{"id":10129,"date":"2023-11-28T21:27:11","date_gmt":"2023-11-28T13:27:11","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=10129"},"modified":"2023-12-07T10:53:29","modified_gmt":"2023-12-07T02:53:29","slug":"jvm-zhong-nei-cun-ping-zhang-zhi-dao-ma","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/jvm-zhong-nei-cun-ping-zhang-zhi-dao-ma\/","title":{"rendered":"JVM\u4e2d\u5185\u5b58\u5c4f\u969c\u77e5\u9053\u5417\uff1f"},"content":{"rendered":"<p>\u5185\u5b58\u5c4f\u969c\uff08Memory Barrier\uff09\uff0c\u4e5f\u79f0\u4e3a\u5185\u5b58\u6805\u680f\u6216\u5185\u5b58\u6805\u969c\uff0c\u662f\u4e00\u79cd\u540c\u6b65\u673a\u5236\uff0c\u7528\u4e8e\u786e\u4fdd\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u5171\u4eab\u53d8\u91cf\u7684\u53ef\u89c1\u6027\u548c\u6709\u5e8f\u6027\u3002\u5185\u5b58\u5c4f\u969c\u4e3b\u8981\u6709\u4e24\u79cd\u7c7b\u578b\uff1a\u8bfb\u5c4f\u969c\u548c\u5199\u5c4f\u969c\u3002<\/p>\n<h3><a id=\"1%E8%AF%BB%E5%B1%8F%E9%9A%9C%EF%BC%88-read-barrier%EF%BC%89%EF%BC%9A\" class=\"anchor\" aria-hidden=\"true\"><span class=\"octicon octicon-link\"><\/span><\/a>1. \u8bfb\u5c4f\u969c\uff08Read Barrier\uff09\uff1a<\/h3>\n<p>\u8bfb\u5c4f\u969c\u786e\u4fdd\u5728\u8bfb\u53d6\u5171\u4eab\u53d8\u91cf\u4e4b\u524d\uff0c\u5148\u5237\u65b0\u672c\u5730\u7f13\u5b58\uff0c\u4ee5\u83b7\u53d6\u6700\u65b0\u7684\u503c\u3002\u5b83\u4e3b\u8981\u7528\u4e8e\u89e3\u51b3\u53ef\u89c1\u6027\u95ee\u9898\uff0c\u786e\u4fdd\u4e00\u4e2a\u7ebf\u7a0b\u8bfb\u53d6\u5230\u7684\u662f\u5176\u4ed6\u7ebf\u7a0b\u6700\u65b0\u7684\u5199\u5165\u3002<\/p>\n<h3><a id=\"2%E5%86%99%E5%B1%8F%E9%9A%9C%EF%BC%88-write-barrier%EF%BC%89%EF%BC%9A\" class=\"anchor\" aria-hidden=\"true\"><span class=\"octicon octicon-link\"><\/span><\/a>2. \u5199\u5c4f\u969c\uff08Write Barrier\uff09\uff1a<\/h3>\n<p>\u5199\u5c4f\u969c\u7528\u4e8e\u786e\u4fdd\u5728\u5199\u5165\u5171\u4eab\u53d8\u91cf\u4e4b\u540e\uff0c\u5c06\u53d8\u66f4\u540c\u6b65\u5230\u4e3b\u5185\u5b58\uff0c\u4ee5\u4fdd\u8bc1\u5176\u4ed6\u7ebf\u7a0b\u80fd\u591f\u7acb\u5373\u770b\u5230\u8be5\u53d8\u66f4\u3002\u5b83\u4e3b\u8981\u7528\u4e8e\u89e3\u51b3\u53ef\u89c1\u6027\u548c\u6709\u5e8f\u6027\u95ee\u9898\uff0c\u786e\u4fdd\u4e00\u4e2a\u7ebf\u7a0b\u7684\u5199\u5165\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u662f\u53ef\u89c1\u7684\u4e14\u6709\u5e8f\u7684\u3002<\/p>\n<h3><a id=\"%E5%BA%94%E7%94%A8%E5%9C%BA%E6%99%AF%EF%BC%9A\" class=\"anchor\" aria-hidden=\"true\"><span class=\"octicon octicon-link\"><\/span><\/a>\u5e94\u7528\u573a\u666f\uff1a<\/h3>\n<ol>\n<li>\n<strong>\u7981\u6b62\u6307\u4ee4\u91cd\u6392\u5e8f\uff1a<\/strong> \u5185\u5b58\u5c4f\u969c\u53ef\u4ee5\u9632\u6b62\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u5bf9\u6307\u4ee4\u8fdb\u884c\u91cd\u6392\u5e8f\uff0c\u4fdd\u8bc1\u4ee3\u7801\u6267\u884c\u7684\u987a\u5e8f\u7b26\u5408\u9884\u671f\u3002\n<\/li>\n<li>\n<strong>\u4fdd\u8bc1\u53ef\u89c1\u6027\uff1a<\/strong> \u5185\u5b58\u5c4f\u969c\u786e\u4fdd\u5171\u4eab\u53d8\u91cf\u7684\u8bfb\u5199\u64cd\u4f5c\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u662f\u53ef\u89c1\u7684\u3002\n<\/li>\n<li>\n<strong>\u5b9e\u73b0\u540c\u6b65\u63a7\u5236\uff1a<\/strong> \u5185\u5b58\u5c4f\u969c\u5728\u9501\u7684\u5b9e\u73b0\u4e2d\u53d1\u6325\u91cd\u8981\u4f5c\u7528\uff0c\u786e\u4fdd\u7ebf\u7a0b\u5728\u8fdb\u5165\u548c\u9000\u51fa\u540c\u6b65\u5757\u65f6\uff0c\u6b63\u786e\u5730\u83b7\u53d6\u548c\u91ca\u653e\u9501\u3002\n<\/li>\n<\/ol>\n<h3><a