTask(pool);
try {
pool.submit(() -> {
var worker2 = (ForkJoinWorkerThread) Thread.currentThread();
for (int count = 1; count <= 3; count++) {
pool.submit(() -> { });
// task should be in this thread's task queue
assertTrue(worker1.getQueuedTaskCount() == 0);
assertTrue(worker2.getQueuedTaskCount() == count);
assertTrue(pool.getQueuedTaskCount() == count);
assertTrue(pool.getQueuedSubmissionCount() == 0);
}
}).get();
} finally {
LockSupport.unpark(worker1); // release worker1
}
}
}
/**
* Submits a task to the pool, returning the worker thread that runs the
* task. The task runs until the thread is unparked.
*/
static ForkJoinWorkerThread submitBusyTask(ForkJoinPool pool) throws Exception {
var ref = new AtomicReference<ForkJoinWorkerThread>();
pool.submit(() -> {
ref.set((ForkJoinWorkerThread) Thread.currentThread());
LockSupport.park();
});
ForkJoinWorkerThread worker;
while ((worker = ref.get()) == null) {
Thread.sleep(20);
}
return worker;
}
// additions for ScheduledExecutorService
/**
* delayed schedule of callable successfully executes after delay
*/
public void testSchedule1() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(1);
Callable<Boolean> task = new CheckedCallable<>() {
public Boolean realCall() {
done.countDown();
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
return Boolean.TRUE;
}};
Future<Boolean> f = p.schedule(task, timeoutMillis(), MILLISECONDS);
assertSame(Boolean.TRUE, f.get());
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
assertEquals(0L, done.getCount());
}
}
/**
* delayed schedule of callable successfully executes after delay
* even if shutdown.
*/
public void testSchedule1b() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(1);
Callable<Boolean> task = new CheckedCallable<>() {
public Boolean realCall() {
done.countDown();
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
return Boolean.TRUE;
}};
Future<Boolean> f = p.schedule(task, timeoutMillis(), MILLISECONDS);
p.shutdown();
assertSame(Boolean.TRUE, f.get());
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
assertEquals(0L, done.getCount());
}
}
/**
* delayed schedule of runnable successfully executes after delay
*/
public void testSchedule3() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(1);
Runnable task = new CheckedRunnable() {
public void realRun() {
done.countDown();
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
}};
Future<?> f = p.schedule(task, timeoutMillis(), MILLISECONDS);
await(done);
assertNull(f.get(LONG_DELAY_MS, MILLISECONDS));
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
}
}
/**
* scheduleAtFixedRate executes runnable after given initial delay
*/
public void testSchedule4() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(1);
Runnable task = new CheckedRunnable() {
public void realRun() {
done.countDown();
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
}};
ScheduledFuture<?> f =
p.scheduleAtFixedRate(task, timeoutMillis(),
LONG_DELAY_MS, MILLISECONDS);
await(done);
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
f.cancel(true);
}
}
/**
* scheduleAtFixedRate with 0 initial delay re-rexecutes
*/
public void testSchedule4a() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(2);
Runnable task = new Runnable() {
public void run() {
done.countDown();
}};
ScheduledFuture<?> f =
p.scheduleAtFixedRate(task, 0L, timeoutMillis(),
MILLISECONDS);
await(done);
f.cancel(true);
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
}
}
/**
* scheduleWithFixedDelay executes runnable after given initial delay
*/
public void testSchedule5() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(1);
Runnable task = new CheckedRunnable() {
public void realRun() {
done.countDown();
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
}};
ScheduledFuture<?> f =
p.scheduleWithFixedDelay(task, timeoutMillis(),
LONG_DELAY_MS, MILLISECONDS);
await(done);
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
f.cancel(true);
}
}
/**
* scheduleWithFixedDelay with 0 initial delay re-rexecutes
*/
public void testSchedule5a() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
final long startTime = System.nanoTime();
final CountDownLatch done = new CountDownLatch(2);
Runnable task = new Runnable() {
public void run() {
done.countDown();
}};
ScheduledFuture<?> f =
p.scheduleWithFixedDelay(task, 0L, timeoutMillis(),
MILLISECONDS);
await(done);
assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
f.cancel(true);
}
}
static class RunnableCounter implements Runnable {
AtomicInteger count = new AtomicInteger(0);
public void run() { count.getAndIncrement(); }
}
/**
* scheduleAtFixedRate executes series of tasks at given rate.
* Eventually, it must hold that:
* cycles - 1 <= elapsedMillis/delay < cycles
* Additionally, periodic tasks are not run after shutdown.
