![\"img\"](\"https:\/\/qn.199604.com\/\/typoraImg\/1588149067@1619112d5fad7066875d285b03650959.png\")
<\/div><\/p>\n\u5e76\u53d1\u53ef\u4ee5\u63d0\u9ad8\u4ee5\u4e8b\u7269\u7684\u5904\u7406\u6548\u7387, \u5373\u4e00\u6bb5\u65f6\u95f4\u5185\u53ef\u4ee5\u5904\u7406\u6216\u8005\u5b8c\u6210\u66f4\u591a\u7684\u4e8b\u60c5\u3002<\/p>\n
\u5e76\u884c\u662f\u4e00\u79cd\u66f4\u4e3a\u4e25\u683c,\u7406\u60f3\u7684\u5e76\u53d1\u3002<\/p>\n
\u4ece\u786c\u4ef6\u89d2\u5ea6\u6765\u8bf4, \u5982\u679c\u5355\u6838CPU,\u4e00\u4e2a\u5904\u7406\u5668\u4e00\u6b21\u53ea\u80fd\u6267\u884c\u4e00\u4e2a\u7ebf\u7a0b\u7684\u60c5\u51b5\u4e0b,\u5904\u7406\u5668\u53ef\u4ee5\u4f7f\u7528\u65f6\u95f4\u7247\u8f6e\u8f6c\u6280\u672f ,\u53ef\u4ee5\u8ba9CPU\u5feb\u901f\u7684\u5728\u5404\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u8fdb\u884c\u5207\u6362, \u5bf9\u4e8e\u7528\u6765\u6765\u8bf4,\u611f\u89c9\u662f\u4e09\u4e2a\u7ebf\u7a0b\u5728\u540c\u65f6\u6267\u884c.\u5982\u679c\u662f\u591a\u6838\u5fc3CPU,\u53ef\u4ee5\u4e3a\u4e0d\u540c\u7684\u7ebf\u7a0b\u5206\u914d\u4e0d\u540c\u7684CPU\u5185\u6838\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u7684\u521b\u5efa\u4e0e\u542f\u52a8\u65b9\u5f0f<\/h1>\n
\u5728Java\u4e2d,\u521b\u5efa\u4e00\u4e2a\u7ebf\u7a0b\u5c31\u662f\u521b\u5efa\u4e00\u4e2aThread\u7c7b(\u5b50\u7c7b)\u7684\u5bf9\u8c61(\u5b9e\u4f8b)\u3002<\/p>\n
Thread\u7c7b\u6709\u4e24\u4e2a\u5e38\u7528\u7684\u6784\u9020\u65b9\u6cd5:Thread()\u4e0eThread(Runnable).\u5bf9\u5e94\u7684\u521b\u5efa\u7ebf\u7a0b\u7684\u4e24\u79cd\u65b9\u5f0f\uff1a<\/p>\n
- \n
- \u5b9a\u4e49Thread\u7c7b\u7684\u5b50\u7c7b<\/li>\n
- \u5b9a\u4e49\u4e00\u4e2aRunnable\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b<\/li>\n<\/ul>\n
\u8fd9\u4e24\u79cd\u521b\u5efa\u7ebf\u7a0b\u7684\u65b9\u5f0f\u6ca1\u6709\u672c\u8d28\u7684\u533a\u522b\u3002<\/p>\n
Thread\u7c7b\u5b50\u7c7b\uff1a<\/h4>\n
public class MyThread extends Thread{\n @Override\n public void run() {\n System.out.println(\"\u8fd9\u662f\u5b50\u7ebf\u7a0b\u6253\u5370\u7684\u5185\u5bb9\");\n }\n}\n---------\npublic class App\n{\n public static void main( String[] args )\n {\n System.out.println(\"JVM\u542f\u52a8main\u7ebf\u7a0b,main\u7ebf\u7a0b\u6267\u884cmain\u65b9\u6cd5\");\n \/\/ \u521b\u5efa\u5b50\u7ebf\u7a0b\u5bf9\u8c61\n MyThread myThread = new MyThread();\n \/*\n \u8c03\u7528\u7ebf\u7a0b\u7684start()\u65b9\u6cd5\u6765\u542f\u52a8\u7ebf\u7a0b, \u542f\u52a8\u7ebf\u7a0b\u7684\u5b9e\u8d28\u5c31\u662f\u8bf7\u6c42JVM\u8fd0\u884c\u76f8\u5e94\u7684\u7ebf\u7a0b,\u8fd9\u4e2a\u7ebf\u7a0b\u5177\u4f53\u5728\u4ec0\u4e48\u65f6\u5019\u8fd0\u884c\u7531\u7ebf\u7a0b\u8c03\u5ea6\u5668(Scheduler)\u51b3\u5b9a\n \u6ce8\u610f:\n start()\u65b9\u6cd5\u8c03\u7528\u7ed3\u675f\u5e76\u4e0d\u610f\u5473\u7740\u5b50\u7ebf\u7a0b\u5f00\u59cb\u8fd0\u884c\n \u65b0\u5f00\u542f\u7684\u7ebf\u7a0b\u4f1a\u6267\u884crun()\u65b9\u6cd5\n \u5982\u679c\u5f00\u542f\u4e86\u591a\u4e2a\u7ebf\u7a0b,start()\u8c03\u7528\u7684\u987a\u5e8f\u5e76\u4e0d\u4e00\u5b9a\u5c31\u662f\u7ebf\u7a0b\u542f\u52a8\u7684\u987a\u5e8f\n \u591a\u7ebf\u7a0b\u8fd0\u884c\u7ed3\u679c\u4e0e\u4ee3\u7801\u6267\u884c\u987a\u5e8f\u6216\u8c03\u7528\u987a\u5e8f\u65e0\u5173\n *\/\n \/\/ \u542f\u52a8\u7ebf\u7a0b\n myThread.start();\n }\n}\n<\/code><\/pre>\nRunnable\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b:<\/h4>\n
public class MyRunnable implements Runnable{\n @Override\n public void run() {\n System.out.println(\"\u8fd9\u662f\u5b50\u7ebf\u7a0b\u6253\u5370\u7684\u5185\u5bb9\");\n }\n}\n--------\npublic class App\n{\n public static void main( String[] args )\n {\n \/\/ \u521b\u5efaRunnable\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b\u5bf9\u8c61\n MyRunnable myRunnable = new MyRunnable();\n \/\/ \u521b\u5efa\u7ebf\u7a0b\u5bf9\u8c61\n Thread thread = new Thread(myRunnable);\n \/\/ \u5f00\u542f\u7ebf\u7a0b\n thread.start();\n\n\n \/\/ \u6709\u65f6\u8c03\u7528Thread(Runnable)\u6784\u9020\u65b9\u6cd5\u65f6,\u5b9e\u53c2\u4e5f\u4f1a\u4f20\u9012\u533f\u540d\u5185\u90e8\u7c7b\u5bf9\u8c61\n Thread thread1 = new Thread(new Runnable() {\n @Override\n public void run() {\n System.out.println(\"\u533f\u540d\u5185\u90e8\u7c7b\u5bf9\u8c61\u6253\u5370\u7684\u5185\u5bb9\");\n }\n });\n thread1.start();\n }\n}\n<\/code><\/pre>\nJava\u591a\u7ebf\u7a0b\u5e38\u7528\u7684\u65b9\u6cd5<\/h1>\n
currentThread()\u65b9\u6cd5<\/h2>\n
Thread.currentThread()<\/code>\u65b9\u6cd5\u53ef\u4ee5\u83b7\u5f97\u5f53\u524d\u7ebf\u7a0b\u3002<\/p>\nJava\u4e2d\u7684\u4efb\u4f55\u4e00\u6bb5\u4ee3\u7801\u90fd\u662f\u6267\u884c\u5728\u67d0\u4e2a\u7ebf\u7a0b\u5f53\u4e2d\u7684. \u6267\u884c\u5f53\u524d\u4ee3\u7801\u7684\u7ebf\u7a0b\u5c31\u662f\u5f53\u524d\u7ebf\u7a0b\u3002<\/p>\n
\u540c\u4e00\u6bb5\u4ee3\u7801\u53ef\u80fd\u88ab\u4e0d\u540c\u7684\u7ebf\u7a0b\u6267\u884c,\u56e0\u6b64\u5f53\u524d\u7ebf\u7a0b\u662f\u76f8\u5bf9\u7684,
Thread.currentThread()<\/code>\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u662f\u5728\u4ee3\u7801\u5b9e\u9645\u8fd0\u884c\u65f6\u5019\u7684\u7ebf\u7a0b\u5bf9\u8c61\u3002<\/p>\npublic class SubThread extends Thread{\n\n public SubThread() {\n System.out.println(\"\u6784\u9020\u65b9\u6cd5\u6253\u5370\u5f53\u524d\u7ebf\u7a0b\u7684\u540d\u79f0:\"+Thread.currentThread().getName());\n }\n\n @Override\n public void run() {\n System.out.println(\"run\u65b9\u6cd5\u6253\u5370\u5f53\u524d\u7ebf\u7a0b\u540d\u79f0:\" + Thread.currentThread().getName());\n }\n}\n\n------\n @Test\n public void Test01CurrentThread()\n {\n System.out.println(\"main\u65b9\u6cd5\u4e2d\u6253\u5370\u5f53\u524d\u7ebf\u7a0b:\" + Thread.currentThread().getName());\n \/\/\u521b\u5efa\u5b50\u7ebf\u7a0b, \u8c03\u7528SubThread1()\u6784\u9020\u65b9\u6cd5, \u5728main\u7ebf\u7a0b\u4e2d\u8c03\u7528\u6784\u9020\u65b9\u6cd5,\u6240\u4ee5\u6784\u9020\u65b9\u6cd5\u4e2d \u7684\u5f53\u524d\u7ebf\u7a0b\u5c31\u662fmain\u7ebf\u7a0b\n SubThread subThread = new SubThread();\n \/\/\u542f\u52a8\u5b50\u7ebf\u7a0b,\u5b50\u7ebf\u7a0b\u4f1a\u8c03\u7528run()\u65b9\u6cd5,\u6240\u4ee5run()\u65b9\u6cd5\u4e2d \u7684\u5f53\u524d\u7ebf\u7a0b\u5c31\u662fThread-0\u5b50\u7ebf\u7a0b\n \/\/subThread.start();\n \/\/\u5728main\u65b9\u6cd5\u4e2d\u76f4\u63a5\u8c03\u7528run()\u65b9\u6cd5,\u6ca1\u6709\u5f00\u542f\u65b0\u7684\u7ebf\u7a0b,\u6240\u4ee5\u5728run\u65b9\u6cd5\u4e2d\u7684\u5f53\u524d\u7ebf\u7a0b\u5c31\u662fmain\u7ebf\u7a0b\n subThread.run();\n }\n\nmain\u65b9\u6cd5\u4e2d\u6253\u5370\u5f53\u524d\u7ebf\u7a0b:main\n\u6784\u9020\u65b9\u6cd5\u6253\u5370\u5f53\u524d\u7ebf\u7a0b\u7684\u540d\u79f0:main\nrun\u65b9\u6cd5\u6253\u5370\u5f53\u524d\u7ebf\u7a0b\u540d\u79f0:main\n<\/code><\/pre>\npublic class SubThread2 extends Thread{\n\n public SubThread2() {\n System.out.println(\"\u6784\u9020\u65b9\u6cd5\u4e2d,Thread.currentThread().getName() : \" + Thread.currentThread().getName() );\n System.out.println(\"\u6784\u9020\u65b9\u6cd5,this.getName() : \" + this.getName());\n }\n\n @Override\n public void run() {\n System.out.println(\"run\u65b9\u6cd5\u4e2d,Thread.currentThread().getName() : \" + Thread.currentThread().getName() );\n System.out.println(\"run\u65b9\u6cd5,this.getName() : \" + this.getName());\n }\n}\n\n @Test\n public void Test02CurrentThread() throws InterruptedException {\n\n SubThread2 t2 = new SubThread2();\n \/\/ \u8bbe\u7f6e\u7ebf\u7a0b\u540d\u79f0\n t2.setName(\"t2\");\n t2.start();\n\n Thread.sleep(200);\n\n \/\/Thread(Runnable)\u6784\u9020\u65b9\u6cd5\u5f62\u53c2\u662fRunnable\u63a5\u53e3,\u8c03\u7528\u65f6\u4f20\u9012\u7684\u5b9e\u53c2\u662f\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b\u5bf9\u8c61\n Thread t3 = new Thread(t2);\n t3.start();\n }\n\n\u6784\u9020\u65b9\u6cd5\u4e2d,Thread.currentThread().getName() : main\n\u6784\u9020\u65b9\u6cd5,this.getName() : Thread-0\nrun\u65b9\u6cd5\u4e2d,Thread.currentThread().getName() : t2\nrun\u65b9\u6cd5,this.getName() : t2\nrun\u65b9\u6cd5\u4e2d,Thread.currentThread().getName() : Thread-1\nrun\u65b9\u6cd5,this.getName() : t2\n<\/code><\/pre>\nthread.setName<\/code>(\u7ebf\u7a0b\u540d\u79f0), \u8bbe\u7f6e\u7ebf\u7a0b\u540d\u79f0\u3002<\/p>\nthread.getName()<\/code>\u8fd4\u56de\u7ebf\u7a0b\u540d\u79f0\u3002<\/p>\n\u901a\u8fc7\u8bbe\u7f6e\u7ebf\u7a0b\u540d\u79f0,\u6709\u52a9\u4e8e\u7a0b\u5e8f\u8c03\u8bd5,\u63d0\u9ad8\u7a0b\u5e8f\u7684\u53ef\u8bfb\u6027, \u5efa\u8bae\u4e3a\u6bcf\u4e2a\u7ebf\u7a0b\u90fd\u8bbe\u7f6e\u4e00\u4e2a\u80fd\u591f\u4f53\u73b0\u7ebf\u7a0b\u529f\u80fd\u7684\u540d\u79f0\u3002<\/p>\n
isAlive()<\/h2>\n
thread.isAlive()<\/code>\u5224\u65ad\u5f53\u524d\u7ebf\u7a0b\u662f\u5426\u5904\u4e8e\u6d3b\u52a8\u72b6\u6001\u3002<\/p>\n\u6d3b\u52a8\u72b6\u6001\u5c31\u662f\u7ebf\u7a0b\u5df2\u542f\u52a8\u5e76\u4e14\u5c1a\u672a\u7ec8\u6b62\u3002<\/p>\n
public class SubThread3 extends Thread{\n @Override\n public void run() {\n \/\/\u8fd0\u884c\u72b6\u6001,true\n System.out.println(\"run\u65b9\u6cd5\uff0cisAlive = \"+this.isAlive());\n }\n}\n\n\n @Test\n public void Test03CurrentThread() throws InterruptedException {\n SubThread3 t3 = new SubThread3();\n System.out.println(\"begin==\" + t3.isAlive());\/\/false,\u5728\u542f\u52a8\u7ebf\u7a0b\u4e4b\u524d\n t3.start();\n Thread.sleep(500);\n \/\/ \u7ed3\u679c\u4e0d\u4e00\u5b9a,\u6253\u5370\u8fd9\u4e00\u884c\u65f6,\u5982\u679ct3\u7ebf\u7a0b\u8fd8\u6ca1\u7ed3\u675f\u5c31\u8fd4\u56detrue, \u5982\u679ct3\u7ebf\u7a0b\u5df2\u7ed3\u675f,\u8fd4\u56defalse\n System.out.println(\"end==\" + t3.isAlive());\n }\n\n<\/code><\/pre>\nsleep()<\/h2>\n
Thread.sleep(millis)<\/code>\u8ba9\u5f53\u524d\u7ebf\u7a0b\u4f11\u7720\u6307\u5b9a\u7684\u6beb\u79d2\u6570\u3002<\/p>\ngetId()<\/h2>\n
thread.getId()<\/code>\u53ef\u4ee5\u83b7\u5f97\u7ebf\u7a0b\u7684\u552f\u4e00\u6807\u8bc6\u3002<\/p>\n\u6ce8\u610f:<\/p>\n
\u67d0\u4e2a\u7f16\u53f7\u7684\u7ebf\u7a0b\u8fd0\u884c\u7ed3\u675f\u540e,\u8be5\u7f16\u53f7\u53ef\u80fd\u88ab\u540e\u7eed\u521b\u5efa\u7684\u7ebf\u7a0b\u4f7f\u7528\u3002<\/p>\n
\u91cd\u542f\u7684JVM\u540e,\u540c\u4e00\u4e2a\u7ebf\u7a0b\u7684\u7f16\u53f7\u53ef\u80fd\u4e0d\u4e00\u6837\u3002<\/p>\n
public class SubThread5 extends Thread{\n @Override\n public void run() {\n System.out.print(\"thread name = \"+ Thread.currentThread().getName());\n System.out.println(\",thread id = \"+ this.getId());\n }\n}\n\n @Test\n public void Test05CurrentThread() throws InterruptedException {\n\n \/\/\u5b50\u7ebf\u7a0b\u7684id\n for(int i = 1; i <= 10; i++){\n new SubThread5().start();\n Thread.sleep(100);\n }\n }\n----- \nthread name = Thread-0,thread id = 14\nthread name = Thread-1,thread id = 15\nthread name = Thread-2,thread id = 16\nthread name = Thread-3,thread id = 17\nthread name = Thread-4,thread id = 18\nthread name = Thread-5,thread id = 19\nthread name = Thread-6,thread id = 20\nthread name = Thread-7,thread id = 21\nthread name = Thread-8,thread id = 22\nthread name = Thread-9,thread id = 23\n\n<\/code><\/pre>\nyield()<\/h2>\n
