Java\u8bed\u8a00\u7684\u5173\u952e\u5b57\uff0c\u5f53\u5b83\u7528\u6765\u4fee\u9970\u4e00\u4e2a\u65b9\u6cd5\u6216\u8005\u4e00\u4e2a\u4ee3\u7801\u5757\u7684\u65f6\u5019\uff0c\u80fd\u591f\u4fdd\u8bc1\u5728\u540c\u4e00\u65f6\u523b\u6700\u591a\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c\u8be5\u6bb5\u4ee3\u7801\u3002
\n<\/p>\n
\u4e00\u3001\u5f53\u4e24\u4e2a\u5e76\u53d1\u7ebf\u7a0b\u8bbf\u95ee\u540c\u4e00\u4e2a\u5bf9\u8c61object\u4e2d\u7684\u8fd9\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u4e00\u4e2a\u65f6\u95f4\u5185\u53ea\u80fd\u6709\u4e00\u4e2a\u7ebf\u7a0b\u5f97\u5230\u6267\u884c\u3002\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5fc5\u987b\u7b49\u5f85\u5f53\u524d\u7ebf\u7a0b\u6267\u884c\u5b8c\u8fd9\u4e2a\u4ee3\u7801\u5757\u4ee5\u540e\u624d\u80fd\u6267\u884c\u8be5\u4ee3\u7801\u5757\u3002
\n \u4e8c\u3001\u7136\u800c\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4ecd\u7136\u53ef\u4ee5\u8bbf\u95ee\u8be5object\u4e2d\u7684\u975esynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u3002
\n \u4e09\u3001\u5c24\u5176\u5173\u952e\u7684\u662f\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5176\u4ed6\u7ebf\u7a0b\u5bf9object\u4e2d\u6240\u6709\u5176\u5b83synchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u7684\u8bbf\u95ee\u5c06\u88ab\u963b\u585e\u3002
\n \u56db\u3001\u7b2c\u4e09\u4e2a\u4f8b\u5b50\u540c\u6837\u9002\u7528\u5176\u5b83\u540c\u6b65\u4ee3\u7801\u5757\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5b83\u5c31\u83b7\u5f97\u4e86\u8fd9\u4e2aobject\u7684\u5bf9\u8c61\u9501\u3002\u7ed3\u679c\uff0c\u5176\u5b83\u7ebf\u7a0b\u5bf9\u8be5object\u5bf9\u8c61\u6240\u6709\u540c\u6b65\u4ee3\u7801\u90e8\u5206\u7684\u8bbf\u95ee\u90fd\u88ab\u6682\u65f6\u963b\u585e\u3002
\n \u4e94\u3001\u4ee5\u4e0a\u89c4\u5219\u5bf9\u5176\u5b83\u5bf9\u8c61\u9501\u540c\u6837\u9002\u7528.
\n\u4e3e\u4f8b\u8bf4\u660e\uff1a
\n \u4e00\u3001\u5f53\u4e24\u4e2a\u5e76\u53d1\u7ebf\u7a0b\u8bbf\u95ee\u540c\u4e00\u4e2a\u5bf9\u8c61object\u4e2d\u7684\u8fd9\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u4e00\u4e2a\u65f6\u95f4\u5185\u53ea\u80fd\u6709\u4e00\u4e2a\u7ebf\u7a0b\u5f97\u5230\u6267\u884c\u3002\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5fc5\u987b\u7b49\u5f85\u5f53\u524d\u7ebf\u7a0b\u6267\u884c\u5b8c\u8fd9\u4e2a\u4ee3\u7801\u5757\u4ee5\u540e\u624d\u80fd\u6267\u884c\u8be5\u4ee3\u7801\u5757\u3002
\n[java]package ths;
\npublic class Thread1 implements Runnable {
\n public void run() {
\n synchronized(this) {
\n for (int i = 0; i < 5; i++) {
\n System.out.println(Thread.currentThread().getName() + " synchronized loop " + i);
\n }
\n }
\n }
\n public static void main(String[] args) {
\n Thread1 t1 = new Thread1();
\n Thread ta = new Thread(t1, "A");
\n Thread tb = new Thread(t1, "B");
\n ta.start();
\n tb.start();
\n }
\n}[\/java]
\n\u7ed3\u679c\uff1a
\n A synchronized loop 0
\n A synchronized loop 1
\n A synchronized loop 2
\n A synchronized loop 3
\n A synchronized loop 4
\n B synchronized loop 0
\n B synchronized loop 1
\n B synchronized loop 2
\n B synchronized loop 3
\n B synchronized loop 4
\n \u4e8c\u3001\u7136\u800c\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4ecd\u7136\u53ef\u4ee5\u8bbf\u95ee\u8be5object\u4e2d\u7684\u975esynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u3002
\n[java]package ths;
\npublic class Thread2 {
\n public void m4t1() {
\n synchronized(this) {
\n int i = 5;
\n while( i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : " + i);
\n try {
\n Thread.sleep(500);
\n } catch (InterruptedException ie) {
\n }
\n }
\n }
\n }
\n public void m4t2() {
\n int i = 5;
\n while( i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : " + i);
\n try {
\n Thread.sleep(500);
\n } catch (InterruptedException ie) {
\n }
\n }
\n }
\n public static void main(String[] args) {
\n final Thread2 myt2 = new Thread2();
\n Thread t1 = new Thread( new Runnable() { public void run() { myt2.m4t1(); } }, "t1" );
\n Thread t2 = new Thread( new Runnable() { public void run() { myt2.m4t2(); } }, "t2" );
\n t1.start();
\n t2.start();
\n }
\n}[\/java]
\n\u7ed3\u679c\uff1a
\n t1 : 4
\n t2 : 4
\n t1 : 3
\n t2 : 3
\n t1 : 2
\n t2 : 2
\n t1 : 1
\n t2 : 1
\n t1 : 0
\n t2 : 0
