{"id":4003,"date":"2024-05-10T08:20:43","date_gmt":"2024-05-10T00:20:43","guid":{"rendered":"https:\/\/xinchewhd.com.cn\/index.php\/%e9%9d%a2%e8%af%95\/%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e8%b0%88%e8%b0%88%e4%bd%a0%e5%af%b9%e5%86%85%e5%ad%98%e6%a8%a1%e5%9e%8b%ef%bc%88jmm%ef%bc%89%e7%90%86%e8%a7%a3%ef%bc%9f\/"},"modified":"2024-05-10T08:20:43","modified_gmt":"2024-05-10T00:20:43","slug":"%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e8%b0%88%e8%b0%88%e4%bd%a0%e5%af%b9%e5%86%85%e5%ad%98%e6%a8%a1%e5%9e%8b%ef%bc%88jmm%ef%bc%89%e7%90%86%e8%a7%a3%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/xinchewhd.com.cn\/index.php\/%e9%9d%a2%e8%af%95\/%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e8%b0%88%e8%b0%88%e4%bd%a0%e5%af%b9%e5%86%85%e5%ad%98%e6%a8%a1%e5%9e%8b%ef%bc%88jmm%ef%bc%89%e7%90%86%e8%a7%a3%ef%bc%9f\/","title":{"rendered":"\u9762\u8bd5\u5b98\uff1a\u8c08\u8c08\u4f60\u5bf9\u5185\u5b58\u6a21\u578b\uff08JMM\uff09\u7406\u89e3\uff1f"},"content":{"rendered":"
\n

Java \u5185\u5b58\u6a21\u578b\uff08JMM\uff09\u662f\u4e00\u4e2a\u62bd\u8c61\u6982\u5ff5<\/strong>\uff0c\u5b83\u89c4\u5b9a\u4e86\u5728Java\u5e76\u53d1\u7f16\u7a0b\u4e2d\u5982\u4f55\u5904\u7406\u591a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u5185\u5b58\u4ea4\u4e92\u3002JMM \u89e3\u51b3\u5e76\u53d1\u7a0b\u5e8f\u4e2d\u6700\u5173\u952e\u7684\u4e24\u4e2a\u95ee\u9898\uff1a\u7ebf\u7a0b\u95f4\u7684\u53ef\u89c1\u6027<\/strong>\u548c\u6307\u4ee4\u91cd\u6392\u5e8f<\/strong>\u3002<\/span><\/p>\n

\u7ebf\u7a0b\u95f4\u7684\u53ef\u89c1\u6027<\/span><\/strong>\uff1a\u786e\u4fdd\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u4fee\u6539\u4e86\u5171\u4eab\u53d8\u91cf\u7684\u503c\u65f6\uff0c\u5176\u4ed6\u7ebf\u7a0b\u53ef\u4ee5\u7acb\u5373\u770b\u5230\u8fd9\u4e00\u6539\u53d8\u3002\u6ca1\u6709\u826f\u597d\u7684\u53ef\u89c1\u6027\u4fdd\u8bc1\uff0c\u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u53d8\u91cf\u7684\u4fee\u6539\u53ef\u80fd\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u4e0d\u53ef\u89c1\uff0c\u5bfc\u81f4\u6570\u636e\u4e0d\u4e00\u81f4\u3002<\/span><\/span><\/p>\n

\u6307\u4ee4\u91cd\u6392\u5e8f<\/span><\/strong>\uff1a\u4e3a\u4e86\u63d0\u9ad8\u6027\u80fd\uff0c\u7f16\u8bd1\u5668<\/strong>\u548c<\/span>\u5904\u7406\u5668<\/strong>\u5e38\u5e38\u4f1a\u6539\u53d8\u6307\u4ee4\u7684\u6267\u884c\u987a\u5e8f\uff08\u53ea\u8981\u8fd9\u79cd\u6539\u53d8\u4e0d\u5f71\u54cd\u5355\u7ebf\u7a0b\u5185\u7684\u7a0b\u5e8f\u903b\u8f91\uff09\u3002\u7136\u800c\uff0c\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\uff0c\u8fd9\u79cd\u91cd\u6392\u5e8f\u53ef\u80fd\u5bfc\u81f4\u4e25\u91cd\u95ee\u9898\u3002<\/span><\/span><\/p>\n

