{"id":7425,"date":"2026-07-22T11:58:27","date_gmt":"2026-07-22T03:58:27","guid":{"rendered":"https:\/\/i007.cc\/wordpress\/?p=7425"},"modified":"2026-07-22T11:58:27","modified_gmt":"2026-07-22T03:58:27","slug":"stdasync-stdfuture%ef%bc%9a%e6%9b%b4%e9%ab%98%e7%ba%a7%e7%9a%84%e5%bc%82%e6%ad%a5%e4%bb%bb%e5%8a%a1","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/7425","title":{"rendered":"std::async \/ std::future\uff1a\u66f4\u9ad8\u7ea7\u7684\u5f02\u6b65\u4efb\u52a1"},"content":{"rendered":"

std::async<\/code> \/ std::future<\/code>\uff1a\u5f02\u6b65\u4efb\u52a1<\/h3>\n
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\ud83d\udd37 \u4e00\u3001\u4e3a\u4ec0\u4e48\u9700\u8981\u5b83\uff1f<\/h3>\n

std::thread<\/code> \u7684\u95ee\u9898\uff1a\u542f\u52a8\u7ebf\u7a0b\u540e\u62ff\u4e0d\u5230\u8fd4\u56de\u503c<\/strong>\u3002<\/p>\n

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cpp<\/div>\n
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\/\/ \u274c thread \u65e0\u6cd5\u8fd4\u56de\u503c\r\nint result;\r\nstd::thread t([&result]() {\r\n    result = 42;  \/\/ \u53ea\u80fd\u9760\u526f\u4f5c\u7528\"\u4f20\u51fa\"\u7ed3\u679c\uff0c\u5f88\u9ebb\u70e6\r\n});\r\nt.join();<\/pre>\n
 <\/p>\n<\/div>\n<\/div>\n
std::async<\/code> \u89e3\u51b3\u4e86\u8fd9\u4e2a\u95ee\u9898\uff1a\u542f\u52a8\u5f02\u6b65\u4efb\u52a1\uff0c\u8fd4\u56de\u4e00\u4e2a future<\/code> \u5bf9\u8c61\uff0c\u5c06\u6765\u53ef\u4ee5\u4ece\u4e2d\u53d6\u7ed3\u679c\u3002<\/strong><\/p>\n
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\ud83d\udd37 \u4e8c\u3001\u57fa\u672c\u7528\u6cd5<\/h3>\n
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cpp<\/div>\n
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#include <future>\r\n#include <iostream>\r\n\r\nint heavyCalc(int x) {\r\n    \/\/ \u6a21\u62df\u8017\u65f6\u8ba1\u7b97\r\n    std::this_thread::sleep_for(std::chrono::seconds(2));\r\n    return x * x;\r\n}\r\n\r\nint main() {\r\n    \/\/ \u542f\u52a8\u5f02\u6b65\u4efb\u52a1\uff0c\u7acb\u5373\u8fd4\u56de future\r\n    std::future<int> fut = std::async(std::launch::async, heavyCalc, 10);\r\n\r\n    std::cout << \"\u4efb\u52a1\u5df2\u542f\u52a8\uff0c\u4e3b\u7ebf\u7a0b\u7ee7\u7eed\u5e72\u522b\u7684...\" << std::endl;\r\n\r\n    \/\/ \u9700\u8981\u7ed3\u679c\u65f6\u518d get()\uff0c\u4f1a\u963b\u585e\u76f4\u5230\u4efb\u52a1\u5b8c\u6210\r\n    int result = fut.get();\r\n    std::cout << \"\u7ed3\u679c\uff1a\" << result << std::endl;  \/\/ \u2192 100\r\n}<\/pre>\n
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future<\/code> \u5c31\u50cf\u4e00\u5f20”\u53d6\u8d27\u51ed\u8bc1”<\/strong>\uff1a\u4efb\u52a1\u5728\u540e\u53f0\u8dd1\uff0c\u4f60\u5148\u5fd9\u522b\u7684\uff0c\u9700\u8981\u7ed3\u679c\u65f6\u51ed\u8bc1\u53d6\u8d27\u3002<\/p>\n<\/blockquote>\n
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\ud83d\udd37 \u4e09\u3001launch<\/code> \u7b56\u7565<\/h3>\n
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cpp<\/div>\n
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\/\/ \u5f3a\u5236\u65b0\u7ebf\u7a0b\u8fd0\u884c\r\nstd::async(std::launch::async, task);\r\n\r\n\/\/ \u5ef6\u8fdf\u6267\u884c\uff1a\u8c03\u7528 get() \u65f6\u624d\u5728\u5f53\u524d\u7ebf\u7a0b\u8fd0\u884c\uff08\u4e0d\u5f00\u65b0\u7ebf\u7a0b\uff09\r\nstd::async(std::launch::deferred, task);\r\n\r\n\/\/ \u9ed8\u8ba4\uff1a\u7531\u7cfb\u7edf\u51b3\u5b9a\uff08\u901a\u5e38\u7b49\u540c\u4e8e async\uff09\r\nstd::async(task);<\/pre>\n