\n \u4e09\u3001\u5c24\u5176\u5173\u952e\u7684\u662f\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5176\u4ed6\u7ebf\u7a0b\u5bf9object\u4e2d\u6240\u6709\u5176\u5b83synchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u7684\u8bbf\u95ee\u5c06\u88ab\u963b\u585e\u3002
\n \/\/\u4fee\u6539Thread2.m4t2()\u65b9\u6cd5\uff1a
\n [java] public void m4t2() {
\n synchronized(this) {
\n int i = 5;
\n while( i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : " + i);
\n try {
\n Thread.sleep(500);
\n } catch (InterruptedException ie) {
\n }
\n }
\n }
\n }[\/java]
\n\u7ed3\u679c\uff1a
\n t1 : 4
\n t1 : 3
\n t1 : 2
\n t1 : 1
\n t1 : 0
\n t2 : 4
\n t2 : 3
\n t2 : 2
\n t2 : 1
\n t2 : 0
\n \u56db\u3001\u7b2c\u4e09\u4e2a\u4f8b\u5b50\u540c\u6837\u9002\u7528\u5176\u5b83\u540c\u6b65\u4ee3\u7801\u5757\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5b83\u5c31\u83b7\u5f97\u4e86\u8fd9\u4e2aobject\u7684\u5bf9\u8c61\u9501\u3002\u7ed3\u679c\uff0c\u5176\u5b83\u7ebf\u7a0b\u5bf9\u8be5object\u5bf9\u8c61\u6240\u6709\u540c\u6b65\u4ee3\u7801\u90e8\u5206\u7684\u8bbf\u95ee\u90fd\u88ab\u6682\u65f6\u963b\u585e\u3002
\n [java] \/\/\u4fee\u6539Thread2.m4t2()\u65b9\u6cd5\u5982\u4e0b\uff1a
\n public synchronized void m4t2() {
\n int i = 5;
\n while( i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : " + i);
\n try {
\n Thread.sleep(500);
\n } catch (InterruptedException ie) {
\n }
\n }
\n }[\/java]
\n\u7ed3\u679c\uff1a
\n t1 : 4
\n t1 : 3
\n t1 : 2
\n t1 : 1
\n t1 : 0
\n t2 : 4
\n t2 : 3
\n t2 : 2
\n t2 : 1
\n t2 : 0
\n \u4e94\u3001\u4ee5\u4e0a\u89c4\u5219\u5bf9\u5176\u5b83\u5bf9\u8c61\u9501\u540c\u6837\u9002\u7528:
\n[java]package ths;
\npublic class Thread3 {
\n class Inner {
\n private void m4t1() {
\n int i = 5;
\n while(i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : Inner.m4t1()=" + i);
\n try {
\n Thread.sleep(500);
\n } catch(InterruptedException ie) {
\n }
\n }
\n }
\n private void m4t2() {
\n int i = 5;
\n while(i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : Inner.m4t2()=" + i);
\n try {
\n Thread.sleep(500);
\n } catch(InterruptedException ie) {
\n }
\n }
\n }
\n }
\n private void m4t1(Inner inner) {
\n synchronized(inner) { \/\/\u4f7f\u7528\u5bf9\u8c61\u9501
\n inner.m4t1();
\n }
\n private void m4t2(Inner inner) {
\n inner.m4t2();
\n }
\n public static void main(String[] args) {
\n final Thread3 myt3 = new Thread3();
\n final Inner inner = myt3.new Inner();
\n Thread t1 = new Thread( new Runnable() {public void run() { myt3.m4t1(inner);} }, "t1");
\n Thread t2 = new Thread( new Runnable() {public void run() { myt3.m4t2(inner);} }, "t2");
\n t1.start();
\n t2.start();
\n }
\n}[\/java]
\n\u7ed3\u679c\uff1a
\n\u5c3d\u7ba1\u7ebf\u7a0bt1\u83b7\u5f97\u4e86\u5bf9Inner\u7684\u5bf9\u8c61\u9501\uff0c\u4f46\u7531\u4e8e\u7ebf\u7a0bt2\u8bbf\u95ee\u7684\u662f\u540c\u4e00\u4e2aInner\u4e2d\u7684\u975e\u540c\u6b65\u90e8\u5206\u3002\u6240\u4ee5\u4e24\u4e2a\u7ebf\u7a0b\u4e92\u4e0d\u5e72\u6270\u3002
\n t1 : Inner.m4t1()=4
\n t2 : Inner.m4t2()=4
\n t1 : Inner.m4t1()=3
\n t2 : Inner.m4t2()=3
\n t1 : Inner.m4t1()=2
\n t2 : Inner.m4t2()=2
\n t1 : Inner.m4t1()=1
\n t2 : Inner.m4t2()=1
\n t1 : Inner.m4t1()=0
\n t2 : Inner.m4t2()=0
\n\u73b0\u5728\u5728Inner.m4t2()\u524d\u9762\u52a0\u4e0asynchronized\uff1a
\n [java] private synchronized void m4t2() {
\n int i = 5;
\n while(i– > 0) {
\n System.out.println(Thread.currentThread().getName() + " : Inner.m4t2()=" + i);
\n try {
\n Thread.sleep(500);
\n } catch(InterruptedException ie) {
\n }
\n }
\n }[\/java]
\n\u7ed3\u679c\uff1a
\n\u5c3d\u7ba1\u7ebf\u7a0bt1\u4e0et2\u8bbf\u95ee\u4e86\u540c\u4e00\u4e2aInner\u5bf9\u8c61\u4e2d\u4e24\u4e2a\u6beb\u4e0d\u76f8\u5173\u7684\u90e8\u5206,\u4f46\u56e0\u4e3at1\u5148\u83b7\u5f97\u4e86\u5bf9Inner\u7684\u5bf9\u8c61\u9501\uff0c\u6240\u4ee5t2\u5bf9Inner.m4t2()\u7684\u8bbf\u95ee\u4e5f\u88ab\u963b\u585e\uff0c\u56e0\u4e3am4t2()\u662fInner\u4e2d\u7684\u4e00\u4e2a\u540c\u6b65\u65b9\u6cd5\u3002
\n t1 : Inner.m4t1()=4
\n t1 : Inner.m4t1()=3
\n t1 : Inner.m4t1()=2
\n t1 : Inner.m4t1()=1
\n t1 : Inner.m4t1()=0
\n t2 : Inner.m4t2()=4
\n t2 : Inner.m4t2()=3
\n t2 : Inner.m4t2()=2
\n t2 : Inner.m4t2()=1
\n t2 : Inner.m4t2()=0
\n\u7b2c\u4e8c\u7bc7\uff1a<\/p>\n
