Java多线程06_重入锁ReentrantLock

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public class TestLock {public static void main(String[] args) {TestLock2 testLock2 = new TestLock2();new Thread(testLock2).start();new Thread(testLock2).start();new Thread(testLock2).start();}
}class TestLock2 implements Runnable {int ticketNums = 10;@Overridepublic void run() {while (true) {if (ticketNums > 0) {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println(ticketNums--);} else {break;}}}}

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import java.util.concurrent.locks.ReentrantLock;public class TestLock {public static void main(String[] args) {TestLock2 testLock2 = new TestLock2();new Thread(testLock2).start();new Thread(testLock2).start();new Thread(testLock2).start();}
}class TestLock2 implements Runnable{int ticketNums = 10;private final ReentrantLock lock = new ReentrantLock();@Overridepublic void run() {while(true) {lock.lock();try {if(ticketNums>0) {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println(ticketNums--);}else {break;}}  finally {lock.unlock();}}}

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synchronized 与 Lock 的对比：

Lock是显示锁（手动开启和关闭锁，别忘记关闭锁）
synchronized 是隐式锁，出了作用域自动释放Lock只有代码块锁synchronized有代码块锁和方法锁使用 Lock 锁，JVM 将花费较少时间来调度线程，性能更好，并且具有更好的扩展性（提供更多的子类，比如 ReentrantLock）