{"id":254,"date":"2021-10-28T10:15:55","date_gmt":"2021-10-28T02:15:55","guid":{"rendered":"http:\/\/qqiuklele.cn\/?p=254"},"modified":"2025-03-26T15:19:30","modified_gmt":"2025-03-26T07:19:30","slug":"%e3%80%90%e5%9f%ba%e6%9c%ac%e5%8a%9f%e3%80%91%e4%b8%8d%e5%8f%af%e4%b8%8d%e8%af%b4%e7%9a%84java%e9%94%81%e4%ba%8b","status":"publish","type":"post","link":"https:\/\/qqiukulele.cn\/?p=254","title":{"rendered":"\u3010\u57fa\u672c\u529f\u3011\u4e0d\u53ef\u4e0d\u8bf4\u7684Java\u201c\u9501\u201d\u4e8b"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><strong>\u524d\u8a00<\/strong><\/h2>\n\n\n\n<p>Java\u63d0\u4f9b\u4e86\u79cd\u7c7b\u4e30\u5bcc\u7684\u9501\uff0c\u6bcf\u79cd\u9501\u56e0\u5176\u7279\u6027\u7684\u4e0d\u540c\uff0c\u5728\u9002\u5f53\u7684\u573a\u666f\u4e0b\u80fd\u591f\u5c55\u73b0\u51fa\u975e\u5e38\u9ad8\u7684\u6548\u7387\u3002\u672c\u6587\u65e8\u5728\u5bf9\u9501\u76f8\u5173\u6e90\u7801\uff08\u672c\u6587\u4e2d\u7684\u6e90\u7801\u6765\u81eaJDK 8\uff09\u3001\u4f7f\u7528\u573a\u666f\u8fdb\u884c\u4e3e\u4f8b\uff0c\u4e3a\u8bfb\u8005\u4ecb\u7ecd\u4e3b\u6d41\u9501\u7684\u77e5\u8bc6\u70b9\uff0c\u4ee5\u53ca\u4e0d\u540c\u7684\u9501\u7684\u9002\u7528\u573a\u666f\u3002<\/p>\n\n\n\n<p>Java\u4e2d\u5f80\u5f80\u662f\u6309\u7167\u662f\u5426\u542b\u6709\u67d0\u4e00\u7279\u6027\u6765\u5b9a\u4e49\u9501\uff0c\u6211\u4eec\u901a\u8fc7\u7279\u6027\u5c06\u9501\u8fdb\u884c\u5206\u7ec4\u5f52\u7c7b\uff0c\u518d\u4f7f\u7528\u5bf9\u6bd4\u7684\u65b9\u5f0f\u8fdb\u884c\u4ecb\u7ecd\uff0c\u5e2e\u52a9\u5927\u5bb6\u66f4\u5feb\u6377\u7684\u7406\u89e3\u76f8\u5173\u77e5\u8bc6\u3002\u4e0b\u9762\u7ed9\u51fa\u672c\u6587\u5185\u5bb9\u7684\u603b\u4f53\u5206\u7c7b\u76ee\u5f55\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe1-1024x900.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe1-1024x900.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. \u4e50\u89c2\u9501 VS \u60b2\u89c2\u9501<\/strong><\/h3>\n\n\n\n<p>\u4e50\u89c2\u9501\u4e0e\u60b2\u89c2\u9501\u662f\u4e00\u79cd\u5e7f\u4e49\u4e0a\u7684\u6982\u5ff5\uff0c\u4f53\u73b0\u4e86\u770b\u5f85\u7ebf\u7a0b\u540c\u6b65\u7684\u4e0d\u540c\u89d2\u5ea6\u3002\u5728Java\u548c\u6570\u636e\u5e93\u4e2d\u90fd\u6709\u6b64\u6982\u5ff5\u5bf9\u5e94\u7684\u5b9e\u9645\u5e94\u7528\u3002<\/p>\n\n\n\n<p>\u5148\u8bf4\u6982\u5ff5\u3002\u5bf9\u4e8e\u540c\u4e00\u4e2a\u6570\u636e\u7684\u5e76\u53d1\u64cd\u4f5c\uff0c\u60b2\u89c2\u9501\u8ba4\u4e3a\u81ea\u5df1\u5728\u4f7f\u7528\u6570\u636e\u7684\u65f6\u5019\u4e00\u5b9a\u6709\u522b\u7684\u7ebf\u7a0b\u6765\u4fee\u6539\u6570\u636e\uff0c\u56e0\u6b64\u5728\u83b7\u53d6\u6570\u636e\u7684\u65f6\u5019\u4f1a\u5148\u52a0\u9501\uff0c\u786e\u4fdd\u6570\u636e\u4e0d\u4f1a\u88ab\u522b\u7684\u7ebf\u7a0b\u4fee\u6539\u3002Java\u4e2d\uff0csynchronized\u5173\u952e\u5b57\u548cLock\u7684\u5b9e\u73b0\u7c7b\u90fd\u662f\u60b2\u89c2\u9501\u3002<\/p>\n\n\n\n<p>\u800c\u4e50\u89c2\u9501\u8ba4\u4e3a\u81ea\u5df1\u5728\u4f7f\u7528\u6570\u636e\u65f6\u4e0d\u4f1a\u6709\u522b\u7684\u7ebf\u7a0b\u4fee\u6539\u6570\u636e\uff0c\u6240\u4ee5\u4e0d\u4f1a\u6dfb\u52a0\u9501\uff0c\u53ea\u662f\u5728\u66f4\u65b0\u6570\u636e\u7684\u65f6\u5019\u53bb\u5224\u65ad\u4e4b\u524d\u6709\u6ca1\u6709\u522b\u7684\u7ebf\u7a0b\u66f4\u65b0\u4e86\u8fd9\u4e2a\u6570\u636e\u3002\u5982\u679c\u8fd9\u4e2a\u6570\u636e\u6ca1\u6709\u88ab\u66f4\u65b0\uff0c\u5f53\u524d\u7ebf\u7a0b\u5c06\u81ea\u5df1\u4fee\u6539\u7684\u6570\u636e\u6210\u529f\u5199\u5165\u3002\u5982\u679c\u6570\u636e\u5df2\u7ecf\u88ab\u5176\u4ed6\u7ebf\u7a0b\u66f4\u65b0\uff0c\u5219\u6839\u636e\u4e0d\u540c\u7684\u5b9e\u73b0\u65b9\u5f0f\u6267\u884c\u4e0d\u540c\u7684\u64cd\u4f5c\uff08\u4f8b\u5982\u62a5\u9519\u6216\u8005\u81ea\u52a8\u91cd\u8bd5\uff09\u3002<\/p>\n\n\n\n<p>\u4e50\u89c2\u9501\u5728Java\u4e2d\u662f\u901a\u8fc7\u4f7f\u7528\u65e0\u9501\u7f16\u7a0b\u6765\u5b9e\u73b0\uff0c\u6700\u5e38\u91c7\u7528\u7684\u662fCAS\u7b97\u6cd5\uff0cJava\u539f\u5b50\u7c7b\u4e2d\u7684\u9012\u589e\u64cd\u4f5c\u5c31\u901a\u8fc7CAS\u81ea\u65cb\u5b9e\u73b0\u7684\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe2-1024x789.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe2-1024x789.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6839\u636e\u4ece\u4e0a\u9762\u7684\u6982\u5ff5\u63cf\u8ff0\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u60b2\u89c2\u9501\u9002\u5408\u5199\u64cd\u4f5c\u591a\u7684\u573a\u666f\uff0c\u5148\u52a0\u9501\u53ef\u4ee5\u4fdd\u8bc1\u5199\u64cd\u4f5c\u65f6\u6570\u636e\u6b63\u786e\u3002<\/li>\n\n\n\n<li>\u4e50\u89c2\u9501\u9002\u5408\u8bfb\u64cd\u4f5c\u591a\u7684\u573a\u666f\uff0c\u4e0d\u52a0\u9501\u7684\u7279\u70b9\u80fd\u591f\u4f7f\u5176\u8bfb\u64cd\u4f5c\u7684\u6027\u80fd\u5927\u5e45\u63d0\u5347\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5149\u8bf4\u6982\u5ff5\u6709\u4e9b\u62bd\u8c61\uff0c\u6211\u4eec\u6765\u770b\u4e0b\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u7684\u8c03\u7528\u65b9\u5f0f\u793a\u4f8b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe3-1024x336.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe3-1024x336.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u901a\u8fc7\u8c03\u7528\u65b9\u5f0f\u793a\u4f8b\uff0c\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\u60b2\u89c2\u9501\u57fa\u672c\u90fd\u662f\u5728\u663e\u5f0f\u7684\u9501\u5b9a\u4e4b\u540e\u518d\u64cd\u4f5c\u540c\u6b65\u8d44\u6e90\uff0c\u800c\u4e50\u89c2\u9501\u5219\u76f4\u63a5\u53bb\u64cd\u4f5c\u540c\u6b65\u8d44\u6e90\u3002\u90a3\u4e48\uff0c\u4e3a\u4f55\u4e50\u89c2\u9501\u80fd\u591f\u505a\u5230\u4e0d\u9501\u5b9a\u540c\u6b65\u8d44\u6e90\u4e5f\u53ef\u4ee5\u6b63\u786e\u7684\u5b9e\u73b0\u7ebf\u7a0b\u540c\u6b65\u5462\uff1f\u6211\u4eec\u901a\u8fc7\u4ecb\u7ecd\u4e50\u89c2\u9501\u7684\u4e3b\u8981\u5b9e\u73b0\u65b9\u5f0f \u201cCAS\u201d \u7684\u6280\u672f\u539f\u7406\u6765\u4e3a\u5927\u5bb6\u89e3\u60d1\u3002<\/p>\n\n\n\n<p>CAS\u5168\u79f0 Compare And Swap\uff08\u6bd4\u8f83\u4e0e\u4ea4\u6362\uff09\uff0c\u662f\u4e00\u79cd\u65e0\u9501\u7b97\u6cd5\u3002\u5728\u4e0d\u4f7f\u7528\u9501\uff08\u6ca1\u6709\u7ebf\u7a0b\u88ab\u963b\u585e\uff09\u7684\u60c5\u51b5\u4e0b\u5b9e\u73b0\u591a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u53d8\u91cf\u540c\u6b65\u3002java.util.concurrent\u5305\u4e2d\u7684\u539f\u5b50\u7c7b\u5c31\u662f\u901a\u8fc7CAS\u6765\u5b9e\u73b0\u4e86\u4e50\u89c2\u9501\u3002<\/p>\n\n\n\n<p>CAS\u7b97\u6cd5\u6d89\u53ca\u5230\u4e09\u4e2a\u64cd\u4f5c\u6570\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9700\u8981\u8bfb\u5199\u7684\u5185\u5b58\u503c V\u3002<\/li>\n\n\n\n<li>\u8fdb\u884c\u6bd4\u8f83\u7684\u503c A\u3002<\/li>\n\n\n\n<li>\u8981\u5199\u5165\u7684\u65b0\u503c B\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5f53\u4e14\u4ec5\u5f53 V \u7684\u503c\u7b49\u4e8e A \u65f6\uff0cCAS\u901a\u8fc7\u539f\u5b50\u65b9\u5f0f\u7528\u65b0\u503cB\u6765\u66f4\u65b0V\u7684\u503c\uff08\u201c\u6bd4\u8f83+\u66f4\u65b0\u201d\u6574\u4f53\u662f\u4e00\u4e2a\u539f\u5b50\u64cd\u4f5c\uff09\uff0c\u5426\u5219\u4e0d\u4f1a\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u201c\u66f4\u65b0\u201d\u662f\u4e00\u4e2a\u4e0d\u65ad\u91cd\u8bd5\u7684\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u4e4b\u524d\u63d0\u5230java.util.concurrent\u5305\u4e2d\u7684\u539f\u5b50\u7c7b\uff0c\u5c31\u662f\u901a\u8fc7CAS\u6765\u5b9e\u73b0\u4e86\u4e50\u89c2\u9501\uff0c\u90a3\u4e48\u6211\u4eec\u8fdb\u5165\u539f\u5b50\u7c7bAtomicInteger\u7684\u6e90\u7801\uff0c\u770b\u4e00\u4e0bAtomicInteger\u7684\u5b9a\u4e49\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe4.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe4.