{"id":519,"date":"2019-10-08T18:00:15","date_gmt":"2019-10-08T10:00:15","guid":{"rendered":"http:\/\/weitaoc.com\/?p=519"},"modified":"2019-10-09T15:50:17","modified_gmt":"2019-10-09T07:50:17","slug":"volatile%e5%92%8csynchronize","status":"publish","type":"post","link":"http:\/\/weitaoc.com\/?p=519","title":{"rendered":"volatile\u548csynchronize"},"content":{"rendered":"\n

volatile\u548csynchronize\u867d\u7136\u76ee\u524d\u4e1a\u52a1\u5c42\u5173\u6ce8\u7684\u6bd4\u8f83\u5c11\uff0c\u4f46\u662f\u4ed6\u4eec\u662f\u5185\u5b58\u6a21\u578b\u91cc\u9762\u6bd4\u8f83\u7279\u6b8a\u7684\u4e24\u4e2a\u5173\u952e\u5b57\uff0c\u6211\u4eec\u53ef\u4ee5\u5229\u7528\u4ed6\u4eec\u6765\u4e86\u89e3\u4e00\u4e0b\u5185\u5b58\u6a21\u578b\u91cc\u662f\u5982\u4f55\u89e3\u51b3\u591a\u7ebf\u7a0b\u95ee\u9898\u7684\u3002<\/p><\/blockquote>\n\n\n\n

\u6307\u4ee4\u91cd\u6392 <\/p>\n\n\n\n

\u8ba1\u7b97\u673a\u5728\u6267\u884c\u7a0b\u5e8f\u65f6\uff0c\u4e3a\u4e86\u63d0\u9ad8\u6027\u80fd\uff0c\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u7684\u5e38\u5e38\u4f1a\u5bf9\u6307\u4ee4\u505a\u91cd\u6392 \u3002<\/p>\n\n\n\n

\u539f\u5b50\u6027<\/p>\n\n\n\n

\u539f\u5b50\u6027\u6307\u7684\u662f\u4e00\u4e2a\u64cd\u4f5c\u662f\u4e0d\u53ef\u4e2d\u65ad\u7684\uff0c\u5373\u4f7f\u662f\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\uff0c\u4e00\u4e2a\u64cd\u4f5c\u4e00\u65e6\u5f00\u59cb\u5c31\u4e0d\u4f1a\u88ab\u5176\u4ed6\u7ebf\u7a0b\u5f71\u54cd\u3002 <\/p>\n\n\n\n

\u53ef\u89c1\u6027<\/p>\n\n\n\n

\u53ef\u89c1\u6027\u6307\u7684\u662f\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u4fee\u6539\u4e86\u67d0\u4e2a\u5171\u4eab\u53d8\u91cf\u7684\u503c\uff0c\u5176\u4ed6\u7ebf\u7a0b\u662f\u5426\u80fd\u591f\u9a6c\u4e0a\u5f97\u77e5\u8fd9\u4e2a\u4fee\u6539\u7684\u503c\u3002 <\/p>\n\n\n\n

volatile\u5b9e\u73b0\u4e86\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u548c\u53ef\u89c1\u6027\uff0c\u5e76\u4e0d\u5177\u5907\u539f\u5b50\u6027\uff0c\u4e25\u683c\u8bf4\u5c31\u662fvolatile\u5bf9\u8c61\u7684\u503c\u5728\u591a\u7ebf\u7a0b\u60c5\u51b5\u4e0b\u5e76\u4e0d\u53ef\u9760\uff0c\u6bd4\u5982\uff0c\u4e00\u4e2a\u5171\u4eab\u53d8\u91cf\u7528\u6765\u505a\u8ba1\u6570\u5668\uff0c\u6bcf\u6b21\u4e00\u4e2a\u7ebf\u7a0b\u66f4\u65b0\u540e\uff0c\u53e6\u5916\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u591f\u663e\u5f0f\u7684\u62ff\u5230\u6700\u65b0\u7684\u503c\uff0c\u4f46\u662f\u5728\u5199\u5165\u65f6\uff0c\u5e76\u4e0d\u5177\u5907\u539f\u5b50\u6027\uff0c\u4e0d\u80fd\u4fdd\u8bc1\u548c\u5176\u4ed6\u5199\u5165\u7ebf\u7a0b\u5e76\u53d1\u65f6\u7684\u552f\u4e00\u6027\u3002<\/p>\n\n\n\n

