\u53ef\u89c1\u6027\u662f\u4e00\u79cd\u590d\u6742\u7684\u5c5e\u6027\uff0c\u56e0\u4e3a\u53ef\u89c1\u6027\u4e2d\u7684\u9519\u8bef\u603b\u662f\u4f1a\u8fdd\u80cc\u6211\u4eec\u7684\u76f4\u89c9\u3002\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e2d\uff0c\u5982\u679c\u5411\u67d0\u4e2a\u53d8\u91cf\u5148\u5199\u5165\u503c\uff0c\u7136\u540e\u5728\u6ca1\u6709\u5176\u4ed6\u5199\u5165\u64cd\u4f5c\u7684\u60c5\u51b5\u4e0b\u8bfb\u53d6\u8fd9\u4e2a\u53d8\u91cf\uff0c\u90a3\u4e48\u603b\u80fd\u5f97\u5230\u76f8\u540c\u7684\u503c\u3002\u8fd9\u770b\u8d77\u6765\u5f88\u81ea\u7136\u3002\u7136\u800c\uff0c\u5f53\u8bfb\u64cd\u4f5c\u548c\u5199\u64cd\u4f5c\u5728\u4e0d\u540c\u7684\u7ebf\u7a0b\u4e2d\u6267\u884c\u65f6\uff0c\u60c5\u51b5\u5374\u5e76\u975e\u5982\u6b64\uff0c\u8fd9\u542c\u8d77\u6765\u6216\u8bb8\u6709\u4e9b\u96be\u4ee5\u63a5\u53d7\u3002\u901a\u5e38\uff0c\u6211\u4eec\u65e0\u6cd5\u786e\u4fdd\u6267\u884c\u8bfb\u64cd\u4f5c\u7684\u7ebf\u7a0b\u80fd\u9002\u65f6\u5730\u770b\u5230\u5176\u4ed6\u7ebf\u7a0b\u5199\u5165\u7684\u503c\uff0c\u6709\u65f6\u751a\u81f3\u662f\u6839\u672c\u4e0d\u53ef\u80fd\u7684\u4e8b\u60c5\u3002\u4e3a\u4e86\u786e\u4fdd\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u5bf9\u5185\u5b58\u5199\u5165\u64cd\u4f5c\u7684\u53ef\u89c1\u6027\uff0c\u5fc5\u987b\u4f7f\u7528\u540c\u6b65\u673a\u5236\u3002<\/p>\n
public class NoVisibility {\n private static boolean ready;\n private static int number;\n\n private static class ReaderThread extends Thread {\n public void run() {\n while (!ready)\n Thread.yield();\n System.out.println(number);\n }\n }\n\n public static void main(String[] args) {\n new ReaderThread().start();\n number = 80;\n ready = true;\n }\n}<\/code><\/pre>\nNoVisibility\u53ef\u80fd\u4f1a\u6301\u7eed\u5faa\u73af\u4e0b\u53bb\uff0c\u56e0\u4e3a\u8bfb\u7ebf\u7a0b\u53ef\u80fd\u6c38\u8fdc\u90fd\u770b\u4e0d\u5230ready\u7684\u503c\u3002\u4e00\u79cd\u66f4\u5947\u602a\u7684\u73b0\u8c61\u662f\uff0cNovisibility\u53ef\u80fd\u4f1a\u8f93\u51fa0\uff0c\u56e0\u4e3a\u8bfb\u7ebf\u7a0b\u53ef\u80fd\u770b\u5230\u4e86\u5199\u5165ready\u7684\u503c\uff0c\u4f46\u5374\u6ca1\u6709\u770b\u5230\u4e4b\u540e\u5199\u5165number\u7684\u503c\uff0c\u8fd9\u79cd\u73b0\u8c61\u88ab\u79f0\u4e3a\u201c\u91cd\u6392\u5e8f\uff08Reordering\uff09\u201d\u3002\u53ea\u8981\u5728\u67d0\u4e2a\u7ebf\u7a0b\u4e2d\u65e0\u6cd5\u68c0\u6d4b\u5230\u91cd\u6392\u5e8f\u60c