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"aspect-ratio:1;width:840px;height:auto\"\/><\/div><\/figure>\n\n\n\n<p>\u6839\u636e\u5b9a\u4e49\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\u5404\u5c5e\u6027\u7684\u4f5c\u7528\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>unsafe\uff1a \u83b7\u53d6\u5e76\u64cd\u4f5c\u5185\u5b58\u7684\u6570\u636e\u3002<\/li>\n\n\n\n<li>valueOffset\uff1a \u5b58\u50a8value\u5728AtomicInteger\u4e2d\u7684\u504f\u79fb\u91cf\u3002<\/li>\n\n\n\n<li>value\uff1a \u5b58\u50a8AtomicInteger\u7684int\u503c\uff0c\u8be5\u5c5e\u6027\u9700\u8981\u501f\u52a9volatile\u5173\u952e\u5b57\u4fdd\u8bc1\u5176\u5728\u7ebf\u7a0b\u95f4\u662f\u53ef\u89c1\u7684\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u67e5\u770bAtomicInteger\u7684\u81ea\u589e\u51fd\u6570incrementAndGet()\u7684\u6e90\u7801\u65f6\uff0c\u53d1\u73b0\u81ea\u589e\u51fd\u6570\u5e95\u5c42\u8c03\u7528\u7684\u662funsafe.getAndAddInt()\u3002\u4f46\u662f\u7531\u4e8eJDK\u672c\u8eab\u53ea\u6709Unsafe.class\uff0c\u53ea\u901a\u8fc7class\u6587\u4ef6\u4e2d\u7684\u53c2\u6570\u540d\uff0c\u5e76\u4e0d\u80fd\u5f88\u597d\u7684\u4e86\u89e3\u65b9\u6cd5\u7684\u4f5c\u7528\uff0c\u6240\u4ee5\u6211\u4eec\u901a\u8fc7OpenJDK 8 \u6765\u67e5\u770bUnsafe\u7684\u6e90\u7801\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe5.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe5.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6839\u636eOpenJDK 8\u7684\u6e90\u7801\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0cgetAndAddInt()\u5faa\u73af\u83b7\u53d6\u7ed9\u5b9a\u5bf9\u8c61o\u4e2d\u7684\u504f\u79fb\u91cf\u5904\u7684\u503cv\uff0c\u7136\u540e\u5224\u65ad\u5185\u5b58\u503c\u662f\u5426\u7b49\u4e8ev\u3002\u5982\u679c\u76f8\u7b49\u5219\u5c06\u5185\u5b58\u503c\u8bbe\u7f6e\u4e3a v + delta\uff0c\u5426\u5219\u8fd4\u56defalse\uff0c\u7ee7\u7eed\u5faa\u73af\u8fdb\u884c\u91cd\u8bd5\uff0c\u76f4\u5230\u8bbe\u7f6e\u6210\u529f\u624d\u80fd\u9000\u51fa\u5faa\u73af\uff0c\u5e76\u4e14\u5c06\u65e7\u503c\u8fd4\u56de\u3002\u6574\u4e2a\u201c\u6bd4\u8f83+\u66f4\u65b0\u201d\u64cd\u4f5c\u5c01\u88c5\u5728compareAndSwapInt()\u4e2d\uff0c\u5728JNI\u91cc\u662f\u501f\u52a9\u4e8e\u4e00\u4e2aCPU\u6307\u4ee4\u5b8c\u6210\u7684\uff0c\u5c5e\u4e8e\u539f\u5b50\u64cd\u4f5c\uff0c\u53ef\u4ee5\u4fdd\u8bc1\u591a\u4e2a\u7ebf\u7a0b\u90fd\u80fd\u591f\u770b\u5230\u540c\u4e00\u4e2a\u53d8\u91cf\u7684\u4fee\u6539\u503c\u3002<\/p>\n\n\n\n<p>\u540e\u7eedJDK\u901a\u8fc7CPU\u7684cmpxchg\u6307\u4ee4\uff0c\u53bb\u6bd4\u8f83\u5bc4\u5b58\u5668\u4e2d\u7684 A \u548c \u5185\u5b58\u4e2d\u7684\u503c V\u3002\u5982\u679c\u76f8\u7b49\uff0c\u5c31\u628a\u8981\u5199\u5165\u7684\u65b0\u503c B \u5b58\u5165\u5185\u5b58\u4e2d\u3002\u5982\u679c\u4e0d\u76f8\u7b49\uff0c\u5c31\u5c06\u5185\u5b58\u503c V \u8d4b\u503c\u7ed9\u5bc4\u5b58\u5668\u4e2d\u7684\u503c A\u3002\u7136\u540e\u901a\u8fc7Java\u4ee3\u7801\u4e2d\u7684while\u5faa\u73af\u518d\u6b21\u8c03\u7528cmpxchg\u6307\u4ee4\u8fdb\u884c\u91cd\u8bd5\uff0c\u76f4\u5230\u8bbe\u7f6e\u6210\u529f\u4e3a\u6b62\u3002<\/p>\n\n\n\n<p>CAS\u867d\u7136\u5f88\u9ad8\u6548\uff0c\u4f46\u662f\u5b83\u4e5f\u5b58\u5728\u4e09\u5927\u95ee\u9898\uff0c\u8fd9\u91cc\u4e5f\u7b80\u5355\u8bf4\u4e00\u4e0b\uff1a<\/p>\n\n\n\n<p>1.&nbsp;<strong>ABA\u95ee\u9898<\/strong>\u3002CAS\u9700\u8981\u5728\u64cd\u4f5c\u503c\u7684\u65f6\u5019\u68c0\u67e5\u5185\u5b58\u503c\u662f\u5426\u53d1\u751f\u53d8\u5316\uff0c\u6ca1\u6709\u53d1\u751f\u53d8\u5316\u624d\u4f1a\u66f4\u65b0\u5185\u5b58\u503c\u3002\u4f46\u662f\u5982\u679c\u5185\u5b58\u503c\u539f\u6765\u662fA\uff0c\u540e\u6765\u53d8\u6210\u4e86B\uff0c\u7136\u540e\u53c8\u53d8\u6210\u4e86A\uff0c\u90a3\u4e48CAS\u8fdb\u884c\u68c0\u67e5\u65f6\u4f1a\u53d1\u73b0\u503c\u6ca1\u6709\u53d1\u751f\u53d8\u5316\uff0c\u4f46\u662f\u5b9e\u9645\u4e0a\u662f\u6709\u53d8\u5316\u7684\u3002ABA\u95ee\u9898\u7684\u89e3\u51b3\u601d\u8def\u5c31\u662f\u5728\u53d8\u91cf\u524d\u9762\u6dfb\u52a0\u7248\u672c\u53f7\uff0c\u6bcf\u6b21\u53d8\u91cf\u66f4\u65b0\u7684\u65f6\u5019\u90fd\u628a\u7248\u672c\u53f7\u52a0\u4e00\uff0c\u8fd9\u6837\u53d8\u5316\u8fc7\u7a0b\u5c31\u4ece\u201cA\uff0dB\uff0dA\u201d\u53d8\u6210\u4e86\u201c1A\uff0d2B\uff0d3A\u201d\u3002<\/p>\n\n\n\n<p>JDK\u4ece1.5\u5f00\u59cb\u63d0\u4f9b\u4e86AtomicStampedReference\u7c7b\u6765\u89e3\u51b3ABA\u95ee\u9898\uff0c\u5177\u4f53\u64cd\u4f5c\u5c01\u88c5\u5728compareAndSet()\u4e2d\u3002compareAndSet()\u9996\u5148\u68c0\u67e5\u5f53\u524d\u5f15\u7528\u548c\u5f53\u524d\u6807\u5fd7\u4e0e\u9884\u671f\u5f15\u7528\u548c\u9884\u671f\u6807\u5fd7\u662f\u5426\u76f8\u7b49\uff0c\u5982\u679c\u90fd\u76f8\u7b49\uff0c\u5219\u4ee5\u539f\u5b50\u65b9\u5f0f\u5c06\u5f15\u7528\u503c\u548c\u6807\u5fd7\u7684\u503c\u8bbe\u7f6e\u4e3a\u7ed9\u5b9a\u7684\u66f4\u65b0\u503c\u3002<\/p>\n\n\n\n<p>2.&nbsp;<strong>\u5faa\u73af\u65f6\u95f4\u957f\u5f00\u9500\u5927<\/strong>\u3002CAS\u64cd\u4f5c\u5982\u679c\u957f\u65f6\u95f4\u4e0d\u6210\u529f\uff0c\u4f1a\u5bfc\u81f4\u5176\u4e00\u76f4\u81ea\u65cb\uff0c\u7ed9CPU\u5e26\u6765\u975e\u5e38\u5927\u7684\u5f00\u9500\u3002<\/p>\n\n\n\n<p>3.&nbsp;<strong>\u53ea\u80fd\u4fdd\u8bc1\u4e00\u4e2a\u5171\u4eab\u53d8\u91cf\u7684\u539f\u5b50\u64cd\u4f5c<\/strong>\u3002\u5bf9\u4e00\u4e2a\u5171\u4eab\u53d8\u91cf\u6267\u884c\u64cd\u4f5c\u65f6\uff0cCAS\u80fd\u591f\u4fdd\u8bc1\u539f\u5b50\u64cd\u4f5c\uff0c\u4f46\u662f\u5bf9\u591a\u4e2a\u5171\u4eab\u53d8\u91cf\u64cd\u4f5c\u65f6\uff0cCAS\u662f\u65e0\u6cd5\u4fdd\u8bc1\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u7684\u3002<\/p>\n\n\n\n<p>Java\u4ece1.5\u5f00\u59cbJDK\u63d0\u4f9b\u4e86AtomicReference\u7c7b\u6765\u4fdd\u8bc1\u5f15\u7528\u5bf9\u8c61\u4e4b\u95f4\u7684\u539f\u5b50\u6027\uff0c\u53ef\u4ee5\u628a\u591a\u4e2a\u53d8\u91cf\u653e\u5728\u4e00\u4e2a\u5bf9\u8c61\u91cc\u6765\u8fdb\u884cCAS\u64cd\u4f5c\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. \u81ea\u65cb\u9501 VS \u9002\u5e94\u6027\u81ea\u65cb\u9501<\/strong><\/h3>\n\n\n\n<p>\u5728\u4ecb\u7ecd\u81ea\u65cb\u9501\u524d\uff0c\u6211\u4eec\u9700\u8981\u4ecb\u7ecd\u4e00\u4e9b\u524d\u63d0\u77e5\u8bc6\u6765\u5e2e\u52a9\u5927\u5bb6\u660e\u767d\u81ea\u65cb\u9501\u7684\u6982\u5ff5\u3002<\/p>\n\n\n\n<p>\u963b\u585e\u6216\u5524\u9192\u4e00\u4e2aJava\u7ebf\u7a0b\u9700\u8981\u64cd\u4f5c\u7cfb\u7edf\u5207\u6362CPU\u72b6\u6001\u6765\u5b8c\u6210\uff0c\u8fd9\u79cd\u72b6\u6001\u8f6c\u6362\u9700\u8981\u8017\u8d39\u5904\u7406\u5668\u65f6\u95f4\u3002\u5982\u679c\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u7684\u5185\u5bb9\u8fc7\u4e8e\u7b80\u5355\uff0c\u72b6\u6001\u8f6c\u6362\u6d88\u8017\u7684\u65f6\u95f4\u6709\u53ef\u80fd\u6bd4\u7528\u6237\u4ee3\u7801\u6267\u884c\u7684\u65f6\u95f4\u8fd8\u8981\u957f\u3002<\/p>\n\n\n\n<p>\u5728\u8bb8\u591a\u573a\u666f\u4e2d\uff0c\u540c\u6b65\u8d44\u6e90\u7684\u9501\u5b9a\u65f6\u95f4\u5f88\u77ed\uff0c\u4e3a\u4e86\u8fd9\u4e00\u5c0f\u6bb5\u65f6\u95f4\u53bb\u5207\u6362\u7ebf\u7a0b\uff0c\u7ebf\u7a0b\u6302\u8d77\u548c\u6062\u590d\u73b0\u573a\u7684\u82b1\u8d39\u53ef\u80fd\u4f1a\u8ba9\u7cfb\u7edf\u5f97\u4e0d\u507f\u5931\u3002\u5982\u679c\u7269\u7406\u673a\u5668\u6709\u591a\u4e2a\u5904\u7406\u5668\uff0c\u80fd\u591f\u8ba9\u4e24\u4e2a\u6216\u4ee5\u4e0a\u7684\u7ebf\u7a0b\u540c\u65f6\u5e76\u884c\u6267\u884c\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u8ba9\u540e\u9762\u90a3\u4e2a\u8bf7\u6c42\u9501\u7684\u7ebf\u7a0b\u4e0d\u653e\u5f03CPU\u7684\u6267\u884c\u65f6\u95f4\uff0c\u770b\u770b\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u662f\u5426\u5f88\u5feb\u5c31\u4f1a\u91ca\u653e\u9501\u3002<\/p>\n\n\n\n<p>\u800c\u4e3a\u4e86\u8ba9\u5f53\u524d\u7ebf\u7a0b\u201c\u7a0d\u7b49\u4e00\u4e0b\u201d\uff0c\u6211\u4eec\u9700\u8ba9\u5f53\u524d\u7ebf\u7a0b\u8fdb\u884c\u81ea\u65cb\uff0c\u5982\u679c\u5728\u81ea\u65cb\u5b8c\u6210\u540e\u524d\u9762\u9501\u5b9a\u540c\u6b65\u8d44\u6e90\u7684\u7ebf\u7a0b\u5df2\u7ecf\u91ca\u653e\u4e86\u9501\uff0c\u90a3\u4e48\u5f53\u524d\u7ebf\u7a0b\u5c31\u53ef\u4ee5\u4e0d\u5fc5\u963b\u585e\u800c\u662f\u76f4\u63a5\u83b7\u53d6\u540c\u6b65\u8d44\u6e90\uff0c\u4ece\u800c\u907f\u514d\u5207\u6362\u7ebf\u7a0b\u7684\u5f00\u9500\u3002\u8fd9\u5c31\u662f\u81ea\u65cb\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe6-1024x990.