JMM \u901a\u8fc7\u4ee5\u4e0b\u51e0\u79cd\u65b9\u5f0f\u6765\u63a7\u5236\u548c\u534f\u8c03\u4e0a\u8ff0\u73b0\u8c61\uff1a<\/span><\/p>\n

    \n
  1. \n

    \u539f\u5b50\u6027(Atomicity)<\/span><\/strong>: JMM \u4fdd\u8bc1\u4e86\u57fa\u672c\u8bfb\u53d6\u548c\u5199\u5165\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u3002\u4f8b\u5982\uff0c\u5bf9\u4e8e\u58f0\u660e\u4e3a volatile \u7684\u53d8\u91cf\uff0c\u5176\u8bfb\u548c\u5199\u64cd\u4f5c\u90fd\u662f\u539f\u5b50\u7684\u3002<\/span><\/span><\/p>\n<\/li>\n

  2. \n
    \u53ef\u89c1\u6027(Visibility):<\/span><\/strong> \u4e3a\u4e86\u786e\u4fdd\u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u5171\u4eab\u53d8\u91cf\u6240\u505a\u7684\u4fee\u6539\u53ef\u4ee5\u88ab\u5176\u4ed6\u7ebf\u7a0b\u770b\u5230\uff0cJMM \u5f15\u5165\u4e86 volatile \u5173\u952e\u5b57\u548c\u9501\uff08synchronization\uff09\u3002\u5f53\u4e00\u4e2a\u53d8\u91cf\u88ab\u58f0\u660e\u4e3a volatile \u540e\uff0c\u5bf9\u8fd9\u4e2a\u53d8\u91cf\u7684\u4fee\u6539\u7acb\u5373\u4f1a\u5237\u65b0\u5230\u4e3b\u5185\u5b58\uff0c\u5176\u4ed6\u7ebf\u7a0b\u8bfb\u8fd9\u4e2a\u53d8\u91cf\u4e5f\u4f1a\u76f4\u63a5\u4ece\u4e3b\u5185\u5b58\u8bfb\u53d6\u3002<\/span><\/span><\/section>\n<\/li>\n
  3. \n

    \u6709\u5e8f\u6027(Ordering)<\/span><\/strong>: \u5373\u4fbf\u662f\u5728\u65e0\u4f9d\u8d56\u7684\u64cd\u4f5c\u4e2d\uff0cJMM \u4e5f\u7981\u6b62\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u8fdb\u884c\u91cd\u6392\u5e8f\u3002\u901a\u8fc7 synchronized \u548c volatile \u5173\u952e\u5b57\uff0c\u4ee5\u53ca final \u5b57\u6bb5\uff0cJMM \u53ef\u4ee5\u5728\u7279\u5b9a\u6761\u4ef6\u4e0b\u907f\u514d\u6307\u4ee4\u91cd\u6392\u5e8f\u3002<\/span><\/span><\/p>\n<\/li>\n<\/ol>\n

