{"id":10006354,"date":"2022-08-30T22:01:07","date_gmt":"2022-08-30T14:01:07","guid":{"rendered":"https:\/\/ityet.com\/?p=10006354"},"modified":"2022-08-30T22:01:07","modified_gmt":"2022-08-30T14:01:07","slug":"%e7%ba%bf%e7%a8%8b%e6%b1%a0%e4%b8%ad%e7%9a%84%e4%b8%80%e4%b8%aa-bug%ef%bc%8c%e6%b3%a8%e6%84%8f%e4%ba%86%ef%bc%81%ef%bc%81","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10006354","title":{"rendered":"\u7ebf\u7a0b\u6c60\u4e2d\u7684\u4e00\u4e2a BUG\uff0c\u6ce8\u610f\u4e86\uff01\uff01"},"content":{"rendered":"

\u6765\u6e90\uff1ahttps:\/\/segmentfault.com\/a\/11…<\/a><\/p>\n

\u95ee\u9898\u63cf\u8ff0<\/h2>\n

\u524d\u51e0\u5929\u5728\u5e2e\u540c\u4e8b\u6392\u67e5\u751f\u4ea7\u4e00\u4e2a\u7ebf\u4e0a\u5076\u53d1\u7684\u7ebf\u7a0b\u6c60\u9519\u8bef<\/p>\n

\u903b\u8f91\u5f88\u7b80\u5355\uff0c\u7ebf\u7a0b\u6c60\u6267\u884c\u4e86\u4e00\u4e2a\u5e26\u7ed3\u679c\u7684\u5f02\u6b65\u4efb\u52a1\u3002\u4f46\u662f\u6700\u8fd1\u6709\u5076\u53d1\u7684\u62a5\u9519\uff1a<\/p>\n

java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.FutureTask@a5acd19 rejected from java.util.concurrent.ThreadPoolExecutor@30890a38[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0]<\/code><\/pre>\n
\u672c\u6587\u4e2d\u7684\u6a21\u62df\u4ee3\u7801\u5df2\u7ecf\u95ee\u9898\u90fd\u662f\u5728HotSpot java8 (1.8.0_221)\u7248\u672c\u4e0b\u6a21\u62df&\u51fa\u73b0\u7684<\/p>\n
\u4e0b\u9762\u662f\u6a21\u62df\u4ee3\u7801\uff0c\u901a\u8fc7Executors.newSingleThreadExecutor\u521b\u5efa\u4e00\u4e2a\u5355\u7ebf\u7a0b\u7684\u7ebf\u7a0b\u6c60\uff0c\u7136\u540e\u5728\u8c03\u7528\u65b9\u83b7\u53d6Future\u7684\u7ed3\u679c<\/p>\n
public class ThreadPoolTest {\n\n    public static void main(String[] args) {\n        final ThreadPoolTest threadPoolTest = new ThreadPoolTest();\n        for (int i = 0; i < 8; i++) {\n            new Thread(new Runnable() {\n                @Override\n                public void run() {\n                    while (true) {\n\n                        Future<String> future = threadPoolTest.submit();\n                        try {\n                            String s = future.get();\n                        } catch (InterruptedException e) {\n                            e.printStackTrace();\n                        } catch (ExecutionException e) {\n                            e.printStackTrace();\n                        } catch (Error e) {\n                            e.printStackTrace();\n                        }\n                    }\n                }\n            }).start();\n        }\n        \n        \/\/\u5b50\u7ebf\u7a0b\u4e0d\u505cgc\uff0c\u6a21\u62df\u5076\u53d1\u7684gc\n        new Thread(new Runnable() {\n            @Override\n            public void run() {\n                while (true) {\n                    System.gc();\n                }\n            }\n        }).start();\n    }\n\n    \/**\n     * \u5f02\u6b65\u6267\u884c\u4efb\u52a1\n     * @return\n     *\/\n    public Future<String> submit() {\n        \/\/\u5173\u952e\u70b9\uff0c\u901a\u8fc7Executors.newSingleThreadExecutor\u521b\u5efa\u4e00\u4e2a\u5355\u7ebf\u7a0b\u7684\u7ebf\u7a0b\u6c60\n        ExecutorService executorService = Executors.newSingleThreadExecutor();\n        FutureTask<String> futureTask = new FutureTask(new Callable() {\n            @Override\n            public Object call() throws Exception {\n                Thread.sleep(50);\n                return System.currentTimeMillis() + "";\n            }\n        });\n        executorService.execute(futureTask);\n        return futureTask;\n    }\n\n}<\/code><\/pre>\n
\u5206\u6790&\u7591\u95ee<\/h2>\n
\u7b2c\u4e00\u4e2a\u601d\u8003\u7684\u95ee\u9898\u662f\uff1a\u7ebf\u7a0b\u6c60\u4e3a\u4ec0\u4e48\u5173\u95ed\u4e86\uff0c\u4ee3\u7801\u4e2d\u5e76\u6ca1\u6709\u624b\u52a8\u5173\u95ed\u7684\u5730\u65b9\u3002\u770b\u4e00\u4e0bExecutors.newSingleThreadExecotor<\/code>\u7684\u6e90\u7801\u5b9e\u73b0\uff1a<\/p>\n
public static ExecutorService newSingleThreadExecutor() {\n    return new FinalizableDelegatedExecutorService\n            (new ThreadPoolExecutor(1, 1,\n                    0L, TimeUnit.MILLISECONDS,\n                    new LinkedBlockingQueue<Runnable>()));\n}<\/code><\/pre>\n
\u8fd9\u91cc\u521b\u5efa\u7684\u5b9e\u9645\u4e0a\u662f\u4e00\u4e2aFinalizableDelegatedExecutorService<\/code>\uff0c\u8fd9\u4e2a\u5305\u88c5\u7c7b\u91cd\u5199\u4e86finalize<\/code>\u51fd\u6570\uff0c\u4e5f\u5c31\u662f\u8bf4\u8fd9\u4e2a\u7c7b\u4f1a\u5728\u88abGC\u56de\u6536\u4e4b\u524d\uff0c\u5148\u6267\u884c\u7ebf\u7a0b\u6c60\u7684shutdown\u65b9\u6cd5\u3002<\/p>\n
\u95ee\u9898\u6765\u4e86\uff0cGC\u53ea\u4f1a\u56de\u6536\u4e0d\u53ef\u8fbe\uff08unreachable\uff09\u7684\u5bf9\u8c61<\/strong>\uff0c\u5728submit<\/code>\u51fd\u6570\u7684\u6808\u5e27\u672a\u6267\u884c\u5b8c\u51fa\u6808\u4e4b\u524d\uff0cexecutorService<\/code>\u5e94\u8be5\u662f\u53ef\u8fbe\u7684\u624d\u5bf9\u3002<\/p>\n
\u66f4\u591a\u591a\u7ebf\u7a0b\u7cfb\u5217\u6559\u7a0b\uff1ahttps:\/\/www.javastack.cn\/cate…<\/a><\/p>\n
\u5bf9\u4e8e\u6b64\u95ee\u9898\uff0c\u5148\u629b\u51fa\u7ed3\u8bba\uff1a<\/p>\n
\u5f53\u5bf9\u8c61\u4ecd\u5b58\u5728\u4e8e\u4f5c\u7528\u57df\uff08stack frame\uff09\u65f6\uff0cfinalize<\/code>\u4e5f\u53ef\u80fd\u4f1a\u88ab\u6267\u884c<\/strong><\/p>\n
oracle jdk\u6587\u6863\u4e2d\u6709\u4e00\u6bb5\u5173\u4e8efinalize\u7684\u4ecb\u7ecd\uff1a<\/p>\n
\n
A reachable object is any object that can be accessed in any potential continuing computation from any live thread.<\/p>\n
