\u4f60\u597d\u5440\uff0c\u6211\u662f\u6b6a\u6b6a\u3002<\/p>\n
\u7ed9\u5927\u5bb6\u5206\u4eab\u4e00\u4e2a\u5173\u4e8e ScheduledExecutorService \u7ebf\u7a0b\u6c60\u7684 BUG \u554a\uff0c\u8fd9\u4e2a BUG \u80fd\u76f4\u63a5\u628a CPU \u7ed9\u98da\u5230 100%\uff0c\u5e0c\u671b\u5927\u5bb6\u6c38\u8fdc\u8e29\u4e0d\u5230\u3002<\/p>\n
\u4f46\u662f\uff0cu1s1\uff0c\u4e00\u822c\u6765\u8bf4\u4e5f\u5f88\u96be\u8e29\u5230\u3002<\/p>\n
\u5230\u5e95\u548b\u56de\u4e8b\u5462\uff0c\u8ba9\u6211\u7ed9\u4f60\u7ec6\u7ec6\u55e6\u55e6\u3002<\/p>\n
\u8001\u89c4\u77e9\uff0c\u6309\u7167\u60ef\u4f8b\uff0c\u5148\u641e\u4e2a Demo \u51fa\u6765\u73a9\u73a9\uff1a<\/p>\n
<\/p>\n
\u9879\u76ee\u91cc\u9762\u4f7f\u7528\u5230\u4e86 ScheduledThreadPoolExecutor \u7ebf\u7a0b\u6c60\uff0c\u8be5\u7ebf\u7a0b\u6c60\u5bf9\u5e94\u7684\u6838\u5fc3\u7ebf\u7a0b\u6570\u653e\u5728\u914d\u7f6e\u6587\u4ef6\u91cc\u9762\uff0c\u901a\u8fc7 @Value \u6ce8\u89e3\u6765\u8bfb\u53d6\u914d\u7f6e\u6587\u4ef6\u3002<\/p>\n
\u7136\u540e\u901a\u8fc7\u63a5\u53e3\u89e6\u53d1\u8fd9\u4e2a\u7ebf\u7a0b\u6c60\u91cc\u9762\u7684\u4efb\u52a1\u3002<\/p>\n
\u5177\u4f53\u6765\u8bf4\u5c31\u662f\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4ee3\u7801\u4e2d\uff0c\u5728\u8c03\u7528 testScheduledPool \u63a5\u53e3\u4e4b\u540e\uff0c\u7a0b\u5e8f\u4f1a\u5728 60 \u79d2\u4e4b\u540e\u8f93\u51fa\u201c\u6267\u884c\u4e1a\u52a1\u903b\u8f91\u201d\u3002<\/p>\n
\u8fd9\u4e2a\u4ee3\u7801\u7684\u903b\u8f91\u8fd8\u662f\u975e\u5e38\u7b80\u5355\u6e05\u6670\u7684\uff0c\u4f46\u662f\u4e0a\u9762\u7684\u4ee3\u7801\u6709\u4e00\u4e2a\u95ee\u9898\uff0c\u4e0d\u77e5\u9053\u4f60\u770b\u51fa\u6765\u6ca1\u6709\uff1f<\/p>\n
<\/p>\n
\u6ca1\u770b\u51fa\u6765\u4e5f\u6ca1\u5173\u7cfb\uff0c\u6211\u8fd9\u91cc\u90fd\u662f\u9f13\u52b1\u5f0f\u6559\u5b66\u7684\uff0c\u4e0d\u6253\u51fb\u540c\u5b66\u7684\u79ef\u6781\u6027\u3002<\/p>\n
\u6240\u4ee5\uff0c\u522b\u7740\u6025\uff0c\u6211\u5148\u7ed9\u4f60\u8dd1\u8d77\u6765\uff0c\u4f60\u7785\u4e00\u773c\u7acb\u9a6c\u5c31\u80fd\u770b\u51fa\u95ee\u9898\u662f\u5565\uff1a<\/p>\n
<\/p>\n
\u4e3a\u4ec0\u4e48 coreSize \u662f 0 \u5462\uff0c\u6211\u4eec\u914d\u7f6e\u6587\u4ef6\u91cc\u9762\u660e\u660e\u5199\u7684\u662f 2 \u554a\uff1f<\/p>\n
\u56e0\u4e3a setCoreSize \u65b9\u6cd5\u662f static \u7684\uff0c\u5bfc\u81f4 @Value \u6ce8\u89e3\u5931\u6548\u3002<\/p>\n
\u5982\u679c\u53bb\u6389 static \u90a3\u4e48\u5c31\u80fd\u6b63\u786e\u8bfb\u53d6\u5230\u914d\u7f6e\u6587\u4ef6\u4e2d\u7684\u914d\u7f6e\uff1a<\/p>\n
<\/p>\n
\u867d\u7136\u8fd9\u91cc\u9762\u4e5f\u5927\u6709\u5b66\u95ee\uff0c\u4f46\u662f\u8fd9\u5e76\u4e0d\u662f\u672c\u6587\u7684\u91cd\u70b9\uff0c\u8fd9\u53ea\u662f\u4e00\u4e2a\u5f15\u5b50\uff0c<\/p>\n
\u4e3a\u7684\u662f\u5f15\u51fa\u4e3a\u4ec0\u4e48\u4f1a\u5728\u9879\u76ee\u91cc\u9762\u51fa\u73b0\u4e0b\u9762\u8fd9\u79cd coreSize \u7b49\u4e8e 0 \u7684\u5947\u602a\u7684\u4ee3\u7801\uff1a<\/p>\n
ScheduledExecutorService executor = Executors.newScheduledThreadPool(0);<\/p><\/blockquote>\n
\u5982\u679c\u6211\u76f4\u63a5\u7ed9\u51fa\u4e0a\u9762\u7684\u4ee3\u7801\uff0c\u4e00\u70b9\u6709\u4eba\u8bf4\u53ea\u6709\u5c0f\uff08\u5927\uff09\u53ef\uff08\u50bb\uff09\u7231\uff08\u903c\uff09\u624d\u4f1a\u8fd9\u6837\u5199\u3002<\/p>\n