volatile\u53ef\u89c1\u6027\u548c\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u5b9e\u73b0<\/p>\n\n\n\n

\u5f53\u5199\u4e00\u4e2avolatile\u53d8\u91cf\u65f6\uff0cJMM\u4f1a\u628a\u8be5\u7ebf\u7a0b\u5bf9\u5e94\u7684\u5de5\u4f5c\u5185\u5b58\u4e2d\u7684\u5171\u4eab\u53d8\u91cf\u503c\u5237\u65b0\u5230\u4e3b\u5185\u5b58\u4e2d\uff0c\u5f53\u8bfb\u53d6\u4e00\u4e2avolatile\u53d8\u91cf\u65f6\uff0cJMM\u4f1a\u628a\u8be5\u7ebf\u7a0b\u5bf9\u5e94\u7684\u5de5\u4f5c\u5185\u5b58\u7f6e\u4e3a\u65e0\u6548\uff0c\u90a3\u4e48\u8be5\u7ebf\u7a0b\u5c06\u53ea\u80fd\u4ece\u4e3b\u5185\u5b58\u4e2d\u91cd\u65b0\u8bfb\u53d6\u5171\u4eab\u53d8\u91cf\u3002volatile\u53d8\u91cf\u6b63\u662f\u901a\u8fc7\u8fd9\u79cd\u5199-\u8bfb\u65b9\u5f0f\u5b9e\u73b0\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u53ef\u89c1\uff08 \u4f46\u5176\u5185\u5b58\u8bed\u4e49\u5b9e\u73b0\u5219\u662f\u901a\u8fc7\u5185\u5b58\u5c4f\u969c \uff09\u3002<\/p>\n\n\n\n

\u5185\u5b58\u5c4f\u969c\uff0c\u53c8\u79f0\u5185\u5b58\u6805\u680f\uff0c\u662f\u4e00\u4e2aCPU\u6307\u4ee4\uff0c\u5b83\u7684\u4f5c\u7528\u6709\u4e24\u4e2a\uff0c\u4e00\u662f\u4fdd\u8bc1\u7279\u5b9a\u64cd\u4f5c\u7684\u6267\u884c\u987a\u5e8f\uff0c\u4e8c\u662f\u4fdd\u8bc1\u67d0\u4e9b\u53d8\u91cf\u7684\u5185\u5b58\u53ef\u89c1\u6027\uff08\u5229\u7528\u8be5\u7279\u6027\u5b9e\u73b0volatile\u7684\u5185\u5b58\u53ef\u89c1\u6027\uff09\u3002\u7531\u4e8e\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u90fd\u80fd\u6267\u884c\u6307\u4ee4\u91cd\u6392\u4f18\u5316\u3002\u5982\u679c\u5728\u6307\u4ee4\u95f4\u63d2\u5165\u4e00\u6761Memory Barrier\u5219\u4f1a\u544a\u8bc9\u7f16\u8bd1\u5668\u548cCPU\uff0c\u4e0d\u7ba1\u4ec0\u4e48\u6307\u4ee4\u90fd\u4e0d\u80fd\u548c\u8fd9\u6761Memory Barrier\u6307\u4ee4\u91cd\u6392\u5e8f\uff0c\u4e5f\u5c31\u662f\u8bf4\u901a\u8fc7\u63d2\u5165\u5185\u5b58\u5c4f\u969c\u7981\u6b62\u5728\u5185\u5b58\u5c4f\u969c\u524d\u540e\u7684\u6307\u4ee4\u6267\u884c\u91cd\u6392\u5e8f\u4f18\u5316\u3002Memory Barrier\u7684\u53e6\u5916\u4e00\u4e2a\u4f5c\u7528\u662f\u5f3a\u5236\u5237\u51fa\u5404\u79cdCPU\u7684\u7f13\u5b58\u6570\u636e\uff0c\u56e0\u6b64\u4efb\u4f55CPU\u4e0a\u7684\u7ebf\u7a0b\u90fd\u80fd\u8bfb\u53d6\u5230\u8fd9\u4e9b\u6570\u636e\u7684\u6700\u65b0\u7248\u672c\u3002\u603b\u4e4b\uff0cvolatile\u53d8\u91cf\u6b63\u662f\u901a\u8fc7\u5185\u5b58\u5c4f\u969c\u5b9e\u73b0\u5176\u5728\u5185\u5b58\u4e2d\u7684\u8bed\u4e49\uff0c\u5373\u53ef\u89c1\u6027\u548c\u7981\u6b62\u91cd\u6392\u4f18\u5316\u3002 <\/p>\n\n\n\n

