compat/w32pthreads.h - third_party/ffmpeg - Git at Google

 /*
  * Copyright (C) 2010-2011 x264 project
  *
  * Authors: Steven Walters <kemuri9@gmail.com>
  *          Pegasys Inc. <http://www.pegasys-inc.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 /**
  * @file
  * w32threads to pthreads wrapper
  */

 #ifndef COMPAT_W32PTHREADS_H
 #define COMPAT_W32PTHREADS_H

 /* Build up a pthread-like API using underlying Windows API. Have only static
  * methods so as to not conflict with a potentially linked in pthread-win32
  * library.
  * As most functions here are used without checking return values,
  * only implement return values as necessary. */

 #include <windows.h>
 #include <process.h>
 #include <time.h>

 #include "libavutil/attributes.h"
 #include "libavutil/common.h"
 #include "libavutil/internal.h"
 #include "libavutil/mem.h"
 #include "libavutil/time.h"
 #include "libavutil/wchar_filename.h"

 typedef struct w32pthread_t {
     void *handle;
     void *(*func)(void* arg);
     void *arg;
     void *ret;
 } *pthread_t;

 /* use light weight mutex/condition variable API for Windows Vista and later */
 typedef SRWLOCK pthread_mutex_t;
 typedef CONDITION_VARIABLE pthread_cond_t;

 #define PTHREAD_MUTEX_INITIALIZER SRWLOCK_INIT
 #define PTHREAD_COND_INITIALIZER CONDITION_VARIABLE_INIT

 #define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
 #define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)

 #define PTHREAD_CANCEL_ENABLE 1
 #define PTHREAD_CANCEL_DISABLE 0

 #if HAVE_WINRT
 #define THREADFUNC_RETTYPE DWORD
 #else
 #define THREADFUNC_RETTYPE unsigned
 #endif

 static av_unused THREADFUNC_RETTYPE
 __stdcall attribute_align_arg win32thread_worker(void *arg)
 {
     pthread_t h = (pthread_t)arg;
     h->ret = h->func(h->arg);
     return 0;
 }

 static av_unused int pthread_create(pthread_t *thread, const void *unused_attr,
                                     void *(*start_routine)(void*), void *arg)
 {
     pthread_t ret;

     ret = (pthread_t)av_mallocz(sizeof(*ret));
     if (!ret)
         return EAGAIN;

     ret->func   = start_routine;
     ret->arg    = arg;
 #if HAVE_WINRT
     ret->handle = (void*)CreateThread(NULL, 0, win32thread_worker, ret,
                                       0, NULL);
 #else
     ret->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, ret,
                                         0, NULL);
 #endif

     if (!ret->handle) {
         av_free(ret);
         return EAGAIN;
     }

     *thread = ret;

     return 0;
 }

 static av_unused int pthread_join(pthread_t thread, void **value_ptr)
 {
     DWORD ret = WaitForSingleObject(thread->handle, INFINITE);
     if (ret != WAIT_OBJECT_0) {
         if (ret == WAIT_ABANDONED)
             return EINVAL;
         else
             return EDEADLK;
     }
     if (value_ptr)
         *value_ptr = thread->ret;
     CloseHandle(thread->handle);
     av_free(thread);
     return 0;
 }

 static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
 {
     InitializeSRWLock(m);
     return 0;
 }
 static inline int pthread_mutex_destroy(pthread_mutex_t *m)
 {
     /* Unlocked SWR locks use no resources */
     return 0;
 }
 static inline int pthread_mutex_lock(pthread_mutex_t *m)
 {
     AcquireSRWLockExclusive(m);
     return 0;
 }
 static inline int pthread_mutex_unlock(pthread_mutex_t *m)
 {
     ReleaseSRWLockExclusive(m);
     return 0;
 }

 typedef INIT_ONCE pthread_once_t;
 #define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT

 static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
 {
     BOOL pending = FALSE;
     InitOnceBeginInitialize(once_control, 0, &pending, NULL);
     if (pending)
         init_routine();
     InitOnceComplete(once_control, 0, NULL);
     return 0;
 }

 static inline int pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
 {
     InitializeConditionVariable(cond);
     return 0;
 }