\u4f46\u662f\u94fa\u57ab\u4e00\u4e2a\u80cc\u666f\u4e4b\u540e\uff0c\u5c31\u5bb9\u6613\u63a5\u53d7\u7684\u591a\u4e86\u3002<\/p>\n
\u4f60\u6c38\u8fdc\u53ef\u4ee5\u76f8\u4fe1\u6211\u7684\u884c\u6587\u7ed3\u6784\uff0c\u8001\u53f8\u5f00\u8f66\u7a33\u5f97\u5f88\uff0c\u4f60\u653e\u5fc3\u3002<\/p>\n
\u597d\uff0c\u7ecf\u8fc7\u524d\u9762\u7684\u94fa\u57ab\uff0c\u5176\u5b9e\u6211\u4eec\u7684 Demo \u80fd\u76f4\u63a5\u7b80\u5316\u5230\u8fd9\u4e2a\u6837\u5b50\uff1a<\/p>\n
public static void main(String[] args){\n ScheduledExecutorService e = Executors.newScheduledThreadPool(0);\n e.schedule(() -> {\n System.out.println("\u4e1a\u52a1\u903b\u8f91");\n }, 60, TimeUnit.SECONDS);\n e.shutdown();\n}<\/code><\/pre>\n\u8fd9\u4e2a\u4ee3\u7801\u662f\u53ef\u4ee5\u6b63\u5e38\u8fd0\u884c\u7684\uff0c\u4f60\u7c98\u8fc7\u53bb\u76f4\u63a5\u5c31\u80fd\u8dd1\uff0c60 \u79d2\u540e\u662f\u4f1a\u6b63\u5e38\u8f93\u51fa\u7684\u3002<\/p>\n
\u5982\u679c\u4f60\u89c9\u5f97 60 \u79d2\u592a\u957f\u4e86\uff0c\u90a3\u4e48\u4f60\u53ef\u4ee5\u6539\u6210 3 \u79d2\u8fd0\u884c\u4e00\u4e0b\uff0c\u770b\u770b\u7a0b\u5e8f\u662f\u4e0d\u662f\u6b63\u5e38\u8fd0\u884c\u5e76\u7ed3\u675f\u4e86\u3002<\/p>\n
\u4f46\u662f\u5c31\u8fd9\u4e2a\u770b\u8d77\u6765\u95ee\u9898\u4e0d\u5927\u7684\u4ee3\u7801\uff0c\u4f1a\u5bfc\u81f4 CPU \u98da\u5230 100% \u53bb\u3002<\/p>\n
\u771f\u7684\uff0c\u513f\u8c41\u561b\u3002<\/p>\n
<\/p>\n
\u548b\u56de\u4e8b\u5462<\/h2>\n
\u5230\u5e95\u548b\u56de\u4e8b\u5462\uff1f<\/p>\n
\u8fd9\u4e2a\u5176\u5b9e\u5c31\u662f JDK \u7684 BUG \u5bfc\u81f4\u7684\uff0c\u6211\u5e26\u4f60\u7785\u7785\uff1a<\/p>\n
https:\/\/bugs.openjdk.org\/brow…<\/a><\/p><\/blockquote>\n
<\/p>\n
\u9996\u5148\uff0c\u4f60\u770b Fix Version \u90a3\u4e2a\u5730\u65b9\u662f 9\uff0c\u4e5f\u5c31\u662f\u8bf4\u660e\u8fd9\u4e2a BUG \u662f\u5728 JDK 9 \u91cc\u9762\u4fee\u590d\u4e86\u3002JDK 8 \u91cc\u9762\u662f\u53ef\u4ee5\u590d\u73b0\u7684\u3002<\/p>\n
\u5176\u6b21\uff0c\u8fd9\u4e2a\u6807\u9898\u5176\u5b9e\u5c31\u5305\u542b\u4e86\u975e\u5e38\u591a\u7684\u4fe1\u606f\u4e86\uff0c\u5b83\u8bf4\u5bf9\u4e8e ScheduledExecutorService \u6765\u8bf4 getTask \u65b9\u6cd5\u91cc\u9762\u5b58\u5728\u9891\u7e41\u7684\u5faa\u73af\u3002<\/p>\n
\u90a3\u4e48\u95ee\u9898\u5c31\u6765\u4e86\uff1a\u9891\u7e41\u7684\u5faa\u73af\uff0c\u6bd4\u5982 for(;;) \uff0cwhile(true) \u8fd9\u6837\u7684\u4ee3\u7801\uff0c\u957f\u65f6\u95f4\u4ece\u5faa\u73af\u91cc\u9762\u8d70\u4e0d\u51fa\u6765\uff0c\u4f1a\u5bfc\u81f4\u4ec0\u4e48\u73b0\u8c61\uff1f<\/p>\n
\u90a3\u4e0d\u5c31\u662f\u5bfc\u81f4 CPU \u98d9\u9ad8\u5417\u3002<\/p>\n
\u6ce8\u610f\uff0c\u8fd9\u91cc\u6211\u8bf4\u7684\u662f\u201c\u957f\u65f6\u95f4\u4ece\u5faa\u73af\u91cc\u9762\u8d70\u4e0d\u51fa\u6765\u201d\uff0c\u800c\u4e0d\u662f\u6b7b\u5faa\u73af\uff0c\u8fd9\u4e24\u8005\u4e4b\u95f4\u7684\u5dee\u5f02\u8fd8\u662f\u5f88\u5927\u7684\u3002<\/p>\n
\u6211\u4ee3\u7801\u91cc\u9762\u7684\u793a\u4f8b\u5c31\u662f\u4f7f\u7528\u7684\u63d0\u51fa BUG \u7684\u54e5\u4eec\u7ed9\u51fa\u7684\u5b9e\u4f8b\uff1a<\/p>\n
<\/p>\n
\u4ed6\u8bf4\uff0c\u5728\u8fd9\u4e2a\u793a\u4f8b\u4e0b\uff0c\u5982\u679c\u4f60\u5728\u4e00\u4e2a\u53ea\u6709\u5355\u6838\u7684\u670d\u52a1\u5668\u4e0a\u8dd1\uff0c\u7136\u540e\u4f7f\u7528 TOP \u547d\u4ee4\uff0c\u4f1a\u770b\u5230\u6301\u7eed 60 \u79d2\u7684 CPU \u4f7f\u7528\u7387\u4e3a 100%\u3002<\/p>\n
