{"id":36,"date":"2024-11-27T15:18:06","date_gmt":"2024-11-27T07:18:06","guid":{"rendered":"https:\/\/genetop.top\/?p=36"},"modified":"2024-12-14T09:22:43","modified_gmt":"2024-12-14T01:22:43","slug":"c-stl-chrono-vs-monotonic_time_get_milliseconds","status":"publish","type":"post","link":"https:\/\/genetop.top\/index.php\/2024\/11\/27\/c-stl-chrono-vs-monotonic_time_get_milliseconds\/","title":{"rendered":"C++ STL chrono\u548cmonotonic_time_get_milliseconds\u7684\u6027\u80fd\u5bf9\u6bd4"},"content":{"rendered":"

1. \u6838\u5fc3\u533a\u522b<\/strong><\/h3>\n
    \n
  1. monotonic_time_get_milliseconds<\/code><\/strong>\uff1a\n
      \n
    • \u901a\u5e38\u662f\u4e00\u4e2a\u81ea\u5b9a\u4e49\u6216\u5e73\u53f0\u76f8\u5173\u7684\u51fd\u6570\u3002<\/li>\n
    • \u5982\u679c\u5e95\u5c42\u5b9e\u73b0\u4f9d\u8d56\u4e8e clock_gettime(CLOCK_MONOTONIC)<\/code>\uff08Linux\/Unix\uff09\u6216\u7c7b\u4f3c\u7684 API\uff0c\u5176\u6027\u80fd\u4f1a\u4e0e\u5e73\u53f0\u7684\u7cfb\u7edf\u8c03\u7528\u5f00\u9500\u76f4\u63a5\u76f8\u5173\u3002<\/li>\n
    • \u63d0\u4f9b\u65f6\u95f4\u6233\u901a\u5e38\u4ee5\u6beb\u79d2\u4e3a\u5355\u4f4d\uff0c\u53ef\u80fd\u4f1a\u6d89\u53ca\u989d\u5916\u7684\u8f6c\u6362\uff08\u5982\u4ece\u7eb3\u79d2\u5230\u6beb\u79d2\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n
    • std::chrono::steady_clock::now()<\/code><\/strong>\uff1a\n
        \n
      • C++ \u6807\u51c6\u5e93\u7684\u4e00\u90e8\u5206\uff0c\u57fa\u4e8e\u5e73\u53f0\u7684\u5355\u8c03\u65f6\u949f\u5b9e\u73b0\u3002<\/li>\n
      • \u5728\u5927\u591a\u6570\u5e73\u53f0\u4e0a\uff0cstd::chrono::steady_clock<\/code> \u901a\u5e38\u5305\u88c5\u4e86\u5e95\u5c42\u7684\u5355\u8c03\u65f6\u949f API\uff1a\n
          \n
        • Linux\/Unix\uff1aclock_gettime(CLOCK_MONOTONIC)<\/code><\/li>\n
        • Windows\uff1aQueryPerformanceCounter<\/code><\/li>\n
        • macOS\uff1amach_absolute_time<\/code><\/li>\n<\/ul>\n<\/li>\n
        • \u63d0\u4f9b\u7684\u65f6\u95f4\u5355\u4f4d\u662f std::chrono::time_point<\/code>\uff0c\u7528\u6237\u53ef\u4ee5\u9009\u62e9\u9700\u8981\u7684\u65f6\u95f4\u7cbe\u5ea6\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
          \n

          2. \u6027\u80fd\u6bd4\u8f83<\/strong><\/h3>\n

          \u4ee5\u4e0b\u662f\u4e24\u8005\u6027\u80fd\u7684\u4e3b\u8981\u6bd4\u8f83\u70b9\uff1a<\/p>\n\n\n\n\n\n\n\n\n\n
          \u6307\u6807<\/strong><\/th>\nmonotonic_time_get_milliseconds<\/code><\/strong><\/th>\nstd::chrono::steady_clock::now()<\/code><\/strong><\/th>\n<\/tr>\n<\/thead>\n
          \u8c03\u7528\u5f00\u9500<\/strong><\/td>\n\u4f9d\u8d56\u4e8e\u5b9e\u73b0\uff0c\u901a\u5e38\u63a5\u8fd1\u5e95\u5c42API\u6027\u80fd<\/td>\n\u5305\u88c5\u5e95\u5c42API\uff0c\u989d\u5916\u5f00\u9500\u6781\u5c0f<\/td>\n<\/tr>\n
          \u65f6\u95f4\u7cbe\u5ea6<\/strong><\/td>\n\u6beb\u79d2\uff08\u53ef\u80fd\u56fa\u5b9a\uff09<\/td>\n\u53ef\u63d0\u4f9b\u7eb3\u79d2\u6216\u5176\u4ed6\u7cbe\u5ea6<\/td>\n<\/tr>\n
          \u53ef\u79fb\u690d\u6027<\/strong><\/td>\n\u53ef\u80fd\u53d7\u9650\u4e8e\u5b9e\u73b0<\/td>\n\u9ad8\uff0c\u8de8\u5e73\u53f0\u4e00\u81f4<\/td>\n<\/tr>\n
          \u989d\u5916\u8f6c\u6362\u5f00\u9500<\/strong><\/td>\n\u53ef\u80fd\u9700\u4ece\u7eb3\u79d2\u5230\u6beb\u79d2\u8f6c\u6362<\/td>\n\u65e0\u9700\u624b\u52a8\u8f6c\u6362\uff0c\u6309\u9700\u9009\u62e9\u5355\u4f4d<\/td>\n<\/tr>\n
          \u5178\u578b\u6027\u80fd\uff08Linux\uff09<\/strong><\/td>\n20-60 \u7eb3\u79d2\uff08\u5982\u679c\u57fa\u4e8e clock_gettime<\/code>\uff09<\/td>\n50-100 \u7eb3\u79d2\uff08\u8f7b\u5fae\u989d\u5916\u5f00\u9500\uff09<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
          \n