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe6-1024x990.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u81ea\u65cb\u9501\u672c\u8eab\u662f\u6709\u7f3a\u70b9\u7684\uff0c\u5b83\u4e0d\u80fd\u4ee3\u66ff\u963b\u585e\u3002\u81ea\u65cb\u7b49\u5f85\u867d\u7136\u907f\u514d\u4e86\u7ebf\u7a0b\u5207\u6362\u7684\u5f00\u9500\uff0c\u4f46\u5b83\u8981\u5360\u7528\u5904\u7406\u5668\u65f6\u95f4\u3002\u5982\u679c\u9501\u88ab\u5360\u7528\u7684\u65f6\u95f4\u5f88\u77ed\uff0c\u81ea\u65cb\u7b49\u5f85\u7684\u6548\u679c\u5c31\u4f1a\u975e\u5e38\u597d\u3002\u53cd\u4e4b\uff0c\u5982\u679c\u9501\u88ab\u5360\u7528\u7684\u65f6\u95f4\u5f88\u957f\uff0c\u90a3\u4e48\u81ea\u65cb\u7684\u7ebf\u7a0b\u53ea\u4f1a\u767d\u6d6a\u8d39\u5904\u7406\u5668\u8d44\u6e90\u3002\u6240\u4ee5\uff0c\u81ea\u65cb\u7b49\u5f85\u7684\u65f6\u95f4\u5fc5\u987b\u8981\u6709\u4e00\u5b9a\u7684\u9650\u5ea6\uff0c\u5982\u679c\u81ea\u65cb\u8d85\u8fc7\u4e86\u9650\u5b9a\u6b21\u6570\uff08\u9ed8\u8ba4\u662f10\u6b21\uff0c\u53ef\u4ee5\u4f7f\u7528-XX:PreBlockSpin\u6765\u66f4\u6539\uff09\u6ca1\u6709\u6210\u529f\u83b7\u5f97\u9501\uff0c\u5c31\u5e94\u5f53\u6302\u8d77\u7ebf\u7a0b\u3002<\/p>\n\n\n\n<p>\u81ea\u65cb\u9501\u7684\u5b9e\u73b0\u539f\u7406\u540c\u6837\u4e5f\u662fCAS\uff0cAtomicInteger\u4e2d\u8c03\u7528unsafe\u8fdb\u884c\u81ea\u589e\u64cd\u4f5c\u7684\u6e90\u7801\u4e2d\u7684do-while\u5faa\u73af\u5c31\u662f\u4e00\u4e2a\u81ea\u65cb\u64cd\u4f5c\uff0c\u5982\u679c\u4fee\u6539\u6570\u503c\u5931\u8d25\u5219\u901a\u8fc7\u5faa\u73af\u6765\u6267\u884c\u81ea\u65cb\uff0c\u76f4\u81f3\u4fee\u6539\u6210\u529f\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe7.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe7.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u81ea\u65cb\u9501\u5728JDK1.4.2\u4e2d\u5f15\u5165\uff0c\u4f7f\u7528-XX:+UseSpinning\u6765\u5f00\u542f\u3002JDK 6\u4e2d\u53d8\u4e3a\u9ed8\u8ba4\u5f00\u542f\uff0c\u5e76\u4e14\u5f15\u5165\u4e86\u81ea\u9002\u5e94\u7684\u81ea\u65cb\u9501\uff08\u9002\u5e94\u6027\u81ea\u65cb\u9501\uff09\u3002<\/p>\n\n\n\n<p>\u81ea\u9002\u5e94\u610f\u5473\u7740\u81ea\u65cb\u7684\u65f6\u95f4\uff08\u6b21\u6570\uff09\u4e0d\u518d\u56fa\u5b9a\uff0c\u800c\u662f\u7531\u524d\u4e00\u6b21\u5728\u540c\u4e00\u4e2a\u9501\u4e0a\u7684\u81ea\u65cb\u65f6\u95f4\u53ca\u9501\u7684\u62e5\u6709\u8005\u7684\u72b6\u6001\u6765\u51b3\u5b9a\u3002\u5982\u679c\u5728\u540c\u4e00\u4e2a\u9501\u5bf9\u8c61\u4e0a\uff0c\u81ea\u65cb\u7b49\u5f85\u521a\u521a\u6210\u529f\u83b7\u5f97\u8fc7\u9501\uff0c\u5e76\u4e14\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u6b63\u5728\u8fd0\u884c\u4e2d\uff0c\u90a3\u4e48\u865a\u62df\u673a\u5c31\u4f1a\u8ba4\u4e3a\u8fd9\u6b21\u81ea\u65cb\u4e5f\u662f\u5f88\u6709\u53ef\u80fd\u518d\u6b21\u6210\u529f\uff0c\u8fdb\u800c\u5b83\u5c06\u5141\u8bb8\u81ea\u65cb\u7b49\u5f85\u6301\u7eed\u76f8\u5bf9\u66f4\u957f\u7684\u65f6\u95f4\u3002\u5982\u679c\u5bf9\u4e8e\u67d0\u4e2a\u9501\uff0c\u81ea\u65cb\u5f88\u5c11\u6210\u529f\u83b7\u5f97\u8fc7\uff0c\u90a3\u5728\u4ee5\u540e\u5c1d\u8bd5\u83b7\u53d6\u8fd9\u4e2a\u9501\u65f6\u5c06\u53ef\u80fd\u7701\u7565\u6389\u81ea\u65cb\u8fc7\u7a0b\uff0c\u76f4\u63a5\u963b\u585e\u7ebf\u7a0b\uff0c\u907f\u514d\u6d6a\u8d39\u5904\u7406\u5668\u8d44\u6e90\u3002<\/p>\n\n\n\n<p>\u5728\u81ea\u65cb\u9501\u4e2d \u53e6\u6709\u4e09\u79cd\u5e38\u89c1\u7684\u9501\u5f62\u5f0f:TicketLock\u3001CLHlock\u548cMCSlock\uff0c\u672c\u6587\u4e2d\u4ec5\u505a\u540d\u8bcd\u4ecb\u7ecd\uff0c\u4e0d\u505a\u6df1\u5165\u8bb2\u89e3\uff0c\u611f\u5174\u8da3\u7684\u540c\u5b66\u53ef\u4ee5\u81ea\u884c\u67e5\u9605\u76f8\u5173\u8d44\u6599\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. \u65e0\u9501 VS \u504f\u5411\u9501 VS \u8f7b\u91cf\u7ea7\u9501 VS \u91cd\u91cf\u7ea7\u9501<\/strong><\/h3>\n\n\n\n<p>\u8fd9\u56db\u79cd\u9501\u662f\u6307\u9501\u7684\u72b6\u6001\uff0c\u4e13\u95e8\u9488\u5bf9synchronized\u7684\u3002\u5728\u4ecb\u7ecd\u8fd9\u56db\u79cd\u9501\u72b6\u6001\u4e4b\u524d\u8fd8\u9700\u8981\u4ecb\u7ecd\u4e00\u4e9b\u989d\u5916\u7684\u77e5\u8bc6\u3002<\/p>\n\n\n\n<p>\u9996\u5148\u4e3a\u4ec0\u4e48Synchronized\u80fd\u5b9e\u73b0\u7ebf\u7a0b\u540c\u6b65\uff1f<\/p>\n\n\n\n<p>\u5728\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\u4e4b\u524d\u6211\u4eec\u9700\u8981\u4e86\u89e3\u4e24\u4e2a\u91cd\u8981\u7684\u6982\u5ff5\uff1a\u201cJava\u5bf9\u8c61\u5934\u201d\u3001\u201cMonitor\u201d\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Java\u5bf9\u8c61\u5934<\/h4>\n\n\n\n<p>synchronized\u662f\u60b2\u89c2\u9501\uff0c\u5728\u64cd\u4f5c\u540c\u6b65\u8d44\u6e90\u4e4b\u524d\u9700\u8981\u7ed9\u540c\u6b65\u8d44\u6e90\u5148\u52a0\u9501\uff0c\u8fd9\u628a\u9501\u5c31\u662f\u5b58\u5728Java\u5bf9\u8c61\u5934\u91cc\u7684\uff0c\u800cJava\u5bf9\u8c61\u5934\u53c8\u662f\u4ec0\u4e48\u5462\uff1f<\/p>\n\n\n\n<p>\u6211\u4eec\u4ee5Hotspot\u865a\u62df\u673a\u4e3a\u4f8b\uff0cHotspot\u7684\u5bf9\u8c61\u5934\u4e3b\u8981\u5305\u62ec\u4e24\u90e8\u5206\u6570\u636e\uff1aMark Word\uff08\u6807\u8bb0\u5b57\u6bb5\uff09\u3001Klass Pointer\uff08\u7c7b\u578b\u6307\u9488\uff09\u3002<\/p>\n\n\n\n<p><strong>Mark Word<\/strong>\uff1a\u9ed8\u8ba4\u5b58\u50a8\u5bf9\u8c61\u7684HashCode\uff0c\u5206\u4ee3\u5e74\u9f84\u548c\u9501\u6807\u5fd7\u4f4d\u4fe1\u606f\u3002\u8fd9\u4e9b\u4fe1\u606f\u90fd\u662f\u4e0e\u5bf9\u8c61\u81ea\u8eab\u5b9a\u4e49\u65e0\u5173\u7684\u6570\u636e\uff0c\u6240\u4ee5Mark Word\u88ab\u8bbe\u8ba1\u6210\u4e00\u4e2a\u975e\u56fa\u5b9a\u7684\u6570\u636e\u7ed3\u6784\u4ee5\u4fbf\u5728\u6781\u5c0f\u7684\u7a7a\u95f4\u5185\u5b58\u5b58\u50a8\u5c3d\u91cf\u591a\u7684\u6570\u636e\u3002\u5b83\u4f1a\u6839\u636e\u5bf9\u8c61\u7684\u72b6\u6001\u590d\u7528\u81ea\u5df1\u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u4e5f\u5c31\u662f\u8bf4\u5728\u8fd0\u884c\u671f\u95f4Mark Word\u91cc\u5b58\u50a8\u7684\u6570\u636e\u4f1a\u968f\u7740\u9501\u6807\u5fd7\u4f4d\u7684\u53d8\u5316\u800c\u53d8\u5316\u3002<\/p>\n\n\n\n<p><strong>Klass Point<\/strong>\uff1a\u5bf9\u8c61\u6307\u5411\u5b83\u7684\u7c7b\u5143\u6570\u636e\u7684\u6307\u9488\uff0c\u865a\u62df\u673a\u901a\u8fc7\u8fd9\u4e2a\u6307\u9488\u6765\u786e\u5b9a\u8fd9\u4e2a\u5bf9\u8c61\u662f\u54ea\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Monitor<\/h4>\n\n\n\n<p>Monitor\u53ef\u4ee5\u7406\u89e3\u4e3a\u4e00\u4e2a\u540c\u6b65\u5de5\u5177\u6216\u4e00\u79cd\u540c\u6b65\u673a\u5236\uff0c\u901a\u5e38\u88ab\u63cf\u8ff0\u4e3a\u4e00\u4e2a\u5bf9\u8c61\u3002\u6bcf\u4e00\u4e2aJava\u5bf9\u8c61\u5c31\u6709\u4e00\u628a\u770b\u4e0d\u89c1\u7684\u9501\uff0c\u79f0\u4e3a\u5185\u90e8\u9501\u6216\u8005Monitor\u9501\u3002<\/p>\n\n\n\n<p>Monitor\u662f\u7ebf\u7a0b\u79c1\u6709\u7684\u6570\u636e\u7ed3\u6784\uff0c\u6bcf\u4e00\u4e2a\u7ebf\u7a0b\u90fd\u6709\u4e00\u4e2a\u53ef\u7528monitor