yield

对线程调度器的一种建议： 我已经执行完重要部分了，可以切换给其他任务执行一段时间。

import java.util.concurrent.*;

class LiftOff implements Runnable {
    protected int countDown =10;
    private static int taskCount = 0;
    private final int id = taskCount++;
    public LiftOff() {};
    public LiftOff(int countDown) {
        this.countDown = countDown;
    }

    private String status() {
        return "#" + id + "(" + (countDown>0? countDown: "LiftOff!") + "),";
    }

    public void run() {
        while(countDown-->0){
            System.out.print(status());
            Thread.yield();
        }
    }
}

public class ThreadDemo {
    public static void main(String... args) {
        for(int i=0; i<5; i++) {
            Thread t = new Thread(new LiftOff());
            t.start();
        }
    }
}



#0(9),#3(9),#0(8),#0(7),#0(6),#0(5),#0(4),#0(3),#0(2),#0(1),#0(LiftOff!),#2(9),#1(9),#3(8),#3(7),#3(6),#3(5),#3(4),#3(3),#3(2),#3(1),#3(LiftOff!),#2(8),#1(8),#2(7),#1(7),#2(6),#1(6),#2(5),#1(5),#2(4),#2(3),#2(2),#1(4),#1(3),#1(2),#1(1),#1(LiftOff!),#2(1),#2(LiftOff!),#4(9),#4(8),#4(7),#4(6),#4(5),#4(4),#4(3),#4(2),#4(1),#4(LiftOff!),

sleep

import java.util.concurrent.*;

class LiftOff implements Runnable {
    protected int countDown =10;
    private static int taskCount = 0;
    private final int id = taskCount++;
    public LiftOff() {};
    public LiftOff(int countDown) {
        this.countDown = countDown;
    }

    private String status() {
        return "#" + id + "(" + (countDown>0? countDown: "LiftOff!") + "),";
    }

    public void run() {
        while(countDown-->0){
            try{
                System.out.print(status());
                TimeUnit.MILLISECONDS.sleep(100);
            } catch(InterruptedException e) {
                System.err.println("Interrupted");
            }
        }
    }
}

public class ThreadDemo {
    public static void main(String... args) {
        for(int i=0; i<5; i++) {
            Thread t = new Thread(new LiftOff());
            t.start();
        }
    }
}



#1(9),#0(9),#2(9),#4(9),#3(9),#0(8),#3(8),#2(8),#1(8),#4(8),#0(7),#4(7),#3(7),#1(7),#2(7),#0(6),#3(6),#1(6),#4(6),#2(6),#0(5),#1(5),#4(5),#3(5),#2(5),#0(4),#1(4),#3(4),#4(4),#2(4),#0(3),#2(3),#4(3),#3(3),#1(3),#0(2),#4(2),#1(2),#3(2),#2(2),#0(1),#4(1),#3(1),#1(1),#2(1),#0(LiftOff!),#2(LiftOff!),#1(LiftOff!),#4(LiftOff!),#3(LiftOff!),

join

import java.util.concurrent.*;

class LiftOff implements Runnable {
    protected int countDown =10;
    private static int taskCount = 0;
    private final int id = taskCount++;
    public LiftOff() {};
    public LiftOff(int countDown) {
        this.countDown = countDown;
    }

    private String status() {
        return "#" + id + "(" + (countDown>0? countDown: "LiftOff!") + "),";
    }

    public void run() {
        while(countDown-->0){
            System.out.print(status());
            Thread.yield();
        }
    }
}

public class Joining {
    public static void main(String... args) {
        for(int i = 0; i<5; i++) {
            try{
                Thread t = new Thread(new LiftOff());
                t.start();
                t.join();
            } catch(InterruptedException e) {
                System.out.println("Interrupted!");
            }
        }
        System.out.println("All threads completed");
    }
}


#0(9),#0(8),#0(7),#0(6),#0(5),#0(4),#0(3),#0(2),#0(1),#0(LiftOff!),#1(9),#1(8),#1(7),#1(6),#1(5),#1(4),#1(3),#1(2),#1(1),#1(LiftOff!),#2(9),#2(8),#2(7),#2(6),#2(5),#2(4),#2(3),#2(2),#2(1),#2(LiftOff!),#3(9),#3(8),#3(7),#3(6),#3(5),#3(4),#3(3),#3(2),#3(1),#3(LiftOff!),#4(9),#4(8),#4(7),#4(6),#4(5),#4(4),#4(3),#4(2),#4(1),#4(LiftOff!),All threads completed