\u4e3a\u4ec0\u4e48\u5462\uff1f<\/p>\n
\u7b54\u6848\u5c31\u85cf\u5728\u524d\u9762\u63d0\u5230\u7684 getTask \u65b9\u6cd5\u4e2d\uff1a<\/p>\n
java.util.concurrent.ThreadPoolExecutor#getTask<\/p><\/blockquote>\n
<\/p>\n
\u8fd9\u4e2a\u65b9\u6cd5\u91cc\u9762\u679c\u7136\u662f\u6709\u4e00\u4e2a\u7c7b\u4f3c\u4e8e\u65e0\u7ebf\u5faa\u73af\u7684\u4ee3\u7801\uff0c\u4f46\u662f\u5b83\u4e3a\u4ec0\u4e48\u4e0d\u505c\u7684\u6267\u884c\u5462\uff1f<\/p>\n
\u73b0\u5728\u8d76\u7d27\u60f3\u4e00\u60f3\u7ebf\u7a0b\u6c60\u7684\u57fa\u672c\u8fd0\u884c\u539f\u7406\u3002\u5f53\u6ca1\u6709\u4efb\u52a1\u5904\u7406\u7684\u65f6\u5019\uff0c\u6838\u5fc3\u7ebf\u7a0b\u5728\u5e72\u5565\uff1f<\/p>\n
<\/p>\n
\u662f\u4e0d\u662f\u5c31\u963b\u585e\u5728\u8fd9\u4e2a\u5730\u65b9\uff0c\u7b49\u7740\u4efb\u52a1\u8fc7\u6765\u8fdb\u884c\u5904\u7406\u7684\uff0c\u8fd9\u4e2a\u80fd\u7406\u89e3\u5427\uff1a<\/p>\n
<\/p>\n
\u90a3\u6211\u518d\u95ee\u4f60\u4e00\u4e2a\u95ee\u9898\uff0c\u8fd9\u884c\u4ee3\u7801\u7684\u4f5c\u7528\u662f\u5e72\u5565\uff1a<\/p>\n
workQueue.poll(keepAliveTime, TimeUnit.NANOSECONDS)<\/p><\/blockquote>\n
\u662f\u4e0d\u662f\u5728\u6307\u5b9a\u65f6\u95f4\u5185\u5982\u679c\u6ca1\u6709\u4ece\u961f\u5217\u91cc\u9762\u62c9\u53d6\u5230\u4efb\u52a1\uff0c\u5219\u629b\u51fa InterruptedException\u3002<\/p>\n
\u90a3\u4e48\u5b83\u4ec0\u4e48\u65f6\u5019\u4f1a\u88ab\u89e6\u53d1\u5462\uff1f<\/p>\n
<\/p>\n
\u5728 timed \u53c2\u6570\u4e3a true \u7684\u65f6\u5019\u3002<\/p>\n
timed \u53c2\u6570\u4ec0\u4e48\u65f6\u5019\u4f1a\u4e3a true \u5462\uff1f<\/p>\n
<\/p>\n
\u5f53 allowCoreThreadTimeOut \u4e3a true \u6216\u8005\u5f53\u524d\u5de5\u4f5c\u7684\u7ebf\u7a0b\u5927\u4e8e\u6838\u5fc3\u7ebf\u7a0b\u6570\u7684\u65f6\u5019\u3002<\/p>\n
\u800c allowCoreThreadTimeOut \u9ed8\u8ba4\u4e3a false\uff1a<\/p>\n
<\/p>\n
\u90a3\u4e48\u4e5f\u5c31\u662f\u5728\u8fd9\u4e2a\u6848\u4f8b\u4e0b\u6ee1\u8db3\u4e86\u5f53\u524d\u5de5\u4f5c\u7684\u7ebf\u7a0b\u5927\u4e8e\u6838\u5fc3\u7ebf\u7a0b\u6570\u8fd9\u4e2a\u6761\u4ef6\uff1a<\/p>\n
wc > corePoolSize<\/p><\/blockquote>\n
\u901a\u8fc7 Debug \u77e5\u9053\uff0cwc \u662f 1\uff0ccorePoolSize \u4e3a 0\uff1a<\/p>\n
<\/p>\n
\u6240\u4ee5 timed \u53d8\u6210\u4e86 true\u3002<\/p>\n
\u597d\uff0c\u8fd9\u91cc\u8981\u6ce8\u610f\u4e86\uff0c\u670b\u53cb\u3002<\/p>\n
<\/p>\n
\u7ecf\u8fc7\u524d\u9762\u7684\u5206\u6790\uff0c\u6211\u4eec\u5df2\u7ecf\u77e5\u9053\u4e86\u5728\u5f53\u524d\u7684\u6848\u4f8b\u4e0b\uff0c\u4f1a\u89e6\u53d1 for(;;)\u8fd9\u4e2a\u903b\u8f91\uff1a<\/p>\n
workQueue.poll(keepAliveTime, TimeUnit.NANOSECONDS)<\/p><\/blockquote>\n
\u90a3\u4e48\u8fd9\u4e2a keepAliveTime \u5230\u5e95\u662f\u591a\u5c11\u5462\uff1f<\/p>\n
<\/p>\n
\u6765\uff0c\u5927\u58f0\u7684\u558a\u51fa\u8fd9\u4e2a\u6570\u5b57\uff1a0\uff0c\u8fd9\u662f\u4e00\u4e2a\u610f\u60f3\u4e0d\u5230\u7684\u3001\u8be1\u8ba1\u591a\u7aef\u7684 0\u3002<\/p>\n
<\/p>\n
\u6240\u4ee5\uff0c\u8fd9\u4e2a\u5730\u65b9\u4e2d\u7684 r \u6bcf\u6b21\u90fd\u4f1a\u8fd4\u56de\u4e00\u4e2a null\uff0c\u7136\u540e\u518d\u6b21\u5f00\u542f\u5faa\u73af\u3002<\/p>\n
