java 线程池怎么加锁操作
时间: 2023-11-14 14:06:11 浏览: 43
Java线程池的加锁操作是通过对Worker对象进行加锁来实现的。在ThreadPoolExecutor的runWorker方法中,会对Worker对象进行加锁来保证线程安全。具体代码如下:
```
final void runWorker(Worker w) {
Thread wt = Thread.currentThread();
Runnable task = w.firstTask;
w.firstTask = null;
w.unlock(); // allow interrupts
boolean completedAbruptly = true;
try {
while (task != null || (task = getTask()) != null) {
w.lock();
// If pool is stopping, ensure thread is interrupted;
// if not, ensure thread is not interrupted. This
// requires a recheck in second case to deal with
// shutdownNow race while clearing interrupt
if ((runStateAtLeast(ctl.get(), STOP) ||
(Thread.interrupted() && runStateAtLeast(ctl.get(), STOP))) &&
!wt.isInterrupted())
wt.interrupt();
try {
beforeExecute(wt, task);
try {
task.run();
afterExecute(task, null);
} catch (Throwable ex) {
afterExecute(task, ex);
throw ex;
}
} finally {
task = null;
w.completedTasks++;
w.unlock();
}
}
completedAbruptly = false;
} finally {
processWorkerExit(w, completedAbruptly);
}
}
```
在这段代码中,通过调用Worker对象的lock和unlock方法来实现对Worker对象的加锁和解锁操作。这样可以确保在多个线程同时访问线程池时,对Worker对象的操作是线程安全的。