 /* native condition variables do not destroy */
 static inline int pthread_cond_destroy(pthread_cond_t *cond)
 {
     return 0;
 }

 static inline int pthread_cond_broadcast(pthread_cond_t *cond)
 {
     WakeAllConditionVariable(cond);
     return 0;
 }

 static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
 {
     SleepConditionVariableSRW(cond, mutex, INFINITE, 0);
     return 0;
 }

 static inline int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
                                          const struct timespec *abstime)
 {
     int64_t abs_milli = abstime->tv_sec * 1000LL + abstime->tv_nsec / 1000000;
     DWORD t = av_clip64(abs_milli - av_gettime() / 1000, 0, UINT32_MAX);

     if (!SleepConditionVariableSRW(cond, mutex, t, 0)) {
         DWORD err = GetLastError();
         if (err == ERROR_TIMEOUT)
             return ETIMEDOUT;
         else
             return EINVAL;
     }
     return 0;
 }

 static inline int pthread_cond_signal(pthread_cond_t *cond)
 {
     WakeConditionVariable(cond);
     return 0;
 }

 static inline int pthread_setcancelstate(int state, int *oldstate)
 {
     return 0;
 }

 static inline int win32_thread_setname(const char *name)
 {
 #if !HAVE_UWP
     typedef HRESULT (WINAPI *SetThreadDescriptionFn)(HANDLE, PCWSTR);

     // Although SetThreadDescription lives in kernel32.dll, on Windows Server 2016,
     // Windows 10 LTSB 2016 and Windows 10 version 1607, it was only available in
     // kernelbase.dll. So, load it from there for maximum coverage.
     HMODULE kernelbase = GetModuleHandleW(L"kernelbase.dll");
     if (!kernelbase)
         return AVERROR(ENOSYS);

     SetThreadDescriptionFn pSetThreadDescription =
         (SetThreadDescriptionFn)GetProcAddress(kernelbase, "SetThreadDescription");
     if (!pSetThreadDescription)
         return AVERROR(ENOSYS);

     wchar_t *wname;
     if (utf8towchar(name, &wname) < 0)
         return AVERROR(ENOMEM);

     HRESULT hr = pSetThreadDescription(GetCurrentThread(), wname);
     av_free(wname);
     return SUCCEEDED(hr) ? 0 : AVERROR(EINVAL);
 #else
     // UWP is not supported because we cannot use LoadLibrary/GetProcAddress to
     // detect the availability of the SetThreadDescription API. There is a small
     // gap in Windows builds 1507-1607 where it was not available. UWP allows
     // querying the availability of APIs with QueryOptionalDelayLoadedAPI, but it
     // requires /DELAYLOAD:kernel32.dll during linking, and we cannot enforce that.
     return AVERROR(ENOSYS);
 #endif
 }

 #endif /* COMPAT_W32PTHREADS_H */
	/*
	* Copyright (C) 2010-2011 x264 project
	*
	* Authors: Steven Walters <kemuri9@gmail.com>
	* Pegasys Inc. <http://www.pegasys-inc.com>
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg 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. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	/**
	* @file
	* w32threads to pthreads wrapper
	*/

	#ifndef COMPAT_W32PTHREADS_H
	#define COMPAT_W32PTHREADS_H

	/* Build up a pthread-like API using underlying Windows API. Have only static
	* methods so as to not conflict with a potentially linked in pthread-win32
	* library.
	* As most functions here are used without checking return values,
	* only implement return values as necessary. */

	#include <windows.h>
	#include <process.h>
	#include <time.h>

	#include "libavutil/attributes.h"
	#include "libavutil/common.h"
	#include "libavutil/internal.h"
	#include "libavutil/mem.h"
	#include "libavutil/time.h"
	#include "libavutil/wchar_filename.h"

	typedef struct w32pthread_t {
	void *handle;
	void (func)(void* arg);
	void *arg;
	void *ret;
	} *pthread_t;

	/* use light weight mutex/condition variable API for Windows Vista and later */
	typedef SRWLOCK pthread_mutex_t;
	typedef CONDITION_VARIABLE pthread_cond_t;

	#define PTHREAD_MUTEX_INITIALIZER SRWLOCK_INIT
	#define PTHREAD_COND_INITIALIZER CONDITION_VARIABLE_INIT

	#define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
	#define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)

	#define PTHREAD_CANCEL_ENABLE 1
	#define PTHREAD_CANCEL_DISABLE 0

	#if HAVE_WINRT
	#define THREADFUNC_RETTYPE DWORD
	#else
	#define THREADFUNC_RETTYPE unsigned
	#endif

	static av_unused THREADFUNC_RETTYPE
	__stdcall attribute_align_arg win32thread_worker(void *arg)
	{
	pthread_t h = (pthread_t)arg;
	h->ret = h->func(h->arg);
	return 0;
	}

	static av_unused int pthread_create(pthread_t thread, const void unused_attr,
	void (start_routine)(void), void arg)
	{
	pthread_t ret;

	ret = (pthread_t)av_mallocz(sizeof(*ret));
	if (!ret)
	return EAGAIN;

	ret->func = start_routine;
	ret->arg = arg;
	#if HAVE_WINRT
	ret->handle = (void*)CreateThread(NULL, 0, win32thread_worker, ret,
	0, NULL);
	#else
	ret->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, ret,
	0, NULL);
	#endif

