源码
个人笔记,不喜勿喷,欢迎指导
public synchronized void start() {
/**
* This method is not invoked for the main method thread or "system"
* group threads created/set up by the VM. Any new functionality added
* to this method in the future may have to also be added to the VM.
*
* A zero status value corresponds to state "NEW".
*/
if (threadStatus != 0)
throw new IllegalThreadStateException();
/* Notify the group that this thread is about to be started
* so that it can be added to the group's list of threads
* and the group's unstarted count can be decremented. */
group.add(this);
boolean started = false;
try {
start0(); //private native void start0(); native调用本机操作系统函数
started = true;
} finally {
try {
if (!started) {
group.threadStartFailed(this);
}
} catch (Throwable ignore) {
/* do nothing. If start0 threw a Throwable then
it will be passed up the call stack */
}
}
}
@Override
public void run() {
if (target != null) {
target.run();
}
}
target是一个Runnable对象。run()就是直接调用Thread线程的Runnable成员的run()方法,并不会新建一个线程。
可以看看这个