\u8bef\u89e3\uff1avolatile\u53d8\u91cf\u5bf9\u6240\u6709\u7ebf\u7a0b\u662f\u7acb\u5373\u53ef\u89c1\u7684\uff0c\u6240\u4ee5\u5bf9volatile\u53d8\u91cf\u7684\u6240\u6709\u4fee\u6539(\u5199\u64cd\u4f5c)\u90fd\u7acb\u523b\u80fd\u53cd\u5e94\u5230\u5176\u4ed6\u7ebf\u7a0b\u4e2d\u3002\u6216\u8005\u6362\u53e5\u8bdd\u8bf4\uff1avolatile\u53d8\u91cf\u5728\u5404\u4e2a\u7ebf\u7a0b\u4e2d\u662f\u4e00\u81f4\u7684\uff0c\u6240\u4ee5\u57fa\u4e8evolatile\u53d8\u91cf\u7684\u8fd0\u7b97\u5728\u5e76\u53d1\u4e0b\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002 <\/p>\u975e\u539f\u5b50\u6027\u610f\u5473\u7740\u5199\u5e76\u53d1\u662f\u6709\u53ef\u80fd\u7684<\/cite><\/blockquote>\n\n\n\n

\u7591\u95ee\uff1a\u4e3a\u4ec0\u4e48\u6211\u4eec\u5199\u4ee3\u7801\u4e0d\u7528\u53ef\u4ee5\u53bb\u5199volatile\u548csynchronize\u6765\u786e\u4fdd\u4ee3\u7801\u7684\u6267\u884c\u987a\u5e8f\u3001\u53ef\u89c1\u6027\u3001\u539f\u5b50\u6027\uff1f<\/p>\u5982\u679cJava\u5185\u5b58\u6a21\u578b\u4e2d\u6240\u6709\u7684\u6709\u5e8f\u6027\u90fd\u8981\u4f9d\u9760volatile\u548csynchronized\u6765\u5b9e\u73b0\uff0c\u90a3\u662f\u4e0d\u662f\u975e\u5e38\u7e41\u7410\u3002Java\u8bed\u8a00\u4e2d\u6709\u4e00\u4e2a\u201c\u5148\u884c\u53d1\u751f\u539f\u5219<\/a>\u201d\uff0c\u662f\u5224\u65ad\u6570\u636e\u662f\u5426\u5b58\u5728\u7ade\u4e89\u3001\u7ebf\u7a0b\u662f\u5426\u5b89\u5168\u7684\u4e3b\u8981\u4f9d\u636e\u3002 <\/cite><\/blockquote>\n\n\n\n

