![哪些std]( "哪些std")
本文介绍了哪些std :: async实现使用线程池？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 使用 std :: async 而不是手动创建 std :: thread 对象的一个优点是是 std :: async 可以使用线程池下的覆盖，以避免超额预订问题。但是哪些实现这样做？我的理解是微软的实现，但是这些其他 async 实现呢？ Gnu的libstdc ++ Gnu的libc ++ Just Software的库 Boost boost :: thread :: async ，而不是 std :: async ） 感谢您提供的任何信息。解决方案 黑盒测试 虽然白盒检查可以通过检查boost，libstdc ++或libc ++源，或检查文档，如 just :: thread 或 MSVC并发运行时，但我不能否认自己编写C ++ 11代码的乐趣！ 我已经使黑盒测试： LIVE DEMO #define BOOST_THREAD_PROVIDES_FUTURE #define BOOST_RESULT_OF_USE_DECLTYPE #include< boost / exception / exception.hpp> #include< boost / range / algorithm.hpp> #include< boost / move / iterator.hpp> #include< boost / phoenix.hpp> #include< boost / thread.hpp> #include< boost / config.hpp> #include< unordered_set> #include< functional> #include< algorithm> #include< iterator> #include< iostream> #include< ostream> #include< cstddef> #include< string> #include< vector> #include< future> #include< thread> #include< chrono> #include< mutex> // _____________________ [CONFIGURATION] ________________________ // namespace async_lib = std; const bool work_is_sleep = false; // ____________________________________________________________ // using namespace std; using boost :: phoenix :: arg_names :: arg1; using boost :: thread_specific_ptr; using boost :: back_move_inserter; using boost :: type_name; using boost :: count_if; using boost :: copy; template< typename Mutex> unique_lock< Mutex> locker（Mutex& m） { return unique_lock< Mutex>（m）; } void do_work（） { if（work_is_sleep） { this_thread :: sleep_for（chrono :: milliseconds ））; } else { volatile double result = 0.0; for（size_t i = 0; i！= 1<< 22; ++ i） result + = 0.1; } } int main（） { typedef thread :: id TID; typedef async_lib :: future< TID> FTID; unordered_set< TID> tids，live_tids; vector< FTID> ftids; vector< int> live_tids_count; async_lib :: mutex m; generate_n （ back_move_inserter（ftids），64 * thread :: hardware_concurrency（）， [&]（） { return async_lib： ：async（[&]（） - > TID { static thread_specific_ptr< bool> fresh; if（fresh.get（）== nullptr） fresh。 reset（new bool（true））; TID tid = this_thread :: get_id（）; locker（m）， live_tids.insert（tid）， live_tids_count.push_back （int（live_tids.size（））*（* fresh？-1：1））; do_work（）; locker（m）， live_tids.erase（tid）; * fresh = false; return tid; }）; } ）; transform （ begin（ftids），end（ftids）， insertionter（tids，tids.end（））， []（FTID& x ）{return x.get（）;} ）; cout<< Compiler =< BOOST_COMPILER<< endl; cout<< Standard library =< BOOST_STDLIB<< endl; cout<< Boost =< BOOST_LIB_VERSION<< endl; cout<< future type =<< type_name< FTID>（）<< endl; cout<< 只睡在do_work =< boolalpha< work_is_sleep<< endl; cout<< string（32，'_'）<< endl; cout<< hardware_concurrency =< thread :: hardware_concurrency（）<< endl; cout<< async count =< ftids.size（）<< endl; cout<< unique thread id's =< tids.size（）<< endl; cout<< 活线程计数（负表示新线程）：; copy（live_tids_count，ostream_iterator< int>（cout，））; cout cout<< fresh count =< count_if（live_tids_count，arg1< 0）<< endl; } Compiler = Microsoft Visual C ++版本11.0 标准库= Dinkumware标准库版本540 Boost = 1_53 未来类型= class std :: future< class std :: thread :: id> 只睡在do_work = false ________________________________ hardware_concurrency = 4 async count = 256 唯一的线程id = 4 活线程数螺纹）： - 1 -2 2 2 -3 -4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 fresh count = 4 Compiler = Microsoft Visual C ++ 11.0版标准库= Dinkumware标准库版本540 Boost = 1_53 future type = class std :: future< class std :: thread :: id> 只睡在do_work = true ________________________________ hardware_concurrency = 4 异步计数= 256 唯一线程ID = 34 活线程计数螺纹）： - 1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 -19 19 -20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 21 21 -22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 - 23 23 23 23 -24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 25 25 25 25 25 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 -27 27 27 27 27 27 -28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 -29 29 29 29 29 29 29 -30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 -31 31 31 31 31 31 31 31 - 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 -33 33 33 33 33 33 33 33 33 -34 34 34 34 34 34 34 34 34 11 12 11 12 13 14 15 16 15 10 11 12 13 14 fresh count = 34 Compiler = Microsoft Visual C ++版本11.0 标准库= Dinkumware标准库版本540 Boost = 1_53 future type = class boost :: future< class std :: thread :: id> 只睡在do_work = false ________________________________ hardware_concurrency = 4 async count = 256 唯一的线程id = 256 活线程计数螺纹）： - 1 -2 -2 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -4 -4 -4 -4 -4 -4 -4 - 4 -4 -4 -3 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 - 4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -2 - 3 -3 -3 -3 -4 -4 -4 -4 -2 -2 -2 -2 -3 -3 -2 -2 -3 -1 -2 -2 -3 -3 -1 -2 - 1 -2 -3 -2 -2 -2 -2 -2 -1 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -2 -2 -2 - 2 -3 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 b $ b -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 - 2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -1 -2 -1 -2 -1 -2 -1 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 - 2 -2 -3 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 b $ b -2 -2 -2 -2 -2 -2 -2 - 2 -2 -2 -2 -3 -3 -3 -2 -2 -3 -1 -2 -1 -2 -2 -2 -3 -2 -3 -1 -2 -2 -2 -3 -2 -3 - 2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 b $ b -2 -2 -2 -2 -2 - 2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -3 -2 -2 -2 -3 -3 新鲜计数= 256 Compiler = Microsoft Visual C + + 11.0 标准库= Dinkumware标准库版本540 Boost = 1_53 未来类型= class boost :: future< class std :: thread :: id> 只睡在do_work = true ________________________________ hardware_concurrency = 4 异步计数= 256 唯一线程ID = 256 活动线程计数螺纹）： - 1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 - 24 -25 -26 -27 -2 8 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -60 -61 -62 -63 -64 -65 -66 -67 -68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80 -81 -82 -83 -84 -85 -86 -87 -88 -89 -90 -91 -92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102 -103 -104 -105 -106 -107 -108 -109 -110 -111 -112 -113 -114 -115 -116 -117 -118 -119 -120 -121 -122 -123 -124 -125 -126 -127 -128 -129 -130 -131 -132 -133 -134 -135 -136 -137 -138 -139 -140 -141 -142 -143 -144 -145 -146 -147 -148 -149 -150 -151 -152 -153 -154 -155 -156 -157 -158 -159 -160 -161 -162 -163 -164 -165 -166 -167 -168 -169 -170 -171 -172 -173 -174 -175 -176 -177 -178 -179 -180 -181 -182 -183 -184 -185 -186 -187 -188 -189 -190 -191 -192 -193 -194 -195 -196 -197 -198 -199 -200 -201 -202 -203 -204 -205 -206 -207 -208 -209 -210 -211 -212 -213 -214 -215 -216 -217 -218 -219 -220 -221 -222 -223 -224 -225 -226 -227 -228 -229 -230 -231 -232 -233 -234 -235 -236 -237 -238 -239 -240 -241 -242 -243 -244 -245 -246 -247 -248 -249 -250 -251 -252 -253 -254 -255 -256 fresh count = 256 Compiler = GNU C ++版本4.8.0-alpha20121216 20121216（实验）标准库= GNU libstdc ++版本20121216 Boost = 1_53 未来类型= std :: future< std :: thread :: id> 只睡在do_work = false ________________________________ hardware_concurrency = 4 async count = 256 唯一的线程id = 1 活线程数螺纹）： - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 fresh count = 1 编译器= GNU C ++版本4.8.0-alpha20121216 20121216（实验）标准库= GNU libstdc ++版本20121216 Boost = 1_53 future type = boost :: future< std :: thread :: id> 只睡在do_work = false ________________________________ hardware_concurrency = 4 async count = 256 唯一的线程id = 122 活线程计数螺纹）： - 1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -20 -21 - 22 -23 -24 -25 -25 -26 -27 -28 -29 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 - 45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -59 -60 -61 -62 -63 -64 -64 -64 -63 -61 - 55 -48 -41 -33 -34 -27 -27 -28 -29 -29 -30 -31 -31 -30 -28 -29 -28 -28 -28 -29 -30 -30 -31 -30 -31 - 31 -31 -32 -31 -26 -24 -25 -26 -25 -23 -23 -22 -20 -21 -19 -20 -20 -19 -20 -21 -21 -22 -21 -22 -23 - 24 -24 -25 -26 -27 -25 -25 -25 -22 -23 -22 -23 -23 -24 -25 -26 -27 -27 -28 -29 -29 -30 -31 -32 -33 - 34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -51 -52 -53 -54 -55 -56 -57 - 56 -54 -3 -3 -4 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 - 24 -25 -26 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 - 49 -50 -51 -52 -53 -54 -55 -55 -56 -57 -58 -59 -60 -61 -61 -61 -62 -63 -64 -65 -64 -62 -63 -63 -61 - 62 -61 -59 -60 -59 -57 -55 -56 新鲜计数= 256 Compiler = Clang版本3.2（标签/ RELEASE_32 / final）标准库= libc ++版本1101 Boost = 1_53 future type = NSt3__16futureINS_11__thread_idEEE 只在do_work = false中进行睡眠 ________________________________ hardware_concurrency = 4 异步计数= 256 唯一线程ID = 255 live threads count（negative means new thread）： - 1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -60 -61 -62 -63 -64 -65 -66 -67 -68 -69 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80 -81 -82 -83 -84 -85 -86 -87 -88 -89 -90 -91 -92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102 -102 -103 -104 -105 -106 -107 -108 -109 -110 -111 -112 -113 -114 -115 -116 -117 -118 -119 -120 -121 -121 -122 -122 -123 -123 -124 -125 -126 -127 -126 -127 -128 -129 -129 -128 -129 -128 -129 -129 -128 -129 -129 -128 -126 -127 -128 -128 -129 -129 -130 -129 -129 -128 -129 -129 -130 -131 -132 -133 -134 -135 -136 -134 -132 -133 -134 -134 -133 -132 -133 -132 -133 -134 -133 -131 -129 -127 -124 -125 -121 -119 -120 -118 -119 -118 -117 -115 -111 -107 -105 -106 -103 -100 -97 -95 -96 -94 -90 -87 -81 -73 -74 -71 -72 -73 -74 -75 -70 -71 -66 -60 -59 -60 -61 -62 -63 -64 -61 -58 -55 -55 -52 -53 -54 -54 -55 -56 -56 -57 -54 -55 -56 -56 -57 -57 -58 -56 -54 -55 -56 -56 -57 -58 -58 -59 -58 -58 -58 -58 -59 -60 新鲜计数= 256 可以看出 - MSVC重用线程，也就是说它很可能是某种类型的线程池。 One of the advantages of using std::async instead of manually creating std::thread objects is supposed to be that std::async can use thread pools under the covers to avoid oversubscription problems. But which implementations do this? My understanding is that Microsoft's implementation does, but what about these other async implementations?Gnu's libstdc++Gnu's libc++Just Software's libraryBoost (for boost::thread::async, not std::async)Thanks for any information you can offer. 解决方案 Black-Box TestThough "white box" check can be done via inspecting boost, libstdc++ or libc++ sources, or checking documentation like just::thread or MSVC Concurrency Runtime, but I can not deny myself the pleasure of writing C++11 code!I have made black-box test:LIVE DEMO#define BOOST_THREAD_PROVIDES_FUTURE#define BOOST_RESULT_OF_USE_DECLTYPE#include <boost/exception/exception.hpp>#include <boost/range/algorithm.hpp>#include <boost/move/iterator.hpp>#include <boost/phoenix.hpp>#include <boost/thread.hpp>#include <boost/config.hpp>#include <unordered_set>#include <functional>#include <algorithm>#include <iterator>#include <iostream>#include <ostream>#include <cstddef>#include <string>#include <vector>#include <future>#include <thread>#include <chrono>#include <mutex>// _____________________[CONFIGURATION]________________________ //namespace async_lib = std;const bool work_is_sleep = false;// ____________________________________________________________ //using namespace std;using boost::phoenix::arg_names::arg1;using boost::thread_specific_ptr;using boost::back_move_inserter;using boost::type_name;using boost::count_if;using boost::copy;template<typename Mutex>unique_lock<Mutex> locker(Mutex &m){ return unique_lock<Mutex>(m);}void do_work(){ if(work_is_sleep) { this_thread::sleep_for( chrono::milliseconds(20) ); } else { volatile double result=0.0; for(size_t i=0; i!