public void testDelayedTasksReusePooledThreadIfExecuteAtDifferentTimes()
throws InterruptedException, ExecutionException {
final AppScheduledExecutorService service = new AppScheduledExecutorService(getName());
final List<LogInfo> log = Collections.synchronizedList(new ArrayList<>());
// pre-start one thread
Future<?> future = service.submit(EmptyRunnable.getInstance());
future.get();
service.setBackendPoolCorePoolSize(1);
assertEquals(1, service.getBackendPoolExecutorSize());
int delay = 500;
ScheduledFuture<?> f1 =
service.schedule((Runnable) () -> log.add(new LogInfo(1)), delay, TimeUnit.MILLISECONDS);
ScheduledFuture<?> f2 =
service.schedule(
(Runnable) () -> log.add(new LogInfo(2)), delay + 100, TimeUnit.MILLISECONDS);
ScheduledFuture<?> f3 =
service.schedule(
(Runnable) () -> log.add(new LogInfo(3)), delay + 200, TimeUnit.MILLISECONDS);
assertEquals(1, service.getBackendPoolExecutorSize());
assertFalse(f1.isDone());
assertFalse(f2.isDone());
assertFalse(f3.isDone());
TimeoutUtil.sleep(delay + 200 + 300);
assertTrue(f1.isDone());
assertTrue(f2.isDone());
assertTrue(f3.isDone());
assertEquals(1, service.getBackendPoolExecutorSize());
assertEquals(3, log.size());
Set<Thread> usedThreads =
new HashSet<>(
Arrays.asList(
log.get(0).currentThread, log.get(1).currentThread, log.get(2).currentThread));
if (usedThreads.size() != 1) {
System.err.println(ThreadDumper.dumpThreadsToString());
}
assertEquals(usedThreads.toString(), 1, usedThreads.size()); // must be executed in same thread
service.shutdownAppScheduledExecutorService();
assertTrue(service.awaitTermination(10, TimeUnit.SECONDS));
}
