{"id":249,"date":"2022-10-09T00:15:38","date_gmt":"2022-10-08T16:15:38","guid":{"rendered":"https:\/\/cococat.top\/?p=249"},"modified":"2022-10-09T00:15:38","modified_gmt":"2022-10-08T16:15:38","slug":"cpp_atomic_and_memory_order","status":"publish","type":"post","link":"https:\/\/cococat.top\/index.php\/2022\/10\/09\/cpp_atomic_and_memory_order\/","title":{"rendered":"\u3010\u65bd\u5de5\u4e2d\u3011C++\u539f\u5b50\u53d8\u91cf\u4e0e\u5185\u5b58\u5e8f\uff1a\u65e0\u9501\u7f16\u7a0b\u7684\u539f\u7406"},"content":{"rendered":"<h1>1. \u95ee\u9898\u7684\u5f15\u5165<\/h1>\n<h2>1.1. \u591a\u7ebf\u7a0b\u5e26\u6765\u7684\u4e09\u4e2a\u95ee\u9898<\/h2>\n<p>\u5728\u591a\u7ebf\u7a0b\u7f16\u7a0b\u4e0b\uff0c\u7a0b\u5e8f\u7684\u8fd0\u884c\u7ed3\u679c\u53ef\u80fd\u5e76\u4e0d\u5982\u6211\u4eec\u6240\u9884\u6599\u7684\u4e00\u81f4\u3002\u8fd9\u4e3b\u8981\u662f\u7531\u4ee5\u4e0b\u4e09\u79cd\u539f\u56e0\u5bfc\u81f4\u7684\uff1a<\/p>\n<h3>1.1.1. \u975e\u539f\u5b50\u64cd\u4f5c<\/h3>\n<p>\u539f\u5b50\u64cd\u4f5c(atomic operation)\u6307\u4e0d\u4f1a\u88ab\u7ebf\u7a0b\u8c03\u5ea6\u673a\u5236\u4e2d\u65ad\u7684\u4e00\u4e2a\u6216\u4e00\u7cfb\u5217\u64cd\u4f5c\u3002\u4ece\u6c47\u7f16\u7684\u89d2\u5ea6\u53bb\u601d\u8003\uff0c\u6211\u4eec\u4f1a\u53d1\u73b0C\/C++\u4e2d\u6709\u4e0d\u5c11\u5e38\u89c1\u8bed\u53e5\u5728\u7f16\u8bd1\u6210\u6c47\u7f16\u8bed\u8a00\u540e\uff0c\u5f80\u5f80\u88ab\u8f6c\u6362\u6210\u4e86\u591a\u6761\u6c47\u7f16\u8bed\u53e5\uff0c\u6b64\u65f6\u8be5\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u5c31\u65e0\u6cd5\u5f97\u5230\u4fdd\u8bc1\u3002<br \/>\n\u4e3e\u4e2a\u6700\u5e38\u89c1\u7684\u975e\u539f\u5b50\u64cd\u4f5c\u4f8b\u5b50\uff0c\u7ecf\u5178\u7684<code>i++<\/code>\u3002\u5176\u6c47\u7f16\u4ee3\u7801\u4e3a\uff1a<\/p>\n<pre><code>mov eax, dword ptr[i]\ninc eax\nmov dword ptr[i], eax<\/code><\/pre>\n<p>\u663e\u7136\uff0c\u5728\u8fd9\u4e09\u884c\u8bed\u53e5\u6267\u884c\u671f\u95f4\u53ef\u4ee5\u53d1\u751f\u4e0a\u4e0b\u6587\u5207\u6362\uff0c\u6240\u4ee5<code>i++<\/code>\u7684\u539f\u5b50\u6027\u662f\u4e0d\u80fd\u4fdd\u8bc1\u7684\u3002<br \/>\n\u6b64\u5916\uff0c\u5bf9\u4e8e\u4e00\u4e2a\u7b80\u5355\u7684\u8d4b\u503c\u8bed\u53e5\uff0c\u4f8b\u5982<code>a = b;<\/code>\uff0c\u4e00\u822c\u4e5f\u4e0d\u662f\u539f\u5b50\u64cd\u4f5c\u3002\u4f8b\u5982X86\u6c47\u7f16\u8bed\u8a00\u4e2d\u7684MOV\u5c31\u4e0d\u652f\u6301\u4ece\u4e3b\u5b58\u5230\u4e3b\u5b58\u7684\u6570\u636e\u4f20\u8f93\uff0c\u6b64\u65f6\u5176\u6c47\u7f16\u4ee3\u7801\u4e3a\uff1a<\/p>\n<pre><code>mov eax, dword ptr [b]  \nmov dword ptr [a], eax <\/code><\/pre>\n<p>\u5982\u679c\u4f7f\u7528C\/C++\u7684\u57fa\u7840\u8bed\u6cd5\uff0c\u90a3\u4e48\u591a\u7ebf\u7a0b\u573a\u666f\u4e0b\u5bf9\u540c\u4e00\u5757\u5185\u5b58\u7684\u5e76\u53d1\u8bfb\u5199\u90fd\u4e0d\u662f\u539f\u5b50\u7684\u3002\u800c\u5f53\u57fa\u7840\u7684\u8bfb\u5199\u539f\u5b50\u6027\u90fd\u65e0\u6cd5\u4fdd\u8bc1\uff0c\u90a3\u4e48\u4e1a\u52a1\u4ee3\u7801\u4e2d\u5e38\u89c1\u7684RMW\u64cd\u4f5c(read-modify-write\uff0c\u8bfb\u53d6\u503c\u3001\u5728\u8bfb\u53d6\u503c\u7684\u57fa\u7840\u4e0a\u8fdb\u884c\u8ba1\u7b97\u3001\u5c06\u8ba1\u7b97\u7ed3\u679c\u5199\u56de)\u7684\u539f\u5b50\u6027\u66f4\u662f\u65e0\u6cd5\u4fdd\u8bc1\u3002\u7efc\u4e0a\u6240\u8ff0\uff0c\u6211\u4eec\u9700\u8981\u8bbe\u6cd5\u5b9e\u73b0\u539f\u5b50\u64cd\u4f5c\u578b\u7684<strong>\u8bfb\u3001\u5199\u548cRMW<\/strong>\u3002<\/p>\n<div class='alert alert-primary'><span class='alert-inner--text'>\u67e5\u9605\u8d44\u6599\uff0c\u5f97\u77e5\u539f\u5b50\u64cd\u4f5c\u7684\u5b9a\u4e49\u662f\u6267\u884c\u671f\u95f4\u4e0d\u80fd\u53d1\u751f**\u4e0a\u4e0b\u6587\u5207\u6362**\uff0c\u8fd9\u662f\u5426\u610f\u5473\u7740\u539f\u5b50\u64cd\u4f5c\u4e2d\u4e0d\u80fd\u8fdb\u5165\u5185\u6838\u6001\uff1f<\/span><\/div>\n<blockquote>\n<p><a href=\"https:\/\/blog.csdn.net\/JMW1407\/article\/details\/108318960\">https:\/\/blog.csdn.net\/JMW1407\/article\/details\/108318960<\/a><\/p>\n<\/blockquote>\n<h3>1.1.2. \u6307\u4ee4\u91cd\u6392\u548cCPU\u4e71\u5e8f\u6267\u884c<\/h3>\n<p>\u6307\u4ee4\u91cd\u6392\u662f\u73b0\u4ee3\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u4f18\u5316\u8fc7\u7a0b\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u6b65\u9aa4\uff0c\u7f16\u8bd1\u5668\u4f1a\u8c03\u6574\u8bed\u53e5\u7684\u6267\u884c\u987a\u5e8f\u4ee5\u63d0\u9ad8\u8fd0\u884c\u6027\u80fd\u3002\u800c\u73b0\u4ee3\u7684CPU\u4e5f\u6709\u4e71\u5e8f\u6267\u884c\u7684\u673a\u5236\uff0cCPU\u4f1a\u5206\u6790\u6307\u4ee4\u4e4b\u95f4\u7684\u6570\u636e\u4f9d\u8d56\uff0c\u800c\u540e\u4e8e\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4\u4fee\u6539\u6307\u4ee4\u5e8f\u5217\u7684\u6267\u884c\u987a\u5e8f\uff0c\u5c06\u4e0d\u4e0e\u6d41\u6c34\u7ebf\u4e2d\u6b63\u5728\u6267\u884c\u7684\u6307\u4ee4\u5b58\u5728\u4f9d\u8d56\u5173\u7cfb\u7684\u6307\u4ee4\u63d0\u524d\u6267\u884c\u3002\u4f8b\u5982\u5e8f\u5217\u4e2d\u6709\u4e24\u6761\u76f8\u90bb\u7684\u6307\u4ee4AB\uff0c\u6307\u4ee4B\u9700\u8981\u7528\u5230\u6307\u4ee4A\u7684\u8fd0\u7b97\u7ed3\u679c\uff0c\u5219B\u5fc5\u987b\u5728A\u5b8c\u6210\u5199\u56de\u540e\u624d\u80fd\u5f00\u59cb\u8fdb\u5165\u6267\u884c\u9636\u6bb5\uff0c\u6b64\u65f6\u6ca1\u6709\u4e71\u5e8f\u6267\u884c\u673a\u5236\u7684CPU\u5c31\u53ea\u80fd\u5728\u6307\u4ee4AB\u4e4b\u95f4\u586b\u5145\u6570\u4e2a\u6c14\u6ce1\uff0c\u800c\u6709\u4e71\u5e8f\u6267\u884c\u673a\u5236\u7684CPU\u53ef\u4ee5\u4ece\u540e\u7ee7\u6307\u4ee4\u91cc\u9009\u51fa\u6570\u6761\u4e0d\u4e0eAB\u5b58\u5728\u6570\u636e\u4f9d\u8d56\u7684\u6307\u4ee4\uff0c\u5c06\u8fd9\u4e9b\u6307\u4ee4\u63d0\u524d\u5230A\u4e4b\u540e\u6267\u884c\uff0c\u907f\u514d\u4e86\u6c14\u6ce1\u5e26\u6765\u7684\u6027\u80fd\u4e0b\u964d\u3002<br \/>\n\u5bf9\u4e8e\u5355\u7ebf\u7a0b\u7684\u7a0b\u5e8f\uff0c\u7f16\u8bd1\u5668\u5728\u8fdb\u884c\u7f16\u8bd1\u4f18\u5316\u65f6\uff0c\u90fd\u4f1a\u9075\u5faa\u201c\u5982\u540c\u89c4\u5219\u201d(as-if rule)\uff0c\u5373\u8bed\u53e5\u987a\u5e8f\u4fee\u6539\u4e0d\u4f1a\u5bfc\u81f4\u7a0b\u5e8f\u8fd0\u884c\u7684\u7ed3\u679c\u53d1\u751f\u53d8\u5316\u3002\u4ece\u7a0b\u5e8f\u5458\u7684\u89d2\u5ea6\u4e0a\u770b\uff0c\u5bf9\u4e8e\u4e00\u4e2a\u9075\u5faaas-if rule\u89c4\u5219\u8fdb\u884c\u91cd\u6392\u7684\u5355\u7ebf\u7a0b\u7a0b\u5e8f\uff0c\u5176\u8fd0\u884c\u7ed3\u679c\u5c31\u597d\u50cf\u672a\u7ecf\u8fc7\u4efb\u4f55\u4f18\u5316\u4e00\u6837\u3002\u540c\u7406\uff0cCPU\u7684\u4e71\u5e8f\u6267\u884c\u53d7\u5230\u6307\u4ee4\u95f4\u6570\u636e\u4f9d\u8d56\u5173\u7cfb\u7684\u9650\u5236\uff0c\u80fd\u786e\u4fdd\u8fd0\u884c\u7ed3\u679c\u548c\u6ca1\u6709\u4e71\u5e8f\u6267\u884c\u673a\u5236\u65f6\u76f8\u540c\u3002\u4f46\u662f\u5728\u591a\u7ebf\u7a0b\u573a\u666f\u4e0b\uff0c\u7f16\u8bd1\u5668\u5f88\u53ef\u80fd\u65e0\u6cd5\u53d1\u73b0\u8de8\u7ebf\u7a0b\u7684\u6570\u636e\u7ade\u4e89\u95ee\u9898\uff0c\u6b64\u65f6\u5982\u540c\u89c4\u5219\u7684\u9650\u5236\u4e0d\u8db3\u4ee5\u907f\u514d\u95ee\u9898\u7684\u53d1\u751f\u3002<br \/>\n\u8fd9\u91cc\u7ed9\u51fa\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<pre><code class=\"language-c++\">#include &lt;iostream&gt;\n#include &lt;thread&gt;\n\nint x = 0, y = 0;\n\nvoid func1() {\n    x = 100;\n    y = 200;\n}\n\nvoid func2() {\n    while(y != 200)\n        ;\n    std::cout &lt;&lt; x;\n}\n\nint main() {\n    std::thread thread1(func1);\n    std::thread thread2(func2);\n    thread1.join();\n    thread2.join();\n    return 0;\n}<\/code><\/pre>\n<p>\u6839\u636e\u76f4\u89c9\uff0c\u8f93\u51fa\u7684\u503c\u5e94\u5f53\u6c38\u8fdc\u662f100\u3002\u4f46\u5b9e\u9645\u4e0a\uff0c\u5f53<code>func1<\/code>\u548c<code>func2<\/code>\u7531\u4e24\u4e2a\u4e0d\u540c\u7684<code>std::thread<\/code>\u5206\u7ebf\u7a0b\u6267\u884c\u65f6\uff0c\u7f16\u8bd1\u5668\u5e76\u4e0d\u80fd\u5206\u6790\u51fa\u6307\u4ee4\u91cd\u6392\u7684\u540e\u679c\uff1b\u6b64\u5916\uff0c\u5bf9\u4e8e\u6267\u884c\u8fd9\u4e24\u4e2a\u7ebf\u7a0b\u7684\u7269\u7406CPU\u6838\u5fc3\uff0c\u5b83\u4eec\u4ece\u5355\u4e2a\u7ebf\u7a0b\u7684\u89d2\u5ea6\u53bb\u5206\u6790\uff0c\u4e5f\u4f1a\u8ba4\u4e3a\u4e0d\u5b58\u5728\u6570\u636e\u4f9d\u8d56\uff0c\u8fdb\u800c\u5141\u8bb8\u4e71\u5e8f\u6267\u884c\u3002\u65e0\u8bba\u8fd9\u4e8c\u8005\u8c01\u662f\u201c\u51f6\u624b\u201d\uff0c\u8fd0\u884c\u65f6\u4e00\u65e6<code>func1<\/code>\u3001<code>func2<\/code>\u4e2d\u7684\u4ee3\u7801\u987a\u5e8f\u88ab\u8c03\u6362\uff0c\u8fd9\u4e2a\u7a0b\u5e8f\u5c31\u53ef\u80fd\u8f93\u51fa0\u3002<\/p>\n<h3>1.1.3. \u591a\u6838CPU\u7f13\u5b58\u4e00\u81f4\u6027<\/h3>\n<p>\u73b0\u4ee3\u591a\u6838CPU\u7684\u67b6\u6784\u4e2d\uff0c\u7f13\u5b58\u5206\u4e3aL1 L2 L3\u4e09\u4e2a\u5c42\u6b21\uff0c\u968f\u7740\u5c42\u7ea7\u7684\u63d0\u9ad8\u7f13\u5b58\u5927\u5c0f\u589e\u5927\u4f46\u662f\u8bbf\u95ee\u6027\u80fd\u4e0b\u964d\u3002\u95ee\u9898\u5728\u4e8e\uff0c\u6bcf\u4e2a\u7269\u7406\u6838\u5fc3\u6709\u81ea\u5df1\u7684L1 L2\u7ea7cache\uff0c\u8fd9\u4fbf\u6d89\u53ca\u5230\u4e86\u7ecf\u5178\u7684\u7f13\u5b58\u4e00\u81f4\u6027\u95ee\u9898\u3002\u4f8b\u5982\u8fd9\u6837\u4e00\u4e2a\u573a\u666f\uff1a\u67d0\u4e00\u6570\u636e\u88ab\u591a\u4e2a\u7269\u7406\u6838\u7684cache\u7f13\u5b58\uff0c\u67d0\u4e00\u65f6\u523b\u5176\u4e2d\u4e00\u4e2a\u7269\u7406\u6838\u66f4\u65b0\u4e86\u8be5\u6570\u636e\uff0c\u800c\u66f4\u65b0\u540e\u7684\u503c\u9996\u5148\u4f1a\u88ab\u5199\u5165\u8be5\u6838\u5fc3\u81ea\u6709\u7684cache\uff0c\u6b64\u65f6\u9700\u8981\u901a\u77e5\u5176\u4ed6\u7f13\u5b58\u4e86\u8be5\u6570\u636e\u7684\u6838\u5fc3\uff0c\u544a\u77e5\u4ed6\u4eec\u7f13\u5b58\u7684\u503c\u5df2\u7ecf\u5931\u6548\u3002\u5426\u5219\uff0c\u5c31\u53ef\u80fd\u5bfc\u81f4\u7a0b\u5e8f\u7684\u8fd0\u884c\u7ed3\u679c\u4e0e\u9884\u671f\u4e0d\u7b26\u3002<\/p>\n<h2>1.2. <code>volatile<\/code>\u5e76\u4e0d\u662f\u597d\u7684\u89e3\u51b3\u65b9\u6848<\/h2>\n<p>C\/C++\u7684<code>volatile<\/code>\u5173\u952e\u5b57\u662f\u4e00\u79cd\u7c7b\u578b\u4fee\u9970\u7b26\uff0c\u5176\u4f5c\u7528\u662f\u544a\u77e5\u7f16\u8bd1\u5668\u6b64\u53d8\u91cf\u53ef\u4ee5\u88ab\u67d0\u4e9b\u7f16\u8bd1\u5668\u672a\u77e5\u7684\u56e0\u7d20\u66f4\u6539\uff0c\u4ece\u800c\u4ee4\u7f16\u8bd1\u5668\u5bf9\u4fee\u9970\u7684\u53d8\u91cf\u4e0d\u518d\u8fdb\u884c\u4f18\u5316\uff1b\u6b64\u5916\uff0c\u5728\u6700\u540e\u751f\u6210\u7684\u6c47\u7f16\/\u673a\u5668\u6307\u4ee4\u4e2d\uff0c\u5bf9\u8be5\u53d8\u91cf\u7684\u6bcf\u6b21\u8bfb\u53d6\u90fd\u4ece\u5185\u5b58\u91cd\u65b0\u8bfb\u53d6\uff0c\u800c\u4e0d\u662f\u4eceCPU