          3. \u5177\u4f53\u6bd4\u8f83\u573a\u666f<\/strong><\/h3>\n
            \n
          1. \u4f4e\u7ea7\u6027\u80fd\u6bd4\u8f83<\/strong>\uff1a\n
              \n
            • \u5982\u679c monotonic_time_get_milliseconds<\/code> \u662f\u76f4\u63a5\u5c01\u88c5\u4e86 clock_gettime(CLOCK_MONOTONIC)<\/code> \u6216\u7c7b\u4f3c\u7684\u51fd\u6570\uff0c\u5176\u6027\u80fd\u53ef\u80fd\u7a0d\u5fae\u4f18\u4e8e std::chrono::steady_clock::now()<\/code>\uff0c\u56e0\u4e3a\u540e\u8005\u4f1a\u7ecf\u8fc7\u8f7b\u91cf\u7684\u6807\u51c6\u5e93\u5c01\u88c5\u3002<\/li>\n
            • \u5bf9\u4e8e\u9ad8\u9891\u8c03\u7528\u573a\u666f\uff08\u5982\u6e38\u620f\u5f15\u64ce\u6216\u5b9e\u65f6\u7cfb\u7edf\uff09\uff0c\u8fd9\u79cd\u5fae\u5c0f\u7684\u5f00\u9500\u53ef\u80fd\u4f1a\u7d2f\u79ef\uff0c\u4f46\u5dee\u5f02\u4ecd\u7136\u975e\u5e38\u5c0f\uff08\u4e00\u822c\u4e0d\u8d85\u8fc7\u51e0\u5341\u7eb3\u79d2\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n
            • \u7075\u6d3b\u6027\u4e0e\u53ef\u7528\u6027<\/strong>\uff1a\n
                \n
              • std::chrono::steady_clock<\/code> \u63d0\u4f9b\u4e86\u66f4\u591a\u7075\u6d3b\u6027\uff0c\u652f\u6301\u591a\u79cd\u65f6\u95f4\u7cbe\u5ea6\uff08\u7eb3\u79d2\u3001\u5fae\u79d2\u3001\u6beb\u79d2\u7b49\uff09\uff0c\u540c\u65f6\u662f\u6807\u51c6\u5e93\u7684\u4e00\u90e8\u5206\uff0c\u5177\u5907\u66f4\u9ad8\u7684\u53ef\u79fb\u690d\u6027\u3002<\/li>\n
              • \u5982\u679c\u53ea\u9700\u8981\u6beb\u79d2\u7cbe\u5ea6\uff0c\u5e76\u4e14\u6027\u80fd\u81f3\u5173\u91cd\u8981\uff0cmonotonic_time_get_milliseconds<\/code> \u7684\u7b80\u5355\u5b9e\u73b0\u53ef\u80fd\u4f1a\u66f4\u5feb\u3002<\/li>\n<\/ul>\n<\/li>\n
              • \u4ee3\u7801\u7ef4\u62a4\u4e0e\u53ef\u9760\u6027<\/strong>\uff1a\n
                  \n
                • \u4f7f\u7528 std::chrono::steady_clock<\/code> \u53ef\u4ee5\u51cf\u5c11\u5bf9\u7279\u5b9a\u5e73\u53f0 API \u7684\u4f9d\u8d56\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\u548c\u8de8\u5e73\u53f0\u6027\u3002<\/li>\n
                • \u81ea\u5b9a\u4e49\u7684 monotonic_time_get_milliseconds<\/code> \u53ef\u80fd\u9700\u8981\u989d\u5916\u8003\u8651\u5e73\u53f0\u517c\u5bb9\u6027\u548c\u6f5c\u5728\u7684\u9519\u8bef\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
                  \n