Optimizing transformations of a program can be designed that reduce the number of objects that are reachable to be less than those which would naively be considered reachable. For example, a Java compiler or code generator may choose to set a variable or parameter that will no longer be used to null to cause the storage for such an object to be potentially reclaimable sooner.<\/p>\n<\/blockquote>\n
\u5927\u6982\u610f\u601d\u662f\uff1a\u53ef\u8fbe\u5bf9\u8c61(reachable object)\u662f\u53ef\u4ee5\u4ece\u4efb\u4f55\u6d3b\u52a8\u7ebf\u7a0b\u7684\u4efb\u4f55\u6f5c\u5728\u7684\u6301\u7eed\u8bbf\u95ee\u4e2d\u7684\u4efb\u4f55\u5bf9\u8c61\uff1bjava\u7f16\u8bd1\u5668\u6216\u4ee3\u7801\u751f\u6210\u5668\u53ef\u80fd\u4f1a\u5bf9\u4e0d\u518d\u8bbf\u95ee\u7684\u5bf9\u8c61\u63d0\u524d\u7f6e\u4e3anull\uff0c\u4f7f\u5f97\u5bf9\u8c61\u53ef\u4ee5\u88ab\u63d0\u524d\u56de\u6536<\/strong><\/p>\n
\u4e5f\u5c31\u662f\u8bf4\uff0c\u5728jvm\u7684\u4f18\u5316\u4e0b\uff0c\u53ef\u80fd\u4f1a\u51fa\u73b0\u5bf9\u8c61\u4e0d\u53ef\u8fbe\u4e4b\u540e\u88ab\u63d0\u524d\u7f6e\u7a7a\u5e76\u56de\u6536\u7684\u60c5\u51b5<\/p>\n
\u4e3e\u4e2a\u4f8b\u5b50\u6765\u9a8c\u8bc1\u4e00\u4e0b\uff0c\u6458\u81ea\uff1ahttps:\/\/stackoverflow.com\/que…<\/a><\/p>\n
class A {\n    @Override protected void finalize() {\n        System.out.println(this + " was finalized!");\n    }\n\n    public static void main(String[] args) throws InterruptedException {\n        A a = new A();\n        System.out.println("Created " + a);\n        for (int i = 0; i < 1_000_000_000; i++) {\n            if (i % 1_000_00 == 0)\n                System.gc();\n        }\n        System.out.println("done.");\n    }\n}\n\n\/\/\u6253\u5370\u7ed3\u679c\nCreated A@1be6f5c3\nA@1be6f5c3 was finalized!\/\/finalize\u65b9\u6cd5\u8f93\u51fa\ndone.<\/code><\/pre>\n
\u4ece\u4f8b\u5b50\u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u5982\u679ca\u5728\u5faa\u73af\u5b8c\u6210\u540e\u5df2\u7ecf\u4e0d\u518d\u4f7f\u7528\u4e86\uff0c\u5219\u4f1a\u51fa\u73b0\u5148\u6267\u884cfinalize\u7684\u60c5\u51b5\uff1b\u867d\u7136\u4ece\u5bf9\u8c61\u4f5c\u7528\u57df\u6765\u8bf4\uff0c\u65b9\u6cd5\u6ca1\u6709\u6267\u884c\u5b8c\uff0c\u6808\u5e27\u5e76\u6ca1\u6709\u51fa\u6808\uff0c\u4f46\u662f\u8fd8\u662f\u4f1a\u88ab\u63d0\u524d\u6267\u884c\u3002<\/p>\n
\u73b0\u5728\u6765\u589e\u52a0\u4e00\u884c\u4ee3\u7801\uff0c\u5728\u6700\u540e\u4e00\u884c\u6253\u5370\u5bf9\u8c61a\uff0c\u8ba9\u7f16\u8bd1\u5668\/\u4ee3\u7801\u751f\u6210\u5668\u8ba4\u4e3a\u540e\u9762\u6709\u5bf9\u8c61a\u7684\u5f15\u7528<\/p>\n
...\nSystem.out.println(a);\n\n\/\/\u6253\u5370\u7ed3\u679c\nCreated A@1be6f5c3\ndone.\nA@1be6f5c3<\/code><\/pre>\n
\u4ece\u7ed3\u679c\u4e0a\u770b\uff0cfinalize\u65b9\u6cd5\u90fd\u6ca1\u6709\u6267\u884c\uff08\u56e0\u4e3amain\u65b9\u6cd5\u6267\u884c\u5b8c\u6210\u540e\u8fdb\u7a0b\u76f4\u63a5\u7ed3\u675f\u4e86\uff09\uff0c\u66f4\u4e0d\u4f1a\u51fa\u73b0\u63d0\u524dfinalize\u7684\u95ee\u9898\u4e86<\/p>\n