synchronized \u5173\u952e\u5b57\uff0c\u5b83\u5305\u62ec\u4e24\u79cd\u7528\u6cd5\uff1asynchronized \u65b9\u6cd5\u548c synchronized \u5757\u3002
\n1. synchronized \u65b9\u6cd5\uff1a\u901a\u8fc7\u5728\u65b9\u6cd5\u58f0\u660e\u4e2d\u52a0\u5165 synchronized\u5173\u952e\u5b57\u6765\u58f0\u660e synchronized \u65b9\u6cd5\u3002\u5982\uff1a
\npublic synchronized void accessVal(int newVal);
\nsynchronized \u65b9\u6cd5\u63a7\u5236\u5bf9\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u8bbf\u95ee\uff1a\u6bcf\u4e2a\u7c7b\u5b9e\u4f8b\u5bf9\u5e94\u4e00\u628a\u9501\uff0c\u6bcf\u4e2a synchronized \u65b9\u6cd5\u90fd\u5fc5\u987b\u83b7\u5f97\u8c03\u7528\u8be5\u65b9\u6cd5\u7684\u7c7b\u5b9e\u4f8b\u7684\u9501\u65b9\u80fd
\n\u6267\u884c\uff0c\u5426\u5219\u6240\u5c5e\u7ebf\u7a0b\u963b\u585e\uff0c\u65b9\u6cd5\u4e00\u65e6\u6267\u884c\uff0c\u5c31\u72ec\u5360\u8be5\u9501\uff0c\u76f4\u5230\u4ece\u8be5\u65b9\u6cd5\u8fd4\u56de\u65f6\u624d\u5c06\u9501\u91ca\u653e\uff0c\u6b64\u540e\u88ab\u963b\u585e\u7684\u7ebf\u7a0b\u65b9\u80fd\u83b7\u5f97\u8be5\u9501\uff0c\u91cd\u65b0\u8fdb\u5165\u53ef\u6267\u884c
\n\u72b6\u6001\u3002\u8fd9\u79cd\u673a\u5236\u786e\u4fdd\u4e86\u540c\u4e00\u65f6\u523b\u5bf9\u4e8e\u6bcf\u4e00\u4e2a\u7c7b\u5b9e\u4f8b\uff0c\u5176\u6240\u6709\u58f0\u660e\u4e3a synchronized \u7684\u6210\u5458\u51fd\u6570\u4e2d\u81f3\u591a\u53ea\u6709\u4e00\u4e2a\u5904\u4e8e\u53ef\u6267\u884c\u72b6\u6001\uff08\u56e0\u4e3a\u81f3\u591a\u53ea\u6709
\n\u4e00\u4e2a\u80fd\u591f\u83b7\u5f97\u8be5\u7c7b\u5b9e\u4f8b\u5bf9\u5e94\u7684\u9501\uff09\uff0c\u4ece\u800c\u6709\u6548\u907f\u514d\u4e86\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u8bbf\u95ee\u51b2\u7a81\uff08\u53ea\u8981\u6240\u6709\u53ef\u80fd\u8bbf\u95ee\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u65b9\u6cd5\u5747\u88ab\u58f0\u660e\u4e3a synchronized\uff09
\n\u3002
\n\u5728 Java \u4e2d\uff0c\u4e0d\u5149\u662f\u7c7b\u5b9e\u4f8b\uff0c\u6bcf\u4e00\u4e2a\u7c7b\u4e5f\u5bf9\u5e94\u4e00\u628a\u9501\uff0c\u8fd9\u6837\u6211\u4eec\u4e5f\u53ef\u5c06\u7c7b\u7684\u9759\u6001\u6210\u5458\u51fd\u6570\u58f0\u660e\u4e3a synchronized \uff0c\u4ee5\u63a7\u5236\u5176\u5bf9\u7c7b\u7684\u9759\u6001\u6210
\n\u5458\u53d8\u91cf\u7684\u8bbf\u95ee\u3002
\nsynchronized \u65b9\u6cd5\u7684\u7f3a\u9677\uff1a\u82e5\u5c06\u4e00\u4e2a\u5927\u7684\u65b9\u6cd5\u58f0\u660e\u4e3asynchronized \u5c06\u4f1a\u5927\u5927\u5f71\u54cd\u6548\u7387\uff0c\u5178\u578b\u5730\uff0c\u82e5\u5c06\u7ebf\u7a0b\u7c7b\u7684\u65b9\u6cd5 run() \u58f0\u660e\u4e3a
\nsynchronized \uff0c\u7531\u4e8e\u5728\u7ebf\u7a0b\u7684\u6574\u4e2a\u751f\u547d\u671f\u5185\u5b83\u4e00\u76f4\u5728\u8fd0\u884c\uff0c\u56e0\u6b64\u5c06\u5bfc\u81f4\u5b83\u5bf9\u672c\u7c7b\u4efb\u4f55 synchronized \u65b9\u6cd5\u7684\u8c03\u7528\u90fd\u6c38\u8fdc\u4e0d\u4f1a\u6210\u529f\u3002\u5f53\u7136\u6211\u4eec\u53ef
\n\u4ee5\u901a\u8fc7\u5c06\u8bbf\u95ee\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u4ee3\u7801\u653e\u5230\u4e13\u95e8\u7684\u65b9\u6cd5\u4e2d\uff0c\u5c06\u5176\u58f0\u660e\u4e3a synchronized \uff0c\u5e76\u5728\u4e3b\u65b9\u6cd5\u4e2d\u8c03\u7528\u6765\u89e3\u51b3\u8fd9\u4e00\u95ee\u9898\uff0c\u4f46\u662f Java \u4e3a\u6211\u4eec\u63d0\u4f9b
\n\u4e86\u66f4\u597d\u7684\u89e3\u51b3\u529e\u6cd5\uff0c\u90a3\u5c31\u662f synchronized \u5757\u3002
\n2. synchronized \u5757\uff1a\u901a\u8fc7 synchronized\u5173\u952e\u5b57\u6765\u58f0\u660esynchronized \u5757\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a
\nsynchronized(syncObject) {
\n\/\/\u5141\u8bb8\u8bbf\u95ee\u63a7\u5236\u7684\u4ee3\u7801
\n}
\nsynchronized \u5757\u662f\u8fd9\u6837\u4e00\u4e2a\u4ee3\u7801\u5757\uff0c\u5176\u4e2d\u7684\u4ee3\u7801\u5fc5\u987b\u83b7\u5f97\u5bf9\u8c61 syncObject \uff08\u5982\u524d\u6240\u8ff0\uff0c\u53ef\u4ee5\u662f\u7c7b\u5b9e\u4f8b\u6216\u7c7b\uff09\u7684\u9501\u65b9\u80fd\u6267\u884c\uff0c\u5177\u4f53\u673a
\n\u5236\u540c\u524d\u6240\u8ff0\u3002\u7531\u4e8e\u53ef\u4ee5\u9488\u5bf9\u4efb\u610f\u4ee3\u7801\u5757\uff0c\u4e14\u53ef\u4efb\u610f\u6307\u5b9a\u4e0a\u9501\u7684\u5bf9\u8c61\uff0c\u6545\u7075\u6d3b\u6027\u8f83\u9ad8\u3002
\n\u5bf9synchronized(this)\u7684\u4e00\u4e9b\u7406\u89e3