\u5bf9\u4e8e\u6b63\u5e38\u7684\u7ebf\u7a0b\u6c60\u6765\u8bf4\uff0c\u89e6\u53d1\u4e86\u8fd9\u4e2a\u903b\u8f91\uff0c\u4ee3\u8868\u6ca1\u6709\u4efb\u52a1\u8981\u6267\u884c\u4e86\uff0c\u53ef\u4ee5\u628a\u5bf9\u5e94\u7ebf\u7a0b\u8fdb\u884c\u56de\u6536\u4e86\u3002<\/p>\n
\u56de\u6536\uff0c\u5bf9\u5e94\u7684\u5c31\u662f\u8fd9\u90e8\u5206\u4ee3\u7801\u4f1a\u8fd4\u56de\u4e00\u4e2a null\uff1a<\/p>\n
<\/p>\n
\u7136\u540e\u5728\u5916\u9762 runWorker \u65b9\u6cd5\u4e2d\u7684\uff0c\u7531\u4e8e getTask \u8fd4\u56de\u4e86 null\uff0c\u4ece\u800c\u6267\u884c\u4e86 finally \u4ee3\u7801\u91cc\u9762\u7684\u903b\u8f91\uff0c\u4e5f\u5c31\u662f\u4ece\u5f53\u524d\u7ebf\u7a0b\u6c60\u79fb\u9664\u7ebf\u7a0b\u7684\u903b\u8f91\uff1a<\/p>\n
<\/p>\n
\u4f46\u662f\uff0c\u670b\u53cb\uff0c\u6211\u8981\u8bf4\u4f46\u662f\u4e86\u3002<\/p>\n
\u5728\u6211\u4eec\u7684\u6848\u4f8b\u4e0b\uff0c\u4f60\u770b if \u5224\u65ad\u7684\u6761\u4ef6\uff1a<\/p>\n
.jpg)<\/p>\n
\u8fd9\u91cc\u9762\u7684 wc > 1 || workQueue.isEmpty()) \u662f false<\/p>\n
\u6240\u4ee5\u8fd9\u4e2a if \u6761\u4ef6\u4e0d\u6210\u7acb\uff0c\u90a3\u4e48\u5b83\u53c8\u8d70\u5230\u4e86 poll \u8fd9\u91cc\uff1a<\/p>\n
\nworkQueue.poll(keepAliveTime, TimeUnit.NANOSECONDS)<\/p><\/blockquote>\n<\/blockquote>\n
\u7531\u4e8e\u8fd9\u91cc\u7684 keepAliveTime \u662f 0\uff0c\u6240\u4ee5\u9a6c\u4e0d\u505c\u8e44\u7684\u7684\u5f00\u542f\u4e0b\u4e00\u8f6e\u5faa\u73af\u3002<\/p>\n
\u90a3\u4e48\u8fd9\u4e2a\u5faa\u73af\u4ec0\u4e48\u65f6\u5019\u7ed3\u675f\u5462\uff1f<\/p>\n
<\/p>\n
\u5c31\u662f\u5728\u4ece\u961f\u5217\u91cc\u9762\u83b7\u53d6\u5230\u4efb\u52a1\u7684\u65f6\u5019\u3002<\/p>\n
\u90a3\u4e48\u961f\u5217\u91cc\u9762\u4ec0\u4e48\u65f6\u5019\u624d\u4f1a\u6709\u4efb\u52a1\u5462\uff1f<\/p>\n
\u5728\u6211\u4eec\u7684\u6848\u4f8b\u91cc\u9762\uff0c\u662f 60 \u79d2\u4e4b\u540e\u3002<\/p>\n
\u6240\u4ee5\uff0c\u5728\u8fd9 60 \u79d2\u5185\uff0c\u8fd9\u90e8\u5206\u4ee3\u7801\u76f8\u5f53\u4e8e\u662f\u4e00\u4e2a\u201c\u6b7b\u5faa\u73af\u201d\uff0c\u5bfc\u81f4 CPU \u6301\u7eed\u98d9\u9ad8\u5230 100%\u3002<\/p>\n
\u8fd9\u5c31\u662f BUG\uff0c\u8fd9\u5c31\u662f\u6839\u672c\u539f\u56e0\u3002<\/p>\n
\u4f46\u662f\u770b\u5230\u8fd9\u91cc\u662f\u4e0d\u662f\u89c9\u5f97\u8fd8\u5dee\u70b9\u610f\u601d\uff1f<\/p>\n
\u6211\u8bf4 100% \u5c31 100% \u5417\uff1f<\/p>\n
\u5f97\u62ff\u51fa\u77f3\u9524\u6765\u624d\u884c\u554a\u3002<\/p>\n
\u6240\u4ee5\uff0c\u4e3a\u4e86\u62ff\u51fa\u5b9e\u9524\uff0c\u773c\u89c1\u4e3a\u5b9e\uff0c\u6211\u628a\u6838\u5fc3\u6d41\u7a0b\u62ff\u51fa\u6765\uff0c\u7136\u540e\u7a0d\u5fae\u6539\u52a8\u4e00\u70b9\u70b9\u4ee3\u7801\uff1a<\/p>\n
public static void main(String[] args) {\n ArrayBlockingQueue<Runnable> workQueue =\n new ArrayBlockingQueue<>(100);\n \/\/\u7ed1\u5b9a\u5230 5 \u53f7 CPU \u4e0a\u6267\u884c\n try (AffinityLock affinityLock = AffinityLock.acquireLock(5)) {\n for (; ; ) {\n try {\n Runnable r = workQueue.poll(0, TimeUnit.NANOSECONDS);\n if (r != null)\n break;\n } catch (InterruptedException retry) {\n }\n }\n }\n}<\/code><\/pre>\nAffinityLock \u8fd9\u4e2a\u7c7b\u5728\u4e4b\u524d\u7684\u6587\u7ae0\u91cc\u9762\u51fa\u73b0\u8fc7\uff1a\u300a\u9762\u8bd5\u5b98:Java\u5982\u4f55\u7ed1\u5b9a\u7ebf\u7a0b\u5230\u6307\u5b9aCPU\u4e0a\u6267\u884c?\u300b<\/a><\/p>\n