\u57fa\u4e8e\u4e0a\u9762\u7684\u6d4b\u8bd5\u7ed3\u679c\uff0c\u518d\u6d4b\u8bd5\u4e00\u79cd\u60c5\u51b5\uff0c\u5728\u5faa\u73af\u4e4b\u524d\u5148\u5c06\u5bf9\u8c61a\u7f6e\u4e3anull\uff0c\u5e76\u4e14\u5728\u6700\u540e\u6253\u5370\u4fdd\u6301\u5bf9\u8c61a\u7684\u5f15\u7528<\/p>\n
A a = new A();\nSystem.out.println("Created " + a);\na = null;\/\/\u624b\u52a8\u7f6enull\nfor (int i = 0; i < 1_000_000_000; i++) {\n    if (i % 1_000_00 == 0)\n        System.gc();\n}\nSystem.out.println("done.");\nSystem.out.println(a);\n\n\/\/\u6253\u5370\u7ed3\u679c\nCreated A@1be6f5c3\nA@1be6f5c3 was finalized!\ndone.\nnull<\/code><\/pre>\n
\u4ece\u7ed3\u679c\u4e0a\u770b\uff0c\u624b\u52a8\u7f6enull\u7684\u8bdd\u4e5f\u4f1a\u5bfc\u81f4\u5bf9\u8c61\u88ab\u63d0\u524d\u56de\u6536\uff0c\u867d\u7136\u5728\u6700\u540e\u8fd8\u6709\u5f15\u7528\uff0c\u4f46\u6b64\u65f6\u5f15\u7528\u7684\u4e5f\u662fnull\u4e86<\/p>\n
\n
\u73b0\u5728\u518d\u56de\u5230\u4e0a\u9762\u7684\u7ebf\u7a0b\u6c60\u95ee\u9898\uff0c\u6839\u636e\u4e0a\u9762\u4ecb\u7ecd\u7684\u673a\u5236\uff0c\u5728\u5206\u6790\u6ca1\u6709\u5f15\u7528\u4e4b\u540e\uff0c\u5bf9\u8c61\u4f1a\u88ab\u63d0\u524dfinalize<\/p>\n
\u53ef\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0creturn\u4e4b\u524d\u660e\u660e\u662f\u6709\u5f15\u7528\u7684executorService.execute(futureTask)<\/code>\uff0c\u4e3a\u4ec0\u4e48\u4e5f\u4f1a\u63d0\u524dfinalize\u5462\uff1f<\/p>\n
\u731c\u6d4b\u53ef\u80fd\u662f\u7531\u4e8e\u5728execute\u65b9\u6cd5\u4e2d\uff0c\u4f1a\u8c03\u7528threadPoolExecutor\uff0c\u4f1a\u521b\u5efa\u5e76\u542f\u52a8\u4e00\u4e2a\u65b0\u7ebf\u7a0b\uff0c\u8fd9\u65f6\u4f1a\u53d1\u751f\u4e00\u6b21\u4e3b\u52a8\u7684\u7ebf\u7a0b\u5207\u6362\uff0c\u5bfc\u81f4\u5728\u6d3b\u52a8\u7ebf\u7a0b\u4e2d\u5bf9\u8c61\u4e0d\u53ef\u8fbe<\/p>\n
\u7ed3\u5408\u4e0a\u9762Oracle Jdk\u6587\u6863\u4e2d\u7684\u63cf\u8ff0\u201c\u53ef\u8fbe\u5bf9\u8c61(reachable object)\u662f\u53ef\u4ee5\u4ece\u4efb\u4f55\u6d3b\u52a8\u7ebf\u7a0b\u7684\u4efb\u4f55\u6f5c\u5728\u7684\u6301\u7eed\u8bbf\u95ee\u4e2d\u7684\u4efb\u4f55\u5bf9\u8c61\u201d\uff0c\u53ef\u4ee5\u8ba4\u4e3a\u53ef\u80fd\u662f\u56e0\u4e3a\u4e00\u6b21\u663e\u793a\u7684\u7ebf\u7a0b\u5207\u6362\uff0c\u5bf9\u8c61\u88ab\u8ba4\u4e3a\u4e0d\u53ef\u8fbe\u4e86\uff0c\u5bfc\u81f4\u7ebf\u7a0b\u6c60\u88ab\u63d0\u524dfinalize\u4e86<\/p>\n
\u4e0b\u9762\u6765\u9a8c\u8bc1\u4e00\u4e0b\u731c\u60f3\uff1a<\/p>\n
\/\/\u5165\u53e3\u51fd\u6570\npublic class FinalizedTest {\n    public static void main(String[] args) {\n        final FinalizedTest finalizedTest = new FinalizedTest();\n        for (int i = 0; i < 8; i++) {\n            new Thread(new Runnable() {\n                @Override\n                public void run() {\n                    while (true) {\n                        TFutureTask future = finalizedTest.submit();\n                    }\n                }\n            }).start();\n        }\n        new Thread(new Runnable() {\n            @Override\n            public void run() {\n                while (true) {\n                    System.gc();\n                }\n            }\n        }).start();\n    }\n    public TFutureTask submit(){\n        TExecutorService TExecutorService = Executors.create();\n        TExecutorService.execute();\n        return null;\n    }\n}\n\n\/\/Executors.java\uff0c\u6a21\u62dfjuc\u7684Executors\npublic class Executors {\n    \/**\n     * \u6a21\u62dfExecutors.createSingleExecutor\n     * @return\n     *\/\n    public static TExecutorService create(){\n        return new FinalizableDelegatedTExecutorService(new TThreadPoolExecutor());\n    }\n\n    static class FinalizableDelegatedTExecutorService extends DelegatedTExecutorService {\n\n        FinalizableDelegatedTExecutorService(TExecutorService executor) {\n            super(executor);\n        }\n        \n        \/**\n         * \u6790\u6784\u51fd\u6570\u4e2d\u6267\u884cshutdown\uff0c\u4fee\u6539\u7ebf\u7a0b\u6c60\u72b6\u6001\n         * @throws Throwable\n         *\/\n        @Override\n        protected void finalize() throws Throwable {\n            super.shutdown();\n        }\n    }\n\n    static class DelegatedTExecutorService extends TExecutorService {\n\n        protected TExecutorService e;\n\n        public DelegatedTExecutorService(TExecutorService executor) {\n            this.e = executor;\n        }\n\n        @Override\n        public void execute() {\n            e.execute();\n        }\n\n        @Override\n        public void shutdown() {\n            e.shutdown();\n        }\n    }\n}\n\n\/\/TThreadPoolExecutor.java\uff0c\u6a21\u62dfjuc\u7684ThreadPoolExecutor\npublic class TThreadPoolExecutor extends TExecutorService {\n\n    \/**\n     * \u7ebf\u7a0b\u6c60\u72b6\u6001\uff0cfalse\uff1a\u672a\u5173\u95ed\uff0ctrue\u5df2\u5173\u95ed\n     *\/\n    private AtomicBoolean ctl = new AtomicBoolean();\n\n    @Override\n    public void execute() {\n        \/\/\u542f\u52a8\u4e00\u4e2a\u65b0\u7ebf\u7a0b\uff0c\u6a21\u62dfThreadPoolExecutor.execute\n        new Thread(new Runnable() {\n            @Override\n            public void run() {\n\n            }\n        }).start();\n        \/\/\u6a21\u62dfThreadPoolExecutor\uff0c\u542f\u52a8\u65b0\u5efa\u7ebf\u7a0b\u540e\uff0c\u5faa\u73af\u68c0\u67e5\u7ebf\u7a0b\u6c60\u72b6\u6001\uff0c\u9a8c\u8bc1\u662f\u5426\u4f1a\u5728finalize\u4e2dshutdown\n        \/\/\u5982\u679c\u7ebf\u7a0b\u6c60\u88ab\u63d0\u524dshutdown\uff0c\u5219\u629b\u51fa\u5f02\u5e38\n        for (int i = 0; i < 1_000_000; i++) {\n            if(ctl.get()){\n                throw new RuntimeException("reject!!!["+ctl.get()+"]");\n            }\n        }\n    }\n\n    @Override\n    public void shutdown() {\n        ctl.compareAndSet(false,true);\n    }\n}<\/code><\/pre>\n
