一、多线程实现输出循环123
1、循环输出123,通过Lock锁和共享变量state实现3个线程循环执行
private static volatile int state; final static Lock lock = new ReentrantLock(); public static void main(String[] args) { for (int i = 0; i < 3; i ++) { } Worker a = new Worker(3, 0); Worker b = new Worker(3, 1); Worker c = new Worker(3, 2); a.start(); b.start(); c.start(); } private static class Worker extends Thread { int mod; int v; Worker(int mod, int v) { this.mod = mod; this.v = v; } @Override public void run() { while (true) { lock.lock(); if (state % mod == v) { System.out.print(v + 1); state++; } lock.unlock(); } } }
二、按照顺序输出1-75
2、通过condition条件的通知机制和原子变量Inc自增实现输出1-75
private static final AtomicInteger inc = new AtomicInteger(); private static Lock lock = new ReentrantLock(); public static void main(String[] args) { Condition conditionA = lock.newCondition(); Condition conditionB = lock.newCondition(); Condition conditionC = lock.newCondition(); Worker workerA = new Worker(conditionA, conditionB, "A"); Worker workerB = new Worker(conditionB, conditionC, "B"); Worker workerC = new Worker(conditionC, conditionA, "C"); workerA.start(); workerB.start(); workerC.start(); } private static class Worker extends Thread { private Condition condition; private Condition nextCondition; private String name; Worker(Condition condition, Condition nextCondition, String name) { this.condition = condition; this.nextCondition = nextCondition; this.name = name; } @Override public void run() { lock.lock(); for (int i = 0; i < 5; i++) { for (int j = 0; j < 5; j ++) { System.out.println("name: " + name + " v: " + inc.incrementAndGet()); } nextCondition.signalAll(); if (i < 5) { try { condition.await(); } catch (InterruptedException e) { e.printStackTrace(); } } } lock.unlock(); } }