record\u5217\u8868\uff0c\u540c\u65f6\u8fd8\u6709\u4e00\u4e2a\u5168\u5c40\u7684\u53ef\u7528\u5217\u8868\u3002\u6bcf\u4e00\u4e2a\u88ab\u9501\u4f4f\u7684\u5bf9\u8c61\u90fd\u4f1a\u548c\u4e00\u4e2amonitor\u5173\u8054\uff0c\u540c\u65f6monitor\u4e2d\u6709\u4e00\u4e2aOwner\u5b57\u6bb5\u5b58\u653e\u62e5\u6709\u8be5\u9501\u7684\u7ebf\u7a0b\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u8868\u793a\u8be5\u9501\u88ab\u8fd9\u4e2a\u7ebf\u7a0b\u5360\u7528\u3002<\/p>\n\n\n\n<p>\u73b0\u5728\u8bdd\u9898\u56de\u5230synchronized\uff0csynchronized\u901a\u8fc7Monitor\u6765\u5b9e\u73b0\u7ebf\u7a0b\u540c\u6b65\uff0cMonitor\u662f\u4f9d\u8d56\u4e8e\u5e95\u5c42\u7684\u64cd\u4f5c\u7cfb\u7edf\u7684Mutex Lock\uff08\u4e92\u65a5\u9501\uff09\u6765\u5b9e\u73b0\u7684\u7ebf\u7a0b\u540c\u6b65\u3002<\/p>\n\n\n\n<p>\u5982\u540c\u6211\u4eec\u5728\u81ea\u65cb\u9501\u4e2d\u63d0\u5230\u7684\u201c\u963b\u585e\u6216\u5524\u9192\u4e00\u4e2aJava\u7ebf\u7a0b\u9700\u8981\u64cd\u4f5c\u7cfb\u7edf\u5207\u6362CPU\u72b6\u6001\u6765\u5b8c\u6210\uff0c\u8fd9\u79cd\u72b6\u6001\u8f6c\u6362\u9700\u8981\u8017\u8d39\u5904\u7406\u5668\u65f6\u95f4\u3002\u5982\u679c\u540c\u6b65\u4ee3\u7801\u5757\u4e2d\u7684\u5185\u5bb9\u8fc7\u4e8e\u7b80\u5355\uff0c\u72b6\u6001\u8f6c\u6362\u6d88\u8017\u7684\u65f6\u95f4\u6709\u53ef\u80fd\u6bd4\u7528\u6237\u4ee3\u7801\u6267\u884c\u7684\u65f6\u95f4\u8fd8\u8981\u957f\u201d\u3002\u8fd9\u79cd\u65b9\u5f0f\u5c31\u662fsynchronized\u6700\u521d\u5b9e\u73b0\u540c\u6b65\u7684\u65b9\u5f0f\uff0c\u8fd9\u5c31\u662fJDK 6\u4e4b\u524dsynchronized\u6548\u7387\u4f4e\u7684\u539f\u56e0\u3002\u8fd9\u79cd\u4f9d\u8d56\u4e8e\u64cd\u4f5c\u7cfb\u7edfMutex Lock\u6240\u5b9e\u73b0\u7684\u9501\u6211\u4eec\u79f0\u4e4b\u4e3a\u201c\u91cd\u91cf\u7ea7\u9501\u201d\uff0cJDK 6\u4e2d\u4e3a\u4e86\u51cf\u5c11\u83b7\u5f97\u9501\u548c\u91ca\u653e\u9501\u5e26\u6765\u7684\u6027\u80fd\u6d88\u8017\uff0c\u5f15\u5165\u4e86\u201c\u504f\u5411\u9501\u201d\u548c\u201c\u8f7b\u91cf\u7ea7\u9501\u201d\u3002<\/p>\n\n\n\n<p>\u6240\u4ee5\u76ee\u524d\u9501\u4e00\u5171\u67094\u79cd\u72b6\u6001\uff0c\u7ea7\u522b\u4ece\u4f4e\u5230\u9ad8\u4f9d\u6b21\u662f\uff1a\u65e0\u9501\u3001\u504f\u5411\u9501\u3001\u8f7b\u91cf\u7ea7\u9501\u548c\u91cd\u91cf\u7ea7\u9501\u3002\u9501\u72b6\u6001\u53ea\u80fd\u5347\u7ea7\u4e0d\u80fd\u964d\u7ea7\u3002<\/p>\n\n\n\n<p>\u901a\u8fc7\u4e0a\u9762\u7684\u4ecb\u7ecd\uff0c\u6211\u4eec\u5bf9synchronized\u7684\u52a0\u9501\u673a\u5236\u4ee5\u53ca\u76f8\u5173\u77e5\u8bc6\u6709\u4e86\u4e00\u4e2a\u4e86\u89e3\uff0c\u90a3\u4e48\u4e0b\u9762\u6211\u4eec\u7ed9\u51fa\u56db\u79cd\u9501\u72b6\u6001\u5bf9\u5e94\u7684\u7684Mark Word\u5185\u5bb9\uff0c\u7136\u540e\u518d\u5206\u522b\u8bb2\u89e3\u56db\u79cd\u9501\u72b6\u6001\u7684\u601d\u8def\u4ee5\u53ca\u7279\u70b9\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe8-1024x328.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe8-1024x328.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p><strong>\u65e0\u9501<\/strong><\/p>\n\n\n\n<p>\u65e0\u9501\u6ca1\u6709\u5bf9\u8d44\u6e90\u8fdb\u884c\u9501\u5b9a\uff0c\u6240\u6709\u7684\u7ebf\u7a0b\u90fd\u80fd\u8bbf\u95ee\u5e76\u4fee\u6539\u540c\u4e00\u4e2a\u8d44\u6e90\uff0c\u4f46\u540c\u65f6\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u4fee\u6539\u6210\u529f\u3002<\/p>\n\n\n\n<p>\u65e0\u9501\u7684\u7279\u70b9\u5c31\u662f\u4fee\u6539\u64cd\u4f5c\u5728\u5faa\u73af\u5185\u8fdb\u884c\uff0c\u7ebf\u7a0b\u4f1a\u4e0d\u65ad\u7684\u5c1d\u8bd5\u4fee\u6539\u5171\u4eab\u8d44\u6e90\u3002\u5982\u679c\u6ca1\u6709\u51b2\u7a81\u5c31\u4fee\u6539\u6210\u529f\u5e76\u9000\u51fa\uff0c\u5426\u5219\u5c31\u4f1a\u7ee7\u7eed\u5faa\u73af\u5c1d\u8bd5\u3002\u5982\u679c\u6709\u591a\u4e2a\u7ebf\u7a0b\u4fee\u6539\u540c\u4e00\u4e2a\u503c\uff0c\u5fc5\u5b9a\u4f1a\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u4fee\u6539\u6210\u529f\uff0c\u800c\u5176\u4ed6\u4fee\u6539\u5931\u8d25\u7684\u7ebf\u7a0b\u4f1a\u4e0d\u65ad\u91cd\u8bd5\u76f4\u5230\u4fee\u6539\u6210\u529f\u3002\u4e0a\u9762\u6211\u4eec\u4ecb\u7ecd\u7684CAS\u539f\u7406\u53ca\u5e94\u7528\u5373\u662f\u65e0\u9501\u7684\u5b9e\u73b0\u3002\u65e0\u9501\u65e0\u6cd5\u5168\u9762\u4ee3\u66ff\u6709\u9501\uff0c\u4f46\u65e0\u9501\u5728\u67d0\u4e9b\u573a\u5408\u4e0b\u7684\u6027\u80fd\u662f\u975e\u5e38\u9ad8\u7684\u3002<\/p>\n\n\n\n<p><strong>\u504f\u5411\u9501<\/strong><\/p>\n\n\n\n<p>\u504f\u5411\u9501\u662f\u6307\u4e00\u6bb5\u540c\u6b65\u4ee3\u7801\u4e00\u76f4\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6240\u8bbf\u95ee\uff0c\u90a3\u4e48\u8be5\u7ebf\u7a0b\u4f1a\u81ea\u52a8\u83b7\u53d6\u9501\uff0c\u964d\u4f4e\u83b7\u53d6\u9501\u7684\u4ee3\u4ef7\u3002<\/p>\n\n\n\n<p>\u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u9501\u603b\u662f\u7531\u540c\u4e00\u7ebf\u7a0b\u591a\u6b21\u83b7\u5f97\uff0c\u4e0d\u5b58\u5728\u591a\u7ebf\u7a0b\u7ade\u4e89\uff0c\u6240\u4ee5\u51fa\u73b0\u4e86\u504f\u5411\u9501\u3002\u5176\u76ee\u6807\u5c31\u662f\u5728\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c\u540c\u6b65\u4ee3\u7801\u5757\u65f6\u80fd\u591f\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n\n\n\n<p>\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u540c\u6b65\u4ee3\u7801\u5757\u5e76\u83b7\u53d6\u9501\u65f6\uff0c\u4f1a\u5728Mark Word\u91cc\u5b58\u50a8\u9501\u504f\u5411\u7684\u7ebf\u7a0bID\u3002\u5728\u7ebf\u7a0b\u8fdb\u5165\u548c\u9000\u51fa\u540c\u6b65\u5757\u65f6\u4e0d\u518d\u901a\u8fc7CAS\u64cd\u4f5c\u6765\u52a0\u9501\u548c\u89e3\u9501\uff0c\u800c\u662f\u68c0\u6d4bMark Word\u91cc\u662f\u5426\u5b58\u50a8\u7740\u6307\u5411\u5f53\u524d\u7ebf\u7a0b\u7684\u504f\u5411\u9501\u3002\u5f15\u5165\u504f\u5411\u9501\u662f\u4e3a\u4e86\u5728\u65e0\u591a\u7ebf\u7a0b\u7ade\u4e89\u7684\u60c5\u51b5\u4e0b\u5c3d\u91cf\u51cf\u5c11\u4e0d\u5fc5\u8981\u7684\u8f7b\u91cf\u7ea7\u9501\u6267\u884c\u8def\u5f84\uff0c\u56e0\u4e3a\u8f7b\u91cf\u7ea7\u9501\u7684\u83b7\u53d6\u53ca\u91ca\u653e\u4f9d\u8d56\u591a\u6b21CAS\u539f\u5b50\u6307\u4ee4\uff0c\u800c\u504f\u5411\u9501\u53ea\u9700\u8981\u5728\u7f6e\u6362ThreadID\u7684\u65f6\u5019\u4f9d\u8d56\u4e00\u6b21CAS\u539f\u5b50\u6307\u4ee4\u5373\u53ef\u3002<\/p>\n\n\n\n<p>\u504f\u5411\u9501\u53ea\u6709\u9047\u5230\u5176\u4ed6\u7ebf\u7a0b\u5c1d\u8bd5\u7ade\u4e89\u504f\u5411\u9501\u65f6\uff0c\u6301\u6709\u504f\u5411\u9501\u7684\u7ebf\u7a0b\u624d\u4f1a\u91ca\u653e\u9501\uff0c\u7ebf\u7a0b\u4e0d\u4f1a\u4e3b\u52a8\u91ca\u653e\u504f\u5411\u9501\u3002\u504f\u5411\u9501\u7684\u64a4\u9500\uff0c\u9700\u8981\u7b49\u5f85\u5168\u5c40\u5b89\u5168\u70b9\uff08\u5728\u8fd9\u4e2a\u65f6\u95f4\u70b9\u4e0a\u6ca1\u6709\u5b57\u8282\u7801\u6b63\u5728\u6267\u884c\uff09\uff0c\u5b83\u4f1a\u9996\u5148\u6682\u505c\u62e5\u6709\u504f\u5411\u9501\u7684\u7ebf\u7a0b\uff0c\u5224\u65ad\u9501\u5bf9\u8c61\u662f\u5426\u5904\u4e8e\u88ab\u9501\u5b9a\u72b6\u6001\u3002\u64a4\u9500\u504f\u5411\u9501\u540e\u6062\u590d\u5230\u65e0\u9501\uff08\u6807\u5fd7\u4f4d\u4e3a\u201c01\u201d\uff09\u6216\u8f7b\u91cf\u7ea7\u9501\uff08\u6807\u5fd7\u4f4d\u4e3a\u201c00\u201d\uff09\u7684\u72b6\u6001\u3002<\/p>\n\n\n\n<p>\u504f\u5411\u9501\u5728JDK 6\u53ca\u4ee5\u540e\u7684JVM\u91cc\u662f\u9ed8\u8ba4\u542f\u7528\u7684\u3002\u53ef\u4ee5\u901a\u8fc7JVM\u53c2\u6570\u5173\u95ed\u504f\u5411\u9501\uff1a-XX:-UseBiasedLocking=false\uff0c\u5173\u95ed\u4e4b\u540e\u7a0b\u5e8f\u9ed8\u8ba4\u4f1a\u8fdb\u5165\u8f7b\u91cf\u7ea7\u9501\u72b6\u6001\u3002<\/p>\n\n\n\n<p><strong>\u8f7b\u91cf\u7ea7\u9501<\/strong><\/p>\n\n\n\n<p>\u662f\u6307\u5f53\u9501\u662f\u504f\u5411\u9501\u7684\u65f6\u5019\uff0c\u88ab\u53e6\u5916\u7684\u7ebf\u7a0b\u6240\u8bbf\u95ee\uff0c\u504f\u5411\u9501\u5c31\u4f1a\u5347\u7ea7\u4e3a\u8f7b\u91cf\u7ea7\u9501\uff0c\u5176\u4ed6\u7ebf\u7a0b\u4f1a\u901a\u8fc7\u81ea\u65cb\u7684\u5f62\u5f0f\u5c1d\u8bd5\u83b7\u53d6\u9501\uff0c\u4e0d\u4f1a\u963b\u585e\uff0c\u4ece\u800c\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n\n\n\n<p>\u5728\u4ee3\u7801\u8fdb\u5165\u540c\u6b65\u5757\u7684\u65f6\u5019\uff0c\u5982\u679c\u540c\u6b65\u5bf9\u8c61\u9501\u72b6\u6001\u4e3a\u65e0\u9501\u72b6\u6001\uff08\u9501\u6807\u5fd7\u4f4d\u4e3a\u201c01\u201d\u72b6\u6001\uff0c\u662f\u5426\u4e3a\u504f\u5411\u9501\u4e3a\u201c0\u201d\uff09\uff0c\u865a\u62df\u673a\u9996\u5148\u5c06\u5728\u5f53\u524d\u7ebf\u7a0b\u7684\u6808\u5e27\u4e2d\u5efa\u7acb\u4e00\u4e2a\u540d\u4e3a\u9501\u8bb0\u5f55\uff08Lock 