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Diffstat (limited to 'libbutl/mingw-thread.hxx')
-rw-r--r-- | libbutl/mingw-thread.hxx | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/libbutl/mingw-thread.hxx b/libbutl/mingw-thread.hxx new file mode 100644 index 0000000..b308dde --- /dev/null +++ b/libbutl/mingw-thread.hxx @@ -0,0 +1,330 @@ +/** +* std::thread implementation for MinGW-w64 +* +* Copyright (c) 2013-2016 by Mega Limited, Auckland, New Zealand +* Copyright (c) 2022 the build2 authors +* +* Licensed under the simplified (2-clause) BSD License. +* You should have received a copy of the license along with this +* program. +* +* This code is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +*/ + +#ifndef LIBBUTL_MINGW_THREAD_HXX +#define LIBBUTL_MINGW_THREAD_HXX + +#if !defined(__cplusplus) || (__cplusplus < 201402L) +# error C++14 compiler required +#endif + +#if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0601 +# error _WIN32_WINNT should be 0x0601 (Windows 7) or greater +#endif + +#include <cstddef> // For std::size_t +#include <cerrno> // Detect error type. +#include <exception> // For std::terminate +#include <system_error> // For std::system_error +#include <functional> // For std::hash, std::invoke (C++17) +#include <tuple> // For std::tuple +#include <chrono> // For sleep timing. +#include <memory> // For std::unique_ptr +#include <iosfwd> // Stream output for thread ids. +#include <utility> // For std::swap, std::forward + +#include <synchapi.h> // For WaitForSingleObject +#include <handleapi.h> // For CloseHandle, etc. +#include <sysinfoapi.h> // For GetNativeSystemInfo +#include <processthreadsapi.h> // For GetCurrentThreadId + +#include <process.h> // For _beginthreadex + +#if __cplusplus < 201703L +# include <libbutl/mingw-invoke.hxx> +#endif + +namespace mingw_stdthread +{ + // @@ I think can get rid of this in C++14. + // + namespace detail + { + template<std::size_t...> + struct IntSeq {}; + + template<std::size_t N, std::size_t... S> + struct GenIntSeq : GenIntSeq<N-1, N-1, S...> { }; + + template<std::size_t... S> + struct GenIntSeq<0, S...> { typedef IntSeq<S...> type; }; + +// Use a template specialization to avoid relying on compiler optimization +// when determining the parameter integer sequence. + template<class Func, class T, typename... Args> + class ThreadFuncCall; +// We can't define the Call struct in the function - the standard forbids template methods in that case + template<class Func, std::size_t... S, typename... Args> + class ThreadFuncCall<Func, detail::IntSeq<S...>, Args...> + { + static_assert(sizeof...(S) == sizeof...(Args), "Args must match."); + using Tuple = std::tuple<typename std::decay<Args>::type...>; + typename std::decay<Func>::type mFunc; + Tuple mArgs; + + public: + ThreadFuncCall(Func&& aFunc, Args&&... aArgs) + : mFunc(std::forward<Func>(aFunc)), + mArgs(std::forward<Args>(aArgs)...) + { + } + + void callFunc() + { +#if __cplusplus < 201703L + detail::invoke(std::move(mFunc), std::move(std::get<S>(mArgs)) ...); +#else + std::invoke (std::move(mFunc), std::move(std::get<S>(mArgs)) ...); +#endif + } + }; + + // Allow construction of threads without exposing implementation. + class ThreadIdTool; + } + + class thread + { + public: + class id + { + DWORD mId = 0; + friend class thread; + friend class std::hash<id>; + friend class detail::ThreadIdTool; + explicit id(DWORD aId) noexcept : mId(aId){} + public: + id () noexcept = default; + friend bool operator==(id x, id y) noexcept {return x.mId == y.mId; } + friend bool operator!=(id x, id y) noexcept {return x.mId != y.mId; } + friend bool operator< (id x, id y) noexcept {return x.mId < y.mId; } + friend bool operator<=(id x, id y) noexcept {return x.mId <= y.mId; } + friend bool operator> (id x, id y) noexcept {return x.mId > y.mId; } + friend bool operator>=(id x, id y) noexcept {return x.mId >= y.mId; } + + template<class _CharT, class _Traits> + friend std::basic_ostream<_CharT, _Traits>& + operator<<(std::basic_ostream<_CharT, _Traits>& __out, id __id) + { + if (__id.mId == 0) + { + return __out << "<invalid std::thread::id>"; + } + else + { + return __out << __id.mId; + } + } + }; + private: + static constexpr HANDLE kInvalidHandle = nullptr; + static constexpr DWORD kInfinite = 0xffffffffl; + HANDLE mHandle; + id mThreadId; + + template <class Call> + static unsigned __stdcall threadfunc(void* arg) + { + std::unique_ptr<Call> call(static_cast<Call*>(arg)); + call->callFunc(); + return 0; + } + + static unsigned int _hardware_concurrency_helper() noexcept + { + SYSTEM_INFO