cache\u6216\u662f\u5bc4\u5b58\u5668\u4e2d\u8bfb\u53d6\u5df2\u6709\u7684\u8be5\u53d8\u91cf\u7684\u65e7\u503c\u3002<br \/>\n<code>volatile<\/code>\u5173\u952e\u5b57\u80fd\u591f\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u89e3\u51b3\u591a\u7ebf\u7a0b\u573a\u666f\u4e0b\u9519\u8bef\u7684\u7f16\u8bd1\u4f18\u5316\u548c\u591a\u6838CPU\u7f13\u5b58\u95ee\u9898\uff0c\u4f46\u662f\u5b58\u5728\u5176\u5c40\u9650\u6027\u3002\u9996\u5148\uff0c\u7b80\u5355\u7c97\u66b4\u5730\u5173\u95ed\u5bf9\u8be5\u53d8\u91cf\u7684\u4f18\u5316\u7b49\u4e8e\u653e\u5f03\u4e86\u9ad8\u901f\u7684\u5bc4\u5b58\u5668\u548c\u7f13\u5b58\uff0c\u4f1a\u5bfc\u81f4\u66f4\u5e7f\u6cdb\u573a\u666f\u4e0b\u7684\u6027\u80fd\u95ee\u9898\uff1b\u5176\u6b21\uff0c<code>volatile<\/code>\u4ecd\u7136\u6ca1\u80fd\u89e3\u51b3CPU\u4e71\u5e8f\u6267\u884c\u5e26\u6765\u7684\u9519\u8bef\u7ed3\u679c\u3002\u6240\u4ee5\uff0c<code>volatile<\/code>\u5e76\u4e0d\u662f\u89e3\u51b3\u4e0a\u8ff0\u4e09\u4e2a\u95ee\u9898\u7684\u6700\u4f73\u65b9\u6848\u3002<\/p>\n<h2>1.3. \u5f15\u5165<\/h2>\n<p>\u53ef\u4ee5\u53d1\u73b0\u4e0a\u8ff0\u4e09\u4e2a\u95ee\u9898\u90fd\u662f\u7531\u4e8e\u786c\u4ef6\u8fdb\u5165\u591a\u6838\u65f6\u4ee3\u800c\u4ea7\u751f\u7684\uff0c\u672c\u8d28\u662f\u786c\u4ef6\u95ee\u9898\u3002\u968f\u7740\u6280\u672f\u7684\u53d1\u5c55\uff0c\u4e00\u7cfb\u5217\u786c\u4ef6\u5c42\u9762\u7684\u6280\u672f\u88ab\u5f00\u53d1\u51fa\u6765\u7528\u4e8e\u89e3\u51b3\u4e0a\u8ff0\u4e09\u4e2a\u95ee\u9898\u3002C++11\u5f15\u5165\u7684\u539f\u5b50\u53d8\u91cf\u548c\u5185\u5b58\u5e8f\u5c31\u662f\u4f7f\u7528\u8fd9\u4e9b\u786c\u4ef6\u6280\u672f\u5b9e\u73b0\u7684\uff0c\u5b66\u4f1a\u4f7f\u7528\u4ed6\u4eec\u53ef\u4ee5\u5199\u51fa\u5065\u58ee\u7684\u591a\u7ebf\u7a0b\u7a0b\u5e8f\uff0c\u8fd8\u80fd\u5c3d\u91cf\u51cf\u5c11\u4e92\u65a5\u9501\u7684\u4f7f\u7528\uff0c\u4ece\u800c\u63d0\u9ad8\u591a\u7ebf\u7a0b\u8fd0\u884c\u6027\u80fd\u3002\u63a5\u4e0b\u6765\uff0c\u672c\u6587\u5c06\u4ecb\u5176\u5b9a\u4e49\u4e0e\u6027\u8d28\uff0c\u5e76\u7b80\u5355\u89e3\u91ca\u5176\u786c\u4ef6\u5c42\u9762\u7684\u5b9e\u73b0\u539f\u7406\u3002<\/p>\n<h1>2. C++11\u539f\u5b50\u53d8\u91cf<code>std::atomic<\/code> \u548c\u5185\u5b58\u5e8f<code>std::memory_order<\/code><\/h1>\n<h2>2.1. \u7b80\u4ecb<\/h2>\n<p>C++11\u5f15\u5165\u4e86\u539f\u5b50\u53d8\u91cf<code>std::atomic<\/code>\u548c\u5185\u5b58\u5e8f<code>std::memory_order<\/code>\uff0c\u4e8c\u8005\u5747\u5305\u542b\u4e8e\u5934\u6587\u4ef6<code>&lt;atomic&gt;<\/code>\u4e2d\u3002\u5185\u5b58\u5e8f\u7528\u4e8e\u63a7\u5236\u539f\u5b50\u53d8\u91cf\u7684\u7ebf\u7a0b\u95f4\u540c\u6b65\u884c\u4e3a\uff0c\u8fd9\u91cc\u6682\u65f6\u53ea\u7b80\u5355\u5b9a\u4e49\u5176\u4f5c\u7528\uff0c\u5c06\u5728\u7b2c\u4e09\u8282\u8be6\u8ff0\u3002<br \/>\n\u539f\u5b50\u53d8\u91cf\u662f\u4e00\u4e2a\u6a21\u677f\u7c7b\uff0c\u5305\u542b\u6210\u5458\u51fd\u6570<code>load<\/code>\u548c<code>store<\/code>\uff0c\u7528\u4e8e\u5bf9\u5176\u8fdb\u884c\u8bfb\u64cd\u4f5c\u548c\u5199\u64cd\u4f5c\u3002\u5373\u4f7f\u662f\u5728\u6700\u4f4e\u7684\u540c\u6b65\u7b49\u7ea7\u4e0b\uff0c\u4e5f\u80fd\u4fdd\u8bc1\u591a\u7ebf\u7a0b\u5e76\u884c\u573a\u666f\u4e2d\u5bf9\u539f\u5b50\u53d8\u91cf\u7684\u8bfb\u5199\u662f\u539f\u5b50\u64cd\u4f5c\u3002<strong>\u8fd9\u6837\u5c31\u89e3\u51b3\u4e86\u95ee\u98981.1\u4e2d\u8bfb\u5199\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u95ee\u9898\u3002<\/strong><\/p>\n<h2>2.2. \u89e3\u51b31.1\u4e2dRMW\u64cd\u4f5c\u7684\u539f\u5b50\u6027\u95ee\u9898<\/h2>\n<p>\u5f53\u6211\u4eec\u62e5\u6709\u4e86\u539f\u5b50\u64cd\u4f5c\u7248\u672c\u7684\u8bfb\u548c\u5199\uff0c\u6211\u4eec\u4fbf\u53ef\u4ee5\u901a\u8fc7CAS(Compare And Swap)\u601d\u60f3\u6765\u5b9e\u73b0\u539f\u5b50\u6027\u7684RMW\u64cd\u4f5c\u3002CAS\u7684\u4f2a\u7801\u5982\u4e0b\uff1a<\/p>\n<pre><code class=\"language-C++\">bool CAS( int * pAddr, int nExpected, int nNew ) {\n    atomically {\n        if ( *pAddr == nExpected ) {\n            *pAddr = nNew ;\n            return true ;\n        }\n        else\n            return false ;\n    }\n}<\/code><\/pre>\n<p><code>std::atomic<\/code>\u7684\u6210\u5458\u51fd\u6570<code>compare_exchange_weak()<\/code>\u5c31\u662f\u4e00\u4e2a\u57fa\u7840\u7684CAS\uff0c\u5176\u8fd4\u56de\u503c\u4e3abool\uff0c\u81f3\u5c11\u63a5\u53d7\u4e24\u4e2a\u53c2\u6570\uff0c\u7b2c\u4e00\u4e2a\u79f0\u4e3a<code>expected<\/code>\uff0c\u7b2c\u4e8c\u4e2a\u79f0\u4e3a<code>desired<\/code>\uff0c\u53ef\u4ee5\u63a5\u53d7\u66f4\u591a\u7684<code>std::memory_order<\/code>\u4f5c\u4e3a\u7b2c\u4e09\u3001\u7b2c\u56db\u53c2\u6570\u6765\u63a7\u5236\u540c\u6b65\u884c\u4e3a\u3002\u5982\u679c<code>*this<\/code>\u548c<code>expected<\/code>\u6309\u4f4d\u76f8\u7b49\uff0c\u90a3\u4e48\u5219\u5c06<code>desired<\/code>\u4e2d\u7684\u503c\u8d4b\u7ed9<code>*this<\/code>\uff0c\u5e76\u8fd4\u56detrue\uff1b\u5426\u5219\uff0c\u5c06<code>*this<\/code>\u4e2d\u7684\u5b9e\u9645\u503c\u52a0\u8f7d\u8fdb<code>expected<\/code>\uff0c\u5e76\u8fd4\u56defalse\u3002\u5229\u7528\u8fd9\u4e2a\u5931\u8d25\u65f6\u4f1a\u5c06\u5f53\u524d\u503c\u8d4b\u7ed9<code>expected<\/code>\u7684\u673a\u5236\uff0c\u6211\u4eec\u53ef\u4ee5\u7528\u4e00\u884cwhile\u8bed\u53e5\u5199\u51faCAS\u3002<br \/>\n\u4f8b\u5982\uff0c\u4e00\u4e2a\u7ebf\u7a0b\u5b89\u5168\u7684\u53cc\u7aef\u94fe\u8868\u4e2d\u7684push_front\u64cd\u4f5c\uff1a<\/p>\n<pre><code class=\"language-C++\">p-&gt;next = head;\nwhile (!head.compare_exchange_weak(p-&gt;next, p)) \n    {}<\/code><\/pre>\n<p>\u518d\u4f8b\u5982\uff0c\u4e00\u4e2a\u7ebf\u7a0b\u5b89\u5168\u7684RMW\u4e58\u6cd5\u51fd\u6570<\/p>\n<pre><code class=\"language-C++\">int fetch_multiply(std::atomic&lt;int&gt;&amp; shared, int multiplier)\n{\n    int oldValue = shared.load();\n    while (!shared.compare_exchange_weak(oldValue, oldValue * multiplier))\n        {}\n    return oldValue;\n}<\/code><\/pre>\n<p><code>std::atomic<\/code>\u5bf9\u4e8e\u4e00\u4e9b\u5e38\u89c1\u7684\u57fa\u7840\u7c7b\u578b\uff08\u4f8b\u5982int\u7b49\u6574\u6570\u7c7b\u578b\u548cfloat\u7b49\u6d6e\u70b9\u7c7b\u578b\uff09\u505a\u4e86\u7279\u5316\uff0c\u5b83\u4eec\u5177\u6709\u989d\u5916\u7684\u7279\u6027\uff0c\u4f8b\u5982\u5177\u6709\u4e00\u7cfb\u5217\u989d\u5916\u7684\u539f\u5b50\u64cd\u4f5c\u578b\u6210\u5458\u51fd\u6570\uff0c\u5176\u4e2d\u5305\u62ec\u7c7b\u4f3c+=\u8fd0\u7b97\u7b26\u7684<code>fetch_add<\/code>\u6210\u5458\u51fd\u6570\u3001++\/--\/+=\/-=\u8fd0\u7b97\u7b26\u7b49\u3002\u663e\u7136\uff0c\u63d0\u5230\u7684\u8fd9\u51e0\u79cd\u64cd\u4f5c\u90fd\u662fRMW\u64cd\u4f5c\uff0c\u800c\u5b83\u4eec\u7684\u539f\u5b50\u6027\u6b63\u662f\u901a\u8fc7CAS\u673a\u5236\u6765\u4fdd\u8bc1\u7684\u3002<\/p>\n<h2>2.3. CAS\u4e0eABA\u95ee\u9898<\/h2>\n<p>CAS\u673a\u5236\u5bb9\u6613\u9047\u5230ABA\u95ee\u9898\uff0c\u53ef\u4ee5\u7528\u4e09\u4e2a\u7ebf\u7a0b\u6765\u89e3\u91ca\u6b21\u95ee\u9898\uff0c\u6b64\u5904\u501f\u7528<a href=\"https:\/\/juejin.cn\/post\/6844903796129136647\">\u7a00\u571f\u6398\u91d1\u793e\u533a\u7684\u4e00\u7bc7\u535a\u5ba2<\/a>\u4e2d\u7684\u7b80\u660e\u4f8b\u5b50\uff1a<\/p>\n<pre><code>\u5c0f\u660e\u5728\u63d0\u6b3e\u673a\uff0c\u63d0\u53d6\u4e8650\u5143\uff0c\u56e0\u4e3a\u63d0\u6b3e\u673a\u95ee\u9898\uff0c\u6709\u4e24\u4e2a\u7ebf\u7a0b\uff0c\u540c\u65f6\u628a\u4f59\u989d\u4ece100\u53d8\u4e3a50\n\u7ebf\u7a0b1\uff08\u63d0\u6b3e\u673a\uff09\uff1a\u83b7\u53d6\u5f53\u524d\u503c100\uff0c\u671f\u671b\u66f4\u65b0\u4e3a50\uff0c\n\u7ebf\u7a0b2\uff08\u63d0\u6b3e\u673a\uff09\uff1a\u83b7\u53d6\u5f53\u524d\u503c100\uff0c\u671f\u671b\u66f4\u65b0\u4e3a50\uff0c\n\u7ebf\u7a0b1\u6210\u529f\u6267\u884c\uff0c\u7ebf\u7a0b2\u67d0\u79cd\u539f\u56e0block\u4e86\uff0c\u8fd9\u65f6\uff0c\u67d0\u4eba\u7ed9\u5c0f\u660e\u6c47\u6b3e50\n\u7ebf\u7a0b3\uff08\u9ed8\u8ba4\uff09\uff1a\u83b7\u53d6\u5f53\u524d\u503c50\uff0c\u671f\u671b\u66f4\u65b0\u4e3a100\uff0c\n\u8fd9\u65f6\u5019\u7ebf\u7a0b3\u6210\u529f\u6267\u884c\uff0c\u4f59\u989d\u53d8\u4e3a100\uff0c\n\u7ebf\u7a0b2\u4eceBlock\u4e2d\u6062\u590d\uff0c\u83b7\u53d6\u5230\u7684\u4e5f\u662f100\uff0ccompare\u4e4b\u540e\uff0c\u7ee7\u7eed\u66f4\u65b0\u4f59\u989d\u4e3a50\uff01\uff01\uff01\n\u6b64\u65f6\u53ef\u4ee5\u770b\u5230\uff0c\u5b9e\u9645\u4f59\u989d\u5e94\u8be5\u4e3a100\uff08100-50+50\uff09\uff0c\u4f46\u662f\u5b9e\u9645\u4e0a\u53d8\u4e3a\u4e8650\uff08100-50+50-50\uff09\u8fd9\u5c31\u662fABA\u95ee\u9898\u5e26\u6765\u7684\u6210\u529f\u63d0\u4ea4\u3002<\/code><\/pre>\n<p>\u4e00\u4e2a\u7b80\u5355\u7684\u89e3\u51b3\u601d\u8def\u662f\u52a0\u552f\u4e00\u4e14\u9012\u589e\u7684\u7248\u672c\u53f7\u3002<\/p>\n<h2>2.4. \u539f\u5b50\u64cd\u4f5c\u7684\u5e95\u5c42\u5b9e\u73b0\u539f\u7406<\/h2>\n<p>\u65e0\u8bba\u662f\u539f\u5b50\u6027\u7684\u8bfb\u5199\uff0c\u8fd8\u662f\u539f\u5b50\u6027\u7684CAS\u673a\u5236\uff0c\u90fd\u662f\u7531\u786c\u4ef6\u5b9e\u73b0\u7684\u3002<br \/>\n\u9996\u5148\u88ab\u5f00\u53d1\u51fa\u6765\u7684\u539f\u5b50\u64cd\u4f5c\u5b9e\u73b0\u65b9\u5f0f\u662fCPU\u9501\u603b\u7ebf\u3002CPU\u82af\u7247\u4e0a\u6709\u4e00\u6761\u5f15\u7ebf#HLOCK pin\uff0c\u5982\u679c\u6c47\u7f16\u8bed\u8a00\u7684\u7a0b\u5e8f\u4e2d\u5728\u4e00\u6761\u6307\u4ee4\u524d\u9762\u52a0\u4e0a\u524d\u7f00&quot;LOCK&quot;\uff0c\u7ecf\u8fc7\u6c47\u7f16\u4ee5\u540e\u7684\u673a\u5668\u4ee3\u7801\u5c31\u4f7f\u7269\u7406\u6838\u5728\u6267\u884c\u8fd9\u6761\u6307\u4ee4\u7684\u65f6\u5019\u628a#HLOCK pin\u7684\u7535\u4f4d\u62c9\u4f4e\uff0c\u6301\u7eed\u5230\u8fd9\u6761\u6307\u4ee4\u7ed3\u675f\u65f6\u653e\u5f00\uff0c\u4ece\u800c\u628a\u603b\u7ebf\u9501\u4f4f\uff0c\u8fd9\u6837\u540c\u4e00\u603b\u7ebf\u4e0a\u522b\u7684\u7269\u7406\u6838\u5c31\u6682\u65f6\u4e0d\u80fd\u901a\u8fc7\u603b\u7ebf\u8bbf\u95ee\u5185\u5b58\u4e86\uff0c\u4fdd\u8bc1\u4e86\u8fd9\u6761\u6307\u4ee4\u5728\u591a\u6838\u73af\u5883\u4e2d\u7684\u539f\u5b50\u6027\u3002\u603b\u7ebf\u9501\u4f1a\u5bfc\u81f4\u5176\u4ed6\u51e0\u4e2a\u6838\u5728\u4e00\u5b9a\u65f6\u949f\u5468\u671f\u5185\u65e0\u6cd5\u8bbf\u95ee\u5185\u5b58\uff0c\u867d\u7136\u4f1a\u5f71\u54cd\u5176\u4ed6\u6838\u7684\u6027\u80fd\uff0c\u4f46\u6bd4\u8d77\u64cd\u4f5c\u7cfb\u7edf\u7ea7\u522b\u7684\u9501\uff0c\u5df2\u7ecf\u8db3\u591f\u8f7b\u91cf\u3002<br \/>\n\u968f\u7740\u6280\u672f\u53d1\u5c55\uff0c\u9501\u7f13\u5b58\u6280\u672f\u88ab\u5f00\u53d1\u51fa\u6765\uff0c\u5373\u5f53\u67d0\u4e2a\u7269\u7406\u6838\u5bf9\u7f13\u5b58\u4e2d\u7684\u6570\u636e\u505a\u51fa\u4fee\u6539\u540e\uff0c\u4f1a\u901a\u8fc7\u7f13\u5b58\u4e00\u81f4\u6027\u534f\u8bae\u4f7f\u5f97\u5176\u4ed6\u7269\u7406\u6838\u7f13\u5b58\u4e2d\u7684\u6570\u636e\u5931\u6548\uff0c\u5176\u4ed6\u7684\u7269\u7406\u6838\u518d\u6b21\u9700\u8981\u8bbf\u95ee\u8be5\u6570\u636e\u65f6\u9700\u8981\u91cd\u65b0\u4ece\u5185\u5b58\u8bfb\u53d6\u3002\u8fd9\u91cc\u6d89\u53ca\u4e86\u7f13\u5b58\u4e00\u81f4\u6027\u534f\u8bae\uff0c\u5c06\u5728\u7b2c4\u8282\u8be6\u8ff0\u3002\u5f53\u4ee3CPU\u4e00\u822c\u662f\u4f18\u5148\u9501\u7f13\u5b58\uff0c\u4f46\u5728\u4e00\u4e9b\u7279\u6b8a\u60c5\u51b5\u4e0b\u4e5f\u4f1a\u4f7f\u7528\u9501\u603b\u7ebf\uff0c\u4f8b\u5982\u8bbf\u95ee\u5bf9\u8c61\u7684\u6570\u636e\u8de8\u591a\u4e2a\u7f13\u5b58\u884c\u6216\u662f\u5c1a\u672a\u88ab\u7f13\u5b58\u65f6\u3002<br \/>\n\u5728X86\u6c47\u7f16\u8bed\u8a00\u4e2d\u6709\u4e00\u6761\u4e13\u95e8\u7684\u6307\u4ee4CMPXCHG\u63d0\u4f9bCAS\u529f\u80fd\u3002\u5b9e\u9645\u4f7f\u7528\u7684\u65f6\u5019\uff0c\u4e00\u822c\u7528\u6cd5\u4e5f\u9700\u8981\u52a0LOCK\u524d\u7f00\u8fdb\u884c\u603b\u7ebf\u9501\u6216\u662f\u7f13\u5b58\u9501\u7684\u65bd\u52a0\uff0c\u4f8b\u5982JDK\u5b9e\u73b0\u4e2d\u5c31\u6709\u51fa\u73b0LOCK CMPXCHG\u3002<\/p>\n<p><a href=\"https:\/\/zhuanlan.zhihu.com\/p\/375706879\">https:\/\/zhuanlan.zhihu.com\/p\/375706879<\/a><\/p>\n<h1>3. \u5185\u5b58\u5e8f\u548c\u5185\u5b58\u6a21\u578b<\/h1>\n<h2>3.1. \u5404\u5185\u5b58\u6a21\u578b\u6d89\u53ca\u5230\u7684\u5185\u5b58\u5e8f<\/h2>\n<p>\u7528\u4e8e\u63cf\u8ff0\u7ebf\u7a0b\u95f4\u540c\u6b65\u884c\u4e3a\u7684\u5185\u5b58\u6a21\u578b(Memory Model)\u53ef\u4ee5\u88ab\u5206\u4e3a\u4ee5\u4e0b\u51e0\u79cd\u7c7b\u578b\uff1a<\/p>\n<ul>\n<li>Relaxed Ordering\uff0c\u5bbd\u677e\u987a\u5e8f (\u6d89\u53ca\u5185\u5b58\u5e8f\u53c2\u6570<code>memory_order_relaxed<\/code>)<\/li>\n<li>Release-Acquire Ordering\uff0c\u91ca\u653e-\u83b7\u5f97\u987a\u5e8f (\u6d89\u53ca\u5185\u5b58\u5e8f\u53c2\u6570<code>memory_order_release<\/code>, <code>memory_order_acquire<\/code>, <code>memory_order_acq_rel<\/code>)<\/li>\n<li>Release-Consume Ordering\uff0c\u91ca\u653e-\u6d88\u8d39\u987a\u5e8f\uff08\u6d89\u53ca\u5185\u5b58\u5e8f\u53c2\u6570<code>memory_order_consume<\/code>\u548c\u4e4b\u524d\u51fa\u73b0\u7684<code>memory_order_release<\/code>\uff09<\/li>\n<li>Sequentially Consistent Ordering\uff0c\u5e8f\u5217\u4e00\u81f4\u987a\u5e8f (\u6d89\u53ca\u5185\u5b58\u5e8f\u53c2\u6570<code>memory_order_seq_cst<\/code>)<\/li>\n<\/ul>\n<p>\u63a5\u4e0b\u6765\u8be6\u7ec6\u4ecb\u7ecd\u5404\u4e2a\u5185\u5b58\u6a21\u578b\u3002<\/p>\n<h2>3.2. Relaxed Ordering\uff0c\u5bbd\u677e\u987a\u5e8f<\/h2>\n<h3>3.2.1. \u6027\u8d28<\/h3>\n<p>Relaxed Ordering\u53ea\u4fdd\u8bc1\u6700\u6700\u6700\u6700\u57fa\u7840\u7684\u540c\u6b65\uff0c\u5373\u539f\u5b50\u64cd\u4f5c\u672c\u8eab\u7684\u6027\u8d28\uff1a\u5bf9\u76ee\u6807\u539f\u5b50\u53d8\u91cf\u7684<code>load<\/code>\u548c<code>store<\/code>\u64cd\u4f5c\u662f\u539f\u5b50\u6027\u7684\u3002<\/p>\n<h3>3.2.2. \u4f7f\u7528\u65b9\u6cd5<\/h3>\n<p>\u82e5\u8981\u4f7f\u7528\u5bbd\u677e\u987a\u5e8f\uff0c\u5219\u5bf9<code>std::atomic<\/code>\u7684<code>load()<\/code>\u548c<code>store()<\/code>\u90fd\u8981\u5e26\u4e0a<code>memory_order_relaxed<\/code>\u53c2\u6570\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre><code class=\"language-cpp\">std::atomic&lt;int&gt; x = 0;\nr1 = x.load(memory_order_relaxed); \nx.store(r1, memory_order_relaxed); <\/code><\/pre>\n<h3>3.2.3. \u9002\u7528\u573a\u666f<\/h3>\n<p>Relaxed Ordering\u4ec5\u4fdd\u8bc1\u8bfb\u5199\u64cd\u4f5c\u7684\u539f\u5b50\u6027\uff0c\u6545\u53ea\u9002\u7528\u4e8e\u6700\u57fa\u7840\u7684\u540c\u6b65\u573a\u666f\uff0c\u4f8b\u5982\u591a\u7ebf\u7a0b\u64cd\u4f5c\u540c\u4e00\u4e2a\u8ba1\u6570\u5668\u3002<\/p>\n<h2>3.3. Release-acquire Ordering\uff0c\u91ca\u653e-\u83b7\u5f97\u987a\u5e8f<\/h2>\n<h3>3.3.1. \u53c2\u6570\u7684\u4f5c\u7528<\/h3>\n<p>\u9996\u5148\u6211\u4eec\u9700\u8981\u4ecb\u7ecd\u6240\u4f7f\u7528\u7684\u4e24\u4e2a\u53c2\u6570\u7684\u4f5c\u7528\uff1a<br \/>\n<code>memory_order_acquire<\/code>\u7528\u4e8e\u9650\u5236load\u64cd\u4f5c\uff0c\u53d7\u6b64\u9650\u5236\u7684\u8bfb\u64cd\u4f5c\u88ab\u79f0\u4e3aAcquire\u64cd\u4f5c\uff0c\u5373<strong>\u83b7\u5f97<\/strong>\u64cd\u4f5c\u3002\u5728\u6b64load\u4e4b\u540e\u7684\u5185\u5b58\u8bfb\u5199\u64cd\u4f5c\u4e0d\u80fd\u88ab\u6307\u4ee4\u91cd\u6392\u5230\u6b64load\u4e4b\u524d\u3002\u6b64\u5916\uff0c\u5f53load\u64cd\u4f5c\u6210\u529f<strong>\u83b7\u5f97<\/strong>\u5176\u4ed6\u7ebf\u7a0b<strong>\u91ca\u653e<\/strong>\u7684\u503c\u540e\uff0c\u5728\u8be5\u91ca\u653e\u64cd\u4f5c\u4e4b\u524d\u7684\u6240\u6709\u5185\u5b58\u5199\u5165\u90fd\u5bf9\u672cload\u6240\u5728\u7ebf\u7a0b\u53ef\u89c1\u3002<br \/>\n<code>memory_order_release<\/code>\u7528\u4e8e\u9650\u5236store\u64cd\u4f5c\uff0c\u53d7\u6b64\u9650\u5236\u7684\u5199\u64cd\u4f5c\u88ab\u79f0\u4e3arelease\u64cd\u4f5c\uff0c\u5373<strong>\u91ca\u653e<\/strong>\u64cd\u4f5c\u3002\u5728\u6b64store\u4e4b\u524d\u7684\u5185\u5b58\u8bfb\u5199\u64cd\u4f5c\u4e0d\u80fd\u88ab\u6307\u4ee4\u91cd\u6392\u5230\u6b64store\u4e4b\u540e\u3002\u5f53\u524d\u7ebf\u7a0b\u7684\u6240\u6709\u5185\u5b58\u5199\u5165\uff0c\u53ef\u89c1\u4e8e<strong>\u83b7\u5f97<\/strong>\u8be5\u540c\u4e00\u539f\u5b50\u53d8\u91cf\u7684\u5176\u4ed6\u7ebf\u7a0b\u3002<\/p>\n<p>\u989d\u5916\u5f3a\u8c03\uff1a\u6839\u636e<a