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Word\u7684\u9501\u6807\u5fd7\u4f4d\u8bbe\u7f6e\u4e3a\u201c00\u201d\uff0c\u8868\u793a\u6b64\u5bf9\u8c61\u5904\u4e8e\u8f7b\u91cf\u7ea7\u9501\u5b9a\u72b6\u6001\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u8f7b\u91cf\u7ea7\u9501\u7684\u66f4\u65b0\u64cd\u4f5c\u5931\u8d25\u4e86\uff0c\u865a\u62df\u673a\u9996\u5148\u4f1a\u68c0\u67e5\u5bf9\u8c61\u7684Mark Word\u662f\u5426\u6307\u5411\u5f53\u524d\u7ebf\u7a0b\u7684\u6808\u5e27\uff0c\u5982\u679c\u662f\u5c31\u8bf4\u660e\u5f53\u524d\u7ebf\u7a0b\u5df2\u7ecf\u62e5\u6709\u4e86\u8fd9\u4e2a\u5bf9\u8c61\u7684\u9501\uff0c\u90a3\u5c31\u53ef\u4ee5\u76f4\u63a5\u8fdb\u5165\u540c\u6b65\u5757\u7ee7\u7eed\u6267\u884c\uff0c\u5426\u5219\u8bf4\u660e\u591a\u4e2a\u7ebf\u7a0b\u7ade\u4e89\u9501\u3002<\/p>\n\n\n\n<p>\u82e5\u5f53\u524d\u53ea\u6709\u4e00\u4e2a\u7b49\u5f85\u7ebf\u7a0b\uff0c\u5219\u8be5\u7ebf\u7a0b\u901a\u8fc7\u81ea\u65cb\u8fdb\u884c\u7b49\u5f85\u3002\u4f46\u662f\u5f53\u81ea\u65cb\u8d85\u8fc7\u4e00\u5b9a\u7684\u6b21\u6570\uff0c\u6216\u8005\u4e00\u4e2a\u7ebf\u7a0b\u5728\u6301\u6709\u9501\uff0c\u4e00\u4e2a\u5728\u81ea\u65cb\uff0c\u53c8\u6709\u7b2c\u4e09\u4e2a\u6765\u8bbf\u65f6\uff0c\u8f7b\u91cf\u7ea7\u9501\u5347\u7ea7\u4e3a\u91cd\u91cf\u7ea7\u9501\u3002<\/p>\n\n\n\n<p><strong>\u91cd\u91cf\u7ea7\u9501<\/strong><\/p>\n\n\n\n<p>\u5347\u7ea7\u4e3a\u91cd\u91cf\u7ea7\u9501\u65f6\uff0c\u9501\u6807\u5fd7\u7684\u72b6\u6001\u503c\u53d8\u4e3a\u201c10\u201d\uff0c\u6b64\u65f6Mark Word\u4e2d\u5b58\u50a8\u7684\u662f\u6307\u5411\u91cd\u91cf\u7ea7\u9501\u7684\u6307\u9488\uff0c\u6b64\u65f6\u7b49\u5f85\u9501\u7684\u7ebf\u7a0b\u90fd\u4f1a\u8fdb\u5165\u963b\u585e\u72b6\u6001\u3002<\/p>\n\n\n\n<p>\u6574\u4f53\u7684\u9501\u72b6\u6001\u5347\u7ea7\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe9-1024x105.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe9-1024x105.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u7efc\u4e0a\uff0c\u504f\u5411\u9501\u901a\u8fc7\u5bf9\u6bd4Mark Word\u89e3\u51b3\u52a0\u9501\u95ee\u9898\uff0c\u907f\u514d\u6267\u884cCAS\u64cd\u4f5c\u3002\u800c\u8f7b\u91cf\u7ea7\u9501\u662f\u901a\u8fc7\u7528CAS\u64cd\u4f5c\u548c\u81ea\u65cb\u6765\u89e3\u51b3\u52a0\u9501\u95ee\u9898\uff0c\u907f\u514d\u7ebf\u7a0b\u963b\u585e\u548c\u5524\u9192\u800c\u5f71\u54cd\u6027\u80fd\u3002\u91cd\u91cf\u7ea7\u9501\u662f\u5c06\u9664\u4e86\u62e5\u6709\u9501\u7684\u7ebf\u7a0b\u4ee5\u5916\u7684\u7ebf\u7a0b\u90fd\u963b\u585e\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>4. \u516c\u5e73\u9501 VS \u975e\u516c\u5e73\u9501<\/strong><\/h3>\n\n\n\n<p>\u516c\u5e73\u9501\u662f\u6307\u591a\u4e2a\u7ebf\u7a0b\u6309\u7167\u7533\u8bf7\u9501\u7684\u987a\u5e8f\u6765\u83b7\u53d6\u9501\uff0c\u7ebf\u7a0b\u76f4\u63a5\u8fdb\u5165\u961f\u5217\u4e2d\u6392\u961f\uff0c\u961f\u5217\u4e2d\u7684\u7b2c\u4e00\u4e2a\u7ebf\u7a0b\u624d\u80fd\u83b7\u5f97\u9501\u3002\u516c\u5e73\u9501\u7684\u4f18\u70b9\u662f\u7b49\u5f85\u9501\u7684\u7ebf\u7a0b\u4e0d\u4f1a\u997f\u6b7b\u3002\u7f3a\u70b9\u662f\u6574\u4f53\u541e\u5410\u6548\u7387\u76f8\u5bf9\u975e\u516c\u5e73\u9501\u8981\u4f4e\uff0c\u7b49\u5f85\u961f\u5217\u4e2d\u9664\u7b2c\u4e00\u4e2a\u7ebf\u7a0b\u4ee5\u5916\u7684\u6240\u6709\u7ebf\u7a0b\u90fd\u4f1a\u963b\u585e\uff0cCPU\u5524\u9192\u963b\u585e\u7ebf\u7a0b\u7684\u5f00\u9500\u6bd4\u975e\u516c\u5e73\u9501\u5927\u3002<\/p>\n\n\n\n<p>\u975e\u516c\u5e73\u9501\u662f\u591a\u4e2a\u7ebf\u7a0b\u52a0\u9501\u65f6\u76f4\u63a5\u5c1d\u8bd5\u83b7\u53d6\u9501\uff0c\u83b7\u53d6\u4e0d\u5230\u624d\u4f1a\u5230\u7b49\u5f85\u961f\u5217\u7684\u961f\u5c3e\u7b49\u5f85\u3002\u4f46\u5982\u679c\u6b64\u65f6\u9501\u521a\u597d\u53ef\u7528\uff0c\u90a3\u4e48\u8fd9\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u65e0\u9700\u963b\u585e\u76f4\u63a5\u83b7\u53d6\u5230\u9501\uff0c\u6240\u4ee5\u975e\u516c\u5e73\u9501\u6709\u53ef\u80fd\u51fa\u73b0\u540e\u7533\u8bf7\u9501\u7684\u7ebf\u7a0b\u5148\u83b7\u53d6\u9501\u7684\u573a\u666f\u3002\u975e\u516c\u5e73\u9501\u7684\u4f18\u70b9\u662f\u53ef\u4ee5\u51cf\u5c11\u5524\u8d77\u7ebf\u7a0b\u7684\u5f00\u9500\uff0c\u6574\u4f53\u7684\u541e\u5410\u6548\u7387\u9ad8\uff0c\u56e0\u4e3a\u7ebf\u7a0b\u6709\u51e0\u7387\u4e0d\u963b\u585e\u76f4\u63a5\u83b7\u5f97\u9501\uff0cCPU\u4e0d\u5fc5\u5524\u9192\u6240\u6709\u7ebf\u7a0b\u3002\u7f3a\u70b9\u662f\u5904\u4e8e\u7b49\u5f85\u961f\u5217\u4e2d\u7684\u7ebf\u7a0b\u53ef\u80fd\u4f1a\u997f\u6b7b\uff0c\u6216\u8005\u7b49\u5f88\u4e45\u624d\u4f1a\u83b7\u5f97\u9501\u3002<\/p>\n\n\n\n<p>\u76f4\u63a5\u7528\u8bed\u8a00\u63cf\u8ff0\u53ef\u80fd\u6709\u70b9\u62bd\u8c61\uff0c\u8fd9\u91cc\u4f5c\u8005\u7528\u4ece\u522b\u5904\u770b\u5230\u7684\u4e00\u4e2a\u4f8b\u5b50\u6765\u8bb2\u8ff0\u4e00\u4e0b\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe10-1024x584.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe10-1024x584.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u5982\u4e0a\u56fe\u6240\u793a\uff0c\u5047\u8bbe\u6709\u4e00\u53e3\u6c34\u4e95\uff0c\u6709\u7ba1\u7406\u5458\u770b\u5b88\uff0c\u7ba1\u7406\u5458\u6709\u4e00\u628a\u9501\uff0c\u53ea\u6709\u62ff\u5230\u9501\u7684\u4eba\u624d\u80fd\u591f\u6253\u6c34\uff0c\u6253\u5b8c\u6c34\u8981\u628a\u9501\u8fd8\u7ed9\u7ba1\u7406\u5458\u3002\u6bcf\u4e2a\u8fc7\u6765\u6253\u6c34\u7684\u4eba\u90fd\u8981\u7ba1\u7406\u5458\u7684\u5141\u8bb8\u5e76\u62ff\u5230\u9501\u4e4b\u540e\u624d\u80fd\u53bb\u6253\u6c34\uff0c\u5982\u679c\u524d\u9762\u6709\u4eba\u6b63\u5728\u6253\u6c34\uff0c\u90a3\u4e48\u8fd9\u4e2a\u60f3\u8981\u6253\u6c34\u7684\u4eba\u5c31\u5fc5\u987b\u6392\u961f\u3002\u7ba1\u7406\u5458\u4f1a\u67e5\u770b\u4e0b\u4e00\u4e2a\u8981\u53bb\u6253\u6c34\u7684\u4eba\u662f\u4e0d\u662f\u961f\u4f0d\u91cc\u6392\u6700\u524d\u9762\u7684\u4eba\uff0c\u5982\u679c\u662f\u7684\u8bdd\uff0c\u624d\u4f1a\u7ed9\u4f60\u9501\u8ba9\u4f60\u53bb\u6253\u6c34\uff1b\u5982\u679c\u4f60\u4e0d\u662f\u6392\u7b2c\u4e00\u7684\u4eba\uff0c\u5c31\u5fc5\u987b\u53bb\u961f\u5c3e\u6392\u961f\uff0c\u8fd9\u5c31\u662f\u516c\u5e73\u9501\u3002<\/p>\n\n\n\n<p>\u4f46\u662f\u5bf9\u4e8e\u975e\u516c\u5e73\u9501\uff0c\u7ba1\u7406\u5458\u5bf9\u6253\u6c34\u7684\u4eba\u6ca1\u6709\u8981\u6c42\u3002\u5373\u4f7f\u7b49\u5f85\u961f\u4f0d\u91cc\u6709\u6392\u961f\u7b49\u5f85\u7684\u4eba\uff0c\u4f46\u5982\u679c\u5728\u4e0a\u4e00\u4e2a\u4eba\u521a\u6253\u5b8c\u6c34\u628a\u9501\u8fd8\u7ed9\u7ba1\u7406\u5458\u800c\u4e14\u7ba1\u7406\u5458\u8fd8\u6ca1\u6709\u5141\u8bb8\u7b49\u5f85\u961f\u4f0d\u91cc\u4e0b\u4e00\u4e2a\u4eba\u53bb\u6253\u6c34\u65f6\uff0c\u521a\u597d\u6765\u4e86\u4e00\u4e2a\u63d2\u961f\u7684\u4eba\uff0c\u8fd9\u4e2a\u63d2\u961f\u7684\u4eba\u662f\u53ef\u4ee5\u76f4\u63a5\u4ece\u7ba1\u7406\u5458\u90a3\u91cc\u62ff\u5230\u9501\u53bb\u6253\u6c34\uff0c\u4e0d\u9700\u8981\u6392\u961f\uff0c\u539f\u672c\u6392\u961f\u7b49\u5f85\u7684\u4eba\u53ea\u80fd\u7ee7\u7eed\u7b49\u5f85\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe11-1024x871.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe11-1024x871.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u63a5\u4e0b\u6765\u6211\u4eec\u901a\u8fc7ReentrantLock\u7684\u6e90\u7801\u6765\u8bb2\u89e3\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe13.