*/
public void testFixedRateSequence() throws InterruptedException {
final ForkJoinPool p = new ForkJoinPool(4);
try (PoolCleaner cleaner = cleaner(p)) {
for (int delay = 1; delay <= LONG_DELAY_MS; delay *= 3) {
final long startTime = System.nanoTime();
final int cycles = 8;
final CountDownLatch done = new CountDownLatch(cycles);
final Runnable task = new CheckedRunnable() {
public void realRun() { done.countDown(); }};
final ScheduledFuture<?> periodicTask =
p.scheduleAtFixedRate(task, 0, delay, MILLISECONDS);
final int totalDelayMillis = (cycles - 1) * delay;
await(done, totalDelayMillis + LONG_DELAY_MS);
final long elapsedMillis = millisElapsedSince(startTime);
assertTrue(elapsedMillis >= totalDelayMillis);
if (elapsedMillis <= cycles * delay)
return;
periodicTask.cancel(true); // retry with longer delay
}
fail("unexpected execution rate");
}
}
/**
* scheduleWithFixedDelay executes series of tasks with given
* period. Eventually, it must hold that each task starts at
* least delay and at most 2 * delay after the termination of the
* previous task. Additionally, periodic tasks are not run after
* shutdown.
*/
public void testFixedDelaySequence() throws InterruptedException {
final ForkJoinPool p = new ForkJoinPool(1);
try (PoolCleaner cleaner = cleaner(p)) {
for (int delay = 1; delay <= LONG_DELAY_MS; delay *= 3) {
final long startTime = System.nanoTime();
final AtomicLong previous = new AtomicLong(startTime);
final AtomicBoolean tryLongerDelay = new AtomicBoolean(false);
final int cycles = 8;
final CountDownLatch done = new CountDownLatch(cycles);
final int d = delay;
final Runnable task = new CheckedRunnable() {
public void realRun() {
long now = System.nanoTime();
long elapsedMillis
= NANOSECONDS.toMillis(now - previous.get());
if (elapsedMillis >= (done.getCount() == cycles ? d : 2 * d))
tryLongerDelay.set(true);
previous.set(now);
done.countDown();
}};
final ScheduledFuture<?> periodicTask =
p.scheduleWithFixedDelay(task, 0, delay, MILLISECONDS);
final int totalDelayMillis = (cycles - 1) * delay;
await(done, totalDelayMillis + cycles * LONG_DELAY_MS);
final long elapsedMillis = millisElapsedSince(startTime);
assertTrue(elapsedMillis >= totalDelayMillis);
if (!tryLongerDelay.get())
return;
periodicTask.cancel(true); // retry with longer delay
}
fail("unexpected execution rate");
}
}
/**
* Submitting null tasks throws NullPointerException
*/
public void testNullTaskSubmission() {
final ForkJoinPool p = new ForkJoinPool(1);
try (PoolCleaner cleaner = cleaner(p)) {
assertNullTaskSubmissionThrowsNullPointerException(p);
}
}
/**
* Submitted tasks are rejected when shutdown
*/
public void testSubmittedTasksRejectedWhenShutdown() throws InterruptedException {
final ForkJoinPool p = new ForkJoinPool(4);
final ThreadLocalRandom rnd = ThreadLocalRandom.current();
final CountDownLatch threadsStarted = new CountDownLatch(p.getParallelism());
final CountDownLatch done = new CountDownLatch(1);
final Runnable r = () -> {
threadsStarted.countDown();
for (;;) {
try {
done.await();
return;
} catch (InterruptedException shutdownNowDeliberatelyIgnored) {}
}};
final Callable<Boolean> c = () -> {
threadsStarted.countDown();
for (;;) {
try {
done.await();
return Boolean.TRUE;
} catch (InterruptedException shutdownNowDeliberatelyIgnored) {}
}};
try (PoolCleaner cleaner = cleaner(p, done)) {
for (int i = p.getParallelism(); i-- > 0; ) {
switch (rnd.nextInt(4)) {
case 0: p.execute(r); break;
case 1: assertFalse(p.submit(r).isDone()); break;
case 2: assertFalse(p.submit(r, Boolean.TRUE).isDone()); break;
case 3: assertFalse(p.submit(c).isDone()); break;
}
}
await(threadsStarted);
p.shutdown();
done.countDown(); // release blocking tasks
assertTrue(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
}
}
/**
* A fixed delay task with overflowing period should not prevent a
* one-shot task from executing.