5\u51b5\uff08\u5373\u4f7f\u5728\u5176\u4ed6\u7ebf\u7a0b\u4e2d\u53ef\u4ee5\u5f88\u660e\u663e\u5730\u770b\u5230\u8be5\u7ebf\u7a0b\u4e2d\u7684\u91cd\u6392\u5e8f\uff09\uff0c\u90a3\u4e48\u5c31\u65e0\u6cd5\u786e\u4fdd\u7ebf\u7a0b\u4e2d\u7684\u64cd\u4f5c\u5c06\u6309\u7167\u7a0b\u5e8f\u4e2d\u6307\u5b9a\u7684\u987a\u5e8f\u6765\u6267\u884c\u3002\u5f53\u4e3b\u7ebf\u7a0b\u9996\u5148\u5199\u5165number\uff0c\u7136\u540e\u5728\u6ca1\u6709\u540c\u6b65\u7684\u60c5\u51b5\u4e0b\u5199\u5165ready\uff0c\u90a3\u4e48\u8bfb\u7ebf\u7a0b\u770b\u5230\u7684\u987a\u5e8f\u53ef\u80fd\u4e0e\u5199\u5165\u7684\u987a\u5e8f\u5b8c\u5168\u76f8\u53cd\u3002
\n\u5728\u6ca1\u6709\u540c\u6b65\u7684\u60c5\u51b5\u4e0b\uff0c\u7f16\u8bd1\u5668\u3001\u5904\u7406\u5668\u4ee5\u53ca\u8fd0\u884c\u65f6\u7b49\u90fd\u53ef\u80fd\u5bf9\u64cd\u4f5c\u7684\u6267\u884c\u987a\u5e8f\u8fdb\u884c\u4e00\u4e9b\u610f\u60f3\u4e0d\u5230\u7684\u8c03\u6574\u3002\u5728\u7f3a\u4e4f\u8db3\u591f\u540c\u6b65\u7684\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u4e2d\uff0c\u8981\u76f8\u5bf9\u5185\u5b58\u64cd\u4f5c\u7684\u6267\u884c\u987a\u5e8f\u8fdb\u884c\u5224\u65ad\uff0c\u51e0\u4e4e\u65e0\u6cd5\u5f97\u51fa\u6b63\u786e\u7684\u7ed3\u8bba\u3002<\/p>\n
\u8fd9\u770b\u4e0a\u53bb\u4f3c\u4e4e\u662f\u4e00\u79cd\u5931\u8d25\u7684\u8bbe\u8ba1\uff0c\u4f46\u5374\u80fd\u4f7fJVM\u5145\u5206\u5730\u5229\u7528\u73b0\u4ee3\u591a\u6838\u5904\u7406\u5668\u7684\u5f3a\u5927\u6027\u80fd\u3002\u4f8b\u5982\uff0c\u5728\u7f3a\u5c11\u540c\u6b65\u7684\u60c5\u51b5\u4e0b\uff0cJava\u5185\u5b58\u6a21\u578b\u5141\u8bb8\u7f16\u8bd1\u5668\u5bf9\u64cd\u4f5c\u987a\u5e8f\u8fdb\u884c\u91cd\u6392\u5e8f\uff0c\u5e76\u5c06\u6570\u503c\u7f13\u5b58\u5728\u5bc4\u5b58\u5668\u4e2d\u3002\u6b64\u5916\uff0c\u5b83\u8fd8\u5141\u8bb8CPU\u5bf9\u64cd\u4f5c\u987a\u5e8f\u8fdb\u884c\u91cd\u6392\u5e8f\uff0c\u5e76\u5c06\u6570\u503c\u7f13\u5b58\u5728\u5904\u7406\u5668\u7279\u5b9a\u7684\u7f13\u5b58\u4e2d\u3002<\/p>\n
Volatile\u53d8\u91cf<\/h2>\n
Java\u8bed\u8a00\u63d0\u4f9b\u4e86\u4e00\u79cd\u7a0d\u5f31\u7684\u540c\u6b65\u673a\u5236\uff0c\u5373volatile\u53d8\u91cf\uff0c\u7528\u6765\u786e\u4fdd\u5c06\u53d8\u91cf\u7684\u66f4\u65b0\u64cd\u4f5c\u901a\u77e5\u5230\u5176\u4ed6\u7ebf\u7a0b\u3002\u5f53\u628a\u53d8\u91cf\u58f0\u660e\u4e3avolatile\u7c7b\u578b\u540e\uff0c\u7f16\u8bd1\u5668\u4e0e\u8fd0\u884c\u65f6\u90fd\u4f1a\u6ce8\u610f\u5230\u8fd9\u4e