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe13.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6839\u636e\u4ee3\u7801\u53ef\u77e5\uff0cReentrantLock\u91cc\u9762\u6709\u4e00\u4e2a\u5185\u90e8\u7c7bSync\uff0cSync\u7ee7\u627fAQS\uff08AbstractQueuedSynchronizer\uff09\uff0c\u6dfb\u52a0\u9501\u548c\u91ca\u653e\u9501\u7684\u5927\u90e8\u5206\u64cd\u4f5c\u5b9e\u9645\u4e0a\u90fd\u662f\u5728Sync\u4e2d\u5b9e\u73b0\u7684\u3002\u5b83\u6709\u516c\u5e73\u9501FairSync\u548c\u975e\u516c\u5e73\u9501NonfairSync\u4e24\u4e2a\u5b50\u7c7b\u3002ReentrantLock\u9ed8\u8ba4\u4f7f\u7528\u975e\u516c\u5e73\u9501\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6784\u9020\u5668\u6765\u663e\u793a\u7684\u6307\u5b9a\u4f7f\u7528\u516c\u5e73\u9501\u3002<\/p>\n\n\n\n<p>\u4e0b\u9762\u6211\u4eec\u6765\u770b\u4e00\u4e0b\u516c\u5e73\u9501\u4e0e\u975e\u516c\u5e73\u9501\u7684\u52a0\u9501\u65b9\u6cd5\u7684\u6e90\u7801:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe14-1024x427.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe14-1024x427.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u901a\u8fc7\u4e0a\u56fe\u4e2d\u7684\u6e90\u4ee3\u7801\u5bf9\u6bd4\uff0c\u6211\u4eec\u53ef\u4ee5\u660e\u663e\u7684\u770b\u51fa\u516c\u5e73\u9501\u4e0e\u975e\u516c\u5e73\u9501\u7684lock()\u65b9\u6cd5\u552f\u4e00\u7684\u533a\u522b\u5c31\u5728\u4e8e\u516c\u5e73\u9501\u5728\u83b7\u53d6\u540c\u6b65\u72b6\u6001\u65f6\u591a\u4e86\u4e00\u4e2a\u9650\u5236\u6761\u4ef6\uff1ahasQueuedPredecessors()\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe16.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe16.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u518d\u8fdb\u5165hasQueuedPredecessors()\uff0c\u53ef\u4ee5\u770b\u5230\u8be5\u65b9\u6cd5\u4e3b\u8981\u505a\u4e00\u4ef6\u4e8b\u60c5\uff1a\u4e3b\u8981\u662f\u5224\u65ad\u5f53\u524d\u7ebf\u7a0b\u662f\u5426\u4f4d\u4e8e\u540c\u6b65\u961f\u5217\u4e2d\u7684\u7b2c\u4e00\u4e2a\u3002\u5982\u679c\u662f\u5219\u8fd4\u56detrue\uff0c\u5426\u5219\u8fd4\u56defalse\u3002<\/p>\n\n\n\n<p>\u7efc\u4e0a\uff0c\u516c\u5e73\u9501\u5c31\u662f\u901a\u8fc7\u540c\u6b65\u961f\u5217\u6765\u5b9e\u73b0\u591a\u4e2a\u7ebf\u7a0b\u6309\u7167\u7533\u8bf7\u9501\u7684\u987a\u5e8f\u6765\u83b7\u53d6\u9501\uff0c\u4ece\u800c\u5b9e\u73b0\u516c\u5e73\u7684\u7279\u6027\u3002\u975e\u516c\u5e73\u9501\u52a0\u9501\u65f6\u4e0d\u8003\u8651\u6392\u961f\u7b49\u5f85\u95ee\u9898\uff0c\u76f4\u63a5\u5c1d\u8bd5\u83b7\u53d6\u9501\uff0c\u6240\u4ee5\u5b58\u5728\u540e\u7533\u8bf7\u5374\u5148\u83b7\u5f97\u9501\u7684\u60c5\u51b5\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>5. \u53ef\u91cd\u5165\u9501 VS \u975e\u53ef\u91cd\u5165\u9501<\/strong><\/h3>\n\n\n\n<p>\u53ef\u91cd\u5165\u9501\u53c8\u540d\u9012\u5f52\u9501\uff0c\u662f\u6307\u5728\u540c\u4e00\u4e2a\u7ebf\u7a0b\u5728\u5916\u5c42\u65b9\u6cd5\u83b7\u53d6\u9501\u7684\u65f6\u5019\uff0c\u518d\u8fdb\u5165\u8be5\u7ebf\u7a0b\u7684\u5185\u5c42\u65b9\u6cd5\u4f1a\u81ea\u52a8\u83b7\u53d6\u9501\uff08\u524d\u63d0\u9501\u5bf9\u8c61\u5f97\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\u6216\u8005class\uff09\uff0c\u4e0d\u4f1a\u56e0\u4e3a\u4e4b\u524d\u5df2\u7ecf\u83b7\u53d6\u8fc7\u8fd8\u6ca1\u91ca\u653e\u800c\u963b\u585e\u3002Java\u4e2dReentrantLock\u548csynchronized\u90fd\u662f\u53ef\u91cd\u5165\u9501\uff0c\u53ef\u91cd\u5165\u9501\u7684\u4e00\u4e2a\u4f18\u70b9\u662f\u53ef\u4e00\u5b9a\u7a0b\u5ea6\u907f\u514d\u6b7b\u9501\u3002\u4e0b\u9762\u7528\u793a\u4f8b\u4ee3\u7801\u6765\u8fdb\u884c\u5206\u6790\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe18.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe18.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u4e2d\uff0c\u7c7b\u4e2d\u7684\u4e24\u4e2a\u65b9\u6cd5\u90fd\u662f\u88ab\u5185\u7f6e\u9501synchronized\u4fee\u9970\u7684\uff0cdoSomething()\u65b9\u6cd5\u4e2d\u8c03\u7528doOthers()\u65b9\u6cd5\u3002\u56e0\u4e3a\u5185\u7f6e\u9501\u662f\u53ef\u91cd\u5165\u7684\uff0c\u6240\u4ee5\u540c\u4e00\u4e2a\u7ebf\u7a0b\u5728\u8c03\u7528doOthers()\u65f6\u53ef\u4ee5\u76f4\u63a5\u83b7\u5f97\u5f53\u524d\u5bf9\u8c61\u7684\u9501\uff0c\u8fdb\u5165doOthers()\u8fdb\u884c\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u662f\u4e00\u4e2a\u4e0d\u53ef\u91cd\u5165\u9501\uff0c\u90a3\u4e48\u5f53\u524d\u7ebf\u7a0b\u5728\u8c03\u7528doOthers()\u4e4b\u524d\u9700\u8981\u5c06\u6267\u884cdoSomething()\u65f6\u83b7\u53d6\u5f53\u524d\u5bf9\u8c61\u7684\u9501\u91ca\u653e\u6389\uff0c\u5b9e\u9645\u4e0a\u8be5\u5bf9\u8c61\u9501\u5df2\u88ab\u5f53\u524d\u7ebf\u7a0b\u6240\u6301\u6709\uff0c\u4e14\u65e0\u6cd5\u91ca\u653e\u3002\u6240\u4ee5\u6b64\u65f6\u4f1a\u51fa\u73b0\u6b7b\u9501\u3002<\/p>\n\n\n\n<p>\u800c\u4e3a\u4ec0\u4e48\u53ef\u91cd\u5165\u9501\u5c31\u53ef\u4ee5\u5728\u5d4c\u5957\u8c03\u7528\u65f6\u53ef\u4ee5\u81ea\u52a8\u83b7\u5f97\u9501\u5462\uff1f\u6211\u4eec\u901a\u8fc7\u56fe\u793a\u548c\u6e90\u7801\u6765\u5206\u522b\u89e3\u6790\u4e00\u4e0b\u3002<\/p>\n\n\n\n<p>\u8fd8\u662f\u6253\u6c34\u7684\u4f8b\u5b50\uff0c\u6709\u591a\u4e2a\u4eba\u5728\u6392\u961f\u6253\u6c34\uff0c\u6b64\u65f6\u7ba1\u7406\u5458\u5141\u8bb8\u9501\u548c\u540c\u4e00\u4e2a\u4eba\u7684\u591a\u4e2a\u6c34\u6876\u7ed1\u5b9a\u3002\u8fd9\u4e2a\u4eba\u7528\u591a\u4e2a\u6c34\u6876\u6253\u6c34\u65f6\uff0c\u7b2c\u4e00\u4e2a\u6c34\u6876\u548c\u9501\u7ed1\u5b9a\u5e76\u6253\u5b8c\u6c34\u4e4b\u540e\uff0c\u7b2c\u4e8c\u4e2a\u6c34\u6876\u4e5f\u53ef\u4ee5\u76f4\u63a5\u548c\u9501\u7ed1\u5b9a\u5e76\u5f00\u59cb\u6253\u6c34\uff0c\u6240\u6709\u7684\u6c34\u6876\u90fd\u6253\u5b8c\u6c34\u4e4b\u540e\u6253\u6c34\u4eba\u624d\u4f1a\u5c06\u9501\u8fd8\u7ed9\u7ba1\u7406\u5458\u3002\u8fd9\u4e2a\u4eba\u7684\u6240\u6709\u6253\u6c34\u6d41\u7a0b\u90fd\u80fd\u591f\u6210\u529f\u6267\u884c\uff0c\u540e\u7eed\u7b49\u5f85\u7684\u4eba\u4e5f\u80fd\u591f\u6253\u5230\u6c34\u3002\u8fd9\u5c31\u662f\u53ef\u91cd\u5165\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe20-1024x589.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe20-1024x589.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u4f46\u5982\u679c\u662f\u975e\u53ef\u91cd\u5165\u9501\u7684\u8bdd\uff0c\u6b64\u65f6\u7ba1\u7406\u5458\u53ea\u5141\u8bb8\u9501\u548c\u540c\u4e00\u4e2a\u4eba\u7684\u4e00\u4e2a\u6c34\u6876\u7ed1\u5b9a\u3002\u7b2c\u4e00\u4e2a\u6c34\u6876\u548c\u9501\u7ed1\u5b9a\u6253\u5b8c\u6c34\u4e4b\u540e\u5e76\u4e0d\u4f1a\u91ca\u653e\u9501\uff0c\u5bfc\u81f4\u7b2c\u4e8c\u4e2a\u6c34\u6876\u4e0d\u80fd\u548c\u9501\u7ed1\u5b9a\u4e5f\u65e0\u6cd5\u6253\u6c34\u3002\u5f53\u524d\u7ebf\u7a0b\u51fa\u73b0\u6b7b\u9501\uff0c\u6574\u4e2a\u7b49\u5f85\u961f\u5217\u4e2d\u7684\u6240\u6709\u7ebf\u7a0b\u90fd\u65e0\u6cd5\u88ab\u5524\u9192\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe21-1024x595.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe21-1024x595.