Thread.yield()<\/code>\u65b9\u6cd5\u7684\u4f5c\u7528\u662f\u653e\u5f03\u5f53\u524d\u7684CPU\u8d44\u6e90\u3002\uff08\u7ebf\u7a0b\u8ba9\u6b65\uff09<\/p>\n\u7528\u4e00\u4e2a\u7b80\u5355\u7684\u6bd4\u55bb\u6765\u5f62\u5bb9\u5c31\u662f\uff1a<\/p>\n
\u4e09\u4e2a\u4eba\u585e\u7c73\u8d5b\u8dd1\uff0c\u4e09\u4eba\u90fd\u5feb\u8dd1\u523090m\u4f4d\u7f6e\u7684\u65f6\u5019\uff0c2\u53f7\u7a81\u7136\u88ab\u4f20\u9001\u5230\u4e86\u8d77\u70b9\uff0c\u4e09\u4eba\u7ee7\u7eed\u8dd1\uff0c\u8fd9\u68371\u53f7\u548c3\u53f7\u8d62\u7684\u673a\u4f1a\u5c31\u5927\u5f97\u591a<\/strong><\/p>\n
2\u53f7\u5c31\u76f8\u5f53\u4e8e\u8c03\u7528\u4e86
yield()<\/code>\u7684\u7ebf\u7a0b\uff0c\u7ebf\u7a0b\u8c03\u7528\u4e86yiled()<\/code>\u4e4b\u540e\u56de\u9000\u5230\u53ef\u8fd0\u884c\u72b6\u6001\uff0c\u5c06\u62a2\u5360\u8d44\u6e90\u7684\u673a\u4f1a\u8ba9\u7ed9\u5176\u4ed6\u76f8\u540c\u4f18\u5148\u7ea7\u7684\u7ebf\u7a0b\u3002<\/p>\npublic class SubThread6 extends Thread {\n @Override\n public void run() {\n long begin = System.currentTimeMillis();\n long sum = 0;\n for (int i =1;i<=100000;i++){\n sum +=i;\n \/\/\u7ebf\u7a0b\u8ba9\u6b65, \u653e\u5f03CPU\u6267\u884c\u6743\n Thread.yield();\n }\n long end = System.currentTimeMillis();\n System.out.println(\"\u7528\u65f6: \" + (end - begin)+\",sum=\"+sum);\n }\n}\n--------\n @Test\n public void Test06CurrentThread(){\n SubThread6 t6 = new SubThread6();\n t6.start();\n\n long begin = System.currentTimeMillis();\n long sum = 0;\n for(int i = 1; i <= 1000000; i++){\n sum += i;\n }\n long end = System.currentTimeMillis();\n System.out.println(\"\u7528\u65f6: \" + (end - begin)+\",sum=\"+sum);\n }\n<\/code><\/pre>\nsetPriority()<\/h2>\n
thread.setPriority( num )<\/code> \u8bbe\u7f6e\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u3002<\/p>\nJava\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u53d6\u503c\u8303\u56f4\u662f 1 ~ 10 , \u5982\u679c\u8d85\u51fa\u8fd9\u4e2a\u8303\u56f4\u4f1a\u629b\u51fa\u5f02\u5e38
IllegalArgumentException<\/code>\u3002<\/p>\n\u5728\u64cd\u4f5c\u7cfb\u7edf\u4e2d,\u4f18\u5148\u7ea7\u8f83\u9ad8\u7684\u7ebf\u7a0b\u83b7\u5f97CPU\u7684\u8d44\u6e90\u8d8a\u591a\u3002<\/p>\n
\u7ebf\u7a0b\u4f18\u5148\u7ea7\u672c\u8d28\u4e0a\u662f\u53ea\u662f\u7ed9\u7ebf\u7a0b\u8c03\u5ea6\u5668\u4e00\u4e2a\u63d0\u793a\u4fe1\u606f,\u4ee5\u4fbf\u4e8e\u8c03\u5ea6\u5668\u51b3\u5b9a\u5148\u8c03\u5ea6\u54ea\u4e9b\u7ebf\u7a0b. \u6ce8\u610f\u4e0d\u80fd\u4fdd\u8bc1\u4f18\u5148\u7ea7\u9ad8\u7684\u7ebf\u7a0b\u5148\u8fd0\u884c\u3002<\/p>\n
Java\u4f18\u5148\u7ea7\u8bbe\u7f6e\u4e0d\u5f53\u6216\u8005\u6ee5\u7528\u53ef\u80fd\u4f1a\u5bfc\u81f4\u67d0\u4e9b\u7ebf\u7a0b\u6c38\u8fdc\u65e0\u6cd5\u5f97\u5230\u8fd0\u884c,\u5373\u4ea7\u751f\u4e86\u7ebf\u7a0b\u9965\u997f\u3002<\/p>\n
\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u5e76\u4e0d\u662f\u8bbe\u7f6e\u7684\u8d8a\u9ad8\u8d8a\u597d,\u4e00\u822c\u60c5\u51b5\u4e0b\u4f7f\u7528\u666e\u901a\u7684\u4f18\u5148\u7ea7\u5373\u53ef,\u5373\u5728\u5f00\u53d1\u65f6\u4e0d\u5fc5\u8bbe\u7f6e\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u3002<\/p>\n
\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u5177\u6709\u7ee7\u627f\u6027, \u5728A\u7ebf\u7a0b\u4e2d\u521b\u5efa\u4e86B\u7ebf\u7a0b,\u5219B\u7ebf\u7a0b\u7684\u4f18\u5148\u7ea7\u4e0eA\u7ebf\u7a0b\u662f\u4e00\u6837\u7684\u3002<\/p>\n
interrupt()<\/h2>\n
\u4e2d\u65ad\u7ebf\u7a0b\u3002<\/p>\n
\u6ce8\u610f\u8c03\u7528interrupt()\u65b9\u6cd5\u4ec5\u4ec5\u662f\u5728\u5f53\u524d\u7ebf\u7a0b\u6253\u4e00\u4e2a\u505c\u6b62\u6807\u5fd7,\u5e76\u4e0d\u662f\u771f\u6b63\u7684\u505c\u6b62\u7ebf\u7a0b\u3002<\/p>\n
public class SubThread8 extends Thread{\n @Override\n public void run() {\n super.run();\n int i = 100000;\n for (int i1 = 0; i1 < i; i1++) {\n \/\/\u5224\u65ad\u7ebf\u7a0b\u7684\u4e2d\u65ad\u6807\u5fd7,\u7ebf\u7a0b\u6709 isInterrupted()\u65b9\u6cd5,\u8be5\u65b9\u6cd5\u8fd4\u56de\u7ebf\u7a0b\u7684\u4e2d\u65ad\u6807\u5fd7\n if (this.isInterrupted()) {\n System.out.println(\"\u5f53\u524d\u7ebf\u7a0b\u7684\u4e2d\u65ad\u6807\u5fd7\u4e3atrue, \u6211\u8981\u9000\u51fa\u4e86\");\n return;\n }\n System.out.println(\"sub thread --> \" + i1);\n }\n }\n}\n\n @Test\n public void Test08CurrentThread(){\n SubThread8 t8 = new SubThread8();\n t8.start();\n\n for (int i = 0;i<10;i++){\n System.out.println(\"main ==> \" + i);\n }\n \/\/\u4e2d\u65ad\u5b50\u7ebf\u7a0b\n t8.interrupt();\n }\nmain ==> 0\nmain ==> 1\nmain ==> 2\nmain ==> 3\nmain ==> 4\nmain ==> 5\nmain ==> 6\nmain ==> 7\nsub thread --> 0\nmain ==> 8\nsub thread --> 1\nmain ==> 9\nsub thread --> 2\n\u5f53\u524d\u7ebf\u7a0b\u7684\u4e2d\u65ad\u6807\u5fd7\u4e3atrue, \u6211\u8981\u9000\u51fa\u4e86\n<\/code><\/pre>\nsetDaemon()<\/h2>\n
Java\u4e2d\u7684\u7ebf\u7a0b\u5206\u4e3a\u7528\u6237\u7ebf\u7a0b\u4e0e\u5b88\u62a4\u7ebf\u7a0b\u3002<\/p>\n
\u5b88\u62a4\u7ebf\u7a0b\u662f\u4e3a\u5176\u4ed6\u7ebf\u7a0b\u63d0\u4f9b\u670d\u52a1\u7684\u7ebf\u7a0b,\u5982\u5783\u573e\u56de\u6536\u5668(GC)\u5c31\u662f\u4e00\u4e2a\u5178\u578b\u7684\u5b88\u62a4\u7ebf\u7a0b\u3002<\/p>\n
\u5b88\u62a4\u7ebf\u7a0b\u4e0d\u80fd\u5355\u72ec\u8fd0\u884c, \u5f53JVM\u4e2d\u6ca1\u6709\u5176\u4ed6\u7528\u6237\u7ebf\u7a0b,\u53ea\u6709\u5b88\u62a4\u7ebf\u7a0b\u65f6,\u5b88\u62a4\u7ebf\u7a0b\u4f1a\u81ea\u52a8\u9500\u6bc1, JVM\u4f1a\u9000\u51fa\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u7684\u751f\u547d\u5468\u671f<\/h1>\n
\u7ebf\u7a0b\u7684\u751f\u547d\u5468\u671f\u662f\u7ebf\u7a0b\u5bf9\u8c61\u7684\u751f\u8001\u75c5\u6b7b,\u5373\u7ebf\u7a0b\u7684\u72b6\u6001\u3002<\/p>\n
\u7ebf\u7a0b\u751f\u547d\u5468\u671f\u53ef\u4ee5\u901a\u8fc7
getState()<\/code>\u65b9\u6cd5\u83b7\u5f97, \u7ebf\u7a0b\u7684\u72b6\u6001\u662fThread.State<\/code>\u679a\u4e3e\u7c7b\u578b\u5b9a\u4e49\u7684, \u7531\u4ee5\u4e0b\u51e0\u79cd\uff1a<\/p>\n- \n
NEW<\/code>,\u65b0\u5efa\u72b6\u6001. \u521b\u5efa\u4e86\u7ebf\u7a0b\u5bf9\u8c61,\u5728\u8c03\u7528start()<\/code>\u542f\u52a8\u4e4b\u524d\u7684\u72b6\u6001\u3002<\/li>\nRUNNABLE<\/code>,\u53ef\u8fd0\u884c\u72b6\u6001. \u5b83\u662f\u4e00\u4e2a\u590d\u5408\u72b6\u6001,\u5305\u542b:READY<\/code>\u548cRUNNING<\/code>\u4e24\u4e2a\u72b6\u6001.READY<\/code>\u72b6\u6001\u8be5\u7ebf\u7a0b\u53ef\u4ee5\u88ab\u7ebf\u7a0b\u8c03\u5ea6\u5668\u8fdb\u884c\u8c03\u5ea6\u4f7f\u5b83\u5904\u4e8eRUNNING<\/code>\u72b6\u6001,RUNING<\/code>\u72b6\u6001\u8868\u793a\u8be5\u7ebf\u7a0b\u6b63\u5728\u6267\u884c.Thread.yield()<\/code>\u65b9\u6cd5\u53ef\u4ee5\u628a\u7ebf\u7a0b\u7531RUNNING\u72b6\u6001\u8f6c\u6362\u4e3aREADY\u72b6\u6001<\/li>\nBLOCKED<\/code>\u963b\u585e\u72b6\u6001.\u7ebf\u7a0b\u53d1\u8d77\u963b\u585e\u7684I\/O\u64cd\u4f5c,\u6216\u8005\u7533\u8bf7\u7531\u5176\u4ed6\u7ebf\u7a0b\u5360\u7528\u7684\u72ec\u5360\u8d44\u6e90,\u7ebf\u7a0b\u4f1a\u8f6c\u6362\u4e3aBLOCKED<\/code>\u963b\u585e\u72b6\u6001. \u5904\u4e8e\u963b\u585e\u72b6\u6001\u7684\u7ebf\u7a0b\u4e0d\u4f1a\u5360\u7528CPU\u8d44\u6e90. \u5f53\u963b\u585eI\/O\u64cd\u4f5c\u6267\u884c\u5b8c,\u6216\u8005\u7ebf\u7a0b\u83b7\u5f97\u4e86\u5176\u7533\u8bf7\u7684\u8d44\u6e90,\u7ebf\u7a0b\u53ef\u4ee5\u8f6c\u6362\u4e3aRUNNABLE<\/code>\u3002<\/li>\nWAITING<\/code>\u7b49\u5f85\u72b6\u6001. \u7ebf\u7a0b\u6267\u884c\u4e86object.wait(), thread.join()<\/code>\u65b9\u6cd5\u4f1a\u628a\u7ebf\u7a0b\u8f6c\u6362\u4e3aWAITING<\/code>\u7b49\u5f85\u72b6\u6001, \u6267\u884cobject.notify()<\/code>\u65b9\u6cd5,\u6216\u8005\u52a0\u5165\u7684\u7ebf\u7a0b\u6267\u884c\u5b8c\u6bd5,\u5f53\u524d\u7ebf\u7a0b\u4f1a\u8f6c\u6362\u4e3aRUNNABLE\u72b6\u6001\u3002<\/li>\nTIMED_WAITING<\/code>\u72b6\u6001,\u4e0eWAITING<\/code>\u72b6\u6001\u7c7b\u4f3c,\u90fd\u662f\u7b49\u5f85\u72b6\u6001.\u533a\u522b\u5728\u4e8e\u5904\u4e8e\u8be5\u72b6\u6001\u7684\u7ebf\u7a0b\u4e0d\u4f1a\u65e0\u9650\u7684\u7b49\u5f85,\u5982\u679c\u7ebf\u7a0b\u6ca1\u6709\u5728\u6307\u5b9a\u7684\u65f6\u95f4\u8303\u56f4\u5185\u5b8c\u6210\u671f\u671b\u7684\u64cd\u4f5c,\u8be5\u7ebf\u7a0b\u81ea\u52a8\u8f6c\u6362\u4e3aRUNNABLE<\/code><\/li>\nTERMINATED<\/code>\u7ec8\u6b62\u72b6\u6001,\u7ebf\u7a0b\u7ed3\u675f\u5904\u4e8e\u7ec8\u6b62\u72b6\u6001<\/li>\n<\/ul>\n![\"image-20210907211400969\"](\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\")
<\/div><\/p>\nJava\u591a\u7ebf\u7a0b\u7f16\u7a0b\u7684\u4f18\u52bf\u4e0e\u98ce\u9669<\/h1>\n
Java\u591a\u7ebf\u7a0b\u7f16\u7a0b\u5177\u6709\u4ee5\u4e0b\u4f18\u52bf\uff1a<\/h3>\n
1\u3001\u63d0\u9ad8\u7cfb\u7edf\u7684\u541e\u5410\u7387(Throughout). \u591a\u7ebf\u7a0b\u7f16\u7a0b\u53ef\u4ee5\u4f7f\u4e00\u4e2a\u8fdb\u7a0b\u6709\u591a\u4e2a\u5e76\u53d1(concurrent,\u5373\u540c\u65f6\u8fdb\u884c\u7684)\u7684\u64cd\u4f5c\u3002<\/p>\n
2\u3001\u63d0\u9ad8\u54cd\u5e94\u6027(Responsiveness).Web\u670d\u52a1\u5668\u4f1a\u91c7\u7528\u4e00\u4e9b\u4e13\u95e8\u7684\u7ebf\u7a0b\u8d1f\u8d23\u7528\u6237\u7684\u8bf7\u6c42\u5904\u7406,\u7f29\u77ed\u4e86\u7528\u6237\u7684\u7b49\u5f85\u65f6\u95f4\u3002<\/p>\n
3\u3001\u5145\u5206\u5229\u7528\u591a\u6838(Multicore)\u5904\u7406\u5668\u8d44\u6e90. \u901a\u8fc7\u591a\u7ebf\u7a0b\u53ef\u4ee5\u5145\u5206\u7684\u5229\u7528CPU\u8d44\u6e90\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u7f16\u7a0b\u5b58\u5728\u7684\u95ee\u9898\u4e0e\u98ce\u9669\uff1a<\/h3>\n
1\u3001\u7ebf\u7a0b\u5b89\u5168(Thread safe)\u95ee\u9898.\u591a\u7ebf\u7a0b\u5171\u4eab\u6570\u636e\u65f6,\u5982\u679c\u6ca1\u6709\u91c7\u53d6\u6b63\u786e\u7684\u5e76\u53d1\u8bbf\u95ee\u63a7\u5236\u63aa\u65bd,\u5c31\u53ef\u80fd\u4f1a\u4ea7\u751f\u6570\u636e\u4e00\u81f4\u6027\u95ee\u9898,\u5982\u8bfb\u53d6\u810f\u6570\u636e(\u8fc7\u671f\u7684\u6570\u636e), \u5982\u4e22\u5931\u6570\u636e\u66f4\u65b0\u3002<\/p>\n
2\u3001\u7ebf\u7a0b\u6d3b\u6027(thread liveness)\u95ee\u9898.\u7531\u4e8e\u7a0b\u5e8f\u81ea\u8eab\u7684\u7f3a\u9677\u6216\u8005\u7531\u8d44\u6e90\u7a00\u7f3a\u6027\u5bfc\u81f4\u7ebf\u7a0b\u4e00\u76f4\u5904\u4e8e\u975eRUNNABLE\u72b6\u6001,\u8fd9\u5c31\u662f\u7ebf\u7a0b\u6d3b\u6027\u95ee\u9898,\u5e38\u89c1\u7684\u6d3b\u6027\u6545\u969c\u6709\u4ee5\u4e0b\u51e0\u79cd\uff1a<\/p>\n
- \n
- \u6b7b\u9501(Deadlock). \u7c7b\u4f3c\u9e6c\u868c\u76f8\u4e89<\/li>\n
- \u9501\u6b7b(Lockout), \u7c7b\u4f3c\u4e8e\u7761\u7f8e\u4eba\u6545\u4e8b\u4e2d\u738b\u5b50\u6302\u4e86<\/li>\n
- \u6d3b\u9501(Livelock). \u7c7b\u4f3c\u4e8e\u5c0f\u732b\u54ac\u81ea\u5df1\u5c3e\u5df4<\/li>\n