 <\/p>\n<\/div>\n<\/div>\n
\u5b9e\u9645\u4f7f\u7528\u51e0\u4e4e\u603b\u662f\u7528 std::launch::async<\/code>\uff0c\u884c\u4e3a\u660e\u786e\u53ef\u63a7\u3002<\/p>\n
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\ud83d\udd37 \u56db\u3001\u5f02\u5e38\u4f20\u64ad<\/h3>\n
future<\/code> \u80fd\u81ea\u52a8\u6355\u83b7\u5f02\u6b65\u4efb\u52a1\u4e2d\u7684\u5f02\u5e38\uff0c\u5728 get()<\/code> \u65f6\u91cd\u65b0\u629b\u51fa\uff1a<\/p>\n
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cpp<\/div>\n
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auto fut = std::async(std::launch::async, []() -> int {\r\n    throw std::runtime_error(\"\u4efb\u52a1\u51fa\u9519\u4e86\uff01\");\r\n    return 0;\r\n});\r\n\r\ntry {\r\n    int val = fut.get();  \/\/ \u5f02\u5e38\u5728\u8fd9\u91cc\u91cd\u65b0\u629b\u51fa\r\n} catch (const std::exception& e) {\r\n    std::cout << \"\u6355\u83b7\u5f02\u5e38\uff1a\" << e.what();  \/\/ \u2192 \"\u4efb\u52a1\u51fa\u9519\u4e86\uff01\"\r\n}<\/pre>\n
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\ud83d\udd37 \u4e94\u3001\u5e76\u884c\u52a0\u901f\uff1a\u591a\u4e2a future<\/code> \u540c\u65f6\u8dd1<\/h3>\n
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cpp<\/div>\n
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\/\/ \u4e32\u884c\uff1a\u603b\u5171\u8017\u65f6 3s\r\nint a = heavyCalc(3);   \/\/ 1s\r\nint b = heavyCalc(4);   \/\/ 1s\r\nint c = heavyCalc(5);   \/\/ 1s\r\n\r\n\/\/ \u2705 \u5e76\u884c\uff1a\u603b\u5171\u53ea\u8017\u65f6 ~1s\r\nauto fa = std::async(std::launch::async, heavyCalc, 3);\r\nauto fb = std::async(std::launch::async, heavyCalc, 4);\r\nauto fc = std::async(std::launch::async, heavyCalc, 5);\r\n\r\n\/\/ \u4e09\u4e2a\u4efb\u52a1\u540c\u65f6\u5728\u8dd1\uff0c\u6700\u540e\u7edf\u4e00\u53d6\u7ed3\u679c\r\nint sum = fa.get() + fb.get() + fc.get();\r\n\/\/ \u2192 9 + 16 + 25 = 50<\/pre>\n
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\ud83d\udd37 \u516d\u3001promise<\/code>\uff1a\u624b\u52a8\u63a7\u5236 future<\/code><\/h3>\n
async<\/code> \u662f\u81ea\u52a8\u7684\uff1bpromise<\/code> \u8ba9\u4f60\u624b\u52a8<\/strong>\u51b3\u5b9a\u4f55\u65f6\u628a\u503c”\u653e\u5165” future\uff1a<\/p>\n
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cpp<\/div>\n
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#include <future>\r\n\r\nstd::promise<int> prom;\r\nstd::future<int> fut = prom.get_future();\r\n\r\n\/\/ \u5728\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4e2d\u8bbe\u7f6e\u503c\r\nstd::thread t([&prom]() {\r\n    std::this_thread::sleep_for(std::chrono::seconds(1));\r\n    prom.set_value(42);   \/\/ \u628a\u503c\"\u63a8\u5165\" future\r\n});\r\n\r\nstd::cout << fut.get();  \/\/ \u963b\u585e\u76f4\u5230 set_value \u88ab\u8c03\u7528 \u2192 42\r\nt.join();<\/pre>\n
 <\/p>\n<\/div>\n<\/div>\n
\u9002\u7528\u573a\u666f<\/strong>\uff1a\u56de\u8c03\u5f0f API\u3001\u4e8b\u4ef6\u9a71\u52a8\u3001\u624b\u52a8\u63a7\u5236\u5b8c\u6210\u65f6\u673a\u3002<\/p>\n
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\ud83d\udd37 \u4e03\u3001shared_future<\/code>\uff1a\u7ed3\u679c\u5171\u4eab\u7ed9\u591a\u4e2a\u6d88\u8d39\u8005<\/h3>\n
\u666e\u901a future<\/code> \u53ea\u80fd get()<\/code> \u4e00\u6b21\uff0cshared_future<\/code> \u53ef\u4ee5\u591a\u6b21\u8bfb\u53d6\uff1a<\/p>\n
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cpp<\/div>\n