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u4e4b\u524d\u6211\u4eec\u8bf4\u8fc7ReentrantLock\u548csynchronized\u90fd\u662f\u91cd\u5165\u9501\uff0c\u90a3\u4e48\u6211\u4eec\u901a\u8fc7\u91cd\u5165\u9501ReentrantLock\u4ee5\u53ca\u975e\u53ef\u91cd\u5165\u9501NonReentrantLock\u7684\u6e90\u7801\u6765\u5bf9\u6bd4\u5206\u6790\u4e00\u4e0b\u4e3a\u4ec0\u4e48\u975e\u53ef\u91cd\u5165\u9501\u5728\u91cd\u590d\u8c03\u7528\u540c\u6b65\u8d44\u6e90\u65f6\u4f1a\u51fa\u73b0\u6b7b\u9501\u3002<\/p>\n\n\n\n<p>\u9996\u5148ReentrantLock\u548cNonReentrantLock\u90fd\u7ee7\u627f\u7236\u7c7bAQS\uff0c\u5176\u7236\u7c7bAQS\u4e2d\u7ef4\u62a4\u4e86\u4e00\u4e2a\u540c\u6b65\u72b6\u6001status\u6765\u8ba1\u6570\u91cd\u5165\u6b21\u6570\uff0cstatus\u521d\u59cb\u503c\u4e3a0\u3002<\/p>\n\n\n\n<p>\u5f53\u7ebf\u7a0b\u5c1d\u8bd5\u83b7\u53d6\u9501\u65f6\uff0c\u53ef\u91cd\u5165\u9501\u5148\u5c1d\u8bd5\u83b7\u53d6\u5e76\u66f4\u65b0status\u503c\uff0c\u5982\u679cstatus == 0\u8868\u793a\u6ca1\u6709\u5176\u4ed6\u7ebf\u7a0b\u5728\u6267\u884c\u540c\u6b65\u4ee3\u7801\uff0c\u5219\u628astatus\u7f6e\u4e3a1\uff0c\u5f53\u524d\u7ebf\u7a0b\u5f00\u59cb\u6267\u884c\u3002\u5982\u679cstatus != 0\uff0c\u5219\u5224\u65ad\u5f53\u524d\u7ebf\u7a0b\u662f\u5426\u662f\u83b7\u53d6\u5230\u8fd9\u4e2a\u9501\u7684\u7ebf\u7a0b\uff0c\u5982\u679c\u662f\u7684\u8bdd\u6267\u884cstatus+1\uff0c\u4e14\u5f53\u524d\u7ebf\u7a0b\u53ef\u4ee5\u518d\u6b21\u83b7\u53d6\u9501\u3002\u800c\u975e\u53ef\u91cd\u5165\u9501\u662f\u76f4\u63a5\u53bb\u83b7\u53d6\u5e76\u5c1d\u8bd5\u66f4\u65b0\u5f53\u524dstatus\u7684\u503c\uff0c\u5982\u679cstatus != 0\u7684\u8bdd\u4f1a\u5bfc\u81f4\u5176\u83b7\u53d6\u9501\u5931\u8d25\uff0c\u5f53\u524d\u7ebf\u7a0b\u963b\u585e\u3002<\/p>\n\n\n\n<p>\u91ca\u653e\u9501\u65f6\uff0c\u53ef\u91cd\u5165\u9501\u540c\u6837\u5148\u83b7\u53d6\u5f53\u524dstatus\u7684\u503c\uff0c\u5728\u5f53\u524d\u7ebf\u7a0b\u662f\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u7684\u524d\u63d0\u4e0b\u3002\u5982\u679cstatus-1 == 0\uff0c\u5219\u8868\u793a\u5f53\u524d\u7ebf\u7a0b\u6240\u6709\u91cd\u590d\u83b7\u53d6\u9501\u7684\u64cd\u4f5c\u90fd\u5df2\u7ecf\u6267\u884c\u5b8c\u6bd5\uff0c\u7136\u540e\u8be5\u7ebf\u7a0b\u624d\u4f1a\u771f\u6b63\u91ca\u653e\u9501\u3002\u800c\u975e\u53ef\u91cd\u5165\u9501\u5219\u662f\u5728\u786e\u5b9a\u5f53\u524d\u7ebf\u7a0b\u662f\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u4e4b\u540e\uff0c\u76f4\u63a5\u5c06status\u7f6e\u4e3a0\uff0c\u5c06\u9501\u91ca\u653e\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe23-1024x679.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe23-1024x679.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>6. \u72ec\u4eab\u9501 VS \u5171\u4eab\u9501<\/strong><\/h3>\n\n\n\n<p>\u72ec\u4eab\u9501\u548c\u5171\u4eab\u9501\u540c\u6837\u662f\u4e00\u79cd\u6982\u5ff5\u3002\u6211\u4eec\u5148\u4ecb\u7ecd\u4e00\u4e0b\u5177\u4f53\u7684\u6982\u5ff5\uff0c\u7136\u540e\u901a\u8fc7ReentrantLock\u548cReentrantReadWriteLock\u7684\u6e90\u7801\u6765\u4ecb\u7ecd\u72ec\u4eab\u9501\u548c\u5171\u4eab\u9501\u3002<\/p>\n\n\n\n<p>\u72ec\u4eab\u9501\u4e5f\u53eb\u6392\u4ed6\u9501\uff0c\u662f\u6307\u8be5\u9501\u4e00\u6b21\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u6240\u6301\u6709\u3002\u5982\u679c\u7ebf\u7a0bT\u5bf9\u6570\u636eA\u52a0\u4e0a\u6392\u5b83\u9501\u540e\uff0c\u5219\u5176\u4ed6\u7ebf\u7a0b\u4e0d\u80fd\u518d\u5bf9A\u52a0\u4efb\u4f55\u7c7b\u578b\u7684\u9501\u3002\u83b7\u5f97\u6392\u5b83\u9501\u7684\u7ebf\u7a0b\u5373\u80fd\u8bfb\u6570\u636e\u53c8\u80fd\u4fee\u6539\u6570\u636e\u3002JDK\u4e2d\u7684synchronized\u548cJUC\u4e2dLock\u7684\u5b9e\u73b0\u7c7b\u5c31\u662f\u4e92\u65a5\u9501\u3002<\/p>\n\n\n\n<p>\u5171\u4eab\u9501\u662f\u6307\u8be5\u9501\u53ef\u88ab\u591a\u4e2a\u7ebf\u7a0b\u6240\u6301\u6709\u3002\u5982\u679c\u7ebf\u7a0bT\u5bf9\u6570\u636eA\u52a0\u4e0a\u5171\u4eab\u9501\u540e\uff0c\u5219\u5176\u4ed6\u7ebf\u7a0b\u53ea\u80fd\u5bf9A\u518d\u52a0\u5171\u4eab\u9501\uff0c\u4e0d\u80fd\u52a0\u6392\u5b83\u9501\u3002\u83b7\u5f97\u5171\u4eab\u9501\u7684\u7ebf\u7a0b\u53ea\u80fd\u8bfb\u6570\u636e\uff0c\u4e0d\u80fd\u4fee\u6539\u6570\u636e\u3002<\/p>\n\n\n\n<p>\u72ec\u4eab\u9501\u4e0e\u5171\u4eab\u9501\u4e5f\u662f\u901a\u8fc7AQS\u6765\u5b9e\u73b0\u7684\uff0c\u901a\u8fc7\u5b9e\u73b0\u4e0d\u540c\u7684\u65b9\u6cd5\uff0c\u6765\u5b9e\u73b0\u72ec\u4eab\u6216\u8005\u5171\u4eab\u3002<\/p>\n\n\n\n<p>\u4e0b\u56fe\u4e3aReentrantReadWriteLock\u7684\u90e8\u5206\u6e90\u7801\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe25-1024x596.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe25-1024x596.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6211\u4eec\u770b\u5230ReentrantReadWriteLock\u6709\u4e24\u628a\u9501\uff1aReadLock\u548cWriteLock\uff0c\u7531\u8bcd\u77e5\u610f\uff0c\u4e00\u4e2a\u8bfb\u9501\u4e00\u4e2a\u5199\u9501\uff0c\u5408\u79f0\u201c\u8bfb\u5199\u9501\u201d\u3002\u518d\u8fdb\u4e00\u6b65\u89c2\u5bdf\u53ef\u4ee5\u53d1\u73b0ReadLock\u548cWriteLock\u662f\u9760\u5185\u90e8\u7c7bSync\u5b9e\u73b0\u7684\u9501\u3002Sync\u662fAQS\u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u8fd9\u79cd\u7ed3\u6784\u5728CountDownLatch\u3001ReentrantLock\u3001Semaphore\u91cc\u9762\u4e5f\u90fd\u5b58\u5728\u3002<\/p>\n\n\n\n<p>\u5728ReentrantReadWriteLock\u91cc\u9762\uff0c\u8bfb\u9501\u548c\u5199\u9501\u7684\u9501\u4e3b\u4f53\u90fd\u662fSync\uff0c\u4f46\u8bfb\u9501\u548c\u5199\u9501\u7684\u52a0\u9501\u65b9\u5f0f\u4e0d\u4e00\u6837\u3002\u8bfb\u9501\u662f\u5171\u4eab\u9501\uff0c\u5199\u9501\u662f\u72ec\u4eab\u9501\u3002\u8bfb\u9501\u7684\u5171\u4eab\u9501\u53ef\u4fdd\u8bc1\u5e76\u53d1\u8bfb\u975e\u5e38\u9ad8\u6548\uff0c\u800c\u8bfb\u5199\u3001\u5199\u8bfb\u3001\u5199\u5199\u7684\u8fc7\u7a0b\u4e92\u65a5\uff0c\u56e0\u4e3a\u8bfb\u9501\u548c\u5199\u9501\u662f\u5206\u79bb\u7684\u3002\u6240\u4ee5ReentrantReadWriteLock\u7684\u5e76\u53d1\u6027\u76f8\u6bd4\u4e00\u822c\u7684\u4e92\u65a5\u9501\u6709\u4e86\u5f88\u5927\u63d0\u5347\u3002<\/p>\n\n\n\n<p>\u90a3\u8bfb\u9501\u548c\u5199\u9501\u7684\u5177\u4f53\u52a0\u9501\u65b9\u5f0f\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f\u5728\u4e86\u89e3\u6e90\u7801\u4e4b\u524d\u6211\u4eec\u9700\u8981\u56de\u987e\u4e00\u4e0b\u5176\u4ed6\u77e5\u8bc6\u3002<\/p>\n\n\n\n<p>\u5728\u6700\u5f00\u59cb\u63d0\u53caAQS\u7684\u65f6\u5019\u6211\u4eec\u4e5f\u63d0\u5230\u4e86state\u5b57\u6bb5\uff08int\u7c7b\u578b\uff0c32\u4f4d\uff09\uff0c\u8be5\u5b57\u6bb5\u7528\u6765\u63cf\u8ff0\u6709\u591a\u5c11\u7ebf\u7a0b\u83b7\u6301\u6709\u9501\u3002<\/p>\n\n\n\n<p>\u5728\u72ec\u4eab\u9501\u4e2d\u8fd9\u4e2a\u503c\u901a\u5e38\u662f0\u6216\u80051\uff08\u5982\u679c\u662f\u91cd\u5165\u9501\u7684\u8bddstate\u503c\u5c31\u662f\u91cd\u5165\u7684\u6b21\u6570\uff09\uff0c\u5728\u5171\u4eab\u9501\u4e2dstate\u5c31\u662f\u6301\u6709\u9501\u7684\u6570\u91cf\u3002\u4f46\u662f\u5728ReentrantReadWriteLock\u4e2d\u6709\u8bfb\u3001\u5199\u4e24\u628a\u9501\uff0c\u6240\u4ee5\u9700\u8981\u5728\u4e00\u4e2a\u6574\u578b\u53d8\u91cfstate\u4e0a\u5206\u522b\u63cf\u8ff0\u8bfb\u9501\u548c\u5199\u9501\u7684\u6570\u91cf\uff08\u6216\u8005\u4e5f\u53ef\u4ee5\u53eb\u72b6\u6001\uff09\u3002\u4e8e\u662f\u5c06state\u53d8\u91cf\u201c\u6309\u4f4d\u5207\u5272\u201d\u5207\u5206\u6210\u4e86\u4e24\u4e2a\u90e8\u5206\uff0c\u9ad816\u4f4d\u8868\u793a\u8bfb\u9501\u72b6\u6001\uff08\u8bfb\u9501\u4e2a\u6570\uff09\uff0c\u4f4e16\u4f4d\u8868\u793a\u5199\u9501\u72b6\u6001\uff08\u5199\u9501\u4e2a\u6570\uff09\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe25-1024x106.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe25-1024x106.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u4e86\u89e3\u4e86\u6982\u5ff5\u4e4b\u540e\u6211\u4eec\u518d\u6765\u770b\u4ee3\u7801\uff0c\u5148\u770b\u5199\u9501\u7684\u52a0\u9501\u6e90\u7801\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe26-1024x508.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe26-1024x508.