	if (!ret->handle) {
	av_free(ret);
	return EAGAIN;
	}

	*thread = ret;

	return 0;
	}

	static av_unused int pthread_join(pthread_t thread, void **value_ptr)
	{
	DWORD ret = WaitForSingleObject(thread->handle, INFINITE);
	if (ret != WAIT_OBJECT_0) {
	if (ret == WAIT_ABANDONED)
	return EINVAL;
	else
	return EDEADLK;
	}
	if (value_ptr)
	*value_ptr = thread->ret;
	CloseHandle(thread->handle);
	av_free(thread);
	return 0;
	}

	static inline int pthread_mutex_init(pthread_mutex_t m, void attr)
	{
	InitializeSRWLock(m);
	return 0;
	}
	static inline int pthread_mutex_destroy(pthread_mutex_t *m)
	{
	/* Unlocked SWR locks use no resources */
	return 0;
	}
	static inline int pthread_mutex_lock(pthread_mutex_t *m)
	{
	AcquireSRWLockExclusive(m);
	return 0;
	}
	static inline int pthread_mutex_unlock(pthread_mutex_t *m)
	{
	ReleaseSRWLockExclusive(m);
	return 0;
	}

	typedef INIT_ONCE pthread_once_t;
	#define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT

	static av_unused int pthread_once(pthread_once_t once_control, void (init_routine)(void))
	{
	BOOL pending = FALSE;
	InitOnceBeginInitialize(once_control, 0, &pending, NULL);
	if (pending)
	init_routine();
	InitOnceComplete(once_control, 0, NULL);
	return 0;
	}

	static inline int pthread_cond_init(pthread_cond_t cond, const void unused_attr)
	{
	InitializeConditionVariable(cond);
	return 0;
	}

	/* native condition variables do not destroy */
	static inline int pthread_cond_destroy(pthread_cond_t *cond)
	{
	return 0;
	}

	static inline int pthread_cond_broadcast(pthread_cond_t *cond)
	{
	WakeAllConditionVariable(cond);
	return 0;
	}

	static inline int pthread_cond_wait(pthread_cond_t cond, pthread_mutex_t mutex)
	{
	SleepConditionVariableSRW(cond, mutex, INFINITE, 0);
	return 0;
	}

	static inline int pthread_cond_timedwait(pthread_cond_t cond, pthread_mutex_t mutex,
	const struct timespec *abstime)
	{
	int64_t abs_milli = abstime->tv_sec * 1000LL + abstime->tv_nsec / 1000000;
	DWORD t = av_clip64(abs_milli - av_gettime() / 1000, 0, UINT32_MAX);

	if (!SleepConditionVariableSRW(cond, mutex, t, 0)) {
	DWORD err = GetLastError();
	if (err == ERROR_TIMEOUT)
	return ETIMEDOUT;
	else
	return EINVAL;
	}
	return 0;
	}

	static inline int pthread_cond_signal(pthread_cond_t *cond)
	{
	WakeConditionVariable(cond);
	return 0;
	}

	static inline int pthread_setcancelstate(int state, int *oldstate)
	{
	return 0;
	}

	static inline int win32_thread_setname(const char *name)
	{
	#if !HAVE_UWP
	typedef HRESULT (WINAPI *SetThreadDescriptionFn)(HANDLE, PCWSTR);

	// Although SetThreadDescription lives in kernel32.dll, on Windows Server 2016,
	// Windows 10 LTSB 2016 and Windows 10 version 1607, it was only available in
	// kernelbase.dll. So, load it from there for maximum coverage.
	HMODULE kernelbase = GetModuleHandleW(L"kernelbase.dll");
	if (!kernelbase)
	return AVERROR(ENOSYS);

	SetThreadDescriptionFn pSetThreadDescription =
	(SetThreadDescriptionFn)GetProcAddress(kernelbase, "SetThreadDescription");
	if (!pSetThreadDescription)
	return AVERROR(ENOSYS);

	wchar_t *wname;
	if (utf8towchar(name, &wname) < 0)
	return AVERROR(ENOMEM);

	HRESULT hr = pSetThreadDescription(GetCurrentThread(), wname);
	av_free(wname);
	return SUCCEEDED(hr) ? 0 : AVERROR(EINVAL);
	#else
	// UWP is not supported because we cannot use LoadLibrary/GetProcAddress to
	// detect the availability of the SetThreadDescription API. There is a small
	// gap in Windows builds 1507-1607 where it was not available. UWP allows
	// querying the availability of APIs with QueryOptionalDelayLoadedAPI, but it
	// requires /DELAYLOAD:kernel32.dll during linking, and we cannot enforce that.
	return AVERROR(ENOSYS);
	#endif
	}

	#endif /* COMPAT_W32PTHREADS_H */