- \u9965\u997f(Starvation).\u7c7b\u4f3c\u4e8e\u5065\u58ee\u7684\u96cf\u9e1f\u603b\u662f\u4ece\u6bcd\u9e1f\u5634\u4e2d\u62a2\u5230\u98df\u7269<\/li>\n<\/ul>\n
3\u3001\u4e0a\u4e0b\u6587\u5207\u6362(Context Switch). \u5904\u7406\u5668\u4ece\u6267\u884c\u4e00\u4e2a\u7ebf\u7a0b\u5207\u6362\u5230\u6267\u884c\u53e6\u5916\u4e00\u4e2a\u7ebf\u7a0b\u3002<\/p>\n
4\u3001\u53ef\u9760\u6027. \u53ef\u80fd\u4f1a\u7531\u4e00\u4e2a\u7ebf\u7a0b\u5bfc\u81f4JVM\u610f\u5916\u7ec8\u6b62,\u5176\u4ed6\u7684\u7ebf\u7a0b\u4e5f\u65e0\u6cd5\u6267\u884c\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u539f\u5b50\u6027\u4e0e\u53ef\u89c1\u6027<\/h1>\n
\u975e\u7ebf\u7a0b\u5b89\u5168\u4e3b\u8981\u662f\u6307\u591a\u4e2a\u7ebf\u7a0b\u5bf9\u540c\u4e00\u4e2a\u5bf9\u8c61\u7684\u5b9e\u4f8b\u53d8\u91cf\u8fdb\u884c\u64cd\u4f5c\u65f6,\u4f1a\u51fa\u73b0\u503c\u88ab\u66f4\u6539,\u503c\u4e0d\u540c\u6b65\u7684\u60c5\u51b5\u3002<\/p>\n
\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u8868\u73b0\u4e3a\u4e09\u4e2a\u65b9\u9762: \u539f\u5b50\u6027,\u53ef\u89c1\u6027\u548c\u6709\u5e8f\u6027<\/span>\u3002<\/p>\n
\u539f\u5b50\u6027<\/h2>\n
\u539f\u5b50(Atomic)\u5c31\u662f\u4e0d\u53ef\u5206\u5272\u7684\u610f\u601d. \u539f\u5b50\u64cd\u4f5c\u7684\u4e0d\u53ef\u5206\u5272\u6709\u4e24\u5c42\u542b\u4e49\uff1a<\/p>\n
- \n
- \u8bbf\u95ee(\u8bfb,\u5199)\u67d0\u4e2a\u5171\u4eab\u53d8\u91cf\u7684\u64cd\u4f5c\u4ece\u5176\u4ed6\u7ebf\u7a0b\u6765\u770b,\u8be5\u64cd\u4f5c\u8981\u4e48\u5df2\u7ecf\u6267\u884c\u5b8c\u6bd5,\u8981\u4e48\u5c1a\u672a\u53d1\u751f, \u5373\u5176\u4ed6\u7ebf\u7a0b\u5e74\u793a\u5230\u5f53\u524d\u64cd\u4f5c\u7684\u4e2d\u95f4\u7ed3\u679c\u3002<\/li>\n
- \u8bbf\u95ee\u540c\u4e00\u7ec4\u5171\u4eab\u53d8\u91cf\u7684\u539f\u5b50\u64cd\u4f5c\u662f\u4e0d\u80fd\u591f\u4ea4\u9519\u7684\u3002<\/li>\n<\/ul>\n
\u5982\u73b0\u5b9e\u751f\u6d3b\u4e2d\u4eceATM\u673a\u53d6\u6b3e, \u5bf9\u4e8e\u7528\u6237\u6765\u8bf4,\u8981\u4e48\u64cd\u4f5c\u6210\u529f,\u7528\u6237\u62ff\u5230\u94b1, \u4f59\u989d\u51cf\u5c11\u4e86,\u589e\u52a0\u4e86\u4e00\u6761\u4ea4\u6613\u8bb0\u5f55; \u8981\u4e48\u6ca1\u62ff\u5230\u94b1,\u76f8\u5f53\u4e8e\u53d6\u6b3e\u64cd\u4f5c\u6ca1\u6709\u53d1\u751f\u3002<\/p>\n
Java\u6709\u4e24\u79cd\u65b9\u5f0f\u5b9e\u73b0\u539f\u5b50\u6027\uff1a<\/p>\n
\u4e00\u79cd\u662f\u4f7f\u7528\u9501; \u53e6\u4e00\u79cd\u5229\u7528\u5904\u7406\u5668\u7684CAS(Compare and Swap)\u6307\u4ee4\u3002<\/p>\n
\u9501\u5177\u6709\u6392\u5b83\u6027,\u4fdd\u8bc1\u5171\u4eab\u53d8\u91cf\u5728\u67d0\u4e00\u65f6\u523b\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u3002<\/p>\n
CAS\u6307\u4ee4\u76f4\u63a5\u5728\u786c\u4ef6(\u5904\u7406\u5668\u548c\u5185\u5b58)\u5c42\u6b21\u4e0a\u5b9e\u73b0,\u770b\u4f5c\u662f\u786c\u4ef6\u9501\u3002<\/p>\n
\u53ef\u89c1\u6027<\/h2>\n
\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d, \u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u67d0\u4e2a\u5171\u4eab\u53d8\u91cf\u8fdb\u884c\u66f4\u65b0\u4e4b\u540e , \u540e\u7eed\u5176\u4ed6\u7684\u7ebf\u7a0b\u53ef\u80fd\u65e0\u6cd5\u7acb\u5373\u8bfb\u5230\u8fd9\u4e2a\u66f4\u65b0\u7684\u7ed3\u679c, \u8fd9\u5c31\u662f\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u7684\u53e6\u5916\u4e00\u79cd\u5f62\u5f0f: \u53ef\u89c1\u6027(visibility)\u3002<\/p>\n
\u5982\u679c\u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u53d8\u91cf\u66f4\u65b0\u540e, \u540e\u7eed\u8bbf\u95ee\u8be5\u53d8\u91cf\u7684\u5176\u4ed6\u7ebf\u7a0b\u53ef\u4ee5\u8bfb\u5230\u66f4\u65b0\u7684\u7ed3\u679c, \u79f0\u8fd9\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u53d8\u91cf\u7684\u66f4\u65b0\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u53ef\u89c1, \u5426\u5219\u79f0\u8fd9\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u53d8\u91cf\u7684\u66f4\u65b0\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u4e0d\u53ef\u89c1\u3002<\/p>\n
\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u56e0\u4e3a\u53ef\u89c1\u6027\u95ee\u9898\u53ef\u80fd\u4f1a\u5bfc\u81f4\u5176\u4ed6\u7ebf\u7a0b\u8bfb\u53d6\u5230\u4e86\u65e7\u6570\u636e(\u810f\u6570\u636e)\u3002<\/p>\n
\u6709\u5e8f\u6027<\/h2>\n
\u6709\u5e8f\u6027(Ordering)\u662f\u6307\u5728\u4ec0\u4e48\u60c5\u51b5\u4e0b\u4e00\u4e2a\u5904\u7406\u5668\u4e0a\u8fd0\u884c\u7684\u4e00\u4e2a\u7ebf\u7a0b\u6240\u6267\u884c\u7684 \u5185\u5b58\u8bbf\u95ee\u64cd\u4f5c\u5728\u53e6\u5916\u4e00\u4e2a\u5904\u7406\u5668\u8fd0\u884c\u7684\u5176\u4ed6\u7ebf\u7a0b\u770b\u6765\u662f\u4e71\u5e8f\u7684(Out of Order)\u3002<\/p>\n
\u4e71\u5e8f\u662f\u6307\u5185\u5b58\u8bbf\u95ee\u64cd\u4f5c\u7684\u987a\u5e8f\u770b\u8d77\u6765\u53d1\u751f\u4e86\u53d8\u5316\u3002<\/p>\n
\u91cd\u6392\u5e8f<\/h3>\n
\u5728\u591a\u6838\u5904\u7406\u5668\u7684\u73af\u5883\u4e0b,\u7f16\u5199\u7684\u987a\u5e8f\u7ed3\u6784,\u8fd9\u79cd\u64cd\u4f5c\u6267\u884c\u7684\u987a\u5e8f\u53ef\u80fd\u662f\u6ca1\u6709\u4fdd\u969c\u7684\uff1a<\/h4>\n
1.\u7f16\u8bd1\u5668\u53ef\u80fd\u4f1a\u6539\u53d8\u4e24\u4e2a\u64cd\u4f5c\u7684\u5148\u540e\u987a\u5e8f;<\/p>\n
2.\u5904\u7406\u5668\u4e5f\u53ef\u80fd\u4e0d\u4f1a\u6309\u7167\u76ee\u6807\u4ee3\u7801\u7684\u987a\u5e8f\u6267\u884c;<\/p>\n
\u8fd9\u79cd\u4e00\u4e2a\u5904\u7406\u5668\u4e0a\u6267\u884c\u7684\u591a\u4e2a\u64cd\u4f5c,\u5728\u5176\u4ed6\u5904\u7406\u5668\u6765\u770b\u5b83\u7684\u987a\u5e8f\u4e0e\u76ee\u6807\u4ee3\u7801\u6307\u5b9a\u7684\u987a\u5e8f\u53ef\u80fd\u4e0d\u4e00\u6837,\u8fd9\u79cd\u73b0\u8c61\u79f0\u4e3a\u91cd\u6392\u5e8f<\/p>\n
\u91cd\u6392\u5e8f\u662f\u5bf9\u5185\u5b58\u8bbf\u95ee\u6709\u5e8f\u64cd\u4f5c\u7684\u4e00\u79cd\u4f18\u5316,\u53ef\u4ee5\u5728\u4e0d\u5f71\u54cd\u5355\u7ebf\u7a0b\u7a0b\u5e8f\u6b63\u786e\u7684\u60c5\u51b5\u4e0b\u63d0\u5347\u7a0b\u5e8f\u7684\u6027\u80fd.\u4f46\u662f,\u53ef\u80fd\u5bf9\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u7684\u6b63\u786e\u6027\u4ea7\u751f\u5f71\u54cd,\u5373\u53ef\u80fd\u5bfc\u81f4\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u3002<\/p>\n
\u91cd\u6392\u5e8f\u4e0e\u53ef\u89c1\u6027<\/span>\u95ee\u9898\u7c7b\u4f3c,\u4e0d\u662f\u5fc5\u7136\u51fa\u73b0\u7684\u3002<\/p>\n
\u4e0e\u5185\u5b58\u64cd\u4f5c\u987a\u5e8f\u6709\u5173\u7684\u51e0\u4e2a\u6982\u5ff5:<\/h4>\n
\u6e90\u4ee3\u7801\u987a\u5e8f, \u5c31\u662f\u6e90\u7801\u4e2d\u6307\u5b9a\u7684\u5185\u5b58\u8bbf\u95ee\u987a\u5e8f\u3002<\/p>\n
\u7a0b\u5e8f\u987a\u5e8f, \u5904\u7406\u5668\u4e0a\u8fd0\u884c\u7684\u76ee\u6807\u4ee3\u7801\u6240\u6307\u5b9a\u7684\u5185\u5b58\u8bbf\u95ee\u987a\u5e8f\u3002<\/p>\n
\u6267\u884c\u987a\u5e8f,\u5185\u5b58\u8bbf\u95ee\u64cd\u4f5c\u5728\u5904\u7406\u5668\u4e0a\u7684\u5b9e\u9645\u6267\u884c\u987a\u5e8f\u3002<\/p>\n
\u611f\u77e5\u987a\u5e8f,\u7ed9\u5b9a\u5904\u7406\u5668\u6240\u611f\u77e5\u5230\u7684\u8be5\u5904\u7406\u5668\u53ca\u5176\u4ed6\u5904\u7406\u5668\u7684\u5185\u5b58\u8bbf\u95ee\u64cd\u4f5c\u7684\u987a\u5e8f\u3002<\/p>\n
\u53ef\u4ee5\u628a\u91cd\u6392\u5e8f\u5206\u4e3a\u6307\u4ee4\u91cd\u6392\u5e8f\u4e0e\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f\u4e24\u79cd\uff1a<\/h4>\n
1.\u6307\u4ee4\u91cd\u6392\u5e8f\u4e3b\u8981\u662f\u7531JIT\u7f16\u8bd1\u5668,\u5904\u7406\u5668\u5f15\u8d77\u7684, \u6307\u7a0b\u5e8f\u987a\u5e8f\u4e0e\u6267\u884c\u987a\u5e8f\u4e0d\u4e00\u6837\u3002<\/p>\n
2.\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f\u662f\u7531\u9ad8\u901f\u7f13\u5b58,\u5199\u7f13\u51b2\u5668\u5f15\u8d77\u7684, \u611f\u77e5\u987a\u5e8f\u4e0e\u6267\u884c\u987a\u5e8f\u4e0d\u4e00\u81f4\u3002<\/p>\n
\u6307\u4ee4\u91cd\u6392\u5e8f<\/h3>\n
\u5728\u6e90\u7801\u987a\u5e8f\u4e0e\u7a0b\u5e8f\u987a\u5e8f\u4e0d\u4e00\u81f4,\u6216\u8005 \u7a0b\u5e8f\u987a\u5e8f\u4e0e\u6267\u884c\u987a\u5e8f\u4e0d\u4e00\u81f4\u7684\u60c5\u51b5\u4e0b,\u6211\u4eec\u5c31\u8bf4\u53d1\u751f\u4e86\u6307\u4ee4\u91cd\u6392\u5e8f(Instruction Reorder)\u3002<\/p>\n
\u6307\u4ee4\u91cd\u6392\u662f\u4e00\u79cd\u52a8\u4f5c,\u786e\u5b9e\u5bf9\u6307\u4ee4\u7684\u987a\u5e8f\u505a\u4e86\u8c03\u6574, \u91cd\u6392\u5e8f\u7684\u5bf9\u8c61\u6307\u4ee4\u3002<\/p>\n
javac\u7f16\u8bd1\u5668\u4e00\u822c\u4e0d\u4f1a\u6267\u884c\u6307\u4ee4\u91cd\u6392\u5e8f, \u800cJIT\u7f16\u8bd1\u5668\u53ef\u80fd\u6267\u884c\u6307\u4ee4\u91cd\u6392\u5e8f\u3002<\/p>\n
\u5904\u7406\u5668\u4e5f\u53ef\u80fd\u6267\u884c\u6307\u4ee4\u91cd\u6392\u5e8f, \u4f7f\u5f97\u6267\u884c\u987a\u5e8f\u4e0e\u7a0b\u5e8f\u987a\u5e8f\u4e0d\u4e00\u81f4\u3002<\/p>\n
\u6307\u4ee4\u91cd\u6392\u4e0d\u4f1a\u5bf9\u5355\u7ebf\u7a0b\u7a0b\u5e8f\u7684\u7ed3\u679c\u6b63\u786e\u6027\u4ea7\u751f\u5f71\u54cd,\u53ef\u80fd\u5bfc\u81f4\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u51fa\u73b0\u975e\u9884\u671f\u7684\u7ed3\u679c\u3002<\/p>\n
\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f<\/h3>\n
\u5b58\u50a8\u5b50\u7cfb\u7edf\u662f\u6307\u5199\u7f13\u51b2\u5668\u4e0e\u9ad8\u901f\u7f13\u5b58\u3002<\/p>\n
\u9ad8\u901f\u7f13\u5b58(Cache)\u662fCPU\u4e2d\u4e3a\u4e86\u5339\u914d\u4e0e\u4e3b\u5185\u5b58\u5904\u7406\u901f\u5ea6\u4e0d\u5339\u914d\u800c\u8bbe\u8ba1\u7684\u4e00\u4e2a\u9ad8\u901f\u7f13\u5b58\u3002<\/p>\n
\u5199\u7f13\u51b2\u5668(Store buffer, Write buffer)\u7528\u6765\u63d0\u9ad8\u5199\u9ad8\u901f\u7f13\u5b58\u64cd\u4f5c\u7684\u6548\u7387\u3002<\/p>\n
\u5373\u4f7f\u5904\u7406\u5668\u4e25\u683c\u6309\u7167\u7a0b\u5e8f\u987a\u5e8f\u6267\u884c\u4e24\u4e2a\u5185\u5b58\u8bbf\u95ee\u64cd\u4f5c,\u5728\u5b58\u50a8\u5b50\u7cfb\u7edf\u7684\u4f5c\u7528\u4e0b, \u5176\u4ed6\u5904\u7406\u5668\u5bf9\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7684\u611f\u77e5\u987a\u5e8f\u4e0e\u7a0b\u5e8f\u987a\u5e8f\u4e0d\u4e00\u81f4,\u5373\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7684\u987a\u5e8f\u987a\u5e8f\u770b\u8d77\u6765\u50cf\u662f\u53d1\u751f\u4e86\u53d8\u5316, \u8fd9\u79cd\u73b0\u8c61\u79f0\u4e3a\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f\u3002<\/p>\n
\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f\u5e76\u6ca1\u6709\u771f\u6b63\u7684\u5bf9\u6307\u4ee4\u6267\u884c\u987a\u5e8f\u8fdb\u884c\u8c03\u6574,\u800c\u662f\u9020\u6210\u4e00\u79cd\u6307\u4ee4\u6267\u884c\u987a\u5e8f\u88ab\u8c03\u6574\u7684\u73b0\u8c61\u3002<\/p>\n
\u5b58\u50a8\u5b50\u7cfb\u7edf\u91cd\u6392\u5e8f\u5bf9\u8c61\u662f\u5185\u5b58\u64cd\u4f5c\u7684\u7ed3\u679c\u3002<\/p>\n
\u4fdd\u8bc1\u5185\u5b58\u8bbf\u95ee\u7684\u987a\u5e8f\u6027<\/h3>\n
\u53ef\u4ee5\u4f7f\u7528
volatile<\/code>\u5173\u952e\u5b57,synchronized<\/code>\u5173\u952e\u5b57\u5b9e\u73b0\u6709\u5e8f\u6027\u3002<\/p>\nJava\u591a\u7ebf\u7a0b\u5185\u5b58\u6a21\u578b<\/h1>\n
<\/div><\/p>\n<\/div><\/p>\nJava\u591a\u7ebf\u7a0b\u540c\u6b65\u673a\u5236\u7b80\u4ecb<\/h1>\n