href=\"https:\/\/en.cppreference.com\/w\/cpp\/atomic\/memory_order\">cppreference\u4e0a\u7684\u63cf\u8ff0<\/a>\uff0c\u6b64\u5904\u88ab\u7981\u6b62\u91cd\u6392\u548c\u4fdd\u8bc1\u53ef\u89c1\u7684\u5185\u5b58\u64cd\u4f5c\u662f<strong>\u6240\u6709<\/strong>\u5185\u5b58\u64cd\u4f5c\uff0c\u5373\u4e0d\u5c40\u9650\u4e8e\u5bf9\u539f\u5b50\u53d8\u91cf\u7684\u8bfb\u5199\u3002<\/p>\n<h3>3.3.2. \u6027\u8d28<\/h3>\n<p>\u91ca\u653e-\u83b7\u5f97\u987a\u5e8f\u63d0\u4f9b\u4e86\u66f4\u9ad8\u7b49\u7ea7\u7684\u7ebf\u7a0b\u540c\u6b65\u3002\u9996\u5148\uff0c\u548c\u57fa\u7840\u7684relax ordering\u4e00\u6837\uff0c\u5b83\u80fd\u4fdd\u8bc1\u5bf9\u76ee\u6807\u539f\u5b50\u53d8\u91cf\u7684\u8bfb\u5199\u64cd\u4f5c\u662f\u539f\u5b50\u6027\u7684\uff1b\u5176\u6b21\uff0c\u4e5f\u662f\u6700\u91cd\u8981\u7684\uff0c\u8fd9\u4e2aatomic\u53d8\u91cf\u4f1a\u5728\u7a0b\u5e8f\u4e2d\u5f15\u5165\u591a\u4e2a<strong>\u5185\u5b58\u5c4f\u969c<\/strong>(memory barrier \/ memory fence\uff0c\u6216\u8bd1\u5185\u5b58\u6805\u680f)\uff0c\u4eceGCC\u7684\u62d3\u5c55\u6c47\u7f16\u6307\u4ee4\u7684\u89d2\u5ea6\u53bb\u89e3\u91ca\uff0c\u8fd9\u4e9b\u5185\u5b58\u5c4f\u969c\u65e2\u662fcomplier fence\u53c8\u662fCPU fence\u3002<br \/>\n\u5f15\u5165\u5185\u5b58\u5c4f\u969c\u540e\uff0c\u9996\u5148\u7f16\u8bd1\u5668\u7684\u6307\u4ee4\u91cd\u6392\u5c06\u53d7\u5230\u9650\u5236\uff0c\u4e0d\u5141\u8bb8\u5c06load\u540e\u3001store\u524d\u7684\u6307\u4ee4\u91cd\u6392\u5230\u53e6\u4e00\u4fa7\uff1b\u6b64\u5916\uff0c\u8fd8\u80fd\u9650\u5236CPU\u7684\u4e71\u5e8f\u6267\u884c\uff0c\u4fdd\u8bc1\u5c4f\u969c\u4e4b\u524d\u7684\u5199\u6307\u4ee4\u5168\u90e8\u6267\u884c\u5b8c\u540e\u624d\u80fd\u6267\u884c\u5c4f\u969c\u4e4b\u540e\u7684\u8bfb\u8bed\u53e5\u3002\u8fd9\u6837\u4e00\u6765\uff0c\u5c31\u4ee5\u5185\u5b58\u5c4f\u969c\u4e3a\u540c\u6b65\u70b9\u5b9e\u73b0\u4e86\u591a\u7ebf\u7a0b\u7684\u540c\u6b65\uff0c\u4fdd\u8bc1\u4e00\u4e2aload\u64cd\u4f5c\u6210\u529f<strong>\u83b7\u5f97<\/strong>\u5176\u4ed6\u7ebf\u7a0b<strong>\u91ca\u653e<\/strong>\u7684\u503c\u540e\uff0c\u5728\u8be5\u91ca\u653e\u64cd\u4f5c\u4e4b\u524d\u7684\u6240\u6709\u5185\u5b58\u5199\u5165\u90fd\u5bf9\u672cload\u6240\u5728\u7ebf\u7a0b\u53ef\u89c1\uff0c\u8fd9\u88ab\u79f0\u4e3a\u201c<strong>\u53ef\u89c1\u526f\u6548\u5e94<\/strong>\u201d\u3002<\/p>\n<p>\u5728\u8fd9\u4e2a\u7b49\u7ea7\u7684\u5185\u5b58\u5e8f\u4e0b\uff0c\u6211\u4eec\u5229\u7528\u5185\u5b58\u5c4f\u969c\u89e3\u51b3\u4e86\u95ee\u98981.2.<\/p>\n<blockquote>\n<p><a href=\"https:\/\/zhuanlan.zhihu.com\/p\/413889872\">https:\/\/zhuanlan.zhihu.com\/p\/413889872<\/a><br \/>\n<a href=\"https:\/\/gcc.gnu.org\/onlinedocs\/gcc\/Extended-Asm.html#Clobbers-and-Scratch-Registers\">https:\/\/gcc.gnu.org\/onlinedocs\/gcc\/Extended-Asm.html#Clobbers-and-Scratch-Registers<\/a><\/p>\n<\/blockquote>\n<h3>3.3.3. \u4f7f\u7528\u65b9\u6cd5<\/h3>\n<p>store()\u4f7f\u7528<code>memory_order_release<\/code>\u53c2\u6570\uff0c\u800cload()\u4f7f\u7528<code>memory_order_acquire<\/code>\u3002<\/p>\n<h3>3.3.4. \u9002\u7528\u573a\u666f<\/h3>\n<p>\u80fd\u4fdd\u8bc1\u4e00\u5b9a\u7684\u5e76\u884c\u6027\u80fd\uff0c\u5e76\u4e14\u63d0\u4f9b\u8f83\u9ad8\u7b49\u7ea7\u7684\u540c\u6b65\u3002\u4e92\u65a5\u9501<code>std::mutex<\/code>\u5c31\u662f\u91ca\u653e-\u83b7\u5f97\u540c\u6b65\u7684\u4e00\u4e2a\u7ecf\u5178\u4f8b\u5b50\uff0c\u5176<code>lock()<\/code>\u5c31\u662f\u83b7\u5f97\u64cd\u4f5c\uff0c<code>unlock()<\/code>\u5c31\u662f\u91ca\u653e\u64cd\u4f5c\u3002\u5728\u4e92\u65a5\u9501\u88ab\u7ebf\u7a0bA\u91ca\u653e\u518d\u88ab\u7ebf\u7a0bB\u83b7\u5f97\u540e\uff0cA\u5728\u91ca\u653e\u8be5\u9501\u4e4b\u524d\u6240\u505a\u7684\u6240\u6709\u5199\u5165\u64cd\u4f5c\u90fd\u80fd\u88abB\u770b\u5230\u3002<\/p>\n<h3>3.3.5. \u5176\u4ed6<\/h3>\n<p>\u8fd8\u6709\u4e00\u4e2a\u53c2\u6570<code>memory_order_acq_rel<\/code>\uff0c\u987e\u540d\u601d\u4e49\u662frelease\u548cacquire\u7684\u7ed3\u5408\u4f53\uff0c\u540c\u65f6\u5177\u6709\u4e8c\u8005\u7684\u529f\u80fd\u5e76\u53ef\u4ee5\u540c\u65f6\u4f5c\u4e3astore\u548cload\u7684\u53c2\u6570\u3002\u5e26\u6b64\u53c2\u6570\u7684\u8bfb\u5199\u64cd\u4f5c\u65e2\u662f\u83b7\u5f97\u64cd\u4f5c\u53c8\u662f\u91ca\u653e\u64cd\u4f5c\u3002\u5f53\u524d\u7ebf\u7a0b\u7684\u8bfb\u6216\u5199\u5185\u5b58\u4e0d\u80fd\u88ab\u91cd\u6392\u5230\u6b64store\/load\u4e4b\u524d\u6216\u4e4b\u540e\u3002\u6240\u6709\u91ca\u653e\u540c\u4e00\u539f\u5b50\u53d8\u91cf\u7684\u7ebf\u7a0b\u7684\u5199\u5165\u53ef\u89c1\u4e8e\u4fee\u6539\u4e4b\u524d\uff0c\u800c\u4e14\u4fee\u6539\u53ef\u89c1\u4e8e\u5176\u4ed6\u83b7\u5f97\u540c\u4e00\u539f\u5b50\u53d8\u91cf\u7684\u7ebf\u7a0b\u3002\u6b64\u53c2\u6570\u4e0b\uff0c\u63d0\u4f9b\u7684\u540c\u6b65\u548c\u5185\u5b58\u5c4f\u969c\u9650\u5236\u66f4\u5f3a\u3002<\/p>\n<h2>3.4. Release-Consume\uff0c\u91ca\u653e\u6d88\u8d39\u987a\u5e8f<\/h2>\n<h3>3.4.1. \u6027\u8d28<\/h3>\n<p>\u6ce8\u610f\uff0cC++17\u8d77\u91ca\u653e\u6d88\u8d39\u987a\u5e8f\u7684\u89c4\u8303\u6b63\u5728\u4fee\u8ba2\u4e2d\uff0c\u6682\u65f6\u4e0d\u9f13\u52b1\u4f7f\u7528<code>memory_order_consume<\/code>\u3002C++\u6807\u51c6\u59d4\u5458\u4f1a\u5c1a\u5728\u8ba8\u8bba\u7814\u7a76\u5982\u4f55\u5c06\u6b64\u673a\u5236\u8bbe\u8ba1\u5f97\u80fd\u88ab\u7f16\u8bd1\u5668\u5b9e\u73b0\u3002\u76f8\u5f53\u957f\u4e00\u6bb5\u65f6\u95f4\u4ee5\u6765\uff0c\u5927\u591a\u6570\u7f16\u8bd1\u5668\u5c06consume\u64cd\u4f5c\u89c6\u4e3aacquire\u7684\u540c\u4e49\u64cd\u4f5c\u3002<br \/>\nRelease-Consume\u53ef\u4ee5\u88ab\u89c6\u4e3a\u4e00\u79cd\u7406\u60f3\u7684\u4f18\u5316\u7248Release-Acquire\u987a\u5e8f\u3002\u540e\u8005\u7684\u95ee\u9898\u5728\u4e8e\u5176\u53ef\u89c1\u8d1f\u6548\u5e94\u5e26\u6765\u7684\u540c\u6b65\u7ea6\u675f\u8fc7\u5f3a\uff0c\u5373\u4f7f\u662f\u4e0d\u5b58\u5728\u6570\u636e\u7ade\u4e89\u7684\u5185\u5b58\u64cd\u4f5c\u4e5f\u88ab\u8fdb\u884c\u4e86\u540c\u6b65\uff0c\u5bfc\u81f4\u6307\u4ee4\u91cd\u6392\u5e03\u53d7\u5230\u8f83\u5927\u7684\u9650\u5236\uff0c\u8fdb\u800c\u5bfc\u81f4\u5e76\u884c\u6027\u80fd\u7684\u4e0b\u964d\u3002\u9488\u5bf9\u8fd9\u4e2a\u95ee\u9898\uff0cRelease-Consume\u987a\u5e8f\u88ab\u63d0\u51fa\uff0c\u53ea\u5bf9\u5b58\u5728\u6570\u636e\u4f9d\u8d56\u7684\u5185\u5b58\u64cd\u4f5c\u8fdb\u884c\u9650\u5236\u3002<br \/>\n<code>memory_order_acquire<\/code>\u7528\u4e8e\u9650\u5236load\u64cd\u4f5c\uff0c\u53d7\u6b64\u9650\u5236\u7684\u8bfb\u64cd\u4f5c\u88ab\u79f0\u4e3aConsume\u64cd\u4f5c\uff0c\u5373<strong>\u6d88\u8d39<\/strong>\u64cd\u4f5c\u3002\u5f53\u524d\u7ebf\u7a0b\u4e2d\uff0c\u4f9d\u8d56\u4e8e\u6b64load\u83b7\u53d6\u503c\u7684\u8bfb\u6216\u8005\u5199\u64cd\u4f5c\u4e0d\u80fd\u88ab\u6307\u4ee4\u91cd\u6392\u5230\u6b64load\u4e4b\u524d\u3002\u5f53\u4e00\u4e2aload\u64cd\u4f5c\u6210\u529f<strong>\u6d88\u8d39<\/strong>\u5176\u4ed6\u7ebf\u7a0b<strong>\u91ca\u653e<\/strong>\u7684\u503c\u540e\uff0c\u5728\u8be5\u91ca\u653e\u64cd\u4f5c\u4e4b\u524d\u7684\u6240\u6709\u5185\u5b58\u5199\u5165\u90fd\u5bf9\u672cload\u6240\u5728\u7ebf\u7a0b\u4e2d\u4f7f\u7528\u4ece\u8be5\u6d88\u8d39\u64cd\u4f5c\u83b7\u5f97\u7684\u503c\u7684<strong>\u8fd0\u7b97\u7b26\u548c\u51fd\u6570<\/strong>\u53ef\u89c1\u3002<\/p>\n<h3>3.4.2. \u4f7f\u7528\u65b9\u6cd5<\/h3>\n<p>store()\u4f7f\u7528<code>memory_order_release<\/code>\u53c2\u6570\uff0c\u800cload()\u4f7f\u7528<code>memory_order_consume<\/code>\u3002<\/p>\n<h3>3.4.3. \u9002\u7528\u573a\u666f<\/h3>\n<p>\u6682\u4e0d\u5efa\u8bae\u3002<\/p>\n<h2>3.5. Sequentially Consistent Ordering \u5e8f\u5217\u4e00\u81f4\u987a\u5e8f<\/h2>\n<h3>3.5.1. \u6027\u8d28<\/h3>\n<p>\u5e8f\u5217\u4e00\u81f4\u987a\u5e8f\u63d0\u4f9b\u4e86\u6700\u4e25\u683c\u7684\u7ebf\u7a0b\u540c\u6b65\u3002\u6b64\u987a\u5e8f\u4e5f\u5305\u542b\u4e86\u6240\u6709\u66f4\u4f4e\u7b49\u7ea7\u7684\u5185\u5b58\u5e8f\u6240\u62e5\u6709\u7684\u540c\u6b65\u673a\u5236\uff0c\u5373\u53ef\u4ee5\u4fdd\u8bc1\u64cd\u4f5c\u7684\u539f\u5b50\u6027\uff0c\u4e5f\u62e5\u6709\u53ef\u89c1\u526f\u6548\u5e94\u3002\u5728\u6b64\u57fa\u7840\u4e0a\uff0c\u5e8f\u5217\u4e00\u81f4\u987a\u5e8f\u4fdd\u8bc1\u4e86\u5185\u5b58\u64cd\u4f5c\u7684\u5168\u5c40\u5e8f\u5217\u6027\uff0c\u5373\u6240\u6709\u7ebf\u7a0b\u770b\u5230\u7684\u5185\u5b58\u8bfb\u5199\u64cd\u4f5c\u7684\u987a\u5e8f\u90fd\u5e94\u5f53\u662f\u4e00\u81f4\u7684\uff0c\u5e76\u4e14\u6240\u6709\u7684\u8bfb\u64cd\u4f5c\u90fd\u80fd\u83b7\u5f97\u6700\u65b0\u7684\u5199\u5165\u503c\u3002\u8fd9\u6837\u4e00\u6765\uff0c\u5728\u5e8f\u5217\u4e00\u81f4\u987a\u5e8f\u4e0b\uff0c\u591a\u4e2a\u7ebf\u7a0b\u7684\u5185\u5b58\u64cd\u4f5c\u8868\u73b0\u4e3a(appears)\u7c7b\u4f3c\u5355\u7ebf\u7a0b\u6267\u884c\u7684\u5168\u5c40\u4e32\u884c\u5316\u3002<\/p>\n<h3>3.5.2. \u4f7f\u7528\u65b9\u6cd5<\/h3>\n<p>Load()\u548cstore()\u90fd\u4f7f\u7528\u53c2\u6570<code>memory_order_seq_cst<\/code>\uff0c\u6216\u4e0d\u5e26\u5185\u5b58\u53c2\u6570\u800c\u91c7\u7528<strong>\u9ed8\u8ba4\u53c2\u6570<\/strong>\u3002\u8fd9\u662f\u7531\u4e8e\u5e8f\u5217\u4e00\u81f4\u987a\u5e8f\u7684\u5f3a\u7ea6\u675f\u80fd\u4f7f\u5f97\u7a0b\u5e8f\u8fd0\u884c\u7684\u7ed3\u679c\u7b26\u5408\u7f16\u7a0b\u4eba\u5458\u7684\u76f4\u89c9\uff0c\u6545\u88ab\u8bbe\u7f6e\u4e3a\u4e86load\u548cstore\u7684\u9ed8\u8ba4\u53c2\u6570\u3002<\/p>\n<h3>3.5.3. \u4f7f\u7528\u573a\u666f<\/h3>\n<p>\u4e0d\u8ffd\u6c42\u6781\u81f4\u591a\u7ebf\u7a0b\u6027\u80fd\u7684\u573a\u666f\u3002<\/p>\n<h1>4. TODO: \u7f13\u5b58\u4e00\u81f4\u6027\u534f\u8bae\u548c\u5185\u5b58\u5c4f\u969c\u7684\u786c\u4ef6\u5b9e\u73b0\u539f\u7406<\/h1>\n<h2>4.1. MESI\u534f\u8bae<\/h2>\n<p>MESI \u534f\u8bae\u662f\u6700\u7ecf\u5178\u7684\u7f13\u5b58\u4e00\u81f4\u6027\u534f\u8bae(cache coherence protocols)\u3002<\/p>\n<h2>4.2. X86\u5e73\u53f0\u5185\u5b58\u5c4f\u969c\u5b9e\u73b0\u539f\u7406<\/h2>\n<p>X86\u5e73\u53f0\u4ece\u786c\u4ef6\u5c42\u9762\u63d0\u4f9b\u4e86\u591a\u79cd\u5185\u5b58\u5c4f\u969c\uff0c\u5bf9\u5e94\u7684X86\u6c47\u7f16\u6307\u4ee4\u6709mfence\/sfence\/lfence\u3002\u57282.3\u8282\u63d0\u5230LOCK\u524d\u7f00\u6307\u4ee4\u867d\u7136\u4e0d\u662f\u5185\u5b58\u5c4f\u969c\uff0c\u4f46\u662f\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u4e5f\u63d0\u4f9b\u4e86\u7c7b\u4f3c\u7684\u6548\u679c\u3002\u8be6\u7ec6\u7684\u786c\u4ef6\u89e3\u91ca\u5f85\u8865\u5168\u3002<\/p>\n<blockquote>\n<p><a href=\"https:\/\/zhuanlan.zhihu.com\/p\/125549632\">https:\/\/zhuanlan.zhihu.com\/p\/125549632<\/a><br \/>\n<a href=\"http:\/\/www.puppetmastertrading.com\/images\/hwViewForSwHackers.pdf\">http:\/\/www.puppetmastertrading.com\/images\/hwViewForSwHackers.pdf<\/a><\/p>\n<\/blockquote>\n<h1>5. wait-free\u4e0elock-free<\/h1>\n<p>\u539f\u5b50\u6307\u4ee4\u80fd\u4e3a\u591a\u7ebf\u7a0b\u9ad8\u6027\u80fd\u7f16\u7a0b\u5f15\u5165\u4e24\u4e2a\u91cd\u8981\u7684\u6982\u5ff5\uff1await-free\u548clock-free\uff08\u65e0\u9501\u7f16\u7a0b\uff09\u3002wait-free\u6307\u4e0d\u7ba1OS\u5982\u4f55\u8c03\u5ea6\u7ebf\u7a0b\uff0c\u6bcf\u4e2a\u7ebf\u7a0b\u90fd\u59cb\u7ec8\u5728\u505a\u6709\u7528\u7684\u4e8b\uff1block-free\u5219\u6bd4\u524d\u8005\u5f31\u4e00\u4e9b\uff0c\u6307\u4e0d\u7ba1OS\u5982\u4f55\u8c03\u5ea6\u7ebf\u7a0b\uff0c\u81f3\u5c11\u6709\u4e00\u4e2a\u7ebf\u7a0b\u5728\u505a\u6709\u7528\u7684\u4e8b\u3002<br \/>\n\u5982\u679c\u4e00\u4e2a\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u4e2d\u4f7f\u7528\u4e86\u4e92\u65a5\u9501\uff0c\u90a3\u4e48OS\u8fdb\u884c\u7ebf\u7a0b\u8c03\u5ea6\u65f6\u53ef\u80fd\u628a\u4e00\u4e2a\u521a\u83b7\u5f97\u9501\u7684\u7ebf\u7a0b\u5207\u6362\u4e3a\u5c31\u7eea\u6001\uff0c\u6b64\u65f6\u6240\u6709\u4f9d\u8d56\u4e8e\u8be5\u9501\u7684\u7ebf\u7a0b\u90fd\u5728\u963b\u585e\u6216\u81ea\u65cb\u7b49\u5f85\uff0c\u800c\u6ca1\u6709\u505a\u6709\u7528\u7684\u4e8b\uff0c\u6240\u4ee5\u7528\u5230\u4e86\u9501\u5c31\u4e0d\u662flock-free\uff0c\u66f4\u4e0d\u4f1a\u662fwait-free\u3002\u4e3a\u4e86\u786e\u4fdd\u4e00\u4e2a\u4efb\u52a1\u603b\u5728\u786e\u5b9a\u65f6\u95f4\u5185\u5b8c\u6210\uff0c\u5b9e\u65f6\u7cfb\u7edf\u7684\u5173\u952e\u4ee3\u7801\u5e94\u5f53\u81f3\u5c11\u662flock-free\u7684\u3002<br \/>\n\u5728\u4f7f\u7528\u539f\u5b50\u53d8\u91cf\u7684\u65e0\u9501\u7f16\u7a0b\u4e2d\uff0c\u4e5f\u5b58\u5728\u7740\u9501\u603b\u7ebf\/\u9501\u7f13\u5b58\/\u6267\u884c\u7f13\u5b58\u4e00\u81f4\u6027\u534f\u8bae\u7b49\u5f71\u54cd\u6027\u80fd\u7684\u673a\u5236\uff0c\u5176\u4e2d\u67d0\u4e9b\u64cd\u4f5c\u5b9e\u9645\u4e0a\u4e5f\u201c\u9501\u201d\u4f4f\u4e86\uff08\u6216\u8005\u8bf4\u5ef6\u7f13\u4e86\uff09\u5176\u4ed6\u7ebf\u7a0b\u5728\u7269\u7406\u6838\u4e0a\u7684\u8fd0\u884c\uff0c\u4f46\u662f\u76f8\u5bf9\u4e8e\u76f4\u63a5\u4f7f\u7528\u4e92\u65a5\u9501\u800c\u5bfc\u81f4\u7684OS\u7ebf\u7a0b\u8c03\u5ea6\u7684\u6210\u672c\uff0c\u8fd9\u4e2a\u6027\u80fd\u635f\u5931\u53ef\u4ee5\u7b97\u662f\u76f8\u5f53\u5c0f\u7684\u3002\u53c2\u8003<a href=\"https:\/\/zhuanlan.zhihu.com\/p\/58868634\">linux\u5185\u6838\u7684\u7ebf\u7a0b\u8c03\u5ea6\u4ee3\u7801<\/a>\uff0c\u4e00\u6b21\u7ebf\u7a0b\u8c03\u5ea6\u53ef\u80fd\u4f1a\u7275\u626f\u5230\u51e0\u5341\u4e43\u81f3\u51e0\u767e\u884cC\u4ee3\u7801\u7684\u6267\u884c\uff0c\u6c47\u7f16\u6210\u673a\u5668\u6307\u4ee4\u540e\u8fd9\u4e2a\u6570\u503c\u53ea\u4f1a\u66f4\u5938\u5f20\u3002\u6b64\u5916\uff0c\u65e0\u9501\u7f16\u7a0b\u4e5f\u80fd\u5c3d\u53ef\u80fd\u51cf\u5c11\u6b7b\u9501\u7b49\u95ee\u9898\u7684\u53d1\u751f\u3002\u603b\u7684\u6765\u8bf4\uff0c\u65e0\u9501\u7f16\u7a0b\u53ef\u4ee5\u5927\u5e45\u5ea6\u5730\u63d0\u9ad8\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u7684\u6027\u80fd\u3002<\/p>\n<h1>6. \u53c2\u8003<\/h1>\n<p><a href=\"https:\/\/zh.cppreference.com\/w\/cpp\/atomic\/memory_order\">cppreference\u4e0a\u7684\u5185\u5b58\u5e8f\u6587\u6863<\/a><br \/>\n<a href=\"http:\/\/senlinzhan.github.io\/2017\/12\/04\/cpp-memory-order\/\">http:\/\/senlinzhan.github.io\/2017\/12\/04\/cpp-memory-order\/<\/a><br \/>\n<a href=\"https:\/\/github.com\/apache\/incubator-brpc\/blob\/master\/docs\/cn\/atomic_instructions.md\">https:\/\/github.com\/apache\/incubator-brpc\/blob\/master\/docs\/cn\/atomic_instructions.md<\/a><br \/>\n<a href=\"https:\/\/blog.csdn.net\/smilejiasmile\/article\/details\/114188217\">https:\/\/blog.csdn.net\/smilejiasmile\/article\/details\/114188217<\/a><br \/>\n<a href=\"https:\/\/monkeysayhi.github.io\/2017\/12\/28\/%E4%B8%80%E6%96%87%E8%A7%A3%E5%86%B3%E5%86%85%E5%AD%98%E5%B1%8F%E9%9A%9C\/\">https:\/\/monkeysayhi.github.io\/2017\/12\/28\/%E4%B8%80%E6%96%87%E8%A7%A3%E5%86%B3%E5%86%85%E5%AD%98%E5%B1%8F%E9%9A%9C\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>1. \u95ee\u9898\u7684\u5f15\u5165 1.1. \u591a\u7ebf\u7a0b\u5e26\u6765\u7684\u4e09\u4e2a\u95ee\u9898 \u5728\u591a\u7ebf\u7a0b\u7f16\u7a0b\u4e0b\uff0c\u7a0b\u5e8f\u7684\u8fd0\u884c\u7ed3\u679c\u53ef\u80fd\u5e76\u4e0d\u5982\u6211\u4eec\u6240\u9884\u6599\u7684\u4e00\u81f4\u3002\u8fd9 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[15,28],"class_list":["post-249","post","type-post","status-publish","format-standard","hentry","category-c","tag-c","tag-28"],"_links":{"self":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts\/249","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/comments?post=249"}],"version-history":[{"count":0,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts\/249\/revisions"}],"wp:attachment":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/media?parent=249"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/categories?post=249"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/tags?post=249"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}