    happens-before \u539f\u5219:<\/span><\/strong><\/span><\/section>\n

    Happens-Before\u89c4\u5219\u662fJava\u5185\u5b58\u6a21\u578b\uff08JMM\uff09\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u6982\u5ff5\uff0c\u7528\u4e8e\u63cf\u8ff0\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u64cd\u4f5c\u4e4b\u95f4\u7684\u987a\u5e8f\u548c\u53ef\u89c1\u6027\u3002\u5982\u679c\u64cd\u4f5cA happens-before\u64cd\u4f5cB\uff0c\u90a3\u4e48JMM\u4fdd\u8bc1A\u7684\u7ed3\u679c\u5bf9B\u53ef\u89c1\uff0c\u5e76\u4e14A\u7684\u64cd\u4f5c\u987a\u5e8f\u5728B\u4e4b\u524d\u3002\u8fd9\u4e2a\u89c4\u5219\u63d0\u4f9b\u4e86\u4e00\u79cd\u8de8\u7ebf\u7a0b\u5185\u5b58\u64cd\u4f5c\u7684\u53ef\u9884\u6d4b\u6027\uff0c\u5e2e\u52a9\u7a0b\u5e8f\u5458\u7f16\u5199\u6b63\u786e\u7684\u5e76\u53d1\u4ee3\u7801\u3002\u4e00\u4e9b\u5173\u952e\u7684happens-before\u89c4\u5219\u5305\u62ec\uff1a<\/span><\/p>\n

      \n
    1. \n

      \u7a0b\u5e8f\u987a\u5e8f\u89c4\u5219<\/strong>\uff1a\u5728\u4e00\u4e2a\u7ebf\u7a0b\u5185\uff0c\u6bcf\u4e2a\u64cd\u4f5c\u90fdhappens-before\u4e8e\u8be5\u7ebf\u7a0b\u4e2d\u7684\u4efb\u610f\u540e\u7eed\u64cd\u4f5c\u3002<\/span><\/p>\n<\/li>\n

    2. \n
      \u76d1\u89c6\u5668\u9501\u89c4\u5219<\/strong>\uff1a\u5bf9\u4e00\u4e2a\u9501\u7684\u89e3\u9501happens-before\u4e8e\u968f\u540e\u5bf9\u8fd9\u4e2a\u9501\u7684\u52a0\u9501\u3002<\/span><\/section>\n<\/li>\n
    3. \n
      volatile\u53d8\u91cf\u89c4\u5219<\/strong>\uff1a\u5bf9\u4e00\u4e2avolatile\u5b57\u6bb5\u7684\u5199\u5165happens-before\u4e8e\u4efb\u4f55\u540e\u7eed\u5bf9\u8fd9\u4e2avolatile\u5b57\u6bb5\u7684\u8bfb\u53d6\u3002<\/span><\/section>\n<\/li>\n
    4. \n
      \u7ebf\u7a0b\u542f\u52a8\u89c4\u5219<\/strong>\uff1aThread\u5bf9\u8c61\u7684start()\u65b9\u6cd5happens-before\u4e8e\u6b64\u7ebf\u7a0b\u7684\u6bcf\u4e00\u4e2a\u52a8\u4f5c\u3002<\/span><\/section>\n<\/li>\n
    5. \n
      \u7ebf\u7a0b\u7ec8\u7ed3\u89c4\u5219<\/span><\/strong>\uff1a\u7ebf\u7a0b\u4e2d\u7684\u6240\u6709\u64cd\u4f5c\u90fdhappens-before\u4e8e\u5bf9\u6b64\u7ebf\u7a0b\u7684\u7ec8\u7ed3\u68c0\u6d4b\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7Thread.join()\u65b9\u6cd5\u7ed3\u675f\u3001Thread.isAlive()\u7684\u8fd4\u56de\u503c\u7b49\u624b\u6bb5\u8fdb\u884c\u68c0\u6d4b\u3002<\/span><\/span><\/section>\n<\/li>\n
    6. \n
      \u4e2d\u65ad\u89c4\u5219<\/strong>\uff1a\u5bf9\u7ebf\u7a0binterrupt()\u7684\u8c03\u7528happens-before\u4e8e\u88ab\u4e2d\u65ad\u7ebf\u7a0b\u68c0\u6d4b\u5230\u4e2d\u65ad\u4e8b\u4ef6\u7684\u53d1\u751f\u3002<\/span><\/section>\n<\/li>\n
    7. \n
      \u4f20\u9012\u6027<\/strong>\uff1a\u5982\u679cA happens-before B\uff0c\u4e14B happens-before C\uff0c\u90a3\u4e48A happens-before C\u3002<\/span><\/section>\n<\/li>\n<\/ol>\n
      \u603b\u7ed3<\/span><\/strong>\uff1a\u7531\u4e8e Java \u5e76\u53d1\u7f16\u7a0b\u590d\u6742\u6027\u5f88\u9ad8\uff0cJMM \u63d0\u4f9b\u4e86\u4e00\u5957\u89c4\u5219\u8ba9\u5f00\u53d1\u8005\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u7f16\u5199\u51fa\u80fd\u591f\u6b63\u786e\u4ea4\u4e92\u7684\u4ee3\u7801\u3002\u5c3d\u7ba1 JMM \u4e0d\u76f4\u63a5\u6d89\u53ca\u5783\u573e\u6536\u96c6\u548c\u5176\u4ed6\u5185\u5b58\u7ba1\u7406\u65b9\u9762\uff0c\u4e86\u89e3 JMM \u5bf9\u4e8e\u7406\u89e3\u5185\u5b58\u64cd\u4f5c\u7684\u5e76\u53d1\u95ee\u9898\u975e\u5e38\u5173\u952e\u3002<\/span><\/span><\/section>\n

