这里详细分析interrupt(),interrupted(),isInterrupted()三个方法

interrupt()

中断这个线程，设置中断标识位

public void interrupt() {        if (this != Thread.currentThread())            checkAccess();        synchronized (blockerLock) {            Interruptible b = blocker;            if (b != null) {                interrupt0();           // Just to set the interrupt flag                b.interrupt(this);                return;            }        }        interrupt0();    }

我们来找下如何设置中断标识位的

找到interrupt0()的源码，src/hotspot/share/prims/jvm.cpp

JVM_ENTRY(void, JVM_Interrupt(JNIEnv* env, jobject jthread))  ...  if (is_alive) {    // jthread refers to a live JavaThread.    Thread::interrupt(receiver);  }JVM_END

调用了Thread::interrupt方法

src/hotspot/share/runtime/thread.cpp

void Thread::interrupt(Thread* thread) {  ...  os::interrupt(thread);}

os::interrupt方法，src/hotspot/os/posix/os_posix.cpp

void os::interrupt(Thread* thread) {  ...  OSThread* osthread = thread->osthread();  if (!osthread->interrupted()) {    //设置中断标识位    osthread->set_interrupted(true);    ...  }    ...}

isInterrupted()

测试线程是否被中断，线程的中断状态不会改变

public boolean isInterrupted() {        return isInterrupted(false);    }

查看native isInterrupted(boolean ClearInterrupted)源码，查找方式同上

src/hotspot/os/posix/os_posix.cpp

bool os::is_interrupted(Thread* thread, bool clear_interrupted) {  debug_only(Thread::check_for_dangling_thread_pointer(thread);)  OSThread* osthread = thread->osthread();  // 查看是否被中断  bool interrupted = osthread->interrupted();  // 清除标识位后再设置false  if (interrupted && clear_interrupted) {    osthread->set_interrupted(false);  }  return interrupted;}

Java传递ClearInterrupted为false，对应C++的clear_interrupted

interrupted()

测试线程是否被中断，清除中断标识位

public static boolean interrupted() {        return currentThread().isInterrupted(true);    }

简单的例子

public class MyThread45 {    public static void main(String[] args) throws Exception    {        Runnable runnable = new Runnable()        {            public void run()            {                while (true)                {                    if (Thread.currentThread().isInterrupted())                    {                        System.out.println("线程被中断了");                        return ;                    }                    else                    {                        System.out.println("线程没有被中断");                    }                }            }        };        Thread t = new Thread(runnable);        t.start();        Thread.sleep(500);        t.interrupt();        System.out.println("线程中断了，程序到这里了");    }}

检查线程是否中断，中断线程，运行结果如下

······线程没有被中断线程没有被中断线程没有被中断线程被中断了线程中断了，程序到这里了