sysinfo; + ::GetNativeSystemInfo(&sysinfo); + return sysinfo.dwNumberOfProcessors; + } + public: + typedef HANDLE native_handle_type; + id get_id() const noexcept {return mThreadId;} + native_handle_type native_handle() const {return mHandle;} + thread(): mHandle(kInvalidHandle), mThreadId(){} + + thread(thread&& other) + :mHandle(other.mHandle), mThreadId(other.mThreadId) + { + other.mHandle = kInvalidHandle; + other.mThreadId = id{}; + } + + thread(const thread &other) = delete; + + template<class Func, typename... Args> + explicit thread(Func&& func, Args&&... args) : mHandle(), mThreadId() + { + // Instead of INVALID_HANDLE_VALUE, _beginthreadex returns 0. + + using ArgSequence = typename detail::GenIntSeq<sizeof...(Args)>::type; + using Call = detail::ThreadFuncCall<Func, ArgSequence, Args...>; + auto call = new Call(std::forward<Func>(func), std::forward<Args>(args)...); + unsigned int id_receiver; + auto int_handle = _beginthreadex(NULL, 0, threadfunc<Call>, + static_cast<LPVOID>(call), 0, &id_receiver); + if (int_handle == 0) + { + mHandle = kInvalidHandle; + int errnum = errno; + delete call; + // Note: Should only throw EINVAL, EAGAIN, EACCES + throw std::system_error(errnum, std::generic_category()); + } else { + mThreadId.mId = id_receiver; + mHandle = reinterpret_cast<HANDLE>(int_handle); + } + } + + bool joinable() const {return mHandle != kInvalidHandle;} + + // Note: Due to lack of synchronization, this function has a race + // condition if called concurrently, which leads to undefined + // behavior. The same applies to all other member functions of this + // class, but this one is mentioned explicitly. + void join() + { + using namespace std; + if (get_id() == id(GetCurrentThreadId())) + throw system_error(make_error_code(errc::resource_deadlock_would_occur)); + if (mHandle == kInvalidHandle) + throw system_error(make_error_code(errc::no_such_process)); + if (!joinable()) + throw system_error(make_error_code(errc::invalid_argument)); + WaitForSingleObject(mHandle, kInfinite); + CloseHandle(mHandle); + mHandle = kInvalidHandle; + mThreadId = id{}; + } + + ~thread() + { + if (joinable()) + { + // @@ TODO + /* +#ifndef NDEBUG + std::printf("Error: Must join() or detach() a thread before \ +destroying it.\n"); +#endif + */ + std::terminate(); + } + } + thread& operator=(const thread&) = delete; + thread& operator=(thread&& other) noexcept + { + if (joinable()) + { + // @@ TODO + /* +#ifndef NDEBUG + std::printf("Error: Must join() or detach() a thread before \ +moving another thread to it.\n"); +#endif + */ + std::terminate(); + } + swap(other); + return *this; + } + void swap(thread& other) noexcept + { + std::swap(mHandle, other.mHandle); + std::swap(mThreadId.mId, other.mThreadId.mId); + } + + static unsigned int hardware_concurrency() noexcept + { + // @@ TODO: this seems like a bad idea. + // + /*static*/ unsigned int cached = _hardware_concurrency_helper(); + return cached; + } + + void detach() + { + if (!joinable()) + { + using namespace std; + throw system_error(make_error_code(errc::invalid_argument)); + } + if (mHandle != kInvalidHandle) + { + CloseHandle(mHandle); + mHandle = kInvalidHandle; + } + mThreadId = id{}; + } + }; + + namespace detail + { + class ThreadIdTool + { + public: + static thread::id make_id (DWORD base_id) noexcept + { + return thread::id(base_id); + } + }; + } + + namespace this_thread + { + inline thread::id get_id() noexcept + { + return detail::ThreadIdTool::make_id(GetCurrentThreadId()); + } + inline void yield() noexcept {Sleep(0);} + template< class Rep, class Period > + void sleep_for( const std::chrono::duration<Rep,Period>& sleep_duration) + { + static constexpr DWORD kInfinite = 0xffffffffl; + using namespace std::chrono; + using rep = milliseconds::rep; + rep ms = duration_cast<milliseconds>(sleep_duration).count(); + while (ms > 0) + { + constexpr rep kMaxRep = static_cast<rep>(kInfinite - 1); + auto sleepTime = (ms < kMaxRep) ? ms : kMaxRep; + Sleep(static_cast<DWORD>(sleepTime)); + ms -= sleepTime; + } + } + template <class Clock, class Duration> + void sleep_until(const std::chrono::time_point<Clock,Duration>& sleep_time) + { + sleep_for(sleep_time-Clock::now()); + } + } +} + +namespace std +{ + // Specialize hash for this implementation's thread::id, even if the + // std::thread::id already has a hash. + template<> + struct hash<mingw_stdthread::thread::id> + { + typedef mingw_stdthread::thread::id argument_type; + typedef size_t result_type; + size_t operator() (const argument_type & i) const noexcept + { + return i.mId; + } + }; +} + +#endif // LIBBUTL_MINGW_THREAD_HXX |