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std::shared_future<int> sf = std::async(std::launch::async, []() {\r\n    return 100;\r\n}).share();  \/\/ \u8f6c\u4e3a shared_future\r\n\r\n\/\/ \u591a\u4e2a\u7ebf\u7a0b\u90fd\u53ef\u4ee5\u8bfb\u540c\u4e00\u4e2a\u7ed3\u679c\r\nstd::thread t1([sf]() { std::cout << sf.get(); });\r\nstd::thread t2([sf]() { std::cout << sf.get(); });\r\n\r\nt1.join(); t2.join();\r\n\/\/ \u4e24\u4e2a\u7ebf\u7a0b\u90fd\u8f93\u51fa 100\uff0c\u5b89\u5168\uff01<\/pre>\n
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\ud83d\udd37 \u516b\u3001\u6574\u4f53\u7ed3\u6784\u56fe<\/h3>\n
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\u542f\u52a8                  \u53d6\u7ed3\u679c\r\n\u4f60  \u2500\u2500\u25ba async(task) \u2500\u2500\u25ba future \u2500\u2500\u25ba get() \u2500\u2500\u25ba \u7ed3\u679c\/\u5f02\u5e38\r\n              \u2502\r\n              \u2514\u2500\u2500\u25ba \u540e\u53f0\u7ebf\u7a0b\u9ed8\u9ed8\u8fd0\u884c task...\r\n\r\n\r\n\u624b\u52a8\u63a7\u5236\uff1a\r\n\u4f60  \u2500\u2500\u25ba promise \u2500\u2500\u25ba get_future() \u2500\u2500\u25ba future\r\n              \u2502\r\n              \u2514\u2500\u2500\u25ba \u4efb\u610f\u65f6\u523b set_value() \u89e6\u53d1<\/pre>\n
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\ud83d\udd37 \u9009\u62e9\u6307\u5357<\/h3>\n
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\u573a\u666f<\/th>\n\u7528\u4ec0\u4e48<\/th>\n<\/tr>\n<\/thead>\n
\u7b80\u5355\u5f02\u6b65\u4efb\u52a1\uff0c\u9700\u8981\u8fd4\u56de\u503c<\/td>\nstd::async<\/code><\/td>\n<\/tr>\n
\u591a\u4efb\u52a1\u5e76\u884c\uff0c\u6700\u540e\u6c47\u603b<\/td>\n\u591a\u4e2a std::future<\/code><\/td>\n<\/tr>\n
\u56de\u8c03\/\u4e8b\u4ef6\u9a71\u52a8\uff0c\u624b\u52a8\u63a7\u5236\u5b8c\u6210<\/td>\nstd::promise<\/code><\/td>\n<\/tr>\n
\u591a\u4e2a\u6d88\u8d39\u8005\u5171\u4eab\u540c\u4e00\u7ed3\u679c<\/td>\nstd::shared_future<\/code><\/td>\n<\/tr>\n
\u4e0d\u9700\u8981\u8fd4\u56de\u503c\uff0c\u7eaf\u526f\u4f5c\u7528<\/td>\nstd::thread<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
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\u4e0b\u4e00\u6b65\u53ef\u4ee5\u5b66\uff1a<\/p>\n
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  • std::packaged_task<\/code><\/strong>\uff1a\u628a\u51fd\u6570\u5305\u88c5\u6210\u53ef\u8c03\u5ea6\u7684\u4efb\u52a1<\/li>\n
  • \u7ebf\u7a0b\u6c60<\/strong>\uff1a\u590d\u7528\u7ebf\u7a0b\uff0c\u907f\u514d\u9891\u7e41\u521b\u5efa\u9500\u6bc1\u7684\u5f00\u9500<\/li>\n
  • C++20 \u534f\u7a0b<\/strong>\uff1a\u66f4\u73b0\u4ee3\u7684\u5f02\u6b65\u65b9\u5f0f\uff08co_await<\/code>\uff09<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
    std::async \/ std::fu<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[24],"tags":[],"class_list":["post-7425","post","type-post","status-publish","format-standard","hentry","category-value_docs"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/7425","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=7425"}],"version-history":[{"count":1,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/7425\/revisions"}],"predecessor-version":[{"id":7426,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/7425\/revisions\/7426"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=7425"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=7425"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=7425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}