2a\u53d8\u91cf\u662f\u5171\u4eab\u7684\uff0c\u56e0\u6b64\u4e0d\u4f1a\u5c06\u8be5\u53d8\u91cf\u4e0a\u7684\u64cd\u4f5c\u548c\u5176\u4ed6\u5185\u5b58\u64cd\u4f5c\u4e00\u8d77\u91cd\u6392\u5e8f\u3002volatile\u53d8\u91cf\u4e0d\u4f1a\u88ab\u7f13\u5b58\u5728\u5bc4\u5b58\u5668\u6216\u8005\u5bf9\u5176\u4ed6\u5904\u7406\u5668\u4e0d\u53ef\u89c1\u7684\u5730\u65b9\uff0c\u56e0\u6b64\u5728\u8bfb\u53d6volatile\u7c7b\u578b\u7684\u53d8\u91cf\u65f6\u603b\u4f1a\u8fd4\u56de\u6700\u65b0\u5199\u5165\u7684\u503c\u3002<\/p>\n
volatile\u4e0e\u52a0\u9501\u673a\u5236\u7684\u533a\u522b\uff1a<\/h3>\n
\u52a0\u9501\u673a\u5236\u65e2\u53ef\u4ee5\u786e\u4fdd\u53ef\u89c1\u6027\u53c8\u53ef\u4ee5\u786e\u4fdd\u539f\u5b50\u6027\uff0c\u800cvolatile\u53d8\u91cf\u53ea\u80fd\u786e\u4fdd\u53ef\u89c1\u6027\u3002<\/p>\n
\u5f53\u4e14\u4ec5\u5f53\u6ee1\u8db3\u4ee5\u4e0b\u6240\u6709\u6761\u4ef6\u65f6\uff0c\u624d\u5e94\u8be5\u4f7f\u7528volatile\u53d8\u91cf\uff1a<\/p>\n
\n- \u5bf9\u53d8\u91cf\u7684\u5199\u5165\u64cd\u4f5c\u4e0d\u4f9d\u8d56\u53d8\u91cf\u7684\u5f53\u524d\u503c\uff0c\u6216\u8005\u4f60\u80fd\u786e\u4fdd\u53ea\u6709\u5355\u4e2a\u7ebf\u7a0b\u66f4\u65b0\u53d8\u91cf\u7684\u503c<\/li>\n
- \u8be5\u53d8\u91cf\u4e0d\u4f1a\u4e0e\u5176\u4ed6\u72b6\u6001\u53d8\u91cf\u4e00\u8d77\u7eb3\u5165\u4e0d\u53d8\u6027\u6761\u4ef6\u4e2d<\/li>\n
- \u5728\u8bbf\u95ee\u53d8\u91cf\u65f6\u4e0d\u9700\u8981\u52a0\u9501<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
\u5185\u5b58\u53ef\u89c1\u6027 \u53ef\u89c1\u6027\u662f\u4e00\u79cd\u590d\u6742\u7684\u5c5e\u6027\uff0c\u56e0\u4e3a\u53ef\u89c1\u6027\u4e2d\u7684\u9519\u8bef\u603b\u662f\u4f1a\u8fdd\u80cc\u6211\u4eec\u7684\u76f4\u89c9\u3002\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e2d\uff0c\u5982\u679c\u5411\u67d0\u4e2a\u53d8\u91cf\u5148\u5199 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[50],"class_list":["post-76","post","type-post","status-publish","format-standard","hentry","category-java-basic","tag-volatile"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/76","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=76"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/76\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=76"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=76"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=76"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}