/**
* After invoking a single task, isQuiescent eventually becomes true, at which time queues are
* empty, threads are not active, the task has completed successfully, and construction parameters
* continue to hold
*/
public void testIsQuiescent() throws Exception {
ForkJoinPool p = new ForkJoinPool(2);
try (PoolCleaner cleaner = cleaner(p)) {
assertTrue(p.isQuiescent());
long startTime = System.nanoTime();
FibTask f = new FibTask(20);
p.invoke(f);
assertSame(ForkJoinPool.defaultForkJoinWorkerThreadFactory, p.getFactory());
while (!p.isQuiescent()) {
if (millisElapsedSince(startTime) > LONG_DELAY_MS)
throw new AssertionFailedError("timed out");
assertFalse(p.getAsyncMode());
assertFalse(p.isShutdown());
assertFalse(p.isTerminating());
assertFalse(p.isTerminated());
Thread.yield();
}
assertTrue(p.isQuiescent());
assertFalse(p.getAsyncMode());
assertEquals(0, p.getQueuedTaskCount());
assertEquals(0, p.getQueuedSubmissionCount());
assertFalse(p.hasQueuedSubmissions());
while (p.getActiveThreadCount() != 0 && millisElapsedSince(startTime) < LONG_DELAY_MS)
Thread.yield();
assertFalse(p.isShutdown());
assertFalse(p.isTerminating());
assertFalse(p.isTerminated());
assertTrue(f.isDone());
assertEquals(6765, (int) f.get());
assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
}
}
/** getPoolSize returns number of started workers. */
public void testGetPoolSize() {
final CountDownLatch taskStarted = new CountDownLatch(1);
final CountDownLatch done = new CountDownLatch(1);
final ForkJoinPool p = new ForkJoinPool(1);
try (PoolCleaner cleaner = cleaner(p)) {
assertEquals(0, p.getActiveThreadCount());
final Runnable task =
new CheckedRunnable() {
public void realRun() throws InterruptedException {
taskStarted.countDown();
assertEquals(1, p.getPoolSize());
assertEquals(1, p.getActiveThreadCount());
done.await();
}
};
Future<?> future = p.submit(task);
await(taskStarted);
assertEquals(1, p.getPoolSize());
assertEquals(1, p.getActiveThreadCount());
done.countDown();
}
assertEquals(0, p.getPoolSize());
assertEquals(0, p.getActiveThreadCount());
}
/**
* Successfully constructed pool reports default factory, parallelism and async mode policies, no
* active threads or tasks, and quiescent running state.
*/
public void testDefaultInitialState() {
ForkJoinPool p = new ForkJoinPool(1);
try (PoolCleaner cleaner = cleaner(p)) {
assertSame(ForkJoinPool.defaultForkJoinWorkerThreadFactory, p.getFactory());
assertFalse(p.getAsyncMode());
assertEquals(0, p.getActiveThreadCount());
assertEquals(0, p.getStealCount());
assertEquals(0, p.getQueuedTaskCount());
assertEquals(0, p.getQueuedSubmissionCount());
assertFalse(p.hasQueuedSubmissions());
assertFalse(p.isShutdown());
assertFalse(p.isTerminating());
assertFalse(p.isTerminated());
}
}
/**
* Main method of the example
*
* @param args
*/
public static void main(String[] args) {
// Create a list of products
ProductListGenerator generator = new ProductListGenerator();
List<Product> products = generator.generate(10000);
// Craete a task
Task task = new Task(products, 0, products.size(), 0.20);
// Create a ForkJoinPool
ForkJoinPool pool = new ForkJoinPool();
// Execute the Task
pool.execute(task);
// Write information about the pool
do {
System.out.printf("Main: Thread Count: %d\n", pool.getActiveThreadCount());
System.out.printf("Main: Thread Steal: %d\n", pool.getStealCount());
System.out.printf("Main: Paralelism: %d\n", pool.getParallelism());
try {
TimeUnit.MILLISECONDS.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
} while (!task.isDone());
// Shutdown the pool
pool.shutdown();
// Check if the task has completed normally
if (task.isCompletedNormally()) {
System.out.printf("Main: The process has completed normally.\n");
}
// Expected result: 12. Write products which price is not 12
for (int i = 0; i < products.size(); i++) {
Product product = products.get(i);
if (product.getPrice() != 12) {
System.out.printf("Product %s: %f\n", product.getName(), product.getPrice());
}
}
// End of the program
System.out.println("Main: End of the program.\n");
}
// 16、实现showLog()方法，接受一个ForkJoinPool对象作为参数，输出关于它的状态信息及线程、任务的执行信息
private static void showLog(ForkJoinPool pool) {
System.out.printf("**********************\n");
System.out.printf("Main: Fork/Join Pool log\n");
System.out.printf("Main: Fork/Join Pool: Parallelism: %d\n", pool.getParallelism());
System.out.printf("Main: Fork/Join Pool: Pool Size: %d\n", pool.getPoolSize());
System.out.printf(
"Main: Fork/Join Pool: Active Thread Count: %d\n", pool.getActiveThreadCount());
System.out.printf(
"Main: Fork/Join Pool: Running Thread Count: %d\n", pool.getRunningThreadCount());
System.out.printf(
"Main: Fork/Join Pool: Queued Submission: %d\n", pool.getQueuedSubmissionCount());
System.out.printf("Main: Fork/Join Pool: Queued Tasks: %d\n", pool.getQueuedTaskCount());
System.out.printf(
"Main: Fork/Join Pool: Queued Submissions: %s\n", pool.hasQueuedSubmissions());
System.out.printf("Main: Fork/Join Pool: Steal Count: %d\n", pool.getStealCount());
System.out.printf("Main: Fork/Join Pool: Terminated : %s\n", pool.isTerminated());
System.out.printf("**********************\n");
}
public static int[] sort(int[] input) {
ForkJoinPool mainPool = new ForkJoinPool();
int[] output = new int[input.length];
// from round 0...n, segment length is 2^n.
int round = (int) Math.ceil((Math.log(input.length) / Math.log(2)));
for (int i = 3; i < round; i++) {
// minimal length=16
int segmentLen = 1 << i;
mergeRound(segmentLen, input, output, mainPool);
int[] temp = input;
input = output;
output = temp;
}
System.out.println("\n\tthread account: " + mainPool.getActiveThreadCount());
System.out.println("\tparallelism: " + mainPool.getParallelism());
System.out.println("\tsteal count: " + mainPool.getStealCount());
mainPool.shutdown();
return input;
}