\n\u4e00\u3001\u5f53\u4e24\u4e2a\u5e76\u53d1\u7ebf\u7a0b\u8bbf\u95ee\u540c\u4e00\u4e2a\u5bf9\u8c61object\u4e2d\u7684\u8fd9\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u4e00\u4e2a\u65f6\u95f4\u5185\u53ea\u80fd\u6709\u4e00\u4e2a\u7ebf\u7a0b\u5f97\u5230\u6267\u884c\u3002\u53e6\u4e00\u4e2a\u7ebf
\n\u7a0b\u5fc5\u987b\u7b49\u5f85\u5f53\u524d\u7ebf\u7a0b\u6267\u884c\u5b8c\u8fd9\u4e2a\u4ee3\u7801\u5757\u4ee5\u540e\u624d\u80fd\u6267\u884c\u8be5\u4ee3\u7801\u5757\u3002
\n\u4e8c\u3001\u7136\u800c\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4ecd\u7136\u53ef\u4ee5\u8bbf\u95ee\u8be5object\u4e2d\u7684\u975esynchronized
\n(this)\u540c\u6b65\u4ee3\u7801\u5757\u3002
\n\u4e09\u3001\u5c24\u5176\u5173\u952e\u7684\u662f\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5176\u4ed6\u7ebf\u7a0b\u5bf9object\u4e2d\u6240\u6709\u5176\u5b83synchronized(this)
\n\u540c\u6b65\u4ee3\u7801\u5757\u7684\u8bbf\u95ee\u5c06\u88ab\u963b\u585e\u3002
\n\u56db\u3001\u7b2c\u4e09\u4e2a\u4f8b\u5b50\u540c\u6837\u9002\u7528\u5176\u5b83\u540c\u6b65\u4ee3\u7801\u5757\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95eeobject\u7684\u4e00\u4e2asynchronized(this)\u540c\u6b65\u4ee3\u7801\u5757\u65f6\uff0c\u5b83\u5c31\u83b7\u5f97\u4e86\u8fd9\u4e2a
\nobject\u7684\u5bf9\u8c61\u9501\u3002\u7ed3\u679c\uff0c\u5176\u5b83\u7ebf\u7a0b\u5bf9\u8be5object\u5bf9\u8c61\u6240\u6709\u540c\u6b65\u4ee3\u7801\u90e8\u5206\u7684\u8bbf\u95ee\u90fd\u88ab\u6682\u65f6\u963b\u585e\u3002
\n\u4e94\u3001\u4ee5\u4e0a\u89c4\u5219\u5bf9\u5176\u5b83\u5bf9\u8c61\u9501\u540c\u6837\u9002\u7528
\nhttp:\/\/hi.baidu.com\/sunshibing\/blog\/item\/5235b9b731d48ff430add14a.html
\njava\u4e2dsynchronized\u7528\u6cd5
\n\u6253\u4e2a\u6bd4\u65b9\uff1a\u4e00\u4e2aobject\u5c31\u50cf\u4e00\u4e2a\u5927\u623f\u5b50\uff0c\u5927\u95e8\u6c38\u8fdc\u6253\u5f00\u3002\u623f\u5b50\u91cc\u6709 \u5f88\u591a\u623f\u95f4\uff08\u4e5f\u5c31\u662f\u65b9\u6cd5\uff09\u3002
\n\u8fd9\u4e9b\u623f\u95f4\u6709\u4e0a\u9501\u7684\uff08synchronized\u65b9\u6cd5\uff09\uff0c \u548c\u4e0d\u4e0a\u9501\u4e4b\u5206\uff08\u666e\u901a\u65b9\u6cd5\uff09\u3002\u623f\u95e8\u53e3\u653e\u7740\u4e00\u628a\u94a5\u5319\uff08key\uff09\uff0c\u8fd9\u628a\u94a5\u5319\u53ef\u4ee5\u6253\u5f00\u6240\u6709\u4e0a\u9501\u7684\u623f\u95f4\u3002
\n\u53e6\u5916\u6211\u628a\u6240\u6709\u60f3\u8c03\u7528\u8be5\u5bf9\u8c61\u65b9\u6cd5\u7684\u7ebf\u7a0b\u6bd4\u55bb\u6210\u60f3\u8fdb\u5165\u8fd9\u623f\u5b50\u67d0\u4e2a \u623f\u95f4\u7684\u4eba\u3002\u6240\u6709\u7684\u4e1c\u897f\u5c31\u8fd9\u4e48\u591a\u4e86\uff0c\u4e0b\u9762\u6211\u4eec\u770b\u770b\u8fd9\u4e9b\u4e1c\u897f\u4e4b\u95f4\u5982\u4f55\u4f5c\u7528\u7684\u3002
\n\u5728\u6b64\u6211\u4eec\u5148\u6765\u660e\u786e\u4e00\u4e0b\u6211\u4eec\u7684\u524d\u63d0\u6761\u4ef6\u3002\u8be5\u5bf9\u8c61\u81f3\u5c11\u6709\u4e00\u4e2asynchronized\u65b9\u6cd5\uff0c\u5426\u5219\u8fd9\u4e2akey\u8fd8\u6709\u5565\u610f\u4e49\u3002\u5f53\u7136\u4e5f\u5c31\u4e0d\u4f1a\u6709\u6211\u4eec\u7684\u8fd9\u4e2a\u4e3b\u9898\u4e86\u3002
\n\u4e00\u4e2a\u4eba\u60f3\u8fdb\u5165\u67d0\u95f4\u4e0a\u4e86\u9501\u7684\u623f\u95f4\uff0c\u4ed6\u6765\u5230\u623f\u5b50\u95e8\u53e3\uff0c\u770b\u89c1\u94a5\u5319\u5728\u90a3\u513f\uff08\u8bf4\u660e\u6682\u65f6\u8fd8\u6ca1\u6709\u5176\u4ed6\u4eba\u8981\u4f7f\u7528\u4e0a\u9501\u7684 \u623f\u95f4\uff09\u3002\u4e8e\u662f\u4ed6\u8d70\u4e0a\u53bb\u62ff\u5230\u4e86\u94a5\u5319
\n\uff0c\u5e76\u4e14\u6309\u7167\u81ea\u5df1 \u7684\u8ba1\u5212\u4f7f\u7528\u90a3\u4e9b\u623f\u95f4\u3002\u6ce8\u610f\u4e00\u70b9\uff0c\u4ed6\u6bcf\u6b21\u4f7f\u7528\u5b8c\u4e00\u6b21\u4e0a\u9501\u7684\u623f\u95f4\u540e\u4f1a\u9a6c\u4e0a\u628a\u94a5\u5319\u8fd8\u56de\u53bb\u3002\u5373\u4f7f\u4ed6\u8981\u8fde\u7eed\u4f7f\u7528\u4e24\u95f4\u4e0a\u9501\u7684\u623f\u95f4\uff0c
\n\u4e2d\u95f4\u4ed6\u4e5f\u8981\u628a\u94a5\u5319\u8fd8\u56de\u53bb\uff0c\u518d\u53d6\u56de\u6765\u3002
\n\u56e0\u6b64\uff0c\u666e\u901a\u60c5\u51b5\u4e0b\u94a5\u5319\u7684\u4f7f\u7528\u539f\u5219\u662f\uff1a\u201c\u968f\u7528\u968f\u501f\uff0c\u7528\u5b8c\u5373\u8fd8\u3002\u201d
\n\u8fd9\u65f6\u5176\u4ed6\u4eba\u53ef\u4ee5\u4e0d\u53d7\u9650\u5236\u7684\u4f7f\u7528\u90a3\u4e9b\u4e0d\u4e0a\u9501\u7684\u623f\u95f4\uff0c\u4e00\u4e2a\u4eba\u7528\u4e00\u95f4\u53ef\u4ee5\uff0c\u4e24\u4e2a\u4eba\u7528\u4e00\u95f4\u4e5f\u53ef\u4ee5\uff0c\u6ca1\u9650\u5236\u3002\u4f46\u662f\u5982\u679c\u5f53\u67d0\u4e2a\u4eba\u60f3\u8981\u8fdb\u5165\u4e0a\u9501\u7684\u623f