\u7ebf\u7a0b\u540c\u6b65\u673a\u5236\u662f\u4e00\u5957\u7528\u4e8e\u534f\u8c03\u7ebf\u7a0b\u4e4b\u95f4\u7684\u6570\u636e\u8bbf\u95ee\u7684\u673a\u5236.\u8be5\u673a\u5236\u53ef\u4ee5\u4fdd\u969c\u7ebf\u7a0b\u5b89\u5168\u3002<\/p>\n
Java\u5e73\u53f0\u63d0\u4f9b\u7684\u7ebf\u7a0b\u540c\u6b65\u673a\u5236\u5305\u62ec: \u9501, volatile\u5173\u952e\u5b57, final\u5173\u952e\u5b57,static\u5173\u952e\u5b57,\u4ee5\u53ca\u76f8\u5173\u7684API,\u5982
Object.wait()<\/code>\/Object.notify()<\/code>\u7b49\u3002<\/p>\n\u6bcf\u4e00\u4e2a\u670d\u52a1\u8fdb\u7a0b\u7684\u8fd0\u884c\uff0c\u90fd\u5305\u542b\u82e5\u5e72\u8fdb\u7a0b\uff08Thread\uff09\uff0c\u7ebf\u7a0b\u662f\u8c03\u5ea6\u7684\u57fa\u672c\u5355\u4f4d\uff0c\u8fdb\u7a0b\u5219\u662f\u8d44\u6e90\u62e5\u6709\u7684\u57fa\u672c\u5355\u4f4d\u3002<\/p>\n
\u7ebf\u7a0b\u6709\u81ea\u5df1\u7684\u79c1\u6709\u6570\u636e\uff0c\u6bd4\u5982\u6808\u548c\u5bc4\u5b58\u5668\uff0c\u540c\u65f6\u4e0e\u5176\u5b83\u7ebf\u7a0b\u5171\u4eab\u76f8\u540c\u7684\u865a\u62df\u5185\u5b58\u548c\u5168\u5c40\u53d8\u91cf\u7b49\u8d44\u6e90\uff0c\u5f53\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8bfb\u5199\u540c\u4e00\u4efd\u5171\u4eab\u8d44\u6e90\u7684\u65f6\u5019\uff0c\u4f1a\u5f15\u8d77\u51b2\u7a81\uff0c\u8fd9\u65f6\u5019\u5c31\u9700\u8981\u5f15\u5165\u7ebf\u7a0b\u540c\u6b65\u673a\u5236\u4f7f\u5404\u4e2a\u7ebf\u7a0b\u6392\u961f\u4e00\u4e2a\u4e00\u4e2a\u7684\u5bf9\u5171\u4eab\u8d44\u6e90\u8fdb\u884c\u64cd\u4f5c\uff0c\u800c\u4e0d\u662f\u540c\u65f6\u8fdb\u884c\u3002<\/p>\n
<\/div><\/p>\n- \n
- \u7ebf\u7a0b\u540c\u6b65\u5176\u5b9e\u5b9e\u73b0\u7684\u662f\u7ebf\u7a0b\u6392\u961f<\/li>\n
- \u9632\u6b62\u7ebf\u7a0b\u540c\u6b65\u8bbf\u95ee\u5171\u4eab\u8d44\u6e90\u9020\u6210\u51b2\u7a81<\/li>\n
- \u53d8\u91cf\u9700\u8981\u540c\u6b65\uff0c\u5e38\u91cf\u4e0d\u9700\u8981\uff08\u5e38\u91cf\u5b58\u653e\u4e8e\u65b9\u6cd5\u533a\uff09\u3002<\/li>\n
- \u591a\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u5171\u4eab\u8d44\u6e90\u7684\u4ee3\u7801\u6709\u53ef\u80fd\u662f\u540c\u4e00\u4efd\u4ee3\u7801\uff0c\u4e5f\u6709\u53ef\u80fd\u662f\u4e0d\u540c\u7684\u4ee3\u7801\uff1b\u65e0\u8bba\u662f\u5426\u6267\u884c\u540c\u4e00\u4efd\u4ee3\u7801\uff0c\u53ea\u8981\u8fd9\u4e9b\u7ebf\u7a0b\u7684\u4ee3\u7801\u8bbf\u95ee\u540c\u4e00\u4efd\u53ef\u53d8\u7684\u5171\u4eab\u8d44\u6e90\uff0c\u8fd9\u4e9b\u7ebf\u7a0b\u4e4b\u95f4\u5c31\u9700\u8981\u540c\u6b65\u3002<\/li>\n<\/ol>\n
\u7ebf\u7a0b\u540c\u6b65\u597d\u5904\uff1a<\/h3>\n
\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8bbf\u95ee\u5171\u4eab\u6570\u636e\u65f6\uff0c\u9632\u6b62\u6570\u636e\u88ab\u635f\u574f\u3002<\/p>\n
\u7ebf\u7a0b\u540c\u6b65\u5e26\u6765\u7684\u95ee\u9898\uff1a<\/h3>\n
1\u3001\u5b9e\u73b0\u6bd4\u8f83\u7e41\u7410\uff0c\u800c\u4e14\u5bb9\u6613\u51fa\u9519\u3002<\/p>\n
\u5fc5\u987b\u5bf9\u591a\u4e2a\u7ebf\u7a0b\u53ef\u80fd\u540c\u65f6\u8bbf\u95ee\u7684\u6240\u6709\u6570\u636e\uff0c\u7528\u989d\u5916\u7684\u4ee3\u7801\u5305\u56f4\u8d77\u6765\uff0c\u4ee5\u83b7\u5f97\u548c\u91ca\u653e\u4e00\u4e2a\u540c\u6b65\u9501\u3002\u8fd9\u9700\u8981\u7531\u7a0b\u5e8f\u5458\u6765\u4fdd\u8bc1\u6ca1\u6709\u9057\u6f0f\uff0c\u5bf9\u591a\u7ebf\u7a0b\u5171\u4eab\u7684\u6570\u636e\u7684\u52a0\u9501\u5de5\u4f5c\u3002\u5e76\u4e14\uff0c\u5728\u7a0b\u5e8f\u5b8c\u6210\u65f6\uff0c\u9700\u8981\u8fdb\u884c\u538b\u529b\u6d4b\u8bd5\u4ee5\u4fdd\u8bc1\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u65f6\uff0c\u7ed3\u679c\u5982\u9884\u671f\u3002<\/p>\n
2\u3001\u5b83\u4f1a\u635f\u5bb3\u6027\u80fd\u3002<\/p>\n
\u83b7\u53d6\u548c\u91ca\u653e\u4e00\u4e2a\u9501\u662f\u9700\u8981\u65f6\u95f4\u7684\u3002\u56e0\u4e3a\u9700\u8981\u989d\u5916\u7684\u8c03\u7528\u4e00\u4e9b\u65b9\u6cd5\uff0c\u5e76\u4e14\u9700\u8981\u534f\u8c03\u8c03\u5ea6\u4e0b\u4e00\u4e2a\u83b7\u5f97\u9501\u7684\u7ebf\u7a0b\u3002<\/p>\n
3\u3001\u6bcf\u6b21\u53ea\u80fd\u5141\u8bb8\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u8d44\u6e90\u3002\u8fd9\u662f\u9501\u7684\u5168\u90e8\u610f\u4e49\u6240\u5728\uff0c\u4f46\u4e5f\u662f\u95ee\u9898\u6240\u5728\uff0c\u56e0\u4e3a\u963b\u585e\u4e00\u4e2a\u7ebf\u7a0b\u53ef\u80fd\u4f1a\u9020\u6210\u66f4\u591a\u7684\u7ebf\u7a0b\u88ab\u521b\u5efa\u3002<\/p>\n
\u7ebf\u7a0b\u540c\u6b65\u5efa\u8bae\uff1a<\/h3>\n
1\u3001\u7ebf\u7a0b\u540c\u6b65\u5e76\u4e0d\u662f\u4e00\u4ef6\u597d\u4e8b\uff0c\u8bbe\u8ba1\u81ea\u5df1\u7684\u5e94\u7528\u7a0b\u5e8f\u662f\u5e94\u914c\u60c5\u8003\u8651\uff0c\u5c3d\u91cf\u907f\u514d\u7ebf\u7a0b\u540c\u6b65\u3002<\/p>\n
2\u3001\u907f\u514d\u4f7f\u7528\u4e00\u4e9b\u5171\u4eab\u6570\u636e\uff0c\u5982\u9759\u6001\u5b57\u6bb5\u3002\uff08\u5982\u679c\u6709\u591a\u7ebf\u7a0b\u540c\u65f6\u8bfb\u5199\u8fd9\u4e2a\u9759\u6001\u5b57\u6bb5\u5c31\u6709\u95ee\u9898\uff09<\/p>\n
3\u3001\u8bd5\u7740\u7528\u503c\u7c7b\u578b\uff0c\u56e0\u4e3a\u503c\u7c7b\u578b\u603b\u662f\u4f1a\u88ab\u590d\u5236\uff0c\u6bcf\u4e2a\u7ebf\u7a0b\u64cd\u4f5c\u7684\u90fd\u662f\u81ea\u5df1\u7684\u90a3\u4e2a\u526f\u672c\u3002<\/p>\n
4\u3001\u591a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u6570\u636e\u8fdb\u884c\u53ea\u8bfb\u8bbf\u95ee\u662f\u6ca1\u6709\u4efb\u4f55\u95ee\u9898\u7684\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u9501<\/h1>\n
\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u7684\u4ea7\u751f\u524d\u63d0\u662f\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u8bbf\u95ee\u5171\u4eab\u6570\u636e\u3002<\/p>\n
\u5c06\u591a\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u6570\u636e\u7684\u5e76\u53d1\u8bbf\u95ee\u8f6c\u6362\u4e3a\u4e32\u884c\u8bbf\u95ee,\u5373\u4e00\u4e2a\u5171\u4eab\u6570\u636e\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee.\u9501\u5c31\u662f\u590d\u7528\u8fd9\u79cd\u601d\u8def\u6765\u4fdd\u969c\u7ebf\u7a0b\u5b89\u5168\u7684\u3002<\/p>\n
\u9501(Lock)\u53ef\u4ee5\u7406\u89e3\u4e3a\u5bf9\u5171\u4eab\u6570\u636e\u8fdb\u884c\u4fdd\u62a4\u7684\u4e00\u4e2a\u8bb8\u53ef\u8bc1. \u5bf9\u4e8e\u540c\u4e00\u4e2a\u8bb8\u53ef\u8bc1\u4fdd\u62a4\u7684\u5171\u4eab\u6570\u636e\u6765\u8bf4,\u4efb\u4f55\u7ebf\u7a0b\u60f3\u8981\u8bbf\u95ee\u8fd9\u4e9b\u5171\u4eab\u6570\u636e\u5fc5\u987b\u5148\u6301\u6709\u8be5\u8bb8\u53ef\u8bc1. \u4e00\u4e2a\u7ebf\u7a0b\u53ea\u6709\u5728\u6301\u6709\u8bb8\u53ef\u8bc1\u7684\u60c5\u51b5\u4e0b\u624d\u80fd\u5bf9\u8fd9\u4e9b\u5171\u4eab\u6570\u636e\u8fdb\u884c\u8bbf\u95ee; \u5e76\u4e14\u4e00\u4e2a\u8bb8\u53ef\u8bc1\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709; \u8bb8\u53ef\u8bc1\u7ebf\u7a0b\u5728\u7ed3\u675f\u5bf9\u5171\u4eab\u6570\u636e\u7684\u8bbf\u95ee\u540e\u5fc5\u987b\u91ca\u653e\u5176\u6301\u6709\u7684\u8bb8\u53ef\u8bc1\u3002<\/p>\n
\u4e00\u7ebf\u7a0b\u5728\u8bbf\u95ee\u5171\u4eab\u6570\u636e\u524d\u5fc5\u987b\u5148\u83b7\u5f97\u9501; \u83b7\u5f97\u9501\u7684\u7ebf\u7a0b\u79f0\u4e3a\u9501\u7684\u6301\u6709\u7ebf\u7a0b; \u4e00\u4e2a\u9501\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709. \u9501\u7684\u6301\u6709\u7ebf\u7a0b\u5728\u83b7\u5f97\u9501\u4e4b\u540e \u548c\u91ca\u653e\u9501\u4e4b\u524d\u8fd9\u6bb5\u65f6\u95f4\u6240\u6267\u884c\u7684\u4ee3\u7801\u79f0\u4e3a\u4e34\u754c\u533a(Critical Section)\u3002<\/p>\n
\u9501\u5177\u6709\u6392\u4ed6\u6027(Exclusive)<\/span>, \u5373\u4e00\u4e2a\u9501\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709.\u8fd9\u79cd\u9501\u79f0\u4e3a\u6392\u5b83\u9501\u6216\u4e92\u65a5\u9501(Mutex)<\/span>\u3002<\/p>\n
<\/div><\/p>\nJVM\u628a\u9501\u5206\u4e3a\u5185\u90e8\u9501\u548c\u663e\u793a\u9501\u4e24\u79cd. \u5185\u90e8\u9501\u901a\u8fc7
synchronized<\/code>\u5173\u952e\u5b57\u5b9e\u73b0; \u663e\u793a\u9501\u901a\u8fc7java.concurrent.locks.Lock<\/code>\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b\u5b9e\u73b0\u7684\u3002<\/p>\nJava\u7ebf\u7a0b\u9501\u7684\u4f5c\u7528<\/h2>\n
\u9501\u53ef\u4ee5\u5b9e\u73b0\u5bf9\u5171\u4eab\u6570\u636e\u7684\u5b89\u5168\u8bbf\u95ee. \u4fdd\u969c\u7ebf\u7a0b\u7684\u539f\u5b50\u6027,\u53ef\u89c1\u6027\u4e0e\u6709\u5e8f\u6027\u3002<\/p>\n
\u9501\u662f\u901a\u8fc7\u4e92\u65a5\u4fdd\u969c\u539f\u5b50\u6027. \u4e00\u4e2a\u9501\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709, \u8fd9\u5c31\u4fdd\u8bc1\u4e34\u754c\u533a\u7684\u4ee3\u7801\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c.\u4f7f\u5f97\u4e34\u754c\u533a\u4ee3\u7801\u6240\u6267\u884c\u7684\u64cd\u4f5c\u81ea\u7136\u800c\u7136\u7684\u5177\u6709\u4e0d\u53ef\u5206\u5272\u7684\u7279\u6027,\u5373\u5177\u5907\u4e86
\u539f\u5b50\u6027<\/code>\u3002<\/p>\n\u53ef\u89c1\u6027\u7684\u4fdd\u969c\u662f\u901a\u8fc7\u5199\u7ebf\u7a0b\u51b2\u5237\u5904\u7406\u5668\u7684\u7f13\u5b58\u548c\u8bfb\u7ebf\u7a0b\u5237\u65b0\u5904\u7406\u5668\u7f13\u5b58\u8fd9\u4e24\u4e2a\u52a8\u4f5c\u5b9e\u73b0\u7684. \u5728java\u5e73\u53f0\u4e2d,\u9501\u7684\u83b7\u5f97\u9690\u542b\u7740\u5237\u65b0\u5904\u7406\u5668\u7f13\u5b58\u7684\u52a8\u4f5c, \u9501\u7684\u91ca\u653e\u9690\u542b\u7740\u51b2\u5237\u5904\u7406\u5668\u7f13\u5b58\u7684\u52a8\u4f5c\u3002<\/p>\n
\u9501\u80fd\u591f\u4fdd\u969c\u6709\u5e8f\u6027.\u5199\u7ebf\u7a0b\u5728\u4e34\u754c\u533a\u6240\u6267\u884c\u7684\u5728\u8bfb\u7ebf\u7a0b\u6240\u6267\u884c\u7684\u4e34\u754c\u533a\u770b\u6765\u50cf\u662f\u5b8c\u5168\u6309\u7167\u6e90\u7801\u987a\u5e8f\u6267\u884c\u7684\u3002<\/p>\n
\u6ce8\u610f:<\/p>\n
\u4f7f\u7528\u9501\u4fdd\u969c\u7ebf\u7a0b\u7684\u5b89\u5168\u6027,\u5fc5\u987b\u6ee1\u8db3\u4ee5\u4e0b\u6761\u4ef6:<\/p>\n
- \n
- \u8fd9\u4e9b\u7ebf\u7a0b\u5728\u8bbf\u95ee\u5171\u4eab\u6570\u636e\u65f6\u5fc5\u987b\u4f7f\u7528\u540c\u4e00\u4e2a\u9501\u3002<\/li>\n
- \u5373\u4f7f\u662f\u8bfb\u53d6\u5171\u4eab\u6570\u636e\u7684\u7ebf\u7a0b\u4e5f\u9700\u8981\u4f7f\u7528\u540c\u6b65\u9501\u3002<\/li>\n<\/ul>\n
\u7ebf\u7a0b\u9501\u76f8\u5173\u7684\u6982\u5ff5<\/h2>\n
\u53ef\u91cd\u5165\u6027<\/h3>\n
\u53ef\u91cd\u5165\u6027(Reentrancy)\u63cf\u8ff0\u8fd9\u6837\u4e00\u4e2a\u95ee\u9898: \u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709\u8be5\u9501\u7684\u65f6\u5019\u80fd\u518d\u6b21(\u591a\u6b21)\u7533\u8bf7\u8be5\u9501\u3002<\/p>\n
\u5982\u679c\u4e00\u4e2a\u7ebf\u7a0b\u6301\u6709\u4e00\u4e2a\u9501\u7684\u65f6\u5019\u8fd8\u80fd\u591f\u7ee7\u7eed\u6210\u529f\u7533\u8bf7\u8be5\u9501,\u79f0\u8be5\u9501\u662f\u53ef\u91cd\u5165\u7684, \u5426\u5219\u5c31\u79f0\u8be5\u9501\u4e3a\u4e0d\u53ef\u91cd\u5165\u7684\u3002<\/p>\n
\u9501\u7684\u4e89\u7528\u4e0e\u8c03\u5ea6<\/h3>\n
Java\u5e73\u53f0\u4e2d\u5185\u90e8\u9501\u5c5e\u4e8e\u975e\u516c\u5e73\u9501, \u663e\u793aLock\u9501\u65e2\u652f\u6301\u516c\u5e73\u9501\u53c8\u652f\u6301\u975e\u516c\u5e73\u9501\u3002<\/p>\n
