{"id":10579,"date":"2023-11-28T21:38:50","date_gmt":"2023-11-28T13:38:50","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=10579"},"modified":"2023-12-07T14:28:13","modified_gmt":"2023-12-07T06:28:13","slug":"jvm-zhong-shen-me-shihappenbefore-yuan-ze","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/jvm-zhong-shen-me-shihappenbefore-yuan-ze\/","title":{"rendered":"JVM\u4e2d\u4ec0\u4e48\u662fhappen-before\u539f\u5219\uff1f"},"content":{"rendered":"<p>&quot;Happen-Before&quot; \u662f Java \u5185\u5b58\u6a21\u578b\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u539f\u5219\uff0c\u7528\u4e8e\u5b9a\u4e49\u64cd\u4f5c\u4e4b\u95f4\u7684\u53ef\u89c1\u6027\u548c\u987a\u5e8f\u6027\u5173\u7cfb\u3002\u5b83\u6307\u5bfc\u4e86\u7a0b\u5e8f\u4e2d\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u64cd\u4f5c\u5728\u65f6\u95f4\u4e0a\u7684\u53d1\u751f\u987a\u5e8f\uff0c\u4ee5\u786e\u4fdd\u5728\u4e0d\u540c\u7ebf\u7a0b\u4e2d\u5bf9\u5171\u4eab\u53d8\u91cf\u7684\u8bfb\u5199\u64cd\u4f5c\u80fd\u591f\u6b63\u786e\u5730\u8fdb\u884c\u540c\u6b65\u3002<\/p>\n<p>\u5177\u4f53\u6765\u8bf4\uff0cHappen-Before \u539f\u5219\u5305\u542b\u4ee5\u4e0b\u51e0\u4e2a\u89c4\u5219\uff1a<\/p>\n<ol>\n<li>\n<strong>\u7a0b\u5e8f\u987a\u5e8f\u89c4\u5219\uff08Program Order Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5728\u4e00\u4e2a\u7ebf\u7a0b\u4e2d\uff0c\u6bcf\u4e2a\u64cd\u4f5c\u90fd\u6309\u7167\u7a0b\u5e8f\u4e2d\u7684\u5148\u540e\u987a\u5e8f\u6267\u884c\u3002\u5373\u5728\u4ee3\u7801\u4e2d\u51fa\u73b0\u7684\u5148\u884c\u64cd\u4f5c\uff08program order\uff09\u5bf9\u4e8e\u8be5\u7ebf\u7a0b\u662f\u6709\u5e8f\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u9501\u5b9a\u89c4\u5219\uff08Lock Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5bf9\u4e8e\u4e00\u4e2a\u9501\u7684\u89e3\u9501\u64cd\u4f5c\uff0c\u5fc5\u987b\u5148\u884c\u53d1\u751f\u4e8e\u540e\u7eed\u5bf9\u540c\u4e00\u4e2a\u9501\u7684\u52a0\u9501\u64cd\u4f5c\u3002\u8fd9\u786e\u4fdd\u4e86\u5bf9\u9501\u7684\u89e3\u9501\u64cd\u4f5c\u5bf9\u4e8e\u968f\u540e\u5bf9\u540c\u4e00\u9501\u7684\u52a0\u9501\u64cd\u4f5c\u662f\u53ef\u89c1\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>volatile\u53d8\u91cf\u89c4\u5219\uff08Volatile Variable Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5bf9\u4e00\u4e2a volatile \u53d8\u91cf\u7684\u5199\u64cd\u4f5c\u5148\u884c\u53d1\u751f\u4e8e\u540e\u7eed\u5bf9\u8fd9\u4e2a\u53d8\u91cf\u7684\u8bfb\u64cd\u4f5c\u3002\u8fd9\u786e\u4fdd\u4e86\u5bf9 volatile \u53d8\u91cf\u7684\u8bfb\u5199\u64cd\u4f5c\u662f\u6709\u5e8f\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u7ebf\u7a0b\u542f\u52a8\u89c4\u5219\uff08Thread Start Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u4e00\u4e2a\u7ebf\u7a0b\u7684\u542f\u52a8\u64cd\u4f5c\u5148\u884c\u53d1\u751f\u4e8e\u8be5\u7ebf\u7a0b\u7684\u6bcf\u4e2a\u64cd\u4f5c\u3002\u5373\u5728\u4e00\u4e2a\u7ebf\u7a0b\u5185\u90e8\uff0c\u7ebf\u7a0b\u7684\u542f\u52a8\u64cd\u4f5c\u5bf9\u4e8e\u7ebf\u7a0b\u5185\u7684\u6240\u6709\u5176\u4ed6\u64cd\u4f5c\u662f\u6709\u5e8f\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u7ebf\u7a0b\u7ec8\u6b62\u89c4\u5219\uff08Thread