\n\u95f4\uff0c\u4ed6\u5c31\u8981\u8dd1\u5230\u5927\u95e8\u53e3\u53bb\u770b\u770b\u4e86\u3002\u6709\u94a5\u5319\u5f53\u7136\u62ff\u4e86\u5c31\u8d70\uff0c\u6ca1\u6709\u7684\u8bdd\uff0c\u5c31\u53ea\u80fd\u7b49\u4e86\u3002
\n\u8981\u662f\u5f88\u591a\u4eba\u5728\u7b49\u8fd9\u628a\u94a5\u5319\uff0c\u7b49\u94a5\u5319\u8fd8\u56de\u6765\u4ee5\u540e\uff0c\u8c01\u4f1a\u4f18\u5148\u5f97\u5230\u94a5\u5319\uff1fNot guaranteed\u3002\u8c61\u524d\u9762\u4f8b\u5b50\u91cc\u90a3\u4e2a\u60f3\u8fde\u7eed\u4f7f\u7528\u4e24\u4e2a\u4e0a\u9501\u623f\u95f4\u7684\u5bb6\u4f19\uff0c\u4ed6
\n\u4e2d\u95f4\u8fd8\u94a5\u5319\u7684\u65f6\u5019\u5982\u679c\u8fd8\u6709\u5176\u4ed6\u4eba\u5728\u7b49\u94a5\u5319\uff0c\u90a3\u4e48\u6ca1\u6709\u4efb\u4f55\u4fdd\u8bc1\u8fd9\u5bb6\u4f19\u80fd\u518d\u6b21\u62ff\u5230\u3002 \uff08JAVA\u89c4\u8303\u5728\u5f88\u591a\u5730\u65b9\u90fd\u660e\u786e\u8bf4\u660e\u4e0d\u4fdd\u8bc1\uff0c\u8c61
\nThread.sleep()\u4f11\u606f\u540e\u591a\u4e45\u4f1a\u8fd4\u56de\u8fd0\u884c\uff0c\u76f8\u540c\u4f18\u5148\u6743\u7684\u7ebf\u7a0b\u90a3\u4e2a\u9996\u5148\u88ab\u6267\u884c\uff0c\u5f53\u8981\u8bbf\u95ee\u5bf9\u8c61\u7684\u9501\u88ab \u91ca\u653e\u540e\u5904\u4e8e\u7b49\u5f85\u6c60\u7684\u591a\u4e2a\u7ebf\u7a0b\u54ea\u4e2a\u4f1a\u4f18\u5148\u5f97
\n\u5230\uff0c\u7b49\u7b49\u3002\u6211\u60f3\u6700\u7ec8\u7684\u51b3\u5b9a\u6743\u662f\u5728JVM\uff0c\u4e4b\u6240\u4ee5\u4e0d\u4fdd\u8bc1\uff0c\u5c31\u662f\u56e0\u4e3aJVM\u5728\u505a\u51fa\u4e0a\u8ff0\u51b3\u5b9a\u7684\u65f6\u5019\uff0c\u7edd\u4e0d\u662f\u7b80\u7b80\u5355\u5355\u6839\u636e \u4e00\u4e2a\u6761\u4ef6\u6765\u505a\u51fa\u5224\u65ad\uff0c\u800c\u662f
\n\u6839\u636e\u5f88\u591a\u6761\u3002\u800c\u7531\u4e8e\u5224\u65ad\u6761\u4ef6\u592a\u591a\uff0c\u5982\u679c\u8bf4\u51fa\u6765\u53ef\u80fd\u4f1a\u5f71\u54cdJAVA\u7684\u63a8\u5e7f\uff0c\u4e5f\u53ef\u80fd\u662f\u56e0\u4e3a\u77e5\u8bc6\u4ea7\u6743\u4fdd\u62a4\u7684\u539f\u56e0\u5427\u3002SUN\u7ed9\u4e86\u4e2a\u4e0d\u4fdd\u8bc1 \u5c31\u6df7\u8fc7\u53bb\u4e86
\n\u3002\u65e0\u53ef\u539a\u975e\u3002\u4f46\u6211\u76f8\u4fe1\u8fd9\u4e9b\u4e0d\u786e\u5b9a\uff0c\u5e76\u975e\u5b8c\u5168\u4e0d\u786e\u5b9a\u3002\u56e0\u4e3a\u8ba1\u7b97\u673a\u8fd9\u4e1c\u897f\u672c\u8eab\u5c31\u662f\u6309\u6307\u4ee4\u8fd0\u884c\u7684\u3002\u5373\u4f7f\u770b\u8d77\u6765\u5f88\u968f\u673a\u7684\u73b0\u8c61\uff0c\u5176\u5b9e\u90fd\u662f\u6709\u89c4\u5f8b
\n\u53ef\u5bfb\u3002\u5b66\u8fc7 \u8ba1\u7b97\u673a\u7684\u90fd\u77e5\u9053\uff0c\u8ba1\u7b97\u673a\u91cc\u968f\u673a\u6570\u7684\u5b66\u540d\u662f\u4f2a\u968f\u673a\u6570\uff0c\u662f\u4eba\u8fd0\u7528\u4e00\u5b9a\u7684\u65b9\u6cd5\u5199\u51fa\u6765\u7684\uff0c\u770b\u4e0a\u53bb\u968f\u673a\u7f62\u4e86\u3002\u53e6\u5916\uff0c\u6216\u8bb8\u662f\u56e0\u4e3a\u8981\u60f3\u5f04
\n\u7684\u786e\u5b9a\u592a\u8d39\u4e8b\uff0c\u4e5f\u6ca1\u591a\u5927\u610f\u4e49\uff0c\u6240 \u4ee5\u4e0d\u786e\u5b9a\u5c31\u4e0d\u786e\u5b9a\u4e86\u5427\u3002\uff09
\n\u518d\u6765\u770b\u770b\u540c\u6b65\u4ee3\u7801\u5757\u3002\u548c\u540c\u6b65\u65b9\u6cd5\u6709\u5c0f\u5c0f\u7684\u4e0d\u540c\u3002
\n1.\u4ece\u5c3a\u5bf8\u4e0a\u8bb2\uff0c\u540c\u6b65\u4ee3\u7801\u5757\u6bd4\u540c\u6b65\u65b9\u6cd5\u5c0f\u3002\u4f60\u53ef\u4ee5\u628a\u540c\u6b65\u4ee3\u7801\u5757\u770b\u6210\u662f\u6ca1\u4e0a\u9501\u623f\u95f4\u91cc\u7684\u4e00\u5757\u7528\u5e26\u9501\u7684\u5c4f\u98ce\u9694\u5f00\u7684\u7a7a\u95f4\u3002
\n2.\u540c\u6b65\u4ee3\u7801\u5757\u8fd8\u53ef\u4ee5\u4eba\u4e3a\u7684\u6307\u5b9a\u83b7\u5f97\u67d0\u4e2a\u5176\u5b83\u5bf9\u8c61\u7684key\u3002\u5c31\u50cf\u662f\u6307\u5b9a\u7528\u54ea\u4e00\u628a\u94a5\u5319\u624d\u80fd\u5f00\u8fd9\u4e2a\u5c4f\u98ce\u7684\u9501\uff0c\u4f60\u53ef\u4ee5\u7528\u672c\u623f\u7684\u94a5\u5319\uff1b\u4f60\u4e5f\u53ef\u4ee5\u6307\u5b9a
\n\u7528\u53e6\u4e00\u4e2a\u623f\u5b50\u7684\u94a5\u5319\u624d\u80fd\u5f00\uff0c\u8fd9\u6837\u7684\u8bdd\uff0c\u4f60\u8981\u8dd1\u5230\u53e6\u4e00\u680b\u623f\u5b50\u90a3\u513f\u628a\u90a3\u4e2a\u94a5\u5319\u62ff\u6765\uff0c\u5e76\u7528\u90a3\u4e2a\u623f\u5b50\u7684\u94a5\u5319\u6765\u6253\u5f00\u8fd9\u4e2a\u623f\u5b50\u7684\u5e26\u9501\u7684\u5c4f\u98ce\u3002