\u9501\u7684\u7c92\u5ea6<\/h3>\n
\u4e00\u4e2a\u9501\u53ef\u4ee5\u4fdd\u62a4\u7684\u5171\u4eab\u6570\u636e\u7684\u6570\u91cf\u5927\u5c0f\u79f0\u4e3a\u9501\u7684\u7c92\u5ea6\u3002<\/p>\n
\u9501\u4fdd\u62a4\u5171\u4eab\u6570\u636e\u91cf\u5927,\u79f0\u8be5\u9501\u7684\u7c92\u5ea6\u7c97, \u5426\u5219\u5c31\u79f0\u8be5\u9501\u7684\u7c92\u5ea6\u7ec6\u3002<\/p>\n
\u9501\u7684\u7c92\u5ea6\u8fc7\u7c97\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u5728\u7533\u8bf7\u9501\u65f6\u4f1a\u8fdb\u884c\u4e0d\u5fc5\u8981\u7684\u7b49\u5f85.\u9501\u7684\u7c92\u5ea6\u8fc7\u7ec6\u4f1a\u589e\u52a0\u9501\u8c03\u5ea6\u7684\u5f00\u9500\u3002<\/p>\n
Java\u591a\u7ebf\u7a0b\u540c\u6b65\u4ee3\u7801\u5757Synchronized<\/h1>\n
Java\u4e2d\u7684\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u4e00\u4e2a\u4e0e\u4e4b\u5173\u8054\u7684\u5185\u90e8\u9501(Intrinsic lock). \u8fd9\u79cd\u9501\u4e5f\u79f0\u4e3a\u76d1\u89c6\u5668(Monitor), \u8fd9\u79cd\u5185\u90e8\u9501\u662f\u4e00\u79cd\u6392\u4ed6\u9501,\u53ef\u4ee5\u4fdd\u969c\u539f\u5b50\u6027,\u53ef\u89c1\u6027\u4e0e\u6709\u5e8f\u6027\u3002<\/p>\n
\u5185\u90e8\u9501\u662f\u901a\u8fc7
synchronized<\/code>\u5173\u952e\u5b57\u5b9e\u73b0\u7684.synchronized<\/code>\u5173\u952e\u5b57\u4fee\u9970\u4ee3\u7801\u5757,\u4fee\u9970\u8be5\u65b9\u6cd5\u3002<\/p>\n\u4fee\u9970\u4ee3\u7801\u5757\u7684\u8bed\u6cd5:<\/p>\n
synchronized( \u5bf9\u8c61\u9501 ) {\n \u540c\u6b65\u4ee3\u7801\u5757,\u53ef\u4ee5\u5728\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u8bbf\u95ee\u5171\u4eab\u6570\u636e\n}\n<\/code><\/pre>\n\u4fee\u9970\u5b9e\u4f8b\u65b9\u6cd5\u5c31\u79f0\u4e3a\u540c\u6b65\u5b9e\u4f8b\u65b9\u6cd5<\/span><\/p>\n
\u4fee\u9970\u9759\u6001\u65b9\u6cd5\u79f0\u79f0\u4e3a\u540c\u6b65\u9759\u6001\u65b9\u6cd5<\/span><\/p>\n
synchronized\u540c\u6b65\u4ee3\u7801\u5757\u5b9e\u4f8b\uff1a<\/h3>\n
this\u9501\u5bf9\u8c61<\/h4>\n
public class Test01 {\n\n public void mm(){\n synchronized (this){\n for (int i=0;i<=100;i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n}\n ---\n @Test\n public void Test10CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test01 t1 = new Test01();\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n }\n<\/code><\/pre>\n\u5982\u679c\u7ebf\u7a0b\u7684\u9501\u4e0d\u540c, \u4e0d\u80fd\u5b9e\u73b0\u540c\u6b65,\u60f3\u8981\u540c\u6b65\u5fc5\u987b\u4f7f\u7528\u540c\u4e00\u4e2a\u9501\u5bf9\u8c61<\/p>\n
@Test\n public void Test11CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test01 t1 = new Test01();\n Test01 t2 = new Test01();\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t2.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft2\u5bf9\u8c61\n }\n }).start();\n }\n<\/code><\/pre>\n\u4f7f\u7528\u4e00\u4e2a\u5e38\u91cf\u5bf9\u8c61\u4f5c\u4e3a\u9501\u5bf9\u8c61<\/h4>\n
public class Test01 {\n\n \/\/\u5b9a\u4e49\u4e00\u4e2a\u5e38\u91cf\n public static final Object obj = new Object();\n\n public void mm(){\n synchronized (obj){\n for (int i=0;i<=100;i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n}\n\n @Test\n public void Test12CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test01 t1 = new Test01();\n Test01 t2 = new Test01();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t2.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft2\u5bf9\u8c61\n }\n }).start();\n }\n<\/code><\/pre>\n\u4f7f\u7528\u4e00\u4e2a\u5e38\u91cf\u5bf9\u8c61\u4f5c\u4e3a\u9501\u5bf9\u8c61,\u4e0d\u540c\u65b9\u6cd5\u4e2d \u7684\u540c\u6b65\u4ee3\u7801\u5757\u4e5f\u53ef\u4ee5\u540c\u6b65<\/h4>\n
public class Test01 {\n\n \/\/\u5b9a\u4e49\u4e00\u4e2a\u5e38\u91cf\n public static final Object obj = new Object();\n\n \/\/\u65b9\u6cd51\n public void mm(){\n \/\/\u4f7f\u7528\u4e00\u4e2a\u5e38\u91cf\u5bf9\u8c61\u4f5c\u4e3a\u9501\u5bf9\u8c61\n synchronized (obj){\n for (int i=0;i<=100;i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n \/\/\u65b9\u6cd52\n public void mmm(){\n \/\/\u4f7f\u7528\u4e00\u4e2a\u5e38\u91cf\u5bf9\u8c61\u4f5c\u4e3a\u9501\u5bf9\u8c61\n synchronized (obj){\n for (int i=0;i<=100;i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n}\n\n @Test\n public void Test13CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test01 t1 = new Test01();\n Test01 t2 = new Test01();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t2.mmm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft2\u5bf9\u8c61\n }\n }).start();\n }\n<\/code><\/pre>\nJava\u591a\u7ebf\u7a0b\u540c\u6b65\u65b9\u6cd5<\/h1>\n
synchronized\u540c\u6b65\u5b9e\u4f8b\u65b9\u6cd5<\/h3>\n
\u9ed8\u8ba4\u7684\u9501\u5bf9\u8c61\u662fthis\u5bf9\u8c61<\/h4>\n
public class Test02 {\n public void mm(){\n synchronized (this){\n for (int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n\n public synchronized void mmm (){\n for (int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n}\n\n @Test\n public void Test14CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test02 t1 = new Test02();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n\/\/ t1.mmm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u4e5f\u662fobj\u5bf9\u8c61, \u53ef\u4ee5\u540c\u6b65\n new Test02().mmm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u662f\u521a\u521anew\u521b\u5efa\u7684\u4e00\u4e2a\u65b0\u5bf9\u8c61,\u4e0d\u662f\u540c\u4e00\u4e2a\u9501\u5bf9\u8c61\u4e0d\u80fd\u540c\u6b65\n }\n }).start();\n }\n<\/code><\/pre>\nsynchronized\u540c\u6b65\u9759\u6001\u65b9\u6cd5<\/h3>\n
\u9ed8\u8ba4\u7684\u9501\u5bf9\u8c61\u662f\u5f53\u524d\u7c7b\u7684\u8fd0\u884c\u65f6\u7c7b\u5bf9\u8c61,
Test03.class<\/code>, \u6709\u4eba\u79f0\u5b83\u4e3a\u7c7b\u9501<\/p>\npublic class Test02 {\n public void mm(){\n synchronized (this){\n for (int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n }\n\n public synchronized void mmm (){\n for (int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n}\n----------\n @Test\n public void Test14CurrentThread(){\n \/\/\u521b\u5efa\u4e24\u4e2a\u7ebf\u7a0b,\u5206\u522b\u8c03\u7528mm()\u65b9\u6cd5\n Test02 t1 = new Test02();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n t1.mm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u5c31\u662ft1\u5bf9\u8c61\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n\/\/ t1.mmm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u4e5f\u662fobj\u5bf9\u8c61, \u53ef\u4ee5\u540c\u6b65\n new Test02().mmm();\/\/\u4f7f\u7528\u7684\u9501\u5bf9\u8c61this\u662f\u521a\u521anew\u521b\u5efa\u7684\u4e00\u4e2a\u65b0\u5bf9\u8c61,\u4e0d\u662f\u540c\u4e00\u4e2a\u9501\u5bf9\u8c61\u4e0d\u80fd\u540c\u6b65\n }\n }).start();\n }\n<\/code><\/pre>\n\u540c\u6b65\u65b9\u6cd5\u4e0e\u540c\u6b65\u4ee3\u7801\u5757\u5982\u4f55\u9009\u62e9\uff1f–>\u540c\u6b65\u65b9\u6cd5\u9501\u7684\u7c92\u5ea6\u7c97, \u6267\u884c\u6548\u7387\u4f4e, \u540c\u6b65\u4ee3\u7801\u5757\u6267\u884c\u6548\u7387\u9ad8<\/p>\n
public class Test03 {\n \/**\n * \u540c\u6b65\u65b9\u6cd5, \u6267\u884c\u6548\u7387\u4f4e\n *\/\n public synchronized void doLongTimeTask(){\n try {\n System.out.println(\"Task Begin\");\n Thread.sleep(3000);\n for(int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \"-->\" + i);\n }\n System.out.println(\"Task end\");\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n\n \/**\n * \u540c\u6b65\u4ee3\u7801\u5757,\u9501\u7684\u7c92\u5ea6\u7ec6, \u6267\u884c\u6548\u7387\u9ad8\n *\/\n public void doLongTimeTask2(){\n try {\n System.out.println(\"Task Begin\");\n Thread.sleep(3000);\n synchronized (this){\n for(int i = 1; i <= 100; i++){\n System.out.println(Thread.currentThread().getName() + \"-->\" + i);\n }\n }\n System.out.println(\"Task end\");\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n}\n\n-----\n @Test\n public void Test15CurrentThread(){\n Test03 t3 = new Test03();\n new Thread(new Runnable() {\n @Override\n public void run() {\n t3.doLongTimeTask();\n }\n }).start();\n new Thread(new Runnable() {\n @Override\n public void run() {\n t3.doLongTimeTask2();\n }\n }).start();\n }\n<\/code><\/pre>\nJava\u591a\u7ebf\u7a0b\u810f\u8bfb<\/h1>\n
\u810f\u8bfb:<\/h3>\n
\u51fa\u73b0\u8bfb\u53d6\u5c5e\u6027\u503c\u51fa\u73b0\u4e86\u4e00\u4e9b\u610f\u5916, \u8bfb\u53d6\u7684\u662f\u4e2d\u95f4\u503c,\u800c\u4e0d\u662f\u4fee\u6539\u4e4b\u540e\u7684\u503c.<\/p>\n
\u51fa\u73b0\u810f\u8bfb\u7684\u539f\u56e0\u662f:\u5bf9\u5171\u4eab\u6570\u636e\u7684\u4fee\u6539\u4e0e\u5bf9\u5171\u4eab\u6570\u636e\u7684\u8bfb\u53d6\u4e0d\u540c\u6b65<\/p>\n
\u89e3\u51b3\u65b9\u6cd5:<\/p>\n
\u4e0d\u4ec5\u5bf9\u4fee\u6539\u6570\u636e\u7684\u4ee3\u7801\u5757\u8fdb\u884c\u540c\u6b65,\u8fd8\u8981\u5bf9\u8bfb\u53d6\u6570\u636e\u7684\u4ee3\u7801\u5757\u540c\u6b65<\/p>\n
public class Test04 {\n public static void main(String[] args) throws InterruptedException {\n PublicValue publicValue = new PublicValue();\n SubThread thread = new SubThread(publicValue);\n thread.start();\n\n \/\/\u4e3a\u4e86\u786e\u5b9a\u8bbe\u7f6e\u6210\u529f\n Thread.sleep(100);\n \/\/\u5728main\u7ebf\u7a0b\u4e2d\u8bfb\u53d6\u7528\u6237\u540d,\u5bc6\u7801\n publicValue.getValue();\n }\n\n \/**\n * \u5b9a\u4e49\u7ebf\u7a0b,\u8bbe\u7f6e\u7528\u6237\u540d\u548c\u5bc6\u7801\n *\/\n static class SubThread extends Thread{\n private PublicValue publicValue;\n public SubThread( PublicValue publicValue){\n this.publicValue = publicValue;\n }\n\n @Override\n public void run() {\n publicValue.setValue(\"test\", \"test\");\n }\n }\n\n static class PublicValue{\n private String name = \"glj\";\n private String pwd = \"glj123\";\n\n public synchronized void getValue(){\n System.out.println(Thread.currentThread().getName() + \", getter -- name: \" + name + \",--pwd: \" + pwd);\n }\n\n public synchronized void setValue(String name, String pwd){\n this.name = name;\n try {\n \/\/\u6a21\u62df\u64cd\u4f5cname\u5c5e\u6027\u9700\u8981\u4e00\u5b9a\u65f6\u95f4\n Thread.sleep(1000);\n this.pwd = pwd;\n System.out.println(Thread.currentThread().getName() + \", setter --name:\" + name + \", --pwd: \" + pwd );\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n }\n}\n<\/code><\/pre>\nJava\u591a\u7ebf\u7a0b\u51fa\u73b0\u5f02\u5e38\u4f1a\u81ea\u52a8\u91ca\u653e\u9501<\/h1>\n
\u540c\u6b65\u8fc7\u7a0b\u4e2d\u7ebf\u7a0b\u51fa\u73b0\u5f02\u5e38, \u4f1a\u81ea\u52a8\u91ca\u653e\u9501\u5bf9\u8c61<\/p>\n
