在分析其中一个生产环境的日志时，我在倒计时等待（）上看到了一个处于“WAITING”状态的线程
...sun.misc.Unsafe.park(Native Method)
...java.util.concurrent.locks.LockSupport.park(Unknown Source)
...java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(Unknown Source)
...java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(Unknown Source)
...java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(Unknown Source)
...java.util.concurrent.CountDownLatch.await(Unknown Source)
锁存器被初始化为 1，并且另一个线程确实在锁存器的同一实例上调用了 countDown() 方法，但主线程仍然在锁存器上保持阻塞。这导致 jvm 被无限期挂起。
即使锁存器计数达到零也被阻止听起来不合理，我正在寻找有关进一步解决此问题的建议。
有任何想法吗？
注意 - 使用的 jvm 版本如下
java 版本 "1.5.0_15" Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_15-b04) Java HotSpot(TM) Client VM (build 1.5.0_15-b04, 混合模式, 共享)
更新 - 下面是我在上面谈论的线程的代码片段
private class MyRunnable implements Runnable, Thread.UncaughtExceptionHandler {
private AtomicBoolean shouldStop = new AtomicBoolean(false);
private CountDownLatch stopLatch = new CountDownLatch(1);
private Thread currentThread;
public void run() {
Thread.currentThread().setName("My Thread");
Thread.currentThread().setUncaughtExceptionHandler(this);
currentThread = Thread.currentThread();
if (currentThread.isInterrupted()) {
logger.debug("The pool thread had its interrupted stattus set. Clearing...");
Thread.interrupted();
logger.debug("The pool thread had its interrupted stattus set. Clearing...DONE");
}
try {
doBusinessLogic(shouldStop);
} catch (Exception e) {
logger.error("An exception was encountered in the thread", e);
} finally {
if (currentThread.isInterrupted()) {
logger.debug("Clearing interupted status for the thread and returning to pool...");
Thread.interrupted();
}
stopLatch.countDown();
logger.debug("Stopped task after counting down on the latch");
}
}
public void stopThread() {
shouldStop.set(true);
logger.debug("Stop flag was set to true.. waiting for thread method to return...");
try {
stopLatch.await();
logger.debug("Stop flag was set to true... task has finished. Returning.");
} catch (InterruptedException e) {
logger.error("Interrupted while awaiting thread stop event...", e);
}
}
public void uncaughtException(Thread t, Throwable e) {
logger.error("An uncaught exception occurred in the task thread ", e);
}
private void doBusinessLogic(AtomicBoolean shouldStop) {
long sleepPeriod = 11;
while (!shouldStop.get()) {
try {
Thread.sleep(sleepPeriod);
} catch (InterruptedException e) {
logger.debug("Thread was interrupted.Clearing interrupted status and proceeding", e);
if (Thread.currentThread().isInterrupted())
Thread.interrupted();
}
if (shouldStop.get()) {
logger.debug("Stop flag was set. Returning.");
return;
}
try {
logger.debug("Performing business logic...");
//.....
logger.debug("Performing business logic...DONE");
} catch (Throwable e) {
logger.error("An exception occurred", e);
}
if (shouldStop.get()) {
logger.debug("Stop flag was set. Returning.");
return;
}
}
}
}
这是我在日志中看到的
DEBUG [main Thread] - Stop flag was set to true.. waiting for thread method to return...
DEBUG [My Thread] - Stop flag was set. Returning.
DEBUG [My Thread] - Stopped task after counting down on the latch
在latch.await() 之后的记录器语句从不打印，并且线程转储还表明主线程在latch 上被阻塞。