synth/alchitry-loader/src/mingw.thread.h
2022-05-16 20:59:17 -07:00

415 lines
14 KiB
C++

/**
* @file mingw.thread.h
* @brief std::thread implementation for MinGW
* (c) 2013-2016 by Mega Limited, Auckland, New Zealand
* @author Alexander Vassilev
*
* @copyright 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.
* @note
* This file may become part of the mingw-w64 runtime package. If/when this happens,
* the appropriate license will be added, i.e. this code will become dual-licensed,
* and the current BSD 2-clause license will stay.
*/
#ifndef WIN32STDTHREAD_H
#define WIN32STDTHREAD_H
#if !defined(__cplusplus) || (__cplusplus < 201103L)
#error A C++11 compiler is required!
#endif
// Use the standard classes for std::, if available.
#include <thread>
#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
#include <tuple> // For std::tuple
#include <chrono> // For sleep timing.
#include <memory> // For std::unique_ptr
#include <ostream> // Stream output for thread ids.
#include <utility> // For std::swap, std::forward
// For the invoke implementation only:
#include <type_traits> // For std::result_of, etc.
//#include <utility> // For std::forward
//#include <functional> // For std::reference_wrapper
#include <windows.h>
#include <process.h> // For _beginthreadex
#ifndef NDEBUG
#include <cstdio>
#endif
#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0501)
#error To use the MinGW-std-threads library, you will need to define the macro _WIN32_WINNT to be 0x0501 (Windows XP) or higher.
#endif
// Instead of INVALID_HANDLE_VALUE, _beginthreadex returns 0.
namespace mingw_stdthread
{
namespace detail
{
// For compatibility, implement std::invoke for C++11 and C++14
#if __cplusplus < 201703L
template<bool PMemFunc, bool PMemData>
struct Invoker
{
template<class F, class... Args>
inline static typename std::result_of<F(Args...)>::type invoke (F&& f, Args&&... args)
{
return std::forward<F>(f)(std::forward<Args>(args)...);
}
};
template<bool>
struct InvokerHelper;
template<>
struct InvokerHelper<false>
{
template<class T1>
inline static auto get (T1&& t1) -> decltype(*std::forward<T1>(t1))
{
return *std::forward<T1>(t1);
}
template<class T1>
inline static auto get (const std::reference_wrapper<T1>& t1) -> decltype(t1.get())
{
return t1.get();
}
};
template<>
struct InvokerHelper<true>
{
template<class T1>
inline static auto get (T1&& t1) -> decltype(std::forward<T1>(t1))
{
return std::forward<T1>(t1);
}
};
template<>
struct Invoker<true, false>
{
template<class T, class F, class T1, class... Args>
inline static auto invoke (F T::* f, T1&& t1, Args&&... args) ->\
decltype((InvokerHelper<std::is_base_of<T,typename std::decay<T1>::type>::value>::get(std::forward<T1>(t1)).*f)(std::forward<Args>(args)...))
{
return (InvokerHelper<std::is_base_of<T,typename std::decay<T1>::type>::value>::get(std::forward<T1>(t1)).*f)(std::forward<Args>(args)...);
}
};
template<>
struct Invoker<false, true>
{
template<class T, class F, class T1, class... Args>
inline static auto invoke (F T::* f, T1&& t1, Args&&... args) ->\
decltype(InvokerHelper<std::is_base_of<T,typename std::decay<T1>::type>::value>::get(t1).*f)
{
return InvokerHelper<std::is_base_of<T,typename std::decay<T1>::type>::value>::get(t1).*f;
}
};
template<class F, class... Args>
struct InvokeResult
{
typedef Invoker<std::is_member_function_pointer<typename std::remove_reference<F>::type>::value,
std::is_member_object_pointer<typename std::remove_reference<F>::type>::value &&
(sizeof...(Args) == 1)> invoker;
inline static auto invoke (F&& f, Args&&... args) -> decltype(invoker::invoke(std::forward<F>(f), std::forward<Args>(args)...))
{
return invoker::invoke(std::forward<F>(f), std::forward<Args>(args)...);
};
};
template<class F, class...Args>
auto invoke (F&& f, Args&&... args) -> decltype(InvokeResult<F, Args...>::invoke(std::forward<F>(f), std::forward<Args>(args)...))