public class Test05 {\n public static void main(String[] args) {\n Test05 t5 = new Test05();\n new Thread(new Runnable() {\n @Override\n public void run() {\n t5.m1();\n }\n }).start();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n Test05.m2();\n }\n }).start();\n }\n \/\/\u5b9a\u4e49\u65b9\u6cd5,\u6253\u5370100\u884c\u5b57\u7b26\u4e32\n public void m1(){\n \/\/\u4f7f\u7528\u5f53\u524d\u7c7b\u7684\u8fd0\u884c\u65f6\u7c7b\u5bf9\u8c61\u4f5c\u4e3a\u9501\u5bf9\u8c61,\u53ef\u4ee5\u7b80\u5355\u7684\u7406\u89e3\u4e3a\u628aTest05\u7c7b\u7684\u5b57\u8282\u7801\u6587\u4ef6\u4f5c\u4e3a\u9501\u5bf9\u8c61\n synchronized (Test05.class){\n for (int i = 1; i <= 100; i++) {\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n if ( i == 50){\n \/\/\u628a\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3aint\u7c7b\u578b\u65f6,\u5982\u679c\u5b57\u7b26\u4e32\u4e0d\u7b26\u5408 \u6570\u5b57\u683c\u5f0f\u4f1a\u4ea7\u751f\u5f02\u5e38\n Integer.parseInt(\"abc\");\n }\n }\n }\n }\n \/\/\u4f7f\u7528synchronized\u4fee\u9970\u9759\u6001\u65b9\u6cd5,\u540c\u6b65\u9759\u6001\u65b9\u6cd5, \u9ed8\u8ba4\u8fd0\u884c\u65f6\u7c7bTest05.class\u4f5c\u4e3a\u9501\u5bf9\u8c61\n public synchronized static void m2(){\n for (int i = 1; i <= 100; i++) {\n System.out.println(Thread.currentThread().getName() + \" --> \" + i);\n }\n }\n}\n<\/code><\/pre>\nJava\u591a\u7ebf\u7a0b\u6b7b\u9501<\/h1>\n
\u6b7b\u9501\uff1a<\/h3>\n
\u5728\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u4e2d,\u540c\u6b65\u65f6\u53ef\u80fd\u9700\u8981\u4f7f\u7528\u591a\u4e2a\u9501,\u5982\u679c\u83b7\u5f97\u9501\u7684\u987a\u5e8f\u4e0d\u4e00\u81f4,\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6b7b\u9501<\/p>\n
\u5982\u4f55\u907f\u514d\u6b7b\u9501?\u5f53\u9700\u8981\u83b7\u5f97\u591a\u4e2a\u9501\u65f6,\u6240\u6709\u7ebf\u7a0b\u83b7\u5f97\u9501\u7684\u987a\u5e8f\u4fdd\u6301\u4e00\u81f4\u5373\u53ef<\/p>\n
\u4e0b\u9762\u4f8b\u5b50\u4f1a\u9020\u6210\u6b7b\u9501:<\/p>\n
public class Test06 {\n\n public static void main(String[] args) {\n SubThread t1 = new SubThread();\n t1.setName(\"a\");\n t1.start();\n\n SubThread t2 = new SubThread();\n t2.setName(\"b\");\n t2.start();\n }\n\n static class SubThread extends Thread{\n private static final Object lock1 = new Object();\n private static final Object lock2 = new Object();\n\n @Override\n public void run() {\n if (\"a\".equals(Thread.currentThread().getName())){\n synchronized (lock1){\n System.out.println(\"a\u7ebf\u7a0b\u83b7\u5f97\u4e86lock1\u9501,\u8fd8\u9700\u8981\u83b7\u5f97lock2\u9501\");\n synchronized (lock2){\n System.out.println(\"a\u7ebf\u7a0b\u83b7\u5f97lock1\u540e\u53c8\u83b7\u5f97\u4e86lock2,\u53ef\u4ee5\u60f3\u5e72\u4efb\u4f55\u60f3\u5e72\u7684\u4e8b\");\n }\n }\n }\n if (\"b\".equals(Thread.currentThread().getName())){\n synchronized (lock2){\n System.out.println(\"b\u7ebf\u7a0b\u83b7\u5f97\u4e86lock2\u9501,\u8fd8\u9700\u8981\u83b7\u5f97lock1\u9501\");\n synchronized (lock1){\n System.out.println(\"b\u7ebf\u7a0b\u83b7\u5f97lock2\u540e\u53c8\u83b7\u5f97\u4e86lock1,\u53ef\u4ee5\u60f3\u5e72\u4efb\u4f55\u60f3\u5e72\u7684\u4e8b\");\n }\n }\n }\n }\n }\n}\n\n--------\n<\/code><\/pre>\n\u6240\u6709\u7ebf\u7a0b\u83b7\u5f97\u9501\u7684\u987a\u5e8f\u4fdd\u6301\u4e00\u81f4\u5373\u53ef,\u5c31\u662f\u628a\u7ebf\u7a0bb\u4e5f\u662f\u5148\u83b7\u53d6lock1\u518d\u83b7\u53d6lock2\u5373\u53ef<\/p>\n
Java volatile\u5173\u952e\u5b57\u7684\u4f5c\u7528<\/h1>\n
volatile\u7684\u4f5c\u7528\u53ef\u4ee5\u5f3a\u5236\u7ebf\u7a0b\u4ece\u516c\u5171\u5185\u5b58\u4e2d\u8bfb\u53d6\u53d8\u91cf\u7684\u503c,\u800c\u4e0d\u662f\u4ece\u5de5\u4f5c\u5185\u5b58\u4e2d\u8bfb\u53d6<\/p>\n
public class Test7 {\n\n public static void main(String[] args) throws InterruptedException {\n \/\/\u521b\u5efaPrintString\u5bf9\u8c61\n PrintString printString = new PrintString();\n\n new Thread(new Runnable() {\n @Override\n public void run() {\n printString.printStringMethod();\n }\n }).start();\n\n \/\/main\u7ebf\u7a0b\u7761\u77201000\u6beb\u79d2\n Thread.sleep(1000);\n System.out.println(\"\u5728main\u7ebf\u7a0b\u4e2d\u4fee\u6539\u6253\u5370\u6807\u5fd7\");\n printString.setContinuePrint(false);\n }\n\n static class PrintString{\n private volatile boolean continuePrint = true;\n\n public PrintString setContinuePrint(boolean continuePrint) {\n this.continuePrint = continuePrint;\n return this;\n }\n\n public void printStringMethod(){\n System.out.println(Thread.currentThread().getName() + \"\u5f00\u59cb....\");\n while ( continuePrint ){\n\n }\n System.out.println(Thread.currentThread().getName() + \"\u7ed3\u675f++++++++++++++\");\n }\n\n }\n\n}\n<\/code><\/pre>\nvolatile\u4e0esynchronized\u6bd4\u8f83<\/h3>\n
volatile<\/code>\u5173\u952e\u5b57\u662f\u7ebf\u7a0b\u540c\u6b65\u7684\u8f7b\u91cf\u7ea7\u5b9e\u73b0,\u6240\u4ee5volatile<\/code>\u6027\u80fd\u80af\u5b9a\u6bd4synchronized<\/code>\u8981\u597d;<\/p>\nvolatile<\/code>\u53ea\u80fd\u4fee\u9970\u53d8\u91cf,\u800csynchronized<\/code>\u53ef\u4ee5\u4fee\u9970\u65b9\u6cd5,\u4ee3\u7801\u5757. \u968f\u7740JDK\u65b0\u7248\u672c\u7684\u53d1\u5e03,synchronized<\/code>\u7684\u6267\u884c\u6548\u7387\u4e5f\u6709\u8f83\u5927\u7684\u63d0\u5347,\u5728\u5f00\u53d1\u4e2d\u4f7f\u7528sychronized<\/code>\u7684\u6bd4\u7387\u8fd8\u662f\u5f88\u5927\u7684\u3002<\/p>\n\u591a\u7ebf\u7a0b\u8bbf\u95ee
volatile<\/code>\u53d8\u91cf\u4e0d\u4f1a\u53d1\u751f\u963b\u585e,\u800csynchronized<\/code>\u53ef\u80fd\u4f1a\u963b\u585e\u3002<\/p>\nvolatile<\/code>\u80fd\u4fdd\u8bc1\u6570\u636e\u7684\u53ef\u89c1\u6027,\u4f46\u662f\u4e0d\u80fd\u4fdd\u8bc1\u539f\u5b50\u6027; \u800csynchronized<\/code>\u53ef\u4ee5\u4fdd\u8bc1\u539f\u5b50\u6027,\u4e5f\u53ef\u4ee5\u4fdd\u8bc1\u53ef\u89c1\u6027\u3002<\/p>\n\u5173\u952e\u5b57
volatile<\/code>\u89e3\u51b3\u7684\u662f\u53d8\u91cf\u5728\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u53ef\u89c1\u6027;synchronized<\/code>\u5173\u952e\u5b57\u89e3\u51b3\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u8bbf\u95ee\u516c\u5171\u8d44\u6e90\u7684\u540c\u6b65\u6027\u3002<\/p>\nvolatile\u5173\u952e\u5b57\u589e\u52a0\u4e86\u5b9e\u4f8b\u53d8\u91cf\u5728\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u53ef\u89c1\u6027,\u4f46\u662f\u4e0d\u5177\u5907\u539f\u5b50\u6027\u3002<\/h3>\n
Java\u539f\u5b50\u7c7b\u81ea\u589e\u81ea\u51cf\u64cd\u4f5c<\/h1>\n
\u6211\u4eec\u77e5\u9053i++\u64cd\u4f5c\u4e0d\u662f\u539f\u5b50\u64cd\u4f5c, \u9664\u4e86\u4f7f\u7528
Synchronized<\/code>\u8fdb\u884c\u540c\u6b65\u5916,\u4e5f\u53ef\u4ee5\u4f7f\u7528AtomicInteger\/AtomicLong<\/code>\u539f\u5b50\u7c7b\u8fdb\u884c\u5b9e\u73b0\u3002<\/p>\npublic class Test08 {\n public static void main(String[] args) throws InterruptedException {\n \/\/\u5728main\u7ebf\u7a0b\u4e2d\u521b\u5efa10\u4e2a\u5b50\u7ebf\u7a0b\n for (int i = 0; i < 1000; i++) {\n new MyThread().start();\n }\n Thread.sleep(1000);\n System.out.println( MyThread.count.get());\n }\n\n static class MyThread extends Thread{\n private static AtomicInteger count = new AtomicInteger();\n\n public static void addCounter(){\n for (int i = 0; i < 10000; i++) {\n \/\/\u81ea\u589e\u7684\u540e\u7f00\u5f62\u5f0f\n count.getAndIncrement();\n }\n System.out.println(Thread.currentThread().getName() + \" count=\" + count.get());\n }\n\n @Override\n public void run() {\n addCounter();\n }\n }\n}\n<\/code><\/pre>\nAtomicInteger<\/code>\u5177\u4f53\u7684\u7528\u6cd5\uff1ahttps:\/\/www.jianshu.com\/p\/e5102928f7b2<\/p>\nJava CAS\u591a\u7ebf\u7a0b<\/h1>\n
CAS(Compare And Swap)\u662f\u7531\u786c\u4ef6\u5b9e\u73b0\u7684\u3002<\/p>\n
CAS\u53ef\u4ee5\u5c06read- modify – write\u8fd9\u7c7b\u7684\u64cd\u4f5c\u8f6c\u6362\u4e3a\u539f\u5b50\u64cd\u4f5c\u3002<\/p>\n
i++\u81ea\u589e\u64cd\u4f5c\u5305\u62ec\u4e09\u4e2a\u5b50\u64cd\u4f5c\uff1a<\/p>\n
- \n
- \u4ece\u4e3b\u5185\u5b58\u8bfb\u53d6i\u53d8\u91cf\u503c<\/li>\n
- \u5bf9i\u7684\u503c\u52a01<\/li>\n
- \u518d\u628a\u52a01\u4e4b\u540e \u7684\u503c\u4fdd\u5b58\u5230\u4e3b\u5185\u5b58<\/li>\n<\/ol>\n
CAS\u539f\u7406\uff1a\u5728\u628a\u6570\u636e\u66f4\u65b0\u5230\u4e3b\u5185\u5b58\u65f6,\u518d\u6b21\u8bfb\u53d6\u4e3b\u5185\u5b58\u53d8\u91cf\u7684\u503c,\u5982\u679c\u73b0\u5728\u53d8\u91cf\u7684\u503c\u4e0e\u671f\u671b\u7684\u503c(\u64cd\u4f5c\u8d77\u59cb\u65f6\u8bfb\u53d6\u7684\u503c)\u4e00\u6837\u5c31\u66f4\u65b0\u3002<\/p>\n
<\/div><\/p>\n\u4f7f\u7528CAS\u5b9e\u73b0\u7ebf\u7a0b\u5b89\u5168\u7684\u8ba1\u6570\u5668<\/h3>\n
Public class CASTest {\n\n public static void main(String[] args) {\n CASCounter casCounter = new CASCounter();\n for (int i = 0; i < 100000; i++) {\n new Thread(new Runnable() {\n @Override\n public void run() {\n System.out.println(casCounter.incrementAndGet());\n }\n }).start();\n }\n }\n}\nclass CASCounter{\n \/\/\u4f7f\u7528volatile\u4fee\u9970value\u503c,\u4f7f\u7ebf\u7a0b\u53ef\u89c1\n volatile private long value;\n\n public long getValue(){\n return value;\n }\n\n \/\/\u5b9a\u4e49comare and swap\u65b9\u6cd5\n private boolean compareAndSwap(long expectedValue, long newValue){\n \/\/\u5982\u679c\u5f53\u524dvalue\u7684\u503c\u4e0e\u671f\u671b\u7684expectedVAlue\u503c\u4e00\u6837,\u5c31\u628a\u5f53\u524d\u7684Value\u5b57\u6bb5\u66ff\u6362\u4e3anewValue\u503c\n synchronized (this){\n if ( value == expectedValue){\n value = newValue;\n return true;\n }else {\n return false;\n }\n }\n }\n\n \/\/\u5b9a\u4e49\u81ea\u589e\u7684\u65b9\u6cd5\n public long incrementAndGet(){\n long oldvalue ;\n long newValue;\n do {\n oldvalue = value;\n newValue = oldvalue+1;\n }while ( !compareAndSwap(oldvalue, newValue) );\n return newValue;\n }\n\n}\n<\/code><\/pre>\nJava\u539f\u5b50\u53d8\u91cf<\/h1>\n
\u539f\u5b50\u53d8\u91cf\u7c7b\u57fa\u4e8eCAS\u5b9e\u73b0\u7684, \u5f53\u5bf9\u5171\u4eab\u53d8\u91cf\u8fdb\u884cread-modify-write\u66f4\u65b0\u64cd\u4f5c\u65f6,\u901a\u8fc7\u539f\u5b50\u53d8\u91cf\u7c7b\u53ef\u4ee5\u4fdd\u969c\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u4e0e\u53ef\u89c1\u6027.\u5bf9\u53d8\u91cf\u7684read-modify-write\u66f4\u65b0\u64cd\u4f5c\u662f\u6307\u5f53\u524d\u64cd\u4f5c\u4e0d\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u8d4b\u503c,\u800c\u662f\u53d8\u91cf\u7684\u65b0\u503c\u4f9d\u8d56\u53d8\u91cf\u7684\u65e7\u503c,\u5982\u81ea\u589e\u64cd\u4f5ci++. \u7531\u4e8evolatile\u53ea\u80fd\u4fdd\u8bc1\u53ef\u89c1\u6027,\u65e0\u6cd5\u4fdd\u969c\u539f\u5b50\u6027, \u539f\u5b50\u53d8\u91cf\u7c7b\u5185\u90e8\u5c31\u662f\u501f\u52a9\u4e00\u4e2aVolatile\u53d8\u91cf,\u5e76\u4e14\u4fdd\u969c\u4e86\u8be5\u53d8\u91cf\u7684read-modify-write\u64cd\u4f5c\u7684\u539f\u5b50\u6027, \u6709\u65f6\u628a\u539f\u5b50\u53d8\u91cf\u7c7b\u770b\u4f5c\u589e\u5f3a\u7684volatile\u53d8\u91cf. \u539f\u5b50\u53d8\u91cf\u7c7b\u670912\u4e2a,\u5982:<\/p>\n
\n\n