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u6bb5\u4ee3\u7801\u9996\u5148\u53d6\u5230\u5f53\u524d\u9501\u7684\u4e2a\u6570c\uff0c\u7136\u540e\u518d\u901a\u8fc7c\u6765\u83b7\u53d6\u5199\u9501\u7684\u4e2a\u6570w\u3002\u56e0\u4e3a\u5199\u9501\u662f\u4f4e16\u4f4d\uff0c\u6240\u4ee5\u53d6\u4f4e16\u4f4d\u7684\u6700\u5927\u503c\u4e0e\u5f53\u524d\u7684c\u505a\u4e0e\u8fd0\u7b97\uff08\u00a0int w = exclusiveCount(c);\u00a0\uff09\uff0c\u9ad816\u4f4d\u548c0\u4e0e\u8fd0\u7b97\u540e\u662f0\uff0c\u5269\u4e0b\u7684\u5c31\u662f\u4f4e\u4f4d\u8fd0\u7b97\u7684\u503c\uff0c\u540c\u65f6\u4e5f\u662f\u6301\u6709\u5199\u9501\u7684\u7ebf\u7a0b\u6570\u76ee\u3002<\/li>\n\n\n\n<li>\u5728\u53d6\u5230\u5199\u9501\u7ebf\u7a0b\u7684\u6570\u76ee\u540e\uff0c\u9996\u5148\u5224\u65ad\u662f\u5426\u5df2\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u4e86\u9501\u3002\u5982\u679c\u5df2\u7ecf\u6709\u7ebf\u7a0b\u6301\u6709\u4e86\u9501\uff08c!=0\uff09\uff0c\u5219\u67e5\u770b\u5f53\u524d\u5199\u9501\u7ebf\u7a0b\u7684\u6570\u76ee\uff0c\u5982\u679c\u5199\u7ebf\u7a0b\u6570\u4e3a0\uff08\u5373\u6b64\u65f6\u5b58\u5728\u8bfb\u9501\uff09\u6216\u8005\u6301\u6709\u9501\u7684\u7ebf\u7a0b\u4e0d\u662f\u5f53\u524d\u7ebf\u7a0b\u5c31\u8fd4\u56de\u5931\u8d25\uff08\u6d89\u53ca\u5230\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7684\u5b9e\u73b0\uff09\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u5199\u5165\u9501\u7684\u6570\u91cf\u5927\u4e8e\u6700\u5927\u6570\uff0865535\uff0c2\u768416\u6b21\u65b9-1\uff09\u5c31\u629b\u51fa\u4e00\u4e2aError\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u5f53\u4e14\u5199\u7ebf\u7a0b\u6570\u4e3a0\uff08\u90a3\u4e48\u8bfb\u7ebf\u7a0b\u4e5f\u5e94\u8be5\u4e3a0\uff0c\u56e0\u4e3a\u4e0a\u9762\u5df2\u7ecf\u5904\u7406c!=0\u7684\u60c5\u51b5\uff09\uff0c\u5e76\u4e14\u5f53\u524d\u7ebf\u7a0b\u9700\u8981\u963b\u585e\u90a3\u4e48\u5c31\u8fd4\u56de\u5931\u8d25\uff1b\u5982\u679c\u901a\u8fc7CAS\u589e\u52a0\u5199\u7ebf\u7a0b\u6570\u5931\u8d25\u4e5f\u8fd4\u56de\u5931\u8d25\u3002<\/li>\n\n\n\n<li>\u5982\u679cc=0\uff0cw=0\u6216\u8005c>0\uff0cw>0\uff08\u91cd\u5165\uff09\uff0c\u5219\u8bbe\u7f6e\u5f53\u524d\u7ebf\u7a0b\u6216\u9501\u7684\u62e5\u6709\u8005\uff0c\u8fd4\u56de\u6210\u529f\uff01<\/li>\n<\/ul>\n\n\n\n<p>tryAcquire()\u9664\u4e86\u91cd\u5165\u6761\u4ef6\uff08\u5f53\u524d\u7ebf\u7a0b\u4e3a\u83b7\u53d6\u4e86\u5199\u9501\u7684\u7ebf\u7a0b\uff09\u4e4b\u5916\uff0c\u589e\u52a0\u4e86\u4e00\u4e2a\u8bfb\u9501\u662f\u5426\u5b58\u5728\u7684\u5224\u65ad\u3002\u5982\u679c\u5b58\u5728\u8bfb\u9501\uff0c\u5219\u5199\u9501\u4e0d\u80fd\u88ab\u83b7\u53d6\uff0c\u539f\u56e0\u5728\u4e8e\uff1a\u5fc5\u987b\u786e\u4fdd\u5199\u9501\u7684\u64cd\u4f5c\u5bf9\u8bfb\u9501\u53ef\u89c1\uff0c\u5982\u679c\u5141\u8bb8\u8bfb\u9501\u5728\u5df2\u88ab\u83b7\u53d6\u7684\u60c5\u51b5\u4e0b\u5bf9\u5199\u9501\u7684\u83b7\u53d6\uff0c\u90a3\u4e48\u6b63\u5728\u8fd0\u884c\u7684\u5176\u4ed6\u8bfb\u7ebf\u7a0b\u5c31\u65e0\u6cd5\u611f\u77e5\u5230\u5f53\u524d\u5199\u7ebf\u7a0b\u7684\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\uff0c\u53ea\u6709\u7b49\u5f85\u5176\u4ed6\u8bfb\u7ebf\u7a0b\u90fd\u91ca\u653e\u4e86\u8bfb\u9501\uff0c\u5199\u9501\u624d\u80fd\u88ab\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\uff0c\u800c\u5199\u9501\u4e00\u65e6\u88ab\u83b7\u53d6\uff0c\u5219\u5176\u4ed6\u8bfb\u5199\u7ebf\u7a0b\u7684\u540e\u7eed\u8bbf\u95ee\u5747\u88ab\u963b\u585e\u3002\u5199\u9501\u7684\u91ca\u653e\u4e0eReentrantLock\u7684\u91ca\u653e\u8fc7\u7a0b\u57fa\u672c\u7c7b\u4f3c\uff0c\u6bcf\u6b21\u91ca\u653e\u5747\u51cf\u5c11\u5199\u72b6\u6001\uff0c\u5f53\u5199\u72b6\u6001\u4e3a0\u65f6\u8868\u793a\u5199\u9501\u5df2\u88ab\u91ca\u653e\uff0c\u7136\u540e\u7b49\u5f85\u7684\u8bfb\u5199\u7ebf\u7a0b\u624d\u80fd\u591f\u7ee7\u7eed\u8bbf\u95ee\u8bfb\u5199\u9501\uff0c\u540c\u65f6\u524d\u6b21\u5199\u7ebf\u7a0b\u7684\u4fee\u6539\u5bf9\u540e\u7eed\u7684\u8bfb\u5199\u7ebf\u7a0b\u53ef\u89c1\u3002<\/p>\n\n\n\n<p>\u63a5\u7740\u662f\u8bfb\u9501\u7684\u4ee3\u7801\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe27-1024x564.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe27-1024x564.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u5728tryAcquireShared(int unused)\u65b9\u6cd5\u4e2d\uff0c\u5982\u679c\u5176\u4ed6\u7ebf\u7a0b\u5df2\u7ecf\u83b7\u53d6\u4e86\u5199\u9501\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\u8bfb\u9501\u5931\u8d25\uff0c\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\u3002\u5982\u679c\u5f53\u524d\u7ebf\u7a0b\u83b7\u53d6\u4e86\u5199\u9501\u6216\u8005\u5199\u9501\u672a\u88ab\u83b7\u53d6\uff0c\u5219\u5f53\u524d\u7ebf\u7a0b\uff08\u7ebf\u7a0b\u5b89\u5168\uff0c\u4f9d\u9760CAS\u4fdd\u8bc1\uff09\u589e\u52a0\u8bfb\u72b6\u6001\uff0c\u6210\u529f\u83b7\u53d6\u8bfb\u9501\u3002\u8bfb\u9501\u7684\u6bcf\u6b21\u91ca\u653e\uff08\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u53ef\u80fd\u6709\u591a\u4e2a\u8bfb\u7ebf\u7a0b\u540c\u65f6\u91ca\u653e\u8bfb\u9501\uff09\u5747\u51cf\u5c11\u8bfb\u72b6\u6001\uff0c\u51cf\u5c11\u7684\u503c\u662f\u201c1&lt;&lt;16\u201d\u3002\u6240\u4ee5\u8bfb\u5199\u9501\u624d\u80fd\u5b9e\u73b0\u8bfb\u8bfb\u7684\u8fc7\u7a0b\u5171\u4eab\uff0c\u800c\u8bfb\u5199\u3001\u5199\u8bfb\u3001\u5199\u5199\u7684\u8fc7\u7a0b\u4e92\u65a5\u3002<\/p>\n\n\n\n<p>\u6b64\u65f6\uff0c\u6211\u4eec\u518d\u56de\u5934\u770b\u4e00\u4e0b\u4e92\u65a5\u9501ReentrantLock\u4e2d\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u7684\u52a0\u9501\u6e90\u7801\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe28-1024x515.jpg'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/qqiukulele.cn\/wp-content\/uploads\/2021\/10\/\u56fe28-1024x515.jpg\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6211\u4eec\u53d1\u73b0\u5728ReentrantLock\u867d\u7136\u6709\u516c\u5e73\u9501\u548c\u975e\u516c\u5e73\u9501\u4e24\u79cd\uff0c\u4f46\u662f\u5b83\u4eec\u6dfb\u52a0\u7684\u90fd\u662f\u72ec\u4eab\u9501\u3002\u6839\u636e\u6e90\u7801\u6240\u793a\uff0c\u5f53\u67d0\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528lock\u65b9\u6cd5\u83b7\u53d6\u9501\u65f6\uff0c\u5982\u679c\u540c\u6b65\u8d44\u6e90\u6ca1\u6709\u88ab\u5176\u4ed6\u7ebf\u7a0b\u9501\u4f4f\uff0c\u90a3\u4e48\u5f53\u524d\u7ebf\u7a0b\u5728\u4f7f\u7528CAS\u66f4\u65b0state\u6210\u529f\u540e\u5c31\u4f1a\u6210\u529f\u62a2\u5360\u8be5\u8d44\u6e90\u3002\u800c\u5982\u679c\u516c\u5171\u8d44\u6e90\u88ab\u5360\u7528\u4e14\u4e0d\u662f\u88ab\u5f53\u524d\u7ebf\u7a0b\u5360\u7528\uff0c\u90a3\u4e48\u5c31\u4f1a\u52a0\u9501\u5931\u8d25\u3002\u6240\u4ee5\u53ef\u4ee5\u786e\u5b9aReentrantLock\u65e0\u8bba\u8bfb\u64cd\u4f5c\u8fd8\u662f\u5199\u64cd\u4f5c\uff0c\u6dfb\u52a0\u7684\u9501\u90fd\u662f\u90fd\u662f\u72ec\u4eab\u9501\u3002<\/p>\n\n\n\n<h2 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\u5bb6\u742a<\/a><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8fd9\u7bc7\u6587\u7ae0\u6211\u8ba4\u771f\u770b\u5b8c\u540e\u8868\u793a\u5927\u7231\uff01\u9501\u76f8\u5173\u7684\u77e5\u8bc6\u70b9\u68b3\u7406\u5f97\u8d85\u7ea7\u6e05\u6670\uff01\u611f\u8c22\u539f\u4f5c\u8005\uff01\u5728\u6b64\u8f6c\u8f7d\u8bb0\u5f55\uff01<\/p>\n","protected":false},"author":1,"featured_media":260,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[15],"class_list":["post-254","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-22","tag-java"],"_links":{"self":[{"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/posts\/254","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=254"}],"version-history":[{"count":2,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/posts\/254\/revisions"}],"predecessor-version":[{"id":464,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/posts\/254\/revisions\/464"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=\/wp\/v2\/media\/260"}],"wp:attachment":[{"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=254"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=254"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qqiukulele.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}