Termination Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u4e00\u4e2a\u7ebf\u7a0b\u7684\u6240\u6709\u64cd\u4f5c\u5148\u884c\u53d1\u751f\u4e8e\u5bf9\u8be5\u7ebf\u7a0b\u7684\u7ec8\u6b62\u68c0\u6d4b\u3002\u8fd9\u786e\u4fdd\u4e86\u5728\u5176\u4ed6\u7ebf\u7a0b\u4e2d\u68c0\u6d4b\u5230\u7ebf\u7a0b\u7ec8\u6b62\u65f6\uff0c\u80fd\u591f\u770b\u5230\u7ebf\u7a0b\u5185\u7684\u6240\u6709\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u7ebf\u7a0b\u4e2d\u65ad\u89c4\u5219\uff08Thread Interruption Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5bf9\u7ebf\u7a0b interrupt \u7684\u8c03\u7528\u5148\u884c\u53d1\u751f\u4e8e\u88ab\u4e2d\u65ad\u7ebf\u7a0b\u68c0\u6d4b\u5230\u4e2d\u65ad\u4e8b\u4ef6\u7684\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u5bf9\u8c61\u7ec8\u7ed3\u89c4\u5219\uff08Finalizer Rule\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u7684\u7ed3\u675f\u5148\u884c\u53d1\u751f\u4e8e finalize \u65b9\u6cd5\u7684\u5f00\u59cb\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u4f20\u9012\u6027\uff08Transitivity\uff09\uff1a<\/strong><\/p>\n<ul>\n<li>\u5982\u679c\u64cd\u4f5c A \u5148\u884c\u53d1\u751f\u4e8e\u64cd\u4f5c B\uff0c\u4e14\u64cd\u4f5c B \u5148\u884c\u53d1\u751f\u4e8e\u64cd\u4f5c C\uff0c\u90a3\u4e48\u64cd\u4f5c A \u5148\u884c\u53d1\u751f\u4e8e\u64cd\u4f5c C\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p>Happen-Before \u539f\u5219\u4e3a\u7a0b\u5e8f\u5458\u63d0\u4f9b\u4e86\u4e00\u79cd\u7406\u89e3\u591a\u7ebf\u7a0b\u64cd\u4f5c\u7684\u6846\u67b6\uff0c\u5e2e\u52a9\u786e\u4fdd\u7a0b\u5e8f\u7684\u6b63\u786e\u6027\u548c\u53ef\u9884\u6d4b\u6027\u3002\u901a\u8fc7\u9075\u5faa Happen-Before \u539f\u5219\uff0c\u53ef\u4ee5\u907f\u514d\u4e00\u4e9b\u5178\u578b\u7684\u591a\u7ebf\u7a0b\u7f16\u7a0b\u95ee\u9898\uff0c\u5982\u6570\u636e\u7ade\u4e89\u548c\u5185\u5b58\u4e0d\u4e00\u81f4\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&quot;Happen-Before&quot; \u662f Java \u5185\u5b58\u6a21\u578b\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u539f\u5219\uff0c\u7528\u4e8e\u5b9a\u4e49\u64cd\u4f5c\u4e4b\u95f4\u7684 [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[119],"tags":[],"class_list":["post-10579","post","type-post","status-publish","format-standard","hentry","category-jvm"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10579","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=10579"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10579\/revisions"}],"predecessor-version":[{"id":16863,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10579\/revisions\/16863"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=10579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=10579"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=10579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}