\u6267\u884c\u82e5\u5e72\u65f6\u95f4\u540e\u62a5\u9519\uff1a<\/p>\n
Exception in thread "Thread-1" java.lang.RuntimeException: reject!!![true]<\/code><\/pre>\n
\u4ece\u9519\u8bef\u4e0a\u6765\u770b\uff0c\u201c\u7ebf\u7a0b\u6c60\u201d\u540c\u6837\u88ab\u63d0\u524dshutdown\u4e86\uff0c\u90a3\u4e48\u4e00\u5b9a\u662f\u7531\u4e8e\u65b0\u5efa\u7ebf\u7a0b\u5bfc\u81f4\u7684\u5417\uff1f<\/p>\n
\u4e0b\u9762\u5c06\u65b0\u5efa\u7ebf\u7a0b\u4fee\u6539\u4e3aThread.sleep<\/code>\u6d4b\u8bd5\u4e00\u4e0b\uff1a<\/p>\n
\/\/TThreadPoolExecutor.java\uff0c\u4fee\u6539\u540e\u7684execute\u65b9\u6cd5\npublic void execute() {\n    try {\n        \/\/\u663e\u5f0f\u7684sleep 1 ns\uff0c\u4e3b\u52a8\u5207\u6362\u7ebf\u7a0b\n        TimeUnit.NANOSECONDS.sleep(1);\n    } catch (InterruptedException e) {\n        e.printStackTrace();\n    }\n    \/\/\u6a21\u62dfThreadPoolExecutor\uff0c\u542f\u52a8\u65b0\u5efa\u7ebf\u7a0b\u540e\uff0c\u5faa\u73af\u68c0\u67e5\u7ebf\u7a0b\u6c60\u72b6\u6001\uff0c\u9a8c\u8bc1\u662f\u5426\u4f1a\u5728finalize\u4e2dshutdown\n    \/\/\u5982\u679c\u7ebf\u7a0b\u6c60\u88ab\u63d0\u524dshutdown\uff0c\u5219\u629b\u51fa\u5f02\u5e38\n    for (int i = 0; i < 1_000_000; i++) {\n        if(ctl.get()){\n            throw new RuntimeException("reject!!!["+ctl.get()+"]");\n        }\n    }\n}<\/code><\/pre>\n
\u6267\u884c\u7ed3\u679c\u4e00\u6837\u662f\u62a5\u9519<\/p>\n
Exception in thread "Thread-3" java.lang.RuntimeException: reject!!![true]<\/code><\/pre>\n
\u7531\u6b64\u53ef\u5f97\uff0c\u5982\u679c\u5728\u6267\u884c\u7684\u8fc7\u7a0b\u4e2d\uff0c\u53d1\u751f\u4e00\u6b21\u663e\u5f0f\u7684\u7ebf\u7a0b\u5207\u6362\uff0c\u5219\u4f1a\u8ba9\u7f16\u8bd1\u5668\/\u4ee3\u7801\u751f\u6210\u5668\u8ba4\u4e3a\u5916\u5c42\u5305\u88c5\u5bf9\u8c61\u4e0d\u53ef\u8fbe<\/strong><\/p>\n
\u603b\u7ed3<\/h2>\n
\u867d\u7136GC\u53ea\u4f1a\u56de\u6536\u4e0d\u53ef\u8fbeGC ROOT\u7684\u5bf9\u8c61\uff0c\u4f46\u662f\u5728\u7f16\u8bd1\u5668\uff08\u6ca1\u6709\u660e\u786e\u6307\u51fa\uff0c\u4e5f\u53ef\u80fd\u662fJIT\uff09\/\u4ee3\u7801\u751f\u6210\u5668\u7684\u4f18\u5316\u4e0b\uff0c\u53ef\u80fd\u4f1a\u51fa\u73b0\u5bf9\u8c61\u63d0\u524d\u7f6enull\uff0c\u6216\u8005\u7ebf\u7a0b\u5207\u6362\u5bfc\u81f4\u7684\u201c\u63d0\u524d\u5bf9\u8c61\u4e0d\u53ef\u8fbe\u201d\u7684\u60c5\u51b5\u3002<\/p>\n
\u6240\u4ee5\u5982\u679c\u60f3\u5728finalize\u65b9\u6cd5\u91cc\u505a\u4e9b\u4e8b\u60c5\u7684\u8bdd\uff0c\u4e00\u5b9a\u5728\u6700\u540e\u663e\u793a\u7684\u5f15\u7528\u4e00\u4e0b\u5bf9\u8c61\uff08toString\/hashcode\u90fd\u53ef\u4ee5\uff09\uff0c\u4fdd\u6301\u5bf9\u8c61\u7684\u53ef\u8fbe\u6027\uff08reachable\uff09<\/p>\n
\u4e0a\u9762\u5173\u4e8e\u7ebf\u7a0b\u5207\u6362\u5bfc\u81f4\u7684\u5bf9\u8c61\u4e0d\u53ef\u8fbe\uff0c\u6ca1\u6709\u5b98\u65b9\u6587\u732e\u7684\u652f\u6301\uff0c\u53ea\u662f\u4e2a\u4eba\u4e00\u4e2a\u6d4b\u8bd5\u7ed3\u679c\uff0c\u5982\u6709\u95ee\u9898\u6b22\u8fce\u6307\u51fa<\/p>\n