      <\/mp-style-type><\/p>\n

      \n

      \u672c\u7bc7\u6587\u7ae0\u6765\u6e90\u4e8e\u5fae\u4fe1\u516c\u4f17\u53f7: \u4e92\u8054\u7f51\u9762\u8bd5\u5c0f\u5e2e\u624b <\/p>\n<\/blockquote>\n<\/div>\n","raw":"","protected":false},"excerpt":{"rendered":"

      Java \u5185\u5b58\u6a21\u578b\uff08JMM\uff09\u662f\u4e00\u4e2a\u62bd\u8c61\u6982\u5ff5\uff0c\u5b83\u89c4\u5b9a\u4e86\u5728Java\u5e76\u53d1\u7f16\u7a0b\u4e2d\u5982\u4f55\u5904\u7406\u591a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u5185\u5b58\u4ea4\u4e92\u3002JMM \u89e3\u51b3\u5e76\u53d1\u7a0b\u5e8f\u4e2d\u6700\u5173\u952e …<\/p>\n","protected":false},"author":1,"featured_media":4000,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[30],"tags":[],"class_list":["post-4003","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-30"],"post_thumbnail_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801-150x150.jpeg","content_first_image":null,"post_medium_image_300":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801-300x127.jpeg","post_thumbnail_image_624":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801.jpeg","post_frist_image":null,"post_medium_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801-300x127.jpeg","post_large_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801.jpeg","post_full_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144422801.jpeg","post_all_images":[],"videoAdId":"","listAd":"0","listAdId":"","listAdEvery":6,"total_comments":0,"category_name":"\u9762\u8bd5","post_date":"2024-05-10","like_count":"0","praiseWord":"\u9f13\u52b1","copyright_state":"","excitationAd":"0","rewardedVideoAdId":"","detailAdId":"","detailAd":"0","enterpriseMinapp":"0","audios":[],"postImageUrl":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230519082947553.jpg","avatarurls":[],"related_posts":null,"pageviews":320,"next_post_id":3999,"next_post_title":"\u9762\u8bd5\u5b98\uff1aJava \u4e2d\u7684\u6cdb\u578b\u662f\u5982\u4f55\u5de5\u4f5c\u7684\uff1f\u7c7b\u578b\u64e6\u9664\uff08Type Erasure\uff09\u662f\u4ec0\u4e48\uff1f","previous_post_id":4702,"previous_post_title":"\u9762\u8bd5\u5b98\uff1aSpring \u4e3a\u4ec0\u4e48\u4e0d\u652f\u6301 static \u5b57\u6bb5\u7684\u6ce8\u5165\uff1f","_links":{"self":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/4003","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/comments?post=4003"}],"version-history":[{"count":0,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/4003\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media\/4000"}],"wp:attachment":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media?parent=4003"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/categories?post=4003"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/tags?post=4003"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}