java - JavaLangAccess.blockedOn(Thread t, Interruptible b) 是做什么的？

Question

来自公共(public) javadoc:

void blockedOn(Thread t, Interruptible b)

Set thread's blocker field.

我在 java nio 研究期间确实使用了该方法，特别是 AbstractInterruptibleChannel 源代码

Answer 1

如果你看看 OpenJDK 它调用

/* The object in which this thread is blocked in an interruptible I/O
 * operation, if any.  The blocker's interrupt method should be invoked
 * after setting this thread's interrupt status.
 */
private volatile Interruptible blocker;
private Object blockerLock = new Object();

/* Set the blocker field; invoked via sun.misc.SharedSecrets from java.nio code
 */
void blockedOn(Interruptible b) {
synchronized (blockerLock) {
    blocker = b;
}
}

这用于在线程中断时触发操作。