* https://bugs.openjdk.org/browse/JDK-8051859
*/
@SuppressWarnings("FutureReturnValueIgnored")
public void testScheduleWithFixedDelay_overflow() throws Exception {
final CountDownLatch delayedDone = new CountDownLatch(1);
final CountDownLatch immediateDone = new CountDownLatch(1);
final ForkJoinPool p = new ForkJoinPool(2);
p.cancelDelayedTasksOnShutdown();
try (PoolCleaner cleaner = cleaner(p)) {
final Runnable delayed = () -> {
delayedDone.countDown();
p.submit(() -> immediateDone.countDown());
};
p.scheduleWithFixedDelay(delayed, 0L, Long.MAX_VALUE, SECONDS);
await(delayedDone);
await(immediateDone);
}
}
/**
* shutdownNow cancels tasks that were not run
*/
public void testShutdownNow_delayedTasks() throws InterruptedException {
final ForkJoinPool p = new ForkJoinPool(2);
List<ScheduledFuture<?>> tasks = new ArrayList<>();
final int DELAY = 100;
for (int i = 0; i < 3; i++) {
Runnable r = new NoOpRunnable();
tasks.add(p.schedule(r, DELAY, SECONDS));
tasks.add(p.scheduleAtFixedRate(r, DELAY, DELAY, SECONDS));
tasks.add(p.scheduleWithFixedDelay(r, DELAY, DELAY, SECONDS));
}
p.shutdownNow();
assertTrue(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
for (ScheduledFuture<?> task : tasks) {
assertTrue(task.isDone());
}
assertTrue(p.isTerminated());
}
/**
* submitWithTimeout (eventually) cancels task after timeout
*/
public void testSubmitWithTimeoutCancels() throws InterruptedException {
final ForkJoinPool p = ForkJoinPool.commonPool();
Callable<Boolean> c = new Callable<Boolean>() {
public Boolean call() throws Exception {
Thread.sleep(LONGER_DELAY_MS); return Boolean.TRUE; }};
ForkJoinTask<?> task = p.submitWithTimeout(c, 1, NANOSECONDS, null);
while(!task.isCancelled())
Thread.sleep(timeoutMillis());
}
static final class SubmitWithTimeoutException extends RuntimeException {}
/**
* submitWithTimeout using complete completes after timeout
*/
public void testSubmitWithCompleterTimeoutCompletes() throws InterruptedException {
final ForkJoinPool p = ForkJoinPool.commonPool();
Callable<Item> c = new Callable<Item>() {
public Item call() throws Exception {
Thread.sleep(LONGER_DELAY_MS); return one; }};
ForkJoinTask<Item> task = p.submitWithTimeout(
c, 1, NANOSECONDS,
(ForkJoinTask<Item> t) ->
t.complete(two));
assertEquals(task.join(), two);
}
/**
* submitWithTimeout using completeExceptionally throws after timeout
*/
public void testSubmitWithTimeoutThrows() throws InterruptedException {
final ForkJoinPool p = ForkJoinPool.commonPool();
Callable<Boolean> c = new Callable<Boolean>() {
public Boolean call() throws Exception {
Thread.sleep(LONGER_DELAY_MS); return Boolean.TRUE; }};
ForkJoinTask<Boolean> task = p.submitWithTimeout(
c, 1, NANOSECONDS,
(ForkJoinTask<Boolean> t) ->
t.completeExceptionally(new SubmitWithTimeoutException()));
try {
task.join();
shouldThrow();
}
catch (Exception ex) {
assertTrue(ex instanceof SubmitWithTimeoutException);
}
}
/**
* submitWithTimeout doesn't cancel if completed before timeout
*/
public void testSubmitWithTimeout_NoTimeout() throws InterruptedException {
final ForkJoinPool p = ForkJoinPool.commonPool();
Callable<Boolean> c = new Callable<Boolean>() {
public Boolean call() throws Exception {
return Boolean.TRUE; }};
ForkJoinTask<?> task = p.submitWithTimeout(c, LONGER_DELAY_MS, MILLISECONDS, null);
Thread.sleep(timeoutMillis());
assertFalse(task.isCancelled());
assertEquals(task.join(), Boolean.TRUE);
}
/**
* A delayed task completes (possibly abnormally) if shutdown after
* calling cancelDelayedTasksOnShutdown()
*/
public void testCancelDelayedTasksOnShutdown() throws Exception {
final ForkJoinPool p = new ForkJoinPool(2);
p.cancelDelayedTasksOnShutdown();
try (PoolCleaner cleaner = cleaner(p)) {
Callable<Boolean> task = new CheckedCallable<>() {
public Boolean realCall() {
return Boolean.TRUE;
}};
Future<Boolean> f = p.schedule(task, LONGER_DELAY_MS, MILLISECONDS);
p.shutdown();
assertTrue(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
assertTrue(f.isDone());
}
}
/**
* schedule throws RejectedExecutionException if shutdown before
* first delayed task is submitted
*/
public void testInitialScheduleAfterShutdown() throws InterruptedException {
Runnable r = new NoOpRunnable();
boolean rje = false;
try (final ForkJoinPool p = new ForkJoinPool(1)) {
p.shutdown();
assertTrue(p.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
try {
p.schedule(r, 1, MILLISECONDS);
} catch (RejectedExecutionException ok) {
rje = true;
}
}
assertTrue(rje);
}
}