=1<<22; ++i) result+=0.1; }}int main(){ typedef thread::id TID; typedef async_lib::future<TID> FTID; unordered_set<TID> tids, live_tids; vector<FTID> ftids; vector<int> live_tids_count; async_lib::mutex m; generate_n ( back_move_inserter(ftids), 64*thread::hardware_concurrency(), [&]() { return async_lib::async([&]() -> TID { static thread_specific_ptr<bool> fresh; if(fresh.get() == nullptr) fresh.reset(new bool(true)); TID tid = this_thread::get_id(); locker(m), live_tids.insert(tid), live_tids_count.push_back(int(live_tids.size()) * (*fresh ? -1 : 1)); do_work(); locker(m), live_tids.erase(tid); *fresh = false; return tid; }); } ); transform ( begin(ftids), end(ftids), inserter(tids, tids.end()), [](FTID &x){return x.get();} ); cout << "Compiler = " << BOOST_COMPILER << endl; cout << "Standard library = " << BOOST_STDLIB << endl; cout << "Boost = " << BOOST_LIB_VERSION << endl; cout << "future type = " << type_name<FTID>() << endl; cout << "Only sleep in do_work = " << boolalpha << work_is_sleep << endl; cout << string(32,'_') << endl; cout << "hardware_concurrency = " << thread::hardware_concurrency() << endl; cout << "async count = " << ftids.size() << endl; cout << "unique thread id's = " << tids.size() << endl; cout << "live threads count (negative means fresh thread):" ; copy(live_tids_count, ostream_iterator<int>(cout," ")); cout << endl; cout << "fresh count = " << count_if(live_tids_count, arg1 < 0) << endl;}Compiler = Microsoft Visual C++ version 11.0Standard library = Dinkumware standard library version 540Boost = 1_53future type = class std::future<class std::thread::id>Only sleep in do_work = false________________________________hardware_concurrency = 4async count = 256unique thread id's = 4live threads count (negative means fresh thread):-1 -2 2 2 -3 -4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4fresh count = 4Compiler = Microsoft Visual C++ version 11.0Standard library = Dinkumware standard library version 540Boost = 1_53future type = class std::future<class std::thread::id>Only sleep in do_work = true________________________________hardware_concurrency = 4async count = 256unique thread id's = 34live threads count (negative means fresh thread):-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 -19 19 -20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 -21 21 21 -22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 -23 23 23 23 -24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 -25 25 25 25 25 -26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 2626 26 26 -27 27 27 27 27 27 -28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 -29 29 29 29 29 29 29 -30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 -31 31 31 31 31 31 31 31 -32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 -33 33 33 33 33 33 33 33 33 -34 34 34 34 34 34 34 34 34 11 12 11 12 13 14 15 16 15 10 11 12 13 14fresh count = 34Compiler = Microsoft Visual C++ version 11.0Standard library = Dinkumware standard library version 540Boost = 1_53future type = class boost::future<class std::thread::id>Only sleep in do_work = false________________________________hardware_concurrency = 4async count = 256unique thread id's = 256live threads count (negative means fresh thread):-1 -2 -2 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -3 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -3 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -2 -3 -3 -3 -3 -4 -4 -4 -4 -2 -2 -2 -2 -3 -2 -2 -3 -1 -2 -2 -3 -3 -1 -2 -1 -2 -3 -2 -2 -2 -2 -1 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -2 -2 -2 -2 -3 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -1 -2 -1 -2 -1 -2 -1 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -2 -2 -3 -1 -2 -1 -2 -2 -2 -3 -2 -3 -1 -2 -2 -2 -3 -2 -3 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -2 -3 -3 -3 -2 -2 -2 -3fresh count = 256Compiler = Microsoft Visual C++ version 11.0Standard library = Dinkumware standard library version 540Boost = 1_53future type = class boost::future<class std::thread::id>Only sleep in do_work = true________________________________hardware_concurrency = 4async count = 256unique thread id's = 256live threads count (negative means fresh thread):-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -60 -61 -62 -63 -64 -65-66 -67 -68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80 -81 -82 -83 -84 -85 -86 -87 -88 -89 -90 -91 -92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102 -103 -104 -105 -106 -107 -108 -109 -110 -111 -112 -113 -114 -115 -116 -117 -118 -119 -120 -121 -122 -123 -124 -125 -126 -127 -128 -129 -130 -131 -132 -133 -134 -135 -136 -137 -138 -139 -140 -141 -142 -143 -144 -145 -146 -147 -148 -149 -150 -151 -152 -153 -154 -155 -156 -157 -158 -159 -160 -161 -162 -163 -164 -165 -166 -167 -168 -169 -170 -171 -172 -173 -174 -175 -176 -177 -178 -179 -180 -181 -182 -183 -184 -185 -186 -187 -188 -189 -190 -191 -192 -193 -194 -195 -196 -197 -198 -199 -200 -201 -202 -203 -204 -205 -206 -207 -208 -209 -210 -211 -212 -213 -214 -215 -216 -217 -218 -219 -220 -221 -222 -223 -224 -225 -226 -227 -228 -229 -230 -231 -232 -233 -234 -235 -236 -237 -238 -239 -240 -241 -242 -243 -244 -245 -246 -247 -248 -249 -250 -251 -252 -253 -254 -255 -256fresh count = 256Compiler = GNU C++ version 4.8.0-alpha20121216 20121216 (experimental)Standard library = GNU libstdc++ version 20121216Boost = 1_53future type = std::future<std::thread::id>Only sleep in do_work = false________________________________hardware_concurrency = 4async count = 256unique thread id's = 1live threads count (negative means fresh thread):-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1fresh count = 1Compiler = GNU C++ version 4.8.0-alpha20121216 20121216 (experimental)Standard library = GNU libstdc++ version 20121216Boost = 1_53future type = boost::future<std::thread::id>Only sleep in do_work = false________________________________hardware_concurrency = 4async count = 256unique thread id's = 122live threads count (negative means fresh thread):-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -20 -21 -22 -23 -24 -25 -25 -26 -27 -28 -29 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -59 -60 -61 -62 -63 -64 -64 -64 -63 -61 -55 -48 -41 -33 -34 -27 -27 -28 -29 -29 -30 -31 -31 -30 -28 -29 -28 -28 -28 -29 -30 -30 -31 -30 -31 -31 -31 -32 -31 -26 -24 -25 -26 -25 -23 -23 -22 -20 -21 -19 -20 -20 -19 -20 -21 -21 -22 -21 -22 -23 -24 -24 -25 -26 -27 -25 -25 -25 -22 -23 -22 -23 -23 -24 -25 -26 -27 -27 -28 -29 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -51 -52 -53 -54 -55 -56 -57 -56 -54 -3 -3 -4 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -55 -56 -57 -58 -59 -60 -61 -61 -61 -62 -63 -64 -65 -64 -62 -63 -63 -61 -62 -61 -59 -60 -59 -57 -55 -56fresh count = 256Compiler = Clang version 3.2 (tags/RELEASE_32/final)Standard library = libc++ version 1101Boost = 1_53future type = NSt3__16futureINS_11__thread_idEEEOnly sleep in do_work = false________________________________hardware_concurrency = 4async count = 256unique thread id's = 255live threads count (negative means fresh thread):-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49 -50 -51 -52 -53 -54 -55 -56 -57 -58 -59 -60 -61 -62 -63 -64 -65 -66 -67 -68 -69 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80 -81 -82 -83 -84 -85 -86 -87 -88 -89 -90 -91 -92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102 -102 -103 -104 -105 -106 -107 -108 -109 -110 -111 -112 -113 -114 -115 -116 -117 -118 -119 -120 -121 -121 -122 -122 -123 -123 -124 -125 -126 -127 -126 -127 -128 -129 -129 -128 -129 -128 -129 -129 -128 -129 -129 -128 -126 -127 -128 -128 -129 -129 -130 -129 -129 -128 -129 -129 -130 -131 -132 -133 -134 -135 -136 -134 -132 -133 -134 -134 -133 -132 -133 -132 -133 -134 -133 -131 -129 -127 -124 -125 -121 -119 -120 -118 -119 -118 -117 -115 -111 -107 -105 -106 -103 -100 -97 -95 -96 -94 -90 -87 -81 -73 -74 -71 -72 -73 -74 -75 -70 -71 -66 -60 -59 -60 -61 -62 -63 -64 -61 -58 -55 -55 -52 -53 -54 -54 -55 -56 -56 -57 -54 -55 -56 -56 -57 -57 -58 -56 -54 -55 -56 -56 -57 -58 -58 -59 -58 -58 -58 -58 -59 -60fresh count = 256As can be seen - MSVC does reuse threads, i.e. it is very likely that it's scheme is some kind of thread pool. 这篇关于哪些std :: async实现使用线程池？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！ 06-16 02:20