本文主要是介绍可重入锁的正确姿势，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
package Thread2;/*** 可重入锁示例*/
public class ReenTranLockDemo {private Object currentThread;private int lockTimes = 0;public synchronized void lock() throws InterruptedException {while (Thread.currentThread() == currentThread || currentThread == null || lockTimes > 0) {if (Thread.currentThread() == currentThread) {//当前线程重复加锁lockTimes++;System.out.println(1);System.out.println(currentThread);return;} else if (currentThread == null) {//当前线程首次加锁currentThread = Thread.currentThread();lockTimes++;System.out.println(2);System.out.println(currentThread);return;} else {//锁已被占用，当前线程进入等待wait();System.out.println(3);System.out.println(currentThread);}}System.out.println("lockTime:" + lockTimes);return;}public synchronized void unlock() {if (currentThread != null && Thread.currentThread() == currentThread) {if (1 == lockTimes) {currentThread = null;notify();System.out.println(4);System.out.println(currentThread);} else {System.out.println(5);System.out.println(currentThread);}lockTimes--;}System.out.println("lockTime:" + lockTimes);}}
package Thread2;public class RunReenTranLock3 {private static int a;private static int b;private static ReenTranLockDemo reenTranLockDemo = new ReenTranLockDemo();private static ReenTranLockDemo reenTranLockDemo1 = new ReenTranLockDemo();public static void main(String[] args) throws InterruptedException {Thread thread = getThread();Thread thread1 = getThread();Thread thread2 = getThread1();thread.start();thread1.start();thread2.start();thread.join();thread1.join();thread2.join();System.out.println("a:" + a);System.out.println("b:" + b);}public static Thread getThread() {Thread thread = new Thread(new Runnable() {@Overridepublic void run() {try {reenTranLockDemo.lock();for (int i = 0; i < 10000; i++) {a++;}method1();} catch (InterruptedException e) {e.printStackTrace();} finally {reenTranLockDemo.unlock();}}});return thread;}public static Thread getThread1() {Thread thread = new Thread(new Runnable() {@Overridepublic void run() {try {reenTranLockDemo1.lock();for (int i = 0; i < 10000; i++) {b++;}method2();} catch (InterruptedException e) {e.printStackTrace();} finally {reenTranLockDemo1.unlock();}}});return thread;}public static void method1() throws InterruptedException {reenTranLockDemo.lock();try {for (int i = 0; i < 10000; i++) {a++;}} finally {reenTranLockDemo.unlock();}}public static void method2() throws InterruptedException {reenTranLockDemo1.lock();try {for (int i = 0; i < 10000; i++) {b++;}method3();} finally {reenTranLockDemo1.unlock();}}public static void method3() throws InterruptedException {reenTranLockDemo1.lock();try {for (int i = 0; i < 10000; i++) {b++;}} finally {reenTranLockDemo1.unlock();}}
}
测试结果
2
Thread[Thread-0,5,main]
2
Thread[Thread-2,5,main]
1
Thread[Thread-0,5,main]
1
Thread[Thread-2,5,main]
5
Thread[Thread-0,5,main]
1
Thread[Thread-2,5,main]
5
Thread[Thread-2,5,main]
lockTime:2
5
lockTime:1
Thread[Thread-2,5,main]
4
null
lockTime:1
lockTime:0
4
null
3
null
2
lockTime:0
Thread[Thread-1,5,main]
1
Thread[Thread-1,5,main]
5
Thread[Thread-1,5,main]
lockTime:1
4
null
lockTime:0
a:40000
b:30000这篇关于可重入锁的正确姿势的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