\u5c31\u662f\u628a\u7ebf\u7a0b\u7ed1\u5b9a\u5230\u6307\u5b9a CPU \u4e0a\u53bb\u6267\u884c\uff0c\u51cf\u5c11 CPU \u6296\u52a8\u5e26\u6765\u7684\u635f\u8017\uff0c
\u5177\u4f53\u6211\u5c31\u4e0d\u4ecb\u7ecd\u4e86\uff0c\u6709\u5174\u8da3\u53bb\u770b\u6211\u4e4b\u524d\u7684\u6587\u7ae0\u3002<\/p>\n\u628a\u8fd9\u4e2a\u7a0b\u5e8f\u8dd1\u8d77\u6765\u4e4b\u540e\uff0c\u6253\u5f00\u8d44\u6e90\u76d1\u89c6\u5668\uff0c\u4f60\u53ef\u4ee5\u770b\u5230 5 \u53f7 CPU \u7acb\u9a6c\u5c31\u98da\u5230 100% \u4e86\uff0c\u505c\u6b62\u8fd0\u884c\u4e4b\u540e\uff0c\u7acb\u9a6c\u5c31\u4e0b\u6765\u4e86\uff1a<\/p>\n
<\/p>\n
\u8fd9\u5c31\u662f\u773c\u89c1\u4e3a\u5b9e\uff0c\u8fd9\u771f\u662f JDK \u7684 BUG\uff0c\u6211\u771f\u6ca1\u9a97\u4f60\u3002<\/p>\n
\u600e\u4e48\u4fee\u590d<\/h2>\n
\u5728 JDK 9 \u91cc\u9762\u662f\u600e\u4e48\u4fee\u590d\u8fd9\u4e2a BUG \u7684\u5462\uff1f<\/p>\n
\u5728\u524d\u9762\u63d0\u5230\u7684 BUG \u7684\u94fe\u63a5\u4e2d\uff0c\u6709\u8fd9\u6837\u7684\u4e00\u4e2a\u94fe\u63a5\uff0c\u91cc\u9762\u5c31\u662f JDK 9 \u7248\u672c\u91cc\u9762\u9488\u5bf9\u4e0a\u8ff0\u7684 BUG \u8fdb\u884c\u7684\u4fee\u590d\uff1a<\/p>\n
http:\/\/hg.openjdk.java.net\/jd…<\/a><\/p><\/blockquote>\n
<\/p>\n
\u70b9\u5f00\u8fd9\u4e2a\u94fe\u63a5\u4e4b\u540e\uff0c\u4f60\u53ef\u4ee5\u627e\u5230\u8fd9\u4e2a\u5730\u65b9\uff1a<\/p>\n
<\/p>\n
\u9996\u5148\u5bf9\u6bd4\u4e00\u4e0b\u6807\u53f7\u4e3a \u2460 \u548c \u2461 \u7684\u5730\u65b9\uff0c\u9ed8\u8ba4\u503c\u4ece 0 \u7eb3\u79d2\u4fee\u6539\u4e3a\u4e86 DEFAULT_KEEPALIVE_MILLIS \u6beb\u79d2\u3002<\/p>\n
\u800c DEFAULT_KEEPALIVE_MILLIS \u7684\u503c\u4e3a\u5728\u6807\u53f7\u4e3a \u2462 \u7684\u5730\u65b9\uff0c 10L\u3002<\/p>\n
\u4e5f\u5c31\u662f\u9ed8\u8ba4\u4ece 0 \u7eb3\u79d2\u4fee\u6539\u4e3a\u4e86 10 \u6beb\u79d2\u3002\u800c\u8fd9\u4e00\u5904\u7684\u6539\u52a8\uff0c\u5c31\u662f\u4e3a\u4e86\u9632\u6b62\u51fa\u73b0 coreSize \u4e3a 0 \u7684\u60c5\u51b5\u3002<\/p>\n
\u6211\u4eec\u91cd\u70b9\u5173\u6ce8\u4e00\u4e0b DEFAULT_KEEPALIVE_MILLIS \u4e0a\u9762\u7684\u90a3\u4e00\u5768\u6ce8\u91ca\u3002<\/p>\n
\u6211\u7ed9\u4f60\u7ffb\u8bd1\u4e00\u4e0b\uff0c\u5927\u6982\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
\u8fd9\u4e2a\u503c\u5462\u4e00\u822c\u6765\u8bf4\u662f\u7528\u4e0d\u4e0a\u7684\uff0c\u56e0\u4e3a\u5728 ScheduledThreadPoolExecutor \u7ebf\u7a0b\u6c60\u91cc\u9762\u7684\u7ebf\u7a0b\u90fd\u662f\u6838\u5fc3\u7ebf\u7a0b\u3002<\/p>\n
\u4f46\u662f\uff0c\u5982\u679c\u7528\u6237\u521b\u5efa\u7684\u7ebf\u7a0b\u6c60\u7684\u65f6\u5019\uff0c\u4e0d\u542c\u529d\uff0c\u5934\u94c1\uff0c\u8981\u628a corePoolSize \u8bbe\u7f6e\u4e3a 0 \u4f1a\u53d1\u751f\u4ec0\u4e48\u5462\uff1f<\/p>\n
<\/p>\n
\u56e0\u4e3a keepAlive \u53c2\u6570\u8bbe\u7f6e\u7684\u4e3a 0\uff0c\u90a3\u4e48\u5c31\u4f1a\u5bfc\u81f4\u7ebf\u7a0b\u5728 getTask \u65b9\u6cd5\u91cc\u9762\u975e\u5e38\u9891\u7e41\u7684\u5faa\u73af\uff0c\u4ece\u800c\u5bfc\u81f4 CPU \u98d9\u9ad8\u3002<\/p>\n
\u90a3\u600e\u4e48\u529e\u5462\uff1f<\/p>\n
\u5f88\u7b80\u5355\uff0c\u8bbe\u7f6e\u4e00\u4e2a\u5c0f\u800c\u975e\u96f6\u7684\u503c\u5c31\u53ef\u4ee5\uff0c\u800c\u8fd9\u4e2a\u5c0f\u662f\u76f8\u5bf9\u4e8e JVM \u7684\u8fd0\u884c\u65f6\u95f4\u800c\u8a00\u7684\u3002<\/p>\n
\u6240\u4ee5\u8fd9\u4e2a 10 \u6beb\u79d2\u5c31\u662f\u8fd9\u6837\u6765\u7684\u3002<\/p>\n
