这里是在Java的示例程序从tutorials point:mulithreading在Java示例
// Create a new thread.
class NewThread implements Runnable {
Thread t;
NewThread() {
// Create a new, second thread
t = new Thread(this, "Demo Thread");
System.out.println("Child thread: " + t);
t.start(); // Start the thread
}
// This is the entry point for the second thread.
public void run() {
try {
for(int i = 5; i > 0; i--) {
System.out.println("Child Thread: " + i);
// Let the thread sleep for a while.
Thread.sleep(50);
}
} catch (InterruptedException e) {
System.out.println("Child interrupted.");
}
System.out.println("Exiting child thread.");
}
}
public class ThreadDemo {
public static void main(String args[]) {
new NewThread(); // create a new thread
try {
for(int i = 5; i > 0; i--) {
System.out.println("Main Thread: " + i);
Thread.sleep(100);
}
} catch (InterruptedException e) {
System.out.println("Main thread interrupted.");
}
System.out.println("Main thread exiting.");
}
}
的程序的输出是如下。
Child thread: Thread[Demo Thread,5,main]
Main Thread: 5
Child Thread: 5
Child Thread: 4
Main Thread: 4
Child Thread: 3
Child Thread: 2
Main Thread: 3
Child Thread: 1
Exiting child thread.
Main Thread: 2
Main Thread: 1
Main thread exiting.
我很难理解为什么主线程在子线程之前执行。在程序中你可以看到第一个新的NewThread()被执行。 NewThread类实例化一个新线程,并在新线程上调用start()函数,然后调用run()函数。 只有在创建新线程后,主函数中的循环才会出现。但是,当程序运行时,主线程中的循环在子线程之前运行。请帮助我理解。
我看到你没有应用任何线程同步选项。所以在启动两个不同的线程后,'它不在你的手上'来控制哪个线程执行时,但有一些同步选项,如延迟,优先级和join()也许你可以达到一定数量的控制..不断学习.. – Dreamer