\n \n\u5206\u7ec4<\/th>\n \u539f\u5b50\u53d8\u91cf\u7c7b<\/th>\n<\/tr>\n<\/thead>\n \n \u57fa\u7840\u6570\u636e\u578b<\/td>\n AtomicInteger, AtomicLong, AtomicBoolean<\/td>\n<\/tr>\n \n \u6570\u7ec4\u578b<\/td>\n AtomicIntegerArray, AtomicLongArray,AtomicReferenceArray<\/td>\n<\/tr>\n \n \u5b57\u6bb5\u66f4\u65b0\u5668<\/td>\n AtomicIntegerFieldUpdater, AtomicLongFieldUpdater, AtomicReferenceFieldUpdater<\/td>\n<\/tr>\n \n \u5f15\u7528\u578b<\/td>\n AtomicReference,AtomicStampedReference, AtomicMarkableReference<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Java\u7ebf\u7a0b\u95f4\u7684\u901a\u4fe1\u65b9\u5f0f<\/h1>\n
Java\u7ebf\u7a0b\u95f4\u7684\u901a\u4fe1\u65b9\u5f0f<\/h2>\n
1\u3001\u540c\u6b65<\/h3>\n
\u8fd9\u91cc\u8bb2\u7684\u540c\u6b65\u662f\u6307\u591a\u4e2a\u7ebf\u7a0b\u901a\u8fc7synchronized\u5173\u952e\u5b57\u8fd9\u79cd\u65b9\u5f0f\u6765\u5b9e\u73b0\u7ebf\u7a0b\u95f4\u7684\u901a\u4fe1\u3002<\/p>\n
\u53c2\u8003\u793a\u4f8b\uff1a<\/p>\n
public class MyObject {\n\n synchronized public void methodA() {\n \/\/do something....\n }\n\n synchronized public void methodB() {\n \/\/do some other thing\n }\n}\n<\/code><\/pre>\npublic class ThreadA extends Thread {\n\n private MyObject object;\n \/\/\u7701\u7565\u6784\u9020\u65b9\u6cd5\n @Override\n public void run() {\n super.run();\n object.methodA();\n }\n}\n\n------------\n\npublic class ThreadB extends Thread {\n\n private MyObject object;\n \/\/\u7701\u7565\u6784\u9020\u65b9\u6cd5\n @Override\n public void run() {\n super.run();\n object.methodB();\n }\n}\n<\/code><\/pre>\npublic class Run {\n public static void main(String[] args) {\n MyObject object = new MyObject();\n\n \/\/\u7ebf\u7a0bA\u4e0e\u7ebf\u7a0bB \u6301\u6709\u7684\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61:object\n ThreadA a = new ThreadA(object);\n ThreadB b = new ThreadB(object);\n a.start();\n b.start();\n }\n}\n<\/code><\/pre>\n\u7531\u4e8e\u7ebf\u7a0bA\u548c\u7ebf\u7a0bB\u6301\u6709\u540c\u4e00\u4e2aMyObject\u7c7b\u7684\u5bf9\u8c61object\uff0c\u5c3d\u7ba1\u8fd9\u4e24\u4e2a\u7ebf\u7a0b\u9700\u8981\u8c03\u7528\u4e0d\u540c\u7684\u65b9\u6cd5\uff0c\u4f46\u662f\u5b83\u4eec\u662f\u540c\u6b65\u6267\u884c\u7684\uff0c\u6bd4\u5982\uff1a\u7ebf\u7a0bB\u9700\u8981\u7b49\u5f85\u7ebf\u7a0bA\u6267\u884c\u5b8c\u4e86methodA()\u65b9\u6cd5\u4e4b\u540e\uff0c\u5b83\u624d\u80fd\u6267\u884cmethodB()\u65b9\u6cd5\u3002\u8fd9\u6837\uff0c\u7ebf\u7a0bA\u548c\u7ebf\u7a0bB\u5c31\u5b9e\u73b0\u4e86\u901a\u4fe1\u3002\u8fd9\u79cd\u65b9\u5f0f\uff0c\u672c\u8d28\u4e0a\u5c31\u662f\u201c\u5171\u4eab\u5185\u5b58\u201d\u5f0f\u7684\u901a\u4fe1\u3002\u591a\u4e2a\u7ebf\u7a0b\u9700\u8981\u8bbf\u95ee\u540c\u4e00\u4e2a\u5171\u4eab\u53d8\u91cf\uff0c\u8c01\u62ff\u5230\u4e86\u9501(\u83b7\u5f97\u4e86\u8bbf\u95ee\u6743\u9650)\uff0c\u8c01\u5c31\u53ef\u4ee5\u6267\u884c\u3002<\/p>\n
2\u3001while\u8f6e\u8be2\u7684\u65b9\u5f0f<\/h3>\n
\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
import java.util.ArrayList;\nimport java.util.List;\n\npublic class MyList {\n\n private List<String> list = new ArrayList<String>();\n public void add() {\n list.add(\"elements\");\n }\n public int size() {\n return list.size();\n }\n}\n<\/code><\/pre>\nimport mylist.MyList;\n\npublic class ThreadA extends Thread {\n\n private MyList list;\n\n public ThreadA(MyList list) {\n super();\n this.list = list;\n }\n\n @Override\n public void run() {\n try {\n for (int i = 0; i < 10; i++) {\n list.add();\n System.out.println(\"\u6dfb\u52a0\u4e86\" + (i + 1) + \"\u4e2a\u5143\u7d20\");\n Thread.sleep(1000);\n }\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n}\n<\/code><\/pre>\nimport mylist.MyList;\n\npublic class ThreadB extends Thread {\n\n private MyList list;\n\n public ThreadB(MyList list) {\n super();\n this.list = list;\n }\n\n @Override\n public void run() {\n try {\n while (true) {\n if (list.size() == 5) {\n System.out.println(\"==5, \u7ebf\u7a0bb\u51c6\u5907\u9000\u51fa\u4e86\");\n throw new InterruptedException();\n }\n }\n } catch (InterruptedException e) {\n\n e.printStackTrace();\n }\n }\n}\n<\/code><\/pre>\nimport mylist.MyList;\nimport extthread.ThreadA;\nimport extthread.ThreadB;\n\npublic class Test {\n\n public static void main(String[] args) {\n MyList service = new MyList();\n\n ThreadA a = new ThreadA(service);\n a.setName(\"A\");\n a.start();\n\n ThreadB b = new ThreadB(service);\n b.setName(\"B\");\n b.start();\n }\n}\n<\/code><\/pre>\n\u5728\u8fd9\u79cd\u65b9\u5f0f\u4e0b\uff0c\u7ebf\u7a0bA\u4e0d\u65ad\u5730\u6539\u53d8\u6761\u4ef6\uff0c\u7ebf\u7a0bThreadB\u4e0d\u505c\u5730\u901a\u8fc7while\u8bed\u53e5\u68c0\u6d4b\u8fd9\u4e2a\u6761\u4ef6(list.size()5)\u662f\u5426\u6210\u7acb \uff0c\u4ece\u800c\u5b9e\u73b0\u4e86\u7ebf\u7a0b\u95f4\u7684\u901a\u4fe1\u3002\u4f46\u662f\u8fd9\u79cd\u65b9\u5f0f\u4f1a\u6d6a\u8d39CPU\u8d44\u6e90\u3002\u4e4b\u6240\u4ee5\u8bf4\u5b83\u6d6a\u8d39\u8d44\u6e90\uff0c\u662f\u56e0\u4e3aJVM\u8c03\u5ea6\u5668\u5c06CPU\u4ea4\u7ed9\u7ebf\u7a0bB\u6267\u884c\u65f6\uff0c\u5b83\u6ca1\u505a\u5565\u201c\u6709\u7528\u201d\u7684\u5de5\u4f5c\uff0c\u53ea\u662f\u5728\u4e0d\u65ad\u5730\u6d4b\u8bd5 \u67d0\u4e2a\u6761\u4ef6\u662f\u5426\u6210\u7acb\u3002\u5c31\u7c7b\u4f3c\u4e8e\u73b0\u5b9e\u751f\u6d3b\u4e2d\uff0c\u67d0\u4e2a\u4eba\u4e00\u76f4\u770b\u7740\u624b\u673a\u5c4f\u5e55\u662f\u5426\u6709\u7535\u8bdd\u6765\u4e86\uff0c\u800c\u4e0d\u662f\uff1a \u5728\u5e72\u522b\u7684\u4e8b\u60c5\uff0c\u5f53\u6709\u7535\u8bdd\u6765\u65f6\uff0c\u54cd\u94c3\u901a\u77e5TA\u7535\u8bdd\u6765\u4e86\u3002<\/span><\/p>\n
\u8fd9\u79cd\u65b9\u5f0f\u8fd8\u5b58\u5728\u53e6\u5916\u4e00\u4e2a\u95ee\u9898\uff1a\u8f6e\u8be2\u7684\u6761\u4ef6\u7684\u53ef\u89c1\u6027\u95ee\u9898<\/p>\n
\u7ebf\u7a0b\u90fd\u662f\u5148\u628a\u53d8\u91cf\u8bfb\u53d6\u5230\u672c\u5730\u7ebf\u7a0b\u6808\u7a7a\u95f4\uff0c\u7136\u540e\u518d\u53bb\u518d\u53bb\u4fee\u6539\u7684\u672c\u5730\u53d8\u91cf\u3002\u56e0\u6b64\uff0c\u5982\u679c\u7ebf\u7a0bB\u6bcf\u6b21\u90fd\u5728\u53d6\u672c\u5730\u7684 \u6761\u4ef6\u53d8\u91cf\uff0c\u90a3\u4e48\u5c3d\u7ba1\u53e6\u5916\u4e00\u4e2a\u7ebf\u7a0b\u5df2\u7ecf\u6539\u53d8\u4e86\u8f6e\u8be2\u7684\u6761\u4ef6\uff0c\u5b83\u4e5f\u5bdf\u89c9\u4e0d\u5230\uff0c\u8fd9\u6837\u4e5f\u4f1a\u9020\u6210\u6b7b\u5faa\u73af\u3002<\/p>\n
3\u3001wait\/notify\u673a\u5236<\/h3>\n
\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
import java.util.ArrayList;\nimport java.util.List;\n\npublic class MyList {\n\n private static List<String> list = new ArrayList<String>();\n\n public static void add() {\n list.add(\"anyString\");\n }\n\n public static int size() {\n return list.size();\n }\n}\n<\/code><\/pre>\npublic class ThreadA extends Thread {\n\n private Object lock;\n\n public ThreadA(Object lock) {\n\n\n super();\n this.lock = lock;\n }\n\n\n @Override\n public void run() {\n try {\n synchronized (lock) {\n if (MyList.size() != 5) {\n System.out.println(\"wait begin \"\n + System.currentTimeMillis());\n lock.wait();\n System.out.println(\"wait end \"\n + System.currentTimeMillis());\n }\n }\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n}\n\n<\/code><\/pre>\npublic class ThreadB extends Thread {\n private Object lock;\n\n public ThreadB(Object lock) {\n super();\n this.lock = lock;\n }\n\n @Override\n public void run() {\n try {\n synchronized (lock) {\n for (int i = 0; i < 10; i++) {\n MyList.add();\n if (MyList.size() == 5) {\n lock.notify();\n System.out.println(\"\u5df2\u7ecf\u53d1\u51fa\u4e86\u901a\u77e5\");\n }\n System.out.println(\"\u6dfb\u52a0\u4e86\" + (i + 1) + \"\u4e2a\u5143\u7d20!\");\n Thread.sleep(1000);\n }\n }\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n}\n<\/code><\/pre>\npublic class Run {\n\n public static void main(String[] args) {\n\n try {\n Object lock = new Object();\n\n ThreadA a = new ThreadA(lock);\n a.start();\n\n Thread.sleep(50);\n\n ThreadB b = new ThreadB(lock);\n b.start();\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n}\n<\/code><\/pre>\n\u7ebf\u7a0bA\u8981\u7b49\u5f85\u67d0\u4e2a\u6761\u4ef6\u6ee1\u8db3\u65f6(list.size()5)\uff0c\u624d\u6267\u884c\u64cd\u4f5c\u3002\u7ebf\u7a0bB\u5219\u5411list\u4e2d\u6dfb\u52a0\u5143\u7d20\uff0c\u6539\u53d8list \u7684size\u3002<\/span><\/p>\n
A,B\u4e4b\u95f4\u5982\u4f55\u901a\u4fe1\u7684\u5462?\u4e5f\u5c31\u662f\u8bf4\uff0c\u7ebf\u7a0bA\u5982\u4f55\u77e5\u9053 list.size() \u5df2\u7ecf\u4e3a5\u4e86\u5462?<\/p>\n
\u8fd9\u91cc\u7528\u5230\u4e86Object\u7c7b\u7684
wait(<\/code>) \u548cnotify()<\/code> \u65b9\u6cd5\u3002<\/p>\n\u5f53\u6761\u4ef6\u672a\u6ee1\u8db3\u65f6(list.size() !=5)\uff0c\u7ebf\u7a0bA\u8c03\u7528
wait()<\/code>\u653e\u5f03CPU\uff0c\u5e76\u8fdb\u5165\u963b\u585e\u72b6\u6001\u3002<\/p>\n\u5f53\u6761\u4ef6\u6ee1\u8db3\u65f6\uff0c\u7ebf\u7a0bB\u8c03\u7528
notify()<\/code>\u901a\u77e5 \u7ebf\u7a0bA\uff0c\u6240\u8c13\u901a\u77e5\u7ebf\u7a0bA\uff0c\u5c31\u662f\u5524\u9192\u7ebf\u7a0bA\uff0c\u5e76\u8ba9\u5b83\u8fdb\u5165\u53ef\u8fd0\u884c\u72b6\u6001\u3002<\/p>\n\u8fd9\u79cd\u65b9\u5f0f\u7684\u4e00\u4e2a\u597d\u5904\u5c31\u662fCPU\u7684\u5229\u7528\u7387\u63d0\u9ad8\u4e86\u3002<\/p>\n
\u4f46\u662f\u4e5f\u6709\u4e00\u4e9b\u7f3a\u70b9\uff1a\u6bd4\u5982\uff0c\u7ebf\u7a0bB\u5148\u6267\u884c\uff0c\u4e00\u4e0b\u5b50\u6dfb\u52a0\u4e865\u4e2a\u5143\u7d20\u5e76\u8c03\u7528\u4e86notify()\u53d1\u9001\u4e86\u901a\u77e5\uff0c\u800c\u6b64\u65f6\u7ebf\u7a0bA\u8fd8\u6267\u884c;\u5f53\u7ebf\u7a0bA\u6267\u884c\u5e76\u8c03\u7528wait()\u65f6\uff0c\u90a3\u5b83\u6c38\u8fdc\u5c31\u4e0d\u53ef\u80fd\u88ab\u5524\u9192\u4e86\u3002\u56e0\u4e3a\uff0c\u7ebf\u7a0bB\u5df2\u7ecf\u53d1\u4e86\u901a\u77e5\u4e86\uff0c\u4ee5\u540e\u4e0d\u518d\u53d1\u901a\u77e5\u4e86\u3002\u8fd9\u8bf4\u660e\uff1a\u901a\u77e5\u8fc7\u65e9\uff0c\u4f1a\u6253\u4e71\u7a0b\u5e8f\u7684\u6267\u884c\u903b\u8f91\u3002<\/span><\/p>\n
4\u3001\u7ba1\u9053\u901a\u4fe1<\/h3>\n
\u7ba1\u9053\u901a\u4fe1\u5c31\u662f\u4f7f\u7528
java.io.PipedInputStream<\/code> \u548cjava.io.PipedOutputStream<\/code>\u8fdb\u884c\u901a\u4fe1\u3002<\/p>\nJava\u591a\u7ebf\u7a0b\u7684\u7b49\u5f85\u901a\u77e5\u673a\u5236<\/h1>\n
\u4ec0\u4e48\u662f\u7b49\u5f85\u901a\u77e5\u673a\u5236<\/h3>\n
\u5728\u5355\u7ebf\u7a0b\u7f16\u7a0b\u4e2d,\u8981\u6267\u884c\u7684\u64cd\u4f5c\u9700\u8981\u6ee1\u8db3\u4e00\u5b9a\u7684\u6761\u4ef6\u624d\u80fd\u6267\u884c,\u53ef\u4ee5\u628a\u8fd9\u4e2a\u64cd\u4f5c\u653e\u5728if\u8bed\u53e5\u5757\u4e2d\u3002<\/p>\n
\u5728\u591a\u7ebf\u7a0b\u7f16\u7a0b\u4e2d,\u53ef\u80fdA\u7ebf\u7a0b\u7684\u6761\u4ef6\u6ca1\u6709\u6ee1\u8db3\u53ea\u662f\u6682\u65f6\u7684, \u7a0d\u540e\u5176\u4ed6\u7684\u7ebf\u7a0bB\u53ef\u80fd\u4f1a\u66f4\u65b0\u6761\u4ef6\u4f7f\u5f97A\u7ebf\u7a0b\u7684\u6761\u4ef6\u5f97\u5230\u6ee1\u8db3. \u53ef\u4ee5\u5c06A\u7ebf\u7a0b\u6682\u505c,\u76f4\u5230\u5b83\u7684\u6761\u4ef6\u5f97\u5230\u6ee1\u8db3\u540e\u518d\u5c06A\u7ebf\u7a0b\u5524\u9192.\u5b83\u7684\u4f2a\u4ee3\u7801\uff1a<\/p>\n