synchronize\u7684\u539f\u5b50\u6027\u901a\u8fc7\u52a0\u9501\u6765\u5b9e\u73b0\uff08monitorenter\u548cmonitorexit\u6307\u4ee4\uff09\uff0c\u52a0\u9501\u65f6\u6e05\u7a7a\u5de5\u4f5c\u5185\u5b58\u4e2d\u5171\u4eab\u53d8\u91cf\u7684\u503c\uff0c\u4ece\u800c\u4f7f\u5171\u4eab\u53d8\u91cf\u65f6\u9700\u8981\u4ece\u4e3b\u5185\u5b58\u4e2d\u91cd\u65b0\u83b7\u53d6\u6700\u65b0\u7684\u503c\uff0c\u89e3\u9501\u65f6\u628a\u5171\u4eab\u53d8\u91cf\u7684\u6700\u65b0\u503c\u5237\u65b0\u5230\u4e3b\u5185\u5b58\u4e2d\uff0c\u4ece\u800c\u5b9e\u73b0\u4e86synchronize\u7684\u53ef\u89c1\u6027\u3002<\/p>\n\n\n\n

synchronize\u4fee\u9970\u7684\u4ee3\u7801\uff0c\u5728\u540c\u4e00\u65f6\u95f4\u53ea\u5141\u8bb8\u4e00\u4e2a\u7ebf\u7a0b\u6765\u6267\u884c\uff0c\u4e5f\u5c31\u662f\u5355\u7ebf\u7a0b\u6267\u884c\uff0c\u4e5f\u5c31\u4e0d\u5b58\u5728\u591a\u7ebf\u7a0b\u4e0b\u7684\u6709\u5e8f\u6027\uff0c\u4ece\u53e6\u5916\u4e00\u4e2a\u89d2\u5ea6\u89e3\u51b3\u591a\u591a\u7ebf\u7a0b\u6267\u884c\u7684\u6709\u5e8f\u6027\u3002<\/p>\n

\u8f6c\u8f7d\u8bf7\u6ce8\u660e\uff1a\u8ff7\u8def\u7684\u8001\u9f20<\/a> » volatile\u548csynchronize<\/a><\/p>","protected":false},"excerpt":{"rendered":"

volatile\u548csynchronize\u867d\u7136\u76ee\u524d\u4e1a\u52a1\u5c42\u5173\u6ce8\u7684\u6bd4\u8f83\u5c11\uff0c\u4f46\u662f\u4ed6\u4eec\u662f\u5185\u5b58\u6a21\u578b\u91cc\u9762\u6bd4\u8f83\u7279\u6b8a\u7684\u4e24\u4e2a\u5173\u952e\u5b57\uff0c\u6211\u4eec\u53ef\u4ee5\u5229\u7528\u4ed6\u4eec\u6765\u4e86\u89e3\u4e00\u4e0b\u5185\u5b58\u6a21\u578b\u91cc\u662f\u5982\u4f55\u89e3\u51b3\u591a\u7ebf\u7a0b\u95ee\u9898\u7684\u3002 \u6307\u4ee4\u91cd\u6392 \u8ba1\u7b97\u673a\u5728\u6267\u884c\u7a0b\u5e8f\u65f6\uff0c\u4e3a\u4e86\u63d0\u9ad8\u6027\u80fd\uff0c\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u7684\u5e38\u5e38\u4f1a\u5bf9\u6307\u4ee4\u505a\u91cd […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[57],"tags":[59,60],"class_list":["post-519","post","type-post","status-publish","format-standard","hentry","category-java","tag-java","tag-60"],"views":10875,"_links":{"self":[{"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/posts\/519","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/weitaoc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=519"}],"version-history":[{"count":5,"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/posts\/519\/revisions"}],"predecessor-version":[{"id":563,"href":"http:\/\/weitaoc.com\/index.php?rest_route=\/wp\/v2\/posts\/519\/revisions\/563"}],"wp:attachment":[{"href":"http:\/\/weitaoc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=519"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/weitaoc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=519"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/weitaoc.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}