\u518d\u6765\u4e00\u4e2a<\/h2>\n
\u5728\u7814\u7a76\u524d\u9762\u63d0\u5230\u7684\u7f16\u53f7\u4e3a 8065320 \u7684 BUG \u7684\u65f6\u5019\uff0c\u6211\u8fd8\u53d1\u73b0\u4e00\u4e2a\u610f\u5916\u6536\u83b7\uff0c\u7f16\u53f7\u4e3a 8051859 \u7684 BUG\uff0c\u5b83\u4eec\u662f\u6328\u7740\u7684\uff0c\u6392\u6392\u5750\u3002<\/p>\n
\u6709\u70b9\u610f\u601d\uff0c\u4e5f\u5f88\u7b80\u5355\uff0c\u6240\u4ee5\u5206\u4eab\u4e00\u6ce2\uff1a<\/p>\n
https:\/\/bugs.openjdk.org\/brow…<\/a><\/p><\/blockquote>\n
<\/p>\n
\u8fd9\u4e2a BUG \u53c8\u8bf4\u7684\u662f\u5565\u4e8b\u513f\u5462\uff1a<\/p>\n
<\/p>\n
\u770b\u622a\u56fe\u8fd9\u4e2a BUG \u4e5f\u662f\u5728 JDK 9 \u7248\u672c\u4e4b\u540e\u4fee\u590d\u7684\u3002<\/p>\n
\u8fd9\u4e2a BUG \u7684\u6807\u9898\u8bf4\u7684\u662f ScheduledExecutorService \u7ebf\u7a0b\u6c60\u7684 scheduleWithFixedDelay \u65b9\u6cd5\uff0c\u9047\u5230\u5927\u5ef6\u8fdf\u65f6\u4f1a\u6267\u884c\u5931\u8d25\u3002<\/p>\n
\u5177\u4f53\u5565\u610f\u601d\u5462\uff1f<\/p>\n
\u6211\u4eec\u8fd8\u662f\u5148\u62ff\u7740 Demo \u8bf4\uff1a<\/p>\n
public class ScheduledTaskBug {\n static public void main(String[] args) throws InterruptedException {\n ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();\n \/\/\u7b2c\u4e00\u4e2a\u4efb\u52a1\n executor.scheduleWithFixedDelay(new Runnable() {\n @Override\n public void run() {\n System.out.println("running scheduled task with delay: " + new Date());\n }\n }, 0, Long.MAX_VALUE, TimeUnit.MICROSECONDS);\n\n \/\/\u7b2c\u4e8c\u4e2a\u4efb\u52a1\n executor.submit(new Runnable() {\n @Override\n public void run() {\n System.out.println("running immediate task: " + new Date());\n }\n });\n Thread.sleep(5000);\n executor.shutdownNow();\n }\n}<\/code><\/pre>\n\u4f60\u628a\u8fd9\u4e2a\u4ee3\u7801\u7c98\u8fc7\u53bb\u4e4b\u540e\uff0c\u53d1\u73b0\u8f93\u51fa\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
<\/p>\n
\u53ea\u6709\u7b2c\u4e00\u4e2a\u4efb\u52a1\u6267\u884c\u4e86\uff0c\u7b2c\u4e8c\u4e2a\u4efb\u52a1\u6ca1\u6709\u8f93\u51fa\u7ed3\u679c\u3002<\/p>\n
\u6b63\u5e38\u6765\u8bf4\uff0c\u7b2c\u4e00\u4e2a\u4efb\u52a1\u7684\u5ef6\u8fdf\u65f6\u95f4\uff0c\u4e5f\u5c31\u662f initialDelay \u53c2\u6570\u662f 0\uff0c\u6240\u4ee5\u7b2c\u4e00\u6b21\u6267\u884c\u7684\u65f6\u5019\u662f\u7acb\u5373\u6267\u884c\uff1a<\/p>\n
<\/p>\n
\u6bd4\u5982\u6211\u6539\u6210\u8fd9\u6837\uff0c\u628a\u5468\u671f\u6267\u884c\u7684\u65f6\u95f4\u5355\u4f4d\uff0c\u7531\u5fae\u79d2\u4fee\u6539\u4e3a\u7eb3\u79d2\uff0c\u5c31\u6b63\u5e38\u4e86\uff1a<\/p>\n
<\/p>\n
\u795e\u5947\u4e0d\u795e\u5947\uff1f\u4f60\u8bf4\u8fd9\u4e0d\u662f BUG \u8fd9\u662f\u5565\uff1f<\/p>\n
\u63d0\u51fa BUG \u7684\u8fd9\u4e2a\u54e5\u4eec\u5728\u63cf\u8ff0\u91cc\u9762\u4ecb\u7ecd\u4e86 BUG \u7684\u539f\u56e0\uff0c\u4e3b\u8981\u662f\u63d0\u5230\u4e86\u4e00\u4e2a\u5b57\u6bb5\u548c\u4e24\u4e2a\u65b9\u6cd5\uff1a<\/p>\n
<\/p>\n
\u4e00\u4e2a\u5b57\u6bb5\u662f\u6307 period\uff0c\u4e24\u4e2a\u65b9\u6cd5\u5206\u522b\u662f TimeUnit.toNanos(-delay) \u548c ScheduledFutureTask.setNextRunTime()\u3002<\/p>\n
\u9996\u5148\uff0c\u5728 ScheduledThreadPoolExecutor \u91cc\u9762 period \u5b57\u6bb5\u6709\u4e09\u4e2a\u53d6\u503c\u8303\u56f4\uff1a<\/p>\n
\n