\n \u8bb0\u4f4f\u4f60\u83b7\u5f97\u7684\u90a3\u53e6\u4e00\u680b\u623f\u5b50\u7684\u94a5\u5319\uff0c\u5e76\u4e0d\u5f71\u54cd\u5176\u4ed6\u4eba\u8fdb\u5165\u90a3\u680b\u623f\u5b50\u6ca1\u6709\u9501\u7684\u623f\u95f4\u3002
\n \u4e3a\u4ec0\u4e48\u8981\u4f7f\u7528\u540c\u6b65\u4ee3\u7801\u5757\u5462\uff1f\u6211\u60f3\u5e94\u8be5\u662f\u8fd9\u6837\u7684\uff1a\u9996\u5148\u5bf9\u7a0b\u5e8f\u6765\u8bb2\u540c\u6b65\u7684\u90e8\u5206\u5f88\u5f71\u54cd\u8fd0\u884c\u6548\u7387\uff0c\u800c\u4e00\u4e2a\u65b9\u6cd5\u901a\u5e38\u662f\u5148\u521b\u5efa\u4e00\u4e9b\u5c40\u90e8\u53d8
\n\u91cf\uff0c\u518d\u5bf9\u8fd9\u4e9b\u53d8\u91cf\u505a\u4e00\u4e9b \u64cd\u4f5c\uff0c\u5982\u8fd0\u7b97\uff0c\u663e\u793a\u7b49\u7b49\uff1b\u800c\u540c\u6b65\u6240\u8986\u76d6\u7684\u4ee3\u7801\u8d8a\u591a\uff0c\u5bf9\u6548\u7387\u7684\u5f71\u54cd\u5c31\u8d8a\u4e25\u91cd\u3002\u56e0\u6b64\u6211\u4eec\u901a\u5e38\u5c3d\u91cf\u7f29\u5c0f\u5176\u5f71\u54cd\u8303\u56f4\u3002
\n\u5982\u4f55\u505a\uff1f\u540c\u6b65\u4ee3\u7801\u5757\u3002\u6211\u4eec\u53ea\u628a\u4e00\u4e2a\u65b9\u6cd5\u4e2d\u8be5\u540c \u6b65\u7684\u5730\u65b9\u540c\u6b65\uff0c\u6bd4\u5982\u8fd0\u7b97\u3002
\n \u53e6\u5916\uff0c\u540c\u6b65\u4ee3\u7801\u5757\u53ef\u4ee5\u6307\u5b9a\u94a5\u5319\u8fd9\u4e00\u7279\u70b9\u6709\u4e2a\u989d\u5916\u7684\u597d\u5904\uff0c\u662f\u53ef\u4ee5\u5728\u4e00\u5b9a\u65f6\u671f\u5185\u9738\u5360\u67d0\u4e2a\u5bf9\u8c61\u7684key\u3002\u8fd8\u8bb0\u5f97\u524d\u9762\u8bf4\u8fc7\u666e\u901a\u60c5\u51b5\u4e0b\u94a5
\n\u5319\u7684\u4f7f\u7528\u539f\u5219\u5417\u3002\u73b0\u5728\u4e0d\u662f\u666e\u901a\u60c5\u51b5\u4e86\u3002\u4f60\u6240\u53d6\u5f97\u7684\u90a3\u628a\u94a5\u5319\u4e0d\u662f\u6c38\u8fdc\u4e0d\u8fd8\uff0c\u800c\u662f\u5728\u9000\u51fa\u540c\u6b65\u4ee3\u7801\u5757\u65f6\u624d\u8fd8\u3002
\n \u8fd8\u7528\u524d\u9762\u90a3\u4e2a\u60f3\u8fde\u7eed\u7528\u4e24\u4e2a\u4e0a\u9501\u623f\u95f4\u7684\u5bb6\u4f19\u6253\u6bd4\u65b9\u3002\u600e\u6837\u624d\u80fd\u5728\u7528\u5b8c\u4e00\u95f4\u4ee5\u540e\uff0c\u7ee7\u7eed\u4f7f\u7528\u53e6\u4e00\u95f4\u5462\u3002\u7528\u540c\u6b65\u4ee3\u7801\u5757\u5427\u3002\u5148\u521b\u5efa\u53e6\u5916
\n\u4e00\u4e2a\u7ebf\u7a0b\uff0c\u505a\u4e00\u4e2a\u540c\u6b65\u4ee3\u7801 \u5757\uff0c\u628a\u90a3\u4e2a\u4ee3\u7801\u5757\u7684\u9501\u6307\u5411\u8fd9\u4e2a\u623f\u5b50\u7684\u94a5\u5319\u3002\u7136\u540e\u542f\u52a8\u90a3\u4e2a\u7ebf\u7a0b\u3002\u53ea\u8981\u4f60\u80fd\u5728\u8fdb\u5165\u90a3\u4e2a\u4ee3\u7801\u5757\u65f6\u6293\u5230\u8fd9\u623f\u5b50\u7684\u94a5\u5319
\n\uff0c\u4f60\u5c31\u53ef\u4ee5\u4e00\u76f4\u4fdd\u7559\u5230\u9000\u51fa\u90a3\u4e2a\u4ee3\u7801\u5757\u3002\u4e5f\u5c31\u662f\u8bf4 \u4f60\u751a\u81f3\u53ef\u4ee5\u5bf9\u672c\u623f\u5185\u6240\u6709\u4e0a\u9501\u7684\u623f\u95f4\u904d\u5386\uff0c\u751a\u81f3\u518dsleep(10*60*1000)\uff0c\u800c\u623f\u95e8\u53e3\u5374\u8fd8\u6709
\n1000\u4e2a\u7ebf\u7a0b\u5728\u7b49\u8fd9\u628a\u94a5\u5319\u5462\u3002\u5f88\u8fc7\u763e\u5427\u3002
\n \u5728\u6b64\u5bf9sleep()\u65b9\u6cd5\u548c\u94a5\u5319\u7684\u5173\u8054\u6027\u8bb2\u4e00\u4e0b\u3002\u4e00\u4e2a\u7ebf\u7a0b\u5728\u62ff\u5230key\u540e\uff0c\u4e14\u6ca1\u6709\u5b8c\u6210\u540c\u6b65\u7684\u5185\u5bb9\u65f6\uff0c\u5982\u679c\u88ab\u5f3a\u5236sleep()\u4e86\uff0c\u90a3key\u8fd8\u4e00
\n\u76f4\u5728 \u5b83\u90a3\u513f\u3002\u76f4\u5230\u5b83\u518d\u6b21\u8fd0\u884c\uff0c\u505a\u5b8c\u6240\u6709\u540c\u6b65\u5185\u5bb9\uff0c\u624d\u4f1a\u5f52\u8fd8key\u3002\u8bb0\u4f4f\uff0c\u90a3\u5bb6\u4f19\u53ea\u662f\u5e72\u6d3b\u5e72\u7d2f\u4e86\uff0c\u53bb\u4f11\u606f\u4e00\u4e0b\uff0c\u4ed6\u5e76\u6ca1\u5e72\u5b8c\u4ed6\u8981\u5e72\u7684\u4e8b\u3002\u4e3a
\n\u4e86\u907f\u514d\u522b\u4eba\u8fdb\u5165\u90a3\u4e2a\u623f\u95f4 \u628a\u91cc\u9762\u641e\u7684\u4e00\u56e2\u7cdf\uff0c\u5373\u4f7f\u5728\u7761\u89c9\u7684\u65f6\u5019\u4ed6\u4e5f\u8981\u628a\u90a3\u552f\u4e00\u7684\u94a5\u5319\u6234\u5728\u8eab\u4e0a\u3002
\n \u6700\u540e\uff0c\u4e5f\u8bb8\u6709\u4eba\u4f1a\u95ee\uff0c\u4e3a\u4ec0\u4e48\u8981\u4e00\u628a\u94a5\u5319\u901a\u5f00\uff0c\u800c\u4e0d\u662f\u4e00\u4e2a\u94a5\u5319\u4e00\u4e2a\u95e8\u5462\uff1f\u6211\u60f3\u8fd9\u7eaf\u7cb9\u662f\u56e0\u4e3a\u590d\u6742\u6027\u95ee\u9898\u3002\u4e00\u4e2a\u94a5\u5319\u4e00\u4e2a\u95e8\u5f53\u7136\u66f4
