interrupted()

Posted 2020-11-21 xiaofan156

 1     /**
　　　　　　测试当前线程是否已中断。 
 2      * Tests whether the current thread has been interrupted.  
　　　　　　此方法清除线程的中断状态。 
　　　　　　The <i>interrupted status</i> of the thread is cleared by this method.  
　　　　　　换言之，如果连续两次调用此方法，则第二次调用将返回false（除非在第一次调用清除其中断状态后，第二次调用检查它之前，当前线程再次中断）。 
　　　　　　In other words, if this method were to be called twice in succession, the
 5      * second call would return false (unless the current thread were
 6      * interrupted again, after the first call had cleared its interrupted
 7      * status and before the second call had examined it).
 8      * 由于中断时线程不活动而忽略的线程中断将由返回false的方法反映。
 9      * <p>A thread interruption ignored because a thread was not alive
10      * at the time of the interrupt will be reflected by this method
11      * returning false.
12      * @如果当前线程已中断，则返回<code>true</code>；否则返回<code>false</code>。
13      * @return  <code>true</code> if the current thread has been interrupted;
14      *          <code>false</code> otherwise.
15      * @see #isInterrupted()
16      * @revised 6.0
17      */
18     public static boolean interrupted() {
19         return currentThread().isInterrupted(true);
20     }

 1     /**
　　　　　　测试此线程是否已中断。线程的中断状态不受此方法的影响。
 2      * Tests whether this thread has been interrupted.  The <i>interrupted
 3      * status</i> of the thread is unaffected by this method.
 4      *
 5      * <p>A thread interruption ignored because a thread was not alive
 6      * at the time of the interrupt will be reflected by this method
 7      * returning false.
 8      *
 9      * @return  <code>true</code> if this thread has been interrupted;
10      *          <code>false</code> otherwise.
11      * @see     #interrupted()
12      * @revised 6.0
13      */
14     public boolean isInterrupted() {
15         return isInterrupted(false);
16     }

1     /** 测试某个线程是否被中断。中断状态是否基于传递的ClearInterrupted值重置。
2      * Tests if some Thread has been interrupted.  The interrupted state
3      * is reset or not based on the value of ClearInterrupted that is
4      * passed.
5      */
6     private native boolean isInterrupted(boolean ClearInterrupted);

 1 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
 2 
 3   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
 4 
 5     "possibility of dangling Thread pointer");
 6 
 7 
 8   OSThread* osthread = thread->osthread();
 9 
10 
11   bool interrupted = osthread->interrupted();
12 
13   如果线程被设置中断状态，且移除中断状态，设置中断状态为false
14   if (interrupted && clear_interrupted) {
15 
16     osthread->set_interrupted(false);
17 
18     // consider thread->_SleepEvent->reset() ... optional optimization
19 
20   }
21 
22 
23   return interrupted;
24 
25 }

总结： Thread类中的static boolean interrupted()修改中断状态为false  ,boolean isInterrupted()只判断中断状态，但不修改

public void interrupt()  将调用者线程的中断状态设置为true;

public boolean isInterrupted()  返回调用者线程的中断状态;

public static boolean interrupted()  只能通过Thread.interrupted()调用。

它会做两步操作：

1. 返回currentThread()的中断状态；

2. 将当前线程的中断状态修改为false;