\u7efc\u4e0a\u6240\u8ff0\uff0c\u8fd9\u79cd\u56de\u6536\u673a\u5236\u5e76\u4e0d\u662fJDK\u7684bug\uff0c\u800c\u7b97\u662f\u4e00\u4e2a\u4f18\u5316\u7b56\u7565\uff0c\u63d0\u524d\u56de\u6536\u800c\u5df2\uff1b\u4f46Executors.newSingleThreadExecutor<\/code>\u7684\u5b9e\u73b0\u91cc\u901a\u8fc7finalize\u6765\u81ea\u52a8\u5173\u95ed\u7ebf\u7a0b\u6c60\u7684\u505a\u6cd5\u662f\u6709Bug\u7684\uff0c\u5728\u7ecf\u8fc7\u4f18\u5316\u540e\u53ef\u80fd\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u6c60\u7684\u63d0\u524dshutdown\uff0c\u4ece\u800c\u5bfc\u81f4\u5f02\u5e38\u3002<\/strong><\/p>\n
\u7ebf\u7a0b\u6c60\u7684\u8fd9\u4e2a\u95ee\u9898\uff0c\u5728JDK\u7684\u8bba\u575b\u91cc\u4e5f\u662f\u4e00\u4e2a\u516c\u5f00\u4f46\u672a\u89e3\u51b3\u72b6\u6001\u7684\u95ee\u9898\uff1ahttps:\/\/bugs.openjdk.java.net…<\/a>\u3002<\/p>\n
\u4e0d\u8fc7\u5728JDK11\u4e0b\uff0c\u8be5\u95ee\u9898\u5df2\u7ecf\u88ab\u4fee\u590d\uff1a<\/p>\n
JUC  Executors.FinalizableDelegatedExecutorService\npublic void execute(Runnable command) {\n    try {\n        e.execute(command);\n    } finally { reachabilityFence(this); }\n}<\/code><\/pre>\n
\u8fd1\u671f\u70ed\u6587\u63a8\u8350\uff1a<\/strong><\/p>\n
1.1,000+ \u9053 Java\u9762\u8bd5\u9898\u53ca\u7b54\u6848\u6574\u7406(2022\u6700\u65b0\u7248)<\/a><\/p>\n
2.\u52b2\u7206\uff01Java \u534f\u7a0b\u8981\u6765\u4e86\u3002\u3002\u3002<\/a><\/p>\n
3.Spring Boot 2.x \u6559\u7a0b\uff0c\u592a\u5168\u4e86\uff01<\/a><\/p>\n
4.\u522b\u518d\u5199\u6ee1\u5c4f\u7684\u7206\u7206\u7206\u70b8\u7c7b\u4e86\uff0c\u8bd5\u8bd5\u88c5\u9970\u5668\u6a21\u5f0f\uff0c\u8fd9\u624d\u662f\u4f18\u96c5\u7684\u65b9\u5f0f\uff01\uff01<\/a><\/p>\n
5.\u300aJava\u5f00\u53d1\u624b\u518c\uff08\u5d69\u5c71\u7248\uff09\u300b\u6700\u65b0\u53d1\u5e03\uff0c\u901f\u901f\u4e0b\u8f7d\uff01<\/a><\/p>\n
\u89c9\u5f97\u4e0d\u9519\uff0c\u522b\u5fd8\u4e86\u968f\u624b\u70b9\u8d5e+\u8f6c\u53d1\u54e6\uff01<\/p>\n
https:\/\/segmentfault.com\/a\/1190000042404947<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u6765\u6e90\uff1ahttps:\/\/segmentfault.com\/a\/11… \u95ee\u9898\u63cf\u8ff0 \u524d\u51e0\u5929\u5728\u5e2e\u540c\u4e8b\u6392\u67e5\u751f […]<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-10006354","post","type-post","status-publish","format-standard","hentry"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006354","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10006354"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10006354\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10006354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10006354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10006354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}