\n\u5b89\u5168\uff0c\u4f46\u662f\u4f1a\u7275\u626f\u597d\u591a\u95ee\u9898\u3002\u94a5\u5319 \u7684\u4ea7\u751f\uff0c\u4fdd\u7ba1\uff0c\u83b7\u5f97\uff0c\u5f52\u8fd8\u7b49\u7b49\u3002\u5176\u590d\u6742\u6027\u6709\u53ef\u80fd\u968f\u540c\u6b65\u65b9\u6cd5\u7684\u589e\u52a0\u5448\u51e0\u4f55\u7ea7\u6570\u589e\u52a0\uff0c\u4e25\u91cd\u5f71\u54cd\u6548\u7387\u3002\u8fd9\u4e5f
\n\u7b97\u662f\u4e00\u4e2a\u6743\u8861\u7684\u95ee\u9898\u5427\u3002\u4e3a\u4e86\u589e\u52a0\u4e00\u70b9\u70b9\u5b89\u5168\u6027\uff0c\u5bfc\u81f4\u6548 \u7387\u5927\u5927\u964d\u4f4e\uff0c\u662f\u591a\u4e48\u4e0d\u53ef\u53d6\u554a\u3002
\nsynchronized\u7684\u4e00\u4e2a\u7b80\u5355\u4f8b\u5b50
\n[java]public class TextThread {
\npublic static void main(String[] args) {
\n TxtThread tt = new TxtThread();
\n new Thread(tt).start();
\n new Thread(tt).start();
\n new Thread(tt).start();
\n new Thread(tt).start();
\n}
\n}
\nclass TxtThread implements Runnable {
\nint num = 100;
\nString str = new String();
\npublic void run() {
\n synchronized (str) {
\n while (num > 0) {
\n try {
\n Thread.sleep(1);
\n } catch (Exception e) {
\n e.getMessage();
\n }
\n System.out.println(Thread.currentThread().getName()
\n + "this is " + num–);
\n }
\n }
\n}
\n}[\/java]
\n\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\u4e3a\u4e86\u5236\u9020\u4e00\u4e2a\u65f6\u95f4\u5dee,\u4e5f\u5c31\u662f\u51fa\u9519\u7684\u673a\u4f1a,\u4f7f\u7528\u4e86Thread.sleep(10)
\nJava\u5bf9\u591a\u7ebf\u7a0b\u7684\u652f\u6301\u4e0e\u540c\u6b65\u673a\u5236\u6df1\u53d7\u5927\u5bb6\u7684\u559c\u7231\uff0c\u4f3c\u4e4e\u770b\u8d77\u6765\u4f7f\u7528\u4e86synchronized\u5173\u952e\u5b57\u5c31\u53ef\u4ee5\u8f7b\u677e\u5730\u89e3\u51b3\u591a\u7ebf\u7a0b\u5171\u4eab\u6570\u636e\u540c\u6b65\u95ee\u9898\u3002\u5230\u5e95\u5982
\n\u4f55\uff1f\u2015\u2015\u8fd8\u5f97\u5bf9synchronized\u5173\u952e\u5b57\u7684\u4f5c\u7528\u8fdb\u884c\u6df1\u5165\u4e86\u89e3\u624d\u53ef\u5b9a\u8bba\u3002
\n\u603b\u7684\u8bf4\u6765\uff0csynchronized\u5173\u952e\u5b57\u53ef\u4ee5\u4f5c\u4e3a\u51fd\u6570\u7684\u4fee\u9970\u7b26\uff0c\u4e5f\u53ef\u4f5c\u4e3a\u51fd\u6570\u5185\u7684\u8bed\u53e5\uff0c\u4e5f\u5c31\u662f\u5e73\u65f6\u8bf4\u7684\u540c\u6b65\u65b9\u6cd5\u548c\u540c\u6b65\u8bed\u53e5\u5757\u3002\u5982\u679c\u518d\u7ec6\u7684\u5206\u7c7b\uff0c
\nsynchronized\u53ef\u4f5c\u7528\u4e8einstance\u53d8\u91cf\u3001object reference\uff08\u5bf9\u8c61\u5f15\u7528\uff09\u3001static\u51fd\u6570\u548cclass literals(\u7c7b\u540d\u79f0\u5b57\u9762\u5e38\u91cf)\u8eab\u4e0a\u3002
\n\u5728\u8fdb\u4e00\u6b65\u9610\u8ff0\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u660e\u786e\u51e0\u70b9\uff1a
\nA\uff0e\u65e0\u8bbasynchronized\u5173\u952e\u5b57\u52a0\u5728\u65b9\u6cd5\u4e0a\u8fd8\u662f\u5bf9\u8c61\u4e0a\uff0c\u5b83\u53d6\u5f97\u7684\u9501\u90fd\u662f\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f\u628a\u4e00\u6bb5\u4ee3\u7801\u6216\u51fd\u6570\u5f53\u4f5c\u9501\u2015\u2015\u800c\u4e14\u540c\u6b65\u65b9\u6cd5\u5f88\u53ef\u80fd\u8fd8\u4f1a\u88ab\u5176
\n\u4ed6\u7ebf\u7a0b\u7684\u5bf9\u8c61\u8bbf\u95ee\u3002
\nB\uff0e\u6bcf\u4e2a\u5bf9\u8c61\u53ea\u6709\u4e00\u4e2a\u9501\uff08lock\uff09\u4e0e\u4e4b\u76f8\u5173\u8054\u3002
\nC\uff0e\u5b9e\u73b0\u540c\u6b65\u662f\u8981\u5f88\u5927\u7684\u7cfb\u7edf\u5f00\u9500\u4f5c\u4e3a\u4ee3\u4ef7\u7684\uff0c\u751a\u81f3\u53ef\u80fd\u9020\u6210\u6b7b\u9501\uff0c\u6240\u4ee5\u5c3d\u91cf\u907f\u514d\u65e0\u8c13\u7684\u540c\u6b65\u63a7\u5236\u3002
\n\u63a5\u7740\u6765\u8ba8\u8bbasynchronized\u7528\u5230\u4e0d\u540c\u5730\u65b9\u5bf9\u4ee3\u7801\u4ea7\u751f\u7684\u5f71\u54cd\uff1a
\n\u5047\u8bbeP1\u3001P2\u662f\u540c\u4e00\u4e2a\u7c7b\u7684\u4e0d\u540c\u5bf9\u8c61\uff0c\u8fd9\u4e2a\u7c7b\u4e2d\u5b9a\u4e49\u4e86\u4ee5\u4e0b\u51e0\u79cd\u60c5\u51b5\u7684\u540c\u6b65\u5757\u6216\u540c\u6b65\u65b9\u6cd5\uff0cP1\u3001P2\u5c31\u90fd\u53ef\u4ee5\u8c03\u7528\u5b83\u4eec\u3002
\n1\uff0e \u628asynchronized\u5f53\u4f5c\u51fd\u6570\u4fee\u9970\u7b26\u65f6\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a
\n[java]Public synchronized void methodAAA()
\n{
\n\/\/\u2026.