id=\"%E4%BE%8B%E5%AD%90%EF%BC%9A\" class=\"anchor\" aria-hidden=\"true\"><span class=\"octicon octicon-link\"><\/span><\/a>\u4f8b\u5b50\uff1a<\/h3>\n<p>\u5728Java\u4e2d\uff0c<code>volatile<\/code> \u5173\u952e\u5b57\u7684\u8bfb\u5199\u64cd\u4f5c\u5c31\u5305\u542b\u4e86\u5185\u5b58\u5c4f\u969c\u7684\u7279\u6027\u3002\u4f7f\u7528 <code>volatile<\/code> \u4fee\u9970\u7684\u53d8\u91cf\uff0c\u5728\u5199\u5165\u65f6\u4f1a\u63d2\u5165\u5199\u5c4f\u969c\uff0c\u786e\u4fdd\u5199\u5165\u7684\u503c\u5bf9\u5176\u4ed6\u7ebf\u7a0b\u662f\u53ef\u89c1\u7684\uff1b\u5728\u8bfb\u53d6\u65f6\u4f1a\u63d2\u5165\u8bfb\u5c4f\u969c\uff0c\u786e\u4fdd\u8bfb\u53d6\u5230\u7684\u662f\u6700\u65b0\u7684\u503c\u3002<\/p>\n<pre><code class=\"language-java\">public class SharedResource {\n    private volatile int sharedValue;\n\n    public void writeSharedValue(int newValue) {\n        sharedValue = newValue; \/\/ \u5199\u64cd\u4f5c\u5305\u542b\u5199\u5c4f\u969c\n    }\n\n    public int readSharedValue() {\n        return sharedValue; \/\/ \u8bfb\u64cd\u4f5c\u5305\u542b\u8bfb\u5c4f\u969c\n    }\n}\n<\/code><\/pre>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5185\u5b58\u5c4f\u969c\u7684\u5177\u4f53\u5b9e\u73b0\u4e0e\u786c\u4ef6\u548c\u64cd\u4f5c\u7cfb\u7edf\u76f8\u5173\uff0c\u4e0d\u540c\u7684\u4f53\u7cfb\u7ed3\u6784\u53ef\u80fd\u6709\u4e0d\u540c\u7684\u5b9e\u73b0\u65b9\u5f0f\u3002\u5728Java\u4e2d\uff0c\u901a\u8fc7<code>java.util.concurrent<\/code>\u5305\u63d0\u4f9b\u7684\u5de5\u5177\u7c7b\uff0c\u5982 <code>java.util.concurrent.locks.LockSupport<\/code>\u3001<code>java.util.concurrent.CountDownLatch<\/code> \u7b49\uff0c\u4ee5\u53ca\u5e76\u53d1\u6846\u67b6\u7684\u5185\u90e8\u5b9e\u73b0\uff0c\u4e5f\u6d89\u53ca\u4e86\u5185\u5b58\u5c4f\u969c\u7684\u4f7f\u7528\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5185\u5b58\u5c4f\u969c\uff08Memory Barrier\uff09\uff0c\u4e5f\u79f0\u4e3a\u5185\u5b58\u6805\u680f\u6216\u5185\u5b58\u6805\u969c\uff0c\u662f\u4e00\u79cd\u540c\u6b65\u673a\u5236\uff0c\u7528\u4e8e\u786e\u4fdd\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u5171\u4eab [&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-10129","post","type-post","status-publish","format-standard","hentry","category-jvm"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10129","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=10129"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10129\/revisions"}],"predecessor-version":[{"id":16804,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10129\/revisions\/16804"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=10129"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=10129"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=10129"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}