                  4. \u5b9e\u9645\u6027\u80fd\u6d4b\u8bd5<\/strong><\/h3>\n

                  \u5728\u5b9e\u8df5\u4e2d\uff0c\u6027\u80fd\u5dee\u5f02\u53ef\u4ee5\u901a\u8fc7\u5fae\u57fa\u51c6\u6d4b\u8bd5\u6765\u8bc4\u4f30\u3002\u4f8b\u5982\uff0c\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684 C++ \u6027\u80fd\u6d4b\u8bd5\u4ee3\u7801\uff1a<\/p>\n

                  \n
                  #include
                  \n#include
                  \n#include<\/code><\/code>\/\/ Example monotonic_time_get_milliseconds implementation
                  \nlong long monotonic_time_get_milliseconds() {
                  \nstruct timespec ts;
                  \nclock_gettime(CLOCK_MONOTONIC, &ts);
                  \nreturn ts.tv_sec * 1000LL + ts.tv_nsec \/ 1000000LL;
                  \n}<\/p>\n

                  <\/code><\/code>int main() {
                  \nconstexpr int iterations = 1000000;<\/p>\n

                  <\/code><\/code>\/\/ Test monotonic_time_get_milliseconds
                  \nauto start = std::chrono::high_resolution_clock::now();
                  \nfor (int i = 0; i < iterations; ++i) {
                  \nvolatile auto time = monotonic_time_get_milliseconds();
                  \n}
                  \nauto end = std::chrono::high_resolution_clock::now();
                  \nstd::cout << “monotonic_time_get_milliseconds: ”
                  \n<< std::chrono::duration_cast(end – start).count()
                  \n<< ” microseconds\\n”;<\/p>\n

                  <\/code><\/code>\/\/ Test std::chrono::steady_clock::now
                  \nstart = std::chrono::high_resolution_clock::now();
                  \nfor (int i = 0; i < iterations; ++i) {
                  \nvolatile auto time = std::chrono::steady_clock::now();
                  \n}
                  \nend = std::chrono::high_resolution_clock::now();
                  \nstd::cout << “std::chrono::steady_clock::now: ”
                  \n<< std::chrono::duration_cast(end – start).count()
                  \n<< ” microseconds\\n”;<\/p>\n

                  <\/code><\/code>return 0;
                  \n}<\/p>\n

                  \u8f93\u51fa\uff1a
                  \nmonotonic_time_get_milliseconds: 21185 microseconds
                  \nstd::chrono::steady_clock::now: 21424 microseconds<\/p>\n<\/div>\n<\/div>\n

                  \n

                  5. \u603b\u7ed3<\/strong><\/h3>\n
                    \n
                  • \u6027\u80fd<\/strong>\uff1a\n
                      \n
                    • \u5982\u679c monotonic_time_get_milliseconds<\/code> \u662f\u76f4\u63a5\u8c03\u7528\u5e95\u5c42 API\uff0c\u5b83\u7684\u6027\u80fd\u53ef\u80fd\u7565\u9ad8\uff0c\u4f46\u5dee\u8ddd\u901a\u5e38\u5f88\u5c0f\u3002<\/li>\n
                    • \u5bf9\u4e8e\u7edd\u5927\u591a\u6570\u5e94\u7528\u573a\u666f\uff0cstd::chrono::steady_clock::now()<\/code> \u7684\u989d\u5916\u5f00\u9500\u53ef\u4ee5\u5ffd\u7565\u3002<\/li>\n<\/ul>\n<\/li>\n
                    • \u63a8\u8350<\/strong>\uff1a\n
                        \n
                      • \u5982\u679c\u9700\u8981\u9ad8\u6027\u80fd\u8ba1\u65f6\uff0c\u5e76\u4e14\u4ee3\u7801\u9700\u8de8\u5e73\u53f0\uff0c\u4f7f\u7528 std::chrono::steady_clock::now()<\/code> \u662f\u66f4\u597d\u7684\u9009\u62e9\u3002<\/li>\n
                      • \u5982\u679c\u53ea\u5173\u6ce8\u6beb\u79d2\u7ea7\u522b\u6027\u80fd\uff0c\u4e14\u4ee3\u7801\u9650\u5b9a\u5728\u7279\u5b9a\u5e73\u53f0\u4e0a\uff0cmonotonic_time_get_milliseconds<\/code> \u53ef\u80fd\u4f1a\u6709\u5fae\u5c0f\u4f18\u52bf\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                        1. \u6838\u5fc3\u533a\u522b monotonic_time_get_milliseconds\uff1a \u901a\u5e38\u662f\u4e00\u4e2a\u81ea\u5b9a\u4e49\u6216\u5e73\u53f0\u76f8\u5173\u7684 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,3],"tags":[],"class_list":["post-36","post","type-post","status-publish","format-standard","hentry","category-c","category-language"],"_links":{"self":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/36","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/comments?post=36"}],"version-history":[{"count":5,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/36\/revisions"}],"predecessor-version":[{"id":39,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/36\/revisions\/39"}],"wp:attachment":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/media?parent=36"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/categories?post=36"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/tags?post=36"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}