atomics{ \/\/\u539f\u5b50\u64cd\u4f5c\n while( \u6761\u4ef6\u4e0d\u6210\u7acb ){\n \/\/\u7b49\u5f85\n }\n \/\/\u5f53\u524d\u7ebf\u7a0b\u88ab\u5524\u9192\u6761\u4ef6\u6ee1\u8db3\u540e,\u7ee7\u7eed\u6267\u884c\u4e0b\u9762\u7684\u64cd\u4f5c\n}\n<\/code><\/pre>\n\u7b49\u5f85\/\u901a\u77e5\u673a\u5236\u7684\u5b9e\u73b0<\/p>\n
Object\u7c7b\u4e2d\u7684
wait()<\/code>\u65b9\u6cd5\u53ef\u4ee5\u4f7f\u6267\u884c\u5f53\u524d\u4ee3\u7801\u7684\u7ebf\u7a0b\u7b49\u5f85,\u6682\u505c\u6267\u884c,\u76f4\u5230\u63a5\u5230\u901a\u77e5\u6216\u88ab\u4e2d\u65ad\u4e3a\u6b62\u3002<\/p>\n\u6ce8\u610f:<\/p>\n
- \n
- wait()\u65b9\u6cd5\u53ea\u80fd\u5728\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u7531\u9501\u5bf9\u8c61\u8c03\u7528\u3002<\/li>\n
- \u8c03\u7528wait()\u65b9\u6cd5,\u5f53\u524d\u7ebf\u7a0b\u4f1a\u91ca\u653e\u9501\u3002<\/li>\n<\/ol>\n
\u5176\u4f2a\u4ee3\u7801\u5982\u4e0b:<\/p>\n
\/\/\u5728\u8c03\u7528wait()\u65b9\u6cd5\u524d\u83b7\u5f97\u5bf9\u8c61\u7684\u5185\u90e8\u9501\nsynchronized( \u9501\u5bf9\u8c61 ){\n while( \u6761\u4ef6\u4e0d\u6210\u7acb ){\n \/\/\u901a\u8fc7\u9501\u5bf9\u8c61\u8c03\u7528 wait()\u65b9\u6cd5\u6682\u505c\u7ebf\u7a0b,\u4f1a\u91ca\u653e\u9501\u5bf9\u8c61\n \u9501\u5bf9\u8c61.wait();\n }\n \/\/\u7ebf\u7a0b\u7684\u6761\u4ef6\u6ee1\u8db3\u4e86\u7ee7\u7eed\u5411\u4e0b\u6267\u884c\n}\n<\/code><\/pre>\nObject\u7c7b\u7684
notify()<\/code>\u53ef\u4ee5\u5524\u9192\u7ebf\u7a0b,\u8be5\u65b9\u6cd5\u4e5f\u5fc5\u987b\u5728\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u7531\u9501\u5bf9\u8c61\u8c03\u7528. \u6ca1\u6709\u4f7f\u7528\u9501\u5bf9\u8c61\u8c03\u7528wait()\/notify()<\/code>\u4f1a\u629b\u51faIlegalMonitorStateExeption<\/code>\u5f02\u5e38. \u5982\u679c\u6709\u591a\u4e2a\u7b49\u5f85\u7684\u7ebf\u7a0b,notify()<\/code>\u65b9\u6cd5\u53ea\u80fd\u5524\u9192\u5176\u4e2d\u7684\u4e00\u4e2a. \u5728\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u8c03\u7528notify()<\/code>\u65b9\u6cd5\u540e,\u5e76\u4e0d\u4f1a\u7acb\u5373\u91ca\u653e\u9501\u5bf9\u8c61,\u9700\u8981\u7b49\u5f53\u524d\u540c\u6b65\u4ee3\u7801\u5757\u6267\u884c\u5b8c\u540e\u624d\u4f1a\u91ca\u653e\u9501\u5bf9\u8c61,\u4e00\u822c\u5c06notify()<\/code>\u65b9\u6cd5\u653e\u5728\u540c\u6b65\u4ee3\u7801\u5757\u7684\u6700\u540e. \u5b83\u7684\u4f2a\u4ee3\u7801\u5982\u4e0b:<\/p>\nsynchronized( \u9501\u5bf9\u8c61 ){\n \/\/\u6267\u884c\u4fee\u6539\u4fdd\u62a4\u6761\u4ef6 \u7684\u4ee3\u7801\n \/\/\u5524\u9192\u5176\u4ed6\u7ebf\u7a0b\n \u9501\u5bf9\u8c61.notify();\n}\n<\/code><\/pre>\n\u9700\u8981\u901a\u8fc7
notify()<\/code>\u5524\u9192\u7b49\u5f85\u7684\u7ebf\u7a0b<\/h4>\npublic class Test01 {\n\n public static void main(String[] args) {\n String lock = \"glj\";\n Thread t1 = new Thread(new Runnable() {\n @Override\n public void run() {\n synchronized (lock){\n System.out.println(\"\u7ebf\u7a0b1\u5f00\u59cb\u7b49\u5f85: \" + System.currentTimeMillis());\n \/\/\u7ebf\u7a0b\u7b49\u5f85,\u4f1a\u91ca\u653e\u9501\u5bf9\u8c61,\u5f53\u524d\u7ebf\u7a0b\u8f6c\u5165blocked\u963b\u585e\u72b6\u6001\n try {\n lock.wait();\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n System.out.println(\"\u7ebf\u7a0b1\u7ed3\u675f\u7b49\u5f85:\" + System.currentTimeMillis());\n }\n }\n });\n\n Thread t2 = new Thread(new Runnable() {\n @Override\n public void run() {\n \/\/notify()\u65b9\u6cd5\u4e5f\u9700\u8981\u5728\u540c\u6b65\u4ee3\u7801\u5757\u4e2d,\u7531\u9501\u5bf9\u8c61\u8c03\u7528\n synchronized (lock){\n System.out.println(\"\u7ebf\u7a0b2\u5f00\u59cb\u5524\u9192 : \" + System.currentTimeMillis());\n lock.notify(); \/\/\u5524\u9192\u5728lock\u9501\u5bf9\u8c61\u4e0a\u7b49\u5f85\u7684\u67d0\u4e00\u4e2a\u7ebf\u7a0b\n System.out.println(\"\u7ebf\u7a0b2\u7ed3\u675f\u5524\u9192 : \" + System.currentTimeMillis());\n }\n }\n });\n \/\/\u5f00\u542ft1\u7ebf\u7a0b,t1\u7ebf\u7a0b\u7b49\u5f85\n t1.start();\n try {\n Thread.sleep(3000);\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n \/\/t1\u7ebf\u7a0b\u5f00\u542f3\u79d2\u540e,\u518d\u5f00\u542ft2\u7ebf\u7a0b\u5524\u9192t1\u7ebf\u7a0b\n t2.start();\n }\n\n}\n<\/code><\/pre>\nnotify()\u65b9\u6cd5\u540e\u4e0d\u4f1a\u7acb\u5373\u91ca\u653e\u9501\u5bf9\u8c61<\/h4>\n
public class Test02 {\n\n public static void main(String[] args) throws InterruptedException {\n \/\/\u5b9a\u4e49\u4e00\u4e2aList\u96c6\u5408\u5b58\u50a8String\u6570\u636e\n List<String> list = new ArrayList<>();\n\n \/\/\u5b9a\u4e49\u7b2c\u4e00\u4e2a\u7ebf\u7a0b,\u5f53list\u96c6\u5408\u4e2d\u5143\u7d20\u7684\u6570\u91cf\u4e0d\u7b49\u4e8e5\u65f6\u7ebf\u7a0b\u7b49\u5f85\n Thread t1 = new Thread(new Runnable() {\n @Override\n public void run() {\n synchronized (list){\n if (list.size()!=5) {\n System.out.println(\"\u7ebf\u7a0b1\u5f00\u59cb\u7b49\u5f85: \" + System.currentTimeMillis());\n try {\n System.out.println(\"\u7b49\u5f85\");\n list.wait();\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n System.out.println(\"\u7ebf\u7a0b1\u88ab\u5524\u9192:\" + System.currentTimeMillis());\n }\n }\n }\n });\n\n \/\/\u5b9a\u4e49\u7b2c\u4e8c\u4e2a\u7ebf\u7a0b,\u5411list\u96c6\u5408\u4e2d\u6dfb\u52a0\u5143\u7d20\n Thread t2 = new Thread(new Runnable() {\n @Override\n public void run() {\n synchronized (list){\n for(int i=0; i<10;i++){\n list.add(\"data-->\"+i);\n System.out.println(\"\u7ebf\u7a0b2\u6dfb\u52a0\u4e86\u7b2c\" + (i+1) + \"\u4e2a\u6570\u636e\");\n\n if (list.size()==5) {\n \/\/\u5524\u9192\u7ebf\u7a0b, \u4e0d\u4f1a\u7acb\u5373\u91ca\u653e\u9501\u5bf9\u8c61,\u9700\u8981\u7b49\u5230\u5f53\u524d\u540c\u6b65\u4ee3\u7801\u5757\u90fd\u6267\u884c\u5b8c\u540e\u624d\u80fd\u91ca\u653e\u9501\u5bf9\u8c61\n list.notify();\n System.out.println(\"\u7ebf\u7a0b2\u53d1\u9001\u5524\u9192\u901a\u77e5\");\n }\n\n try {\n Thread.sleep(1000);\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n\n }\n }\n }\n });\n\n t1.start();\n Thread.sleep(3000);\n t2.start();\n\n }\n\n}\n<\/code><\/pre>\ninterrupt()\u4f1a\u4e2d\u65ad\u7ebf\u7a0b\u7684wait()\u7b49\u5f85<\/h4>\n
\u5f53\u7ebf\u7a0b\u5904\u4e8ewait()\u7b49\u5f85\u72b6\u6001\u65f6, \u8c03\u7528\u7ebf\u7a0b\u5bf9\u8c61\u7684interrupt()\u65b9\u6cd5\u4f1a\u4e2d\u65ad\u7ebf\u7a0b\u7684\u7b49\u5f85\u72b6\u6001, \u4f1a\u4ea7\u751fInterruptedException\u5f02\u5e38\u3002<\/p>\n
public class Test03 {\n\n public static void main(String[] args) throws InterruptedException {\n SunThread sub = new SunThread();\n sub.start();\n System.out.println(\"\u5f53\u524d\u65f6\u95f4:\"+System.currentTimeMillis());\n Thread.sleep(3000);\n System.out.println(\"\u5f53\u524d\u65f6\u95f4:\"+System.currentTimeMillis());\n sub.interrupt();\n System.out.println(\"\u5f53\u524d\u65f6\u95f4:\"+System.currentTimeMillis());\n }\n\n\n private static final Object LOCK = new Object();\n\n static class SunThread extends Thread{\n @Override\n public void run() {\n synchronized (LOCK){\n try {\n System.out.println(\"begin wait...\");\n LOCK.wait();\n System.out.println(\"end wait..\");\n } catch (InterruptedException e) {\n System.out.println(\"wait\u7b49\u5f85\u88ab\u4e2d\u65ad\u4e86****\");\n }\n }\n }\n }\n\n}\n<\/code><\/pre>\nnotify()\u4e0enotifyAll()<\/h4>\n
notify()\u4e00\u6b21\u53ea\u80fd\u5524\u9192\u4e00\u4e2a\u7ebf\u7a0b,\u5982\u679c\u6709\u591a\u4e2a\u7b49\u5f85\u7684\u7ebf\u7a0b,\u53ea\u80fd\u968f\u673a\u5524\u9192\u5176\u4e2d\u7684\u67d0\u4e00\u4e2a; \u60f3\u8981\u5524\u9192\u6240\u6709\u7b49\u5f85\u7ebf\u7a0b,\u9700\u8981\u8c03\u7528notifyAll()\u3002<\/p>\n
public class Test04 {\n\n public static void main(String[] args) throws InterruptedException {\n Object lock = new Object();\n SubThread t1 = new SubThread(lock);\n SubThread t2 = new SubThread(lock);\n SubThread t3 = new SubThread(lock);\n t1.setName(\"t1\");\n t2.setName(\"t2\");\n t3.setName(\"t3\");\n t1.start();\n t2.start();\n t3.start();\n\n Thread.sleep(3000);\n synchronized (lock){\n \/\/ \u8c03\u7528\u4e00\u6b21notify()\u53ea\u80fd\u5524\u9192\u5176\u4e2d\u7684\u4e00\u4e2a\u7ebf\u7a0b,\u5176\u4ed6\u7b49\u5f85\u7684\u7ebf\u7a0b\u4f9d\u7136\u5904\u4e8e\u7b49\u5f85\u72b6\u6001,\n \/\/ \u5bf9\u4e8e\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u7684\u7ebf\u7a0b\u6765\u8bf4,\u9519\u8fc7\u4e86\u901a\u77e5\u4fe1\u53f7,\u8fd9\u79cd\u73b0\u8c61\u4e5f\u79f0\u4e3a\u4fe1\u53f7\u4e22\u5931\n \/\/ lock.notify();\n lock.notifyAll();\n }\n }\n\n static class SubThread extends Thread{\n private Object lock; \/\/\u5b9a\u4e49\u5b9e\u4f8b\u53d8\u91cf\u4f5c\u4e3a\u9501\u5bf9\u8c61\n public SubThread(Object lock) {\n this.lock = lock;\n }\n\n @Override\n public void run() {\n synchronized (lock){\n try {\n System.out.println(\"begin wait...\");\n lock.wait();\n System.out.println(\"end wait..\");\n } catch (InterruptedException e) {\n System.out.println(\"wait\u7b49\u5f85\u88ab\u4e2d\u65ad\u4e86****\");\n }\n }\n }\n }\n}\n<\/code><\/pre>\nwait(long)\u7684\u4f7f\u7528<\/h4>\n
wait(long)\u5e26\u6709long\u7c7b\u578b\u53c2\u6570\u7684wait()\u7b49\u5f85,\u5982\u679c\u5728\u53c2\u6570\u6307\u5b9a\u7684\u65f6\u95f4\u5185\u6ca1\u6709\u88ab\u5524\u9192,\u8d85\u65f6\u540e\u4f1a\u81ea\u52a8\u5524\u9192\u3002<\/p>\n
public class Test05 {\n public static void main(String[] args) {\n final Object obj = new Object();\n Thread t = new Thread(new Runnable() {\n @Override\n public void run() {\n synchronized (obj){\n try {\n System.out.println(\"thread begin wait\");\n obj.wait(5000); \/\/\u5982\u679c5000\u6beb\u79d2\u5185\u6ca1\u6709\u88ab\u5524\u9192 ,\u4f1a\u81ea\u52a8\u5524\u9192\n System.out.println(\"end wait....\");\n } catch (InterruptedException e) {\n e.printStackTrace();\n }\n }\n }\n });\n t.start();\n }\n}\n<\/code><\/pre>\n\u907f\u514d\u901a\u77e5\u8fc7\u65e9<\/h4>\n
\u7ebf\u7a0b
wait()<\/code>\u7b49\u5f85\u540e,\u53ef\u4ee5\u8c03\u7528notify()<\/code>\u5524\u9192\u7ebf\u7a0b, \u5982\u679cnotify()<\/code>\u5524\u9192\u7684\u8fc7\u65e9,\u5728\u7b49\u5f85\u4e4b\u524d\u5c31\u8c03\u7528\u4e86
![\"image-20210907211400969\"](\"https:\/\/qn.199604.com\/typoraImg\/image-20210907211400969.png\")
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<\/div><\/p>\n![\"img\"](\"https:\/\/qn.199604.com\/typoraImg\/1588150459@6176b92a3663d18637f2ba180ef9ca61.png\")
<\/div><\/p>\n![\"img\"](\"https:\/\/qn.199604.com\/typoraImg\/1588151254@9fd3dff54b91b8abfe502eba2086d2a9.png\")
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