\n}[\/java]
\n\u8fd9\u4e5f\u5c31\u662f\u540c\u6b65\u65b9\u6cd5\uff0c\u90a3\u8fd9\u65f6synchronized\u9501\u5b9a\u7684\u662f\u54ea\u4e2a\u5bf9\u8c61\u5462\uff1f\u5b83\u9501\u5b9a\u7684\u662f\u8c03\u7528\u8fd9\u4e2a\u540c\u6b65\u65b9\u6cd5\u5bf9\u8c61\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61P1\u5728\u4e0d\u540c\u7684\u7ebf\u7a0b\u4e2d
\n\u6267\u884c\u8fd9\u4e2a\u540c\u6b65\u65b9\u6cd5\u65f6\uff0c\u5b83\u4eec\u4e4b\u95f4\u4f1a\u5f62\u6210\u4e92\u65a5\uff0c\u8fbe\u5230\u540c\u6b65\u7684\u6548\u679c\u3002\u4f46\u662f\u8fd9\u4e2a\u5bf9\u8c61\u6240\u5c5e\u7684Class\u6240\u4ea7\u751f\u7684\u53e6\u4e00\u5bf9\u8c61P2\u5374\u53ef\u4ee5\u4efb\u610f\u8c03\u7528\u8fd9\u4e2a\u88ab\u52a0\u4e86
\nsynchronized\u5173\u952e\u5b57\u7684\u65b9\u6cd5\u3002
\n\u4e0a\u8fb9\u7684\u793a\u4f8b\u4ee3\u7801\u7b49\u540c\u4e8e\u5982\u4e0b\u4ee3\u7801\uff1a
\n[java]public void methodAAA()
\n{
\nsynchronized (this) \/\/ (1)
\n{
\n \/\/\u2026..
\n}
\n}[\/java]
\n(1)\u5904\u7684this\u6307\u7684\u662f\u4ec0\u4e48\u5462\uff1f\u5b83\u6307\u7684\u5c31\u662f\u8c03\u7528\u8fd9\u4e2a\u65b9\u6cd5\u7684\u5bf9\u8c61\uff0c\u5982P1\u3002\u53ef\u89c1\u540c\u6b65\u65b9\u6cd5\u5b9e\u8d28\u662f\u5c06synchronized\u4f5c\u7528\u4e8eobject reference\u3002\u2015\u2015\u90a3\u4e2a
\n\u62ff\u5230\u4e86P1\u5bf9\u8c61\u9501\u7684\u7ebf\u7a0b\uff0c\u624d\u53ef\u4ee5\u8c03\u7528P1\u7684\u540c\u6b65\u65b9\u6cd5\uff0c\u800c\u5bf9P2\u800c\u8a00\uff0cP1\u8fd9\u4e2a\u9501\u4e0e\u5b83\u6beb\u4e0d\u76f8\u5e72\uff0c\u7a0b\u5e8f\u4e5f\u53ef\u80fd\u5728\u8fd9\u79cd\u60c5\u5f62\u4e0b\u6446\u8131\u540c\u6b65\u673a\u5236\u7684\u63a7\u5236\uff0c\u9020
\n\u6210\u6570\u636e\u6df7\u4e71\uff1a\uff08
\n2\uff0e\u540c\u6b65\u5757\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a
\n[java]public void method3(SomeObject so)
\n{
\n synchronized(so)
\n {
\n \/\/\u2026..
\n }
\n}[\/java]
\n\u8fd9\u65f6\uff0c\u9501\u5c31\u662fso\u8fd9\u4e2a\u5bf9\u8c61\uff0c\u8c01\u62ff\u5230\u8fd9\u4e2a\u9501\u8c01\u5c31\u53ef\u4ee5\u8fd0\u884c\u5b83\u6240\u63a7\u5236\u7684\u90a3\u6bb5\u4ee3\u7801\u3002\u5f53\u6709\u4e00\u4e2a\u660e\u786e\u7684\u5bf9\u8c61\u4f5c\u4e3a\u9501\u65f6\uff0c\u5c31\u53ef\u4ee5\u8fd9\u6837\u5199\u7a0b\u5e8f\uff0c\u4f46\u5f53\u6ca1\u6709\u660e
\n\u786e\u7684\u5bf9\u8c61\u4f5c\u4e3a\u9501\uff0c\u53ea\u662f\u60f3\u8ba9\u4e00\u6bb5\u4ee3\u7801\u540c\u6b65\u65f6\uff0c\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u7279\u6b8a\u7684instance\u53d8\u91cf\uff08\u5b83\u5f97\u662f\u4e00\u4e2a\u5bf9\u8c61\uff09\u6765\u5145\u5f53\u9501\uff1a
\n[java]class Foo implements Runnable
\n{
\n private byte[] lock = new byte[0]; \/\/ \u7279\u6b8a\u7684instance\u53d8\u91cf
\n Public void methodA()
\n {
\n synchronized(lock) { \/\/\u2026 }
\n }
\n \/\/\u2026..
\n}[\/java]
\n\u6ce8\uff1a\u96f6\u957f\u5ea6\u7684byte\u6570\u7ec4\u5bf9\u8c61\u521b\u5efa\u8d77\u6765\u5c06\u6bd4\u4efb\u4f55\u5bf9\u8c61\u90fd\u7ecf\u6d4e\u2015\u2015\u67e5\u770b\u7f16\u8bd1\u540e\u7684\u5b57\u8282\u7801\uff1a\u751f\u6210\u96f6\u957f\u5ea6\u7684byte[]\u5bf9\u8c61\u53ea\u97003\u6761\u64cd\u4f5c\u7801\uff0c\u800cObject lock
\n= new Object()\u5219\u9700\u89817\u884c\u64cd\u4f5c\u7801\u3002
\n3\uff0e\u5c06synchronized\u4f5c\u7528\u4e8estatic \u51fd\u6570\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a
\n[java]Class Foo
\n{
\n public synchronized static void methodAAA() \/\/ \u540c\u6b65\u7684static \u51fd\u6570
\n {
\n \/\/\u2026.
\n }
\n public void methodBBB()
\n {
\n synchronized(Foo.class) \/\/ class literal(\u7c7b\u540d\u79f0\u5b57\u9762\u5e38\u91cf)
\n }
\n}[\/java]
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