在同一个类中，线程资源竞争

 

 

/**
 * 在同一个类中，线程资源竞争
 *
 */
public class ThreadTest12 implements Runnable {  
	
    public static ThreadTest12 test1;
    
    public static ThreadTest12 test2;
    
    public static void main(String[] args) throws InterruptedException {
    	new Thread(new ThreadTest12()).start();
    	//new Thread(new ThreadTest12()).start();
    	/*
    	1 都是 synchronized (test1)  
    	Thread-0
    	Thread-1
    	Thread-0start run1
    	Thread-0end   run1
    	Thread-1start run2
    	Thread-1end   run2
    	
    	2  一个是 synchronized (test1)  另一个是 synchronized (test2)
    	Thread-0
		Thread-1
		Thread-0start run1
		Thread-1start run2
		Thread-0end   run1
		Thread-1end   run2
    	 */


	}
    
    
    public static ThreadTest12 instentce() {
    	
    	String name = Thread.currentThread().getName();
		if ("Thread-0".equals(name)) {
			if (test1 == null) {
				test1 = new ThreadTest12();
			}
	    	return test1;
		} else {
			if (test2 == null) {
				test2 = new ThreadTest12();
			}
	    	return test2;
		}
    }
    
    private void run1() throws InterruptedException {
    	System.out.println(Thread.currentThread().getName());
    	synchronized (test1) {
    		System.out.println(Thread.currentThread().getName() + "start run1");
    		Thread.sleep(9900);
    		System.out.println(Thread.currentThread().getName() + "end   run1");
    		//ThreadTest12.instentce().run2();
        }
    }
    
    private void run2() throws InterruptedException {
    	System.out.println(Thread.currentThread().getName());
    	
    	// synchronized (test2)  没有发生资源竞争
    	synchronized (test1) { // 发生资源竞争
    		System.out.println(Thread.currentThread().getName() + "start run2");
    		Thread.sleep(9900);
    		System.out.println(Thread.currentThread().getName() + "end   run2");
        }
    }

	@Override
	public void run() {
		try {
			String name = Thread.currentThread().getName();
			if ("Thread-0".equals(name)) {
				ThreadTest12.instentce().run1();
			} else {
				ThreadTest12.instentce().run2();
			}
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}