{
return InvokeResult<F, Args...>::invoke(std::forward<F>(f), std::forward<Args>(args)...);
}
#else
using std::invoke;
#endif
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; };
// We can't define the Call struct in the function - the standard forbids template methods in that case
template<class Func, typename... Args>
class ThreadFuncCall
{
typedef std::tuple<Args...> Tuple;
Func mFunc;
Tuple mArgs;
template <std::size_t... S>
void callFunc(detail::IntSeq<S...>)
{
detail::invoke(std::forward<Func>(mFunc), std::get<S>(std::forward<Tuple>(mArgs)) ...);
}
public:
ThreadFuncCall(Func&& aFunc, Args&&... aArgs)
:mFunc(std::forward<Func>(aFunc)), mArgs(std::forward<Args>(aArgs)...){}
void callFunc()
{
callFunc(typename detail::GenIntSeq<sizeof...(Args)>::type());
}
};
} // Namespace "detail"
class thread
{
public:
class id
{
DWORD mId;
void clear() {mId = 0;}
friend class thread;
friend class std::hash<id>;
public:
explicit id(DWORD aId=0) noexcept : mId(aId){}
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;
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;
// This is one of the few functions used by the library which has a nearly-
// equivalent function defined in earlier versions of Windows. Include the
// workaround, just as a reminder that it does exist.
#if defined(_WIN32_WINNT) && (_WIN32_WINNT >= 0x0501)
::GetNativeSystemInfo(&sysinfo);
#else
::GetSystemInfo(&sysinfo);
#endif
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.clear();
}
thread(const thread &other)=delete;
template<class Func, typename... Args>
explicit thread(Func&& func, Args&&... args) : mHandle(), mThreadId()
{
typedef detail::ThreadFuncCall<Func, Args...> Call;
auto call = new Call(
std::forward<Func>(func), std::forward<Args>(args)...);
auto int_handle = _beginthreadex(NULL, 0, threadfunc<Call>,
static_cast<LPVOID>(call), 0,
reinterpret_cast<unsigned*>(&(mThreadId.mId)));
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
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, INFINITE);
CloseHandle(mHandle);
mHandle = kInvalidHandle;
mThreadId.clear();
}
~thread()
{
if (joinable())
{
#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())
{
#ifndef NDEBUG
std::printf("Error: Must join() or detach() a thread before \
moving another thread to it.\n");
#endif
std::terminate();
}
swap(std::forward<thread>(other));
return *this;
}
void swap(thread&& other) noexcept
{
HANDLE tmph = mHandle;
mHandle = other.mHandle;
other.mHandle = tmph;
DWORD tmpd = mThreadId.mId;
mThreadId.mId = other.mThreadId.mId;
other.mThreadId.mId = tmpd;
}
static unsigned int hardware_concurrency() noexcept
{
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.clear();
}
};
namespace this_thread
{
inline thread::id get_id() noexcept {return thread::id(GetCurrentThreadId());}
inline void yield() noexcept {Sleep(0);}
template< class Rep, class Period >
void sleep_for( const std::chrono::duration<Rep,Period>& sleep_duration)
{
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>(INFINITE - 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 mingw_stdthread
namespace std
{
// Because of quirks of the compiler, the common "using namespace std;"
// directive would flatten the namespaces and introduce ambiguity where there
// was none. Direct specification (std::), however, would be unaffected.
// Take the safe option, and include only in the presence of MinGW's win32
// implementation.
#if defined(__MINGW32__ ) && !defined(_GLIBCXX_HAS_GTHREADS)
using mingw_stdthread::thread;
// Remove ambiguity immediately, to avoid problems arising from the above.
//using std::thread;
namespace this_thread
{
using namespace mingw_stdthread::this_thread;
}
#elif !defined(MINGW_STDTHREAD_REDUNDANCY_WARNING) // Skip repetition
#define MINGW_STDTHREAD_REDUNDANCY_WARNING
#pragma message "This version of MinGW seems to include a win32 port of\
pthreads, and probably already has C++11 std threading classes implemented,\
based on pthreads. These classes, found in namespace std, are not overridden\
by the mingw-std-thread library. If you would still like to use this\
implementation (as it is more lightweight), use the classes provided in\
namespace mingw_stdthread."
#endif
// 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 // WIN32STDTHREAD_H