- \u6b63\u6570\uff0c\u4ee3\u8868\u7684\u662f\u6309\u7167\u56fa\u5b9a\u901f\u7387\u6267\u884c(scheduleAtFixedRate)\u3002<\/li>\n
- \u8d1f\u6570\uff0c\u4ee3\u8868\u7684\u662f\u6309\u7167\u56fa\u5b9a\u5ef6\u65f6\u6267\u884c(scheduleWithFixedDelay)\u3002<\/li>\n
- 0\uff0c\u4ee3\u8868\u7684\u662f\u975e\u91cd\u590d\u6027\u4efb\u52a1\u3002<\/li>\n<\/ul>\n
<\/p>\n
\u6bd4\u5982\u6211\u4eec\u7684\u793a\u4f8b\u4ee3\u7801\u4e2d\u8c03\u7528\u7684\u662f scheduleWithFixedDelay \u65b9\u6cd5\uff0c\u5b83\u91cc\u9762\u5c31\u4f1a\u5728\u8c03\u7528 TimeUnit.toNanos \u65b9\u6cd5\u7684\u65f6\u5019\u53d6\u53cd\uff0c\u8ba9 period \u5b57\u6bb5\u4e3a\u8d1f\u6570\uff1a<\/p>\n
<\/p>\n
\u597d\uff0c\u6b64\u65f6\u6211\u4eec\u5f00\u59cb Debug \u6211\u4eec\u7684 Demo\uff0c\u5148\u6765\u4e00\u4e2a\u6b63\u5e38\u7684\u3002<\/p>\n
\u6bd4\u5982\u6211\u4eec\u6765\u4e00\u4e2a\u6bcf 30ms \u6267\u884c\u4e00\u6b21\u7684\u5468\u671f\u4efb\u52a1\uff0c\u8bf7\u4ed4\u7ec6\u770b\uff1a<\/p>\n
<\/p>\n
\u5728\u6267\u884c TimeUnit.toNanos(-delay) \u8fd9\u4e00\u884c\u4ee3\u7801\u7684\u65f6\u5019\uff0c\u628a 30 \u5fae\u79d2\u8f6c\u5316\u4e3a\u4e86 -30000 \u7eb3\u79d2\uff0c\u4e5f\u5c31\u662f\u628a period \u8bbe\u7f6e\u4e3a -30000\u3002<\/p>\n
\u7136\u540e\u6765\u5230 setNextRunTime \u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u8ba1\u7b97\u4efb\u52a1\u4e0b\u4e00\u6b21\u89e6\u53d1\u65f6\u95f4\u7684\u65f6\u5019\uff0c\u53c8\u628a period \u8f6c\u4e3a\u6b63\u6570\uff0c\u6ca1\u6709\u4efb\u4f55\u6bdb\u75c5\uff1a<\/p>\n
<\/p>\n
\u4f46\u662f\uff0c\u5f53\u6211\u4eec\u628a 30 \u4fee\u6539\u4e3a Long.MAX_VALUE \u7684\u65f6\u5019\uff0c\u6709\u610f\u601d\u7684\u4e8b\u60c5\u5c31\u51fa\u73b0\u4e86\uff1a<\/p>\n
<\/p>\n
delay=9223372036854775807
-delay=-9223372036854775807
unit.toNanos(-delay)=-9223372036854775808<\/p><\/blockquote>\n\u76f4\u63a5\u7ed9\u5e72\u6ea2\u51fa\u4e86\uff0c\u53d8\u6210\u4e86 Long.MIN_VALUE\uff1a<\/p>\n
<\/p>\n
\u5f53\u6765\u5230 setNextRunTime \u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u4f60\u4f1a\u53d1\u73b0\u7531\u4e8e\u6211\u4eec\u7684 p \u5df2\u7ecf\u662f Long.MIN_VALUE \u4e86\u3002<\/p>\n
\u90a3\u4e48 -p \u662f\u591a\u5c11\u5462\uff1f<\/p>\n
\u7ed9\u4f60\u8dd1\u4e00\u4e0b\uff1a<\/p>\n
<\/p>\n
Long.MIN_VALUE \u7684\u7edd\u5bf9\u503c\uff0c\u8fd8\u662f Long.MIN_VALUE\u3002\u4e00\u4e2a\u795e\u5947\u7684\u5c0f\u77e5\u8bc6\u70b9\u9001\u7ed9\u4f60\uff0c\u4e0d\u5ba2\u6c14\u3002<\/p>\n
\u6240\u4ee5 -p \u8fd8\u662f Long.MIN_VALUE\uff1a<\/p>\n
<\/p>\n
\u6211\u4eec\u6765\u7b97\u4e00\u4e0b\u554a\uff0c\u4e00\u79d2\u7b49\u4e8e 10 \u4ebf\u7eb3\u79d2\uff1a<\/p>\n
<\/p>\n
\u90a3\u4e48\u4e0b\u4e00\u6b21\u89e6\u53d1\u65f6\u95f4\u5c31\u53d8\u6210\u4e86\u8fd9\u6837\uff1a<\/p>\n
<\/p>\n
292 \u5e74\u4e4b\u524d\u3002<\/p>\n
\u8fd9\u5c31\u662f\u5728 BUG \u63cf\u8ff0\u4e2d\u63d0\u5230\u7684\uff1a<\/p>\n
This results in triggerTime returning a time in the distant past.<\/p><\/blockquote>\n
<\/p>\n
the distant past\uff0c\u5c31\u662f long long ago\uff0c\u5c31\u662f 292 \u5e74\u4e4b\u524d\u3002\u5c31\u662f 1731 \u5e74\uff0c\u96cd\u6b63\u4e5d\u5e74\uff0c\u90a3\u4e2a\u65f6\u5019\u7684\u7687\u5e1d\u8fd8\u662f\u4e5d\u5b50\u593a\u5ae1\u4e2d\u4e00\u987f\u4e71\u6740\uff0c\u51b2\u51fa\u91cd\u56f4\u7684\u80e4\u799b\u5927\u4f6c\u3002<\/p>\n
\u786e\u5b9e\u662f\u5f88\u4e45\u5f88\u4e45\u4ee5\u524d\u4e86\u3002<\/p>\n
\u90a3\u4e48\u8fd9\u4e2a BUG \u600e\u4e48\u4fee\u590d\u5462\uff1f<\/p>\n
\u5176\u5b9e\u5f88\u7b80\u5355\uff1a<\/p>\n
<\/p>\n
\u628a unit.toNanos(-delay) \u4fee\u6539\u4e3a -unit.toNanos(delay)\uff0c\u641e\u5b9a\u3002<\/p>\n
\u6211\u7ed9\u4f60\u76d8\u4e00\u4e0b\uff1a<\/p>\n
<\/p>\n
\u8fd9\u6837\u5c31\u4e0d\u4f1a\u6ea2\u51fa\uff0c\u65f6\u95f4\u5c31\u53d8\u6210\u4e86 292 \u5e74\u4e4b\u540e\u3002<\/p>\n
\u90a3\u4e48\u95ee\u9898\u5c31\u6765\u4e86\uff0c\u8c01\u7279\u4e48\u4f1a\u8bbe\u7f6e\u4e00\u4e2a\u6bcf 292 \u5e74\u6267\u884c\u4e00\u6b21\u7684 Java \u5b9a\u65f6\u4efb\u52a1\u5462\uff1f<\/p>\n
\u597d\uff0c\u4f60\u770b\u5230\u8fd9\u91cc\u4e86\uff0c\u672c\u6587\u5c31\u7b97\u7ed3\u675f\u4e86\uff0c\u6211\u6765\u95ee\u4f60\u4e00\u4e2a\u95ee\u9898\uff1a\u4f60\u77e5\u9053\u4e86\u8fd9\u4e24\u4e2a BUG \u4e4b\u540e\uff0c\u5bf9\u4f60\u6765\u8bf4\u6709\u4ec0\u4e48\u6536\u83b7\u5417\uff1f<\/p>\n
<\/p>\n
\u6ca1\u6709\uff0c\u662f\u7684\uff0c\u9664\u4e86\u6d6a\u8d39\u4e86\u51e0\u5206\u949f\u65f6\u95f4\u5916\uff0c\u6ca1\u6709\u4efb\u4f55\u6536\u83b7\u3002<\/p>\n
\u90a3\u4e48\u606d\u559c\u4f60\uff0c\u53c8\u5728\u6211\u8fd9\u91cc\u5b66\u5230\u4e86\u4e24\u4e2a\u6ca1\u6709\u5375\u7528\u7684\u77e5\u8bc6\u70b9\u3002<\/p>\n
<\/p>\n
\u6c47\u603b<\/h2>\n
\u8fd9\u4e2a\u5c0f\u8282\u4e3a\u4ec0\u4e48\u53eb\u505a\u6c47\u603b\u5462\uff1f<\/p>\n
\u56e0\u4e3a\u6211\u53d1\u73b0\u8fd9\u91cc\u51fa\u73b0\u7684\u4e00\u4e32 BUG\uff0c\u9664\u4e86\u672c\u6587\u63d0\u5230\u7684 2 \u4e2a\u5916\uff0c\u8fd8\u6709 3 \u4e2a\u6211\u90fd\u5199\u8fc7\u4e86\uff0c\u6240\u4ee5\u5728\u8fd9\u91cc\u6c47\u4e2a\u603b\uff0c\u5145\u70b9\u5b57\u6570\uff0c\u51d1\u4e2a\u7bc7\u5e45\uff1a<\/p>\n
<\/p>\n
8054446: Repeated offer and remove on ConcurrentLinkedQueue lead to an OutOfMemoryError<\/p><\/blockquote>\n
\u300a\u6211\u7684\u7a0b\u5e8f\u8dd1\u4e8660\u591a\u5c0f\u65f6\uff0c\u5c31\u662f\u4e3a\u4e86\u8ba9\u4f60\u770b\u4e00\u773cJDK\u7684BUG\u5bfc\u81f4\u7684\u5185\u5b58\u6cc4\u6f0f\u3002\u300b<\/a><\/p>\n
\u8fd9\u7bc7\u6587\u7ae0\u5c31\u662f\u4ece ConcurrentLinkedQueue \u961f\u5217\u7684\u4e00\u4e2a BUG \u8bb2\u8d77\u3002jetty \u6846\u67b6\u91cc\u9762\u7684\u7ebf\u7a0b\u6c60\u7528\u5230\u4e86\u8fd9\u4e2a\u961f\u5217\uff0c\u5bfc\u81f4\u4e86\u5185\u5b58\u6cc4\u6f0f\u3002<\/p>\n
\u540c\u65f6\u901a\u8fc7 jconsole\u3001VisualVM\u3001jmc \u8fd9\u4e09\u4e2a\u53ef\u89c6\u5316\u76d1\u63a7\u5de5\u5177\uff0c\u8ba9\u4f60\u770b\u89c1\u201c\u5185\u5b58\u6cc4\u6f0f\u201d\u7684\u53d1\u751f\u3002<\/p>\n
8062841: ConcurrentHashMap.computeIfAbsent stuck in an endless loop<\/p><\/blockquote>\n
\u300a\u9707\u60ca\uff01ConcurrentHashMap\u91cc\u9762\u4e5f\u6709\u6b7b\u5faa\u73af\uff0c\u4f5c\u8005\u7559\u4e0b\u7684\u201c\u5f69\u86cb\u201d\u4e86\u89e3\u4e00\u4e0b\uff1f\u300b<\/a><\/p>\n
\u8fd9\u4e2a BUG \u5728 Dubbo \u548c Seata \u91cc\u9762\u90fd\u6709\u63d0\u5230\u8fc7\uff0c\u4e5f\u88ab Seata \u5b98\u65b9\u7684\u4e00\u7bc7\u535a\u5ba2\u4e2d\u88ab\u5f15\u7528\u8fc7\uff1a<\/p>\n
https:\/\/seata.io\/zh-cn\/blog\/s…<\/a><\/p><\/blockquote>\n
<\/p>\n
8073704: FutureTask.isDone returns true when task has not yet completed<\/p><\/blockquote>\n