/*
* 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. */
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <process.h>
#if _WIN32_WINNT < 0x0600 && defined(__MINGW32__)
#undef MemoryBarrier
#define MemoryBarrier __sync_synchronize
#endif
#include "libavutil/attributes.h"
#include "libavutil/common.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
typedef struct pthread_t {
void *handle;
void *(*func)(void* arg);
void *arg;
void *ret;
} pthread_t;
/* the conditional variable api for windows 6.0+ uses critical sections and
* not mutexes */
typedef CRITICAL_SECTION pthread_mutex_t;
/* This is the CONDITION_VARIABLE typedef for using Windows' native
* conditional variables on kernels 6.0+. */
#if HAVE_CONDITION_VARIABLE_PTR
typedef CONDITION_VARIABLE pthread_cond_t;
#else
typedef struct pthread_cond_t {
void *Ptr;
} pthread_cond_t;
#endif
#if _WIN32_WINNT >= 0x0600
#define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
#define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
#endif
static av_unused unsigned __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)
{
thread->func = start_routine;
thread->arg = arg;
#if HAVE_WINRT
thread->handle = (void*)CreateThread(NULL, 0, win32thread_worker, thread,
0, NULL);
#else
thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
0, NULL);
#endif
return !thread->handle;
}
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);
return 0;
}
static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
{
InitializeCriticalSection(m);
return 0;
}
static inline int pthread_mutex_destroy(pthread_mutex_t *m)
{
DeleteCriticalSection(m);
return 0;
}
static inline int pthread_mutex_lock(pthread_mutex_t *m)
{
EnterCriticalSection(m);
return 0;
}
static inline int pthread_mutex_unlock(pthread_mutex_t *m)
{
LeaveCriticalSection(m);
return 0;
}
#if _WIN32_WINNT >= 0x0600
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)
{
SleepConditionVariableCS(cond, mutex, INFINITE);
return 0;
}
static inline int pthread_cond_signal(pthread_cond_t *cond)
{
WakeConditionVariable(cond);
return 0;
}
#else // _WIN32_WINNT < 0x0600
/* atomic init state of dynamically loaded functions */
static LONG w32thread_init_state = 0;
static av_unused void w32thread_init(void);
/* for pre-Windows 6.0 platforms, define INIT_ONCE struct,
* compatible to the one used in the native API */
typedef union pthread_once_t {
void * Ptr; ///< For the Windows 6.0+ native functions
LONG state; ///< For the pre-Windows 6.0 compat code
} pthread_once_t;
#define PTHREAD_ONCE_INIT {0}
/* function pointers to init once API on windows 6.0+ kernels */
static BOOL (WINAPI *initonce_begin)(pthread_once_t *lpInitOnce, DWORD dwFlags, BOOL *fPending, void **lpContext);
static BOOL (WINAPI *initonce_complete)(pthread_once_t *lpInitOnce, DWORD dwFlags, void *lpContext);
/* pre-Windows 6.0 compat using a spin-lock */
static inline void w32thread_once_fallback(LONG volatile *state, void (*init_routine)(void))
{
switch (InterlockedCompareExchange(state, 1, 0)) {
/* Initial run */
case 0:
init_routine();
InterlockedExchange(state, 2);
break;
/* Another thread is running init */
case 1:
while (1) {
MemoryBarrier();
if (*state == 2)
break;
Sleep(0);
}
break;
/* Initialization complete */
case 2:
break;
}
}
static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
{
w32thread_once_fallback(&w32thread_init_state, w32thread_init);
/* Use native functions on Windows 6.0+ */
if (initonce_begin && initonce_complete) {
BOOL pending = FALSE;
initonce_begin(once_control, 0, &pending, NULL);
if (pending)
init_routine();
initonce_complete(once_control, 0, NULL);
return 0;
}
w32thread_once_fallback(&once_control->state, init_routine);
return 0;
}
/* for pre-Windows 6.0 platforms we need to define and use our own condition
* variable and api */
typedef struct win32_cond_t {
pthread_mutex_t mtx_broadcast;
pthread_mutex_t mtx_waiter_count;
volatile int waiter_count;
HANDLE semaphore;
HANDLE waiters_done;
volatile int is_broadcast;
} win32_cond_t;
/* function pointers to conditional variable API on windows 6.0+ kernels */
static void (WINAPI *cond_broadcast)(pthread_cond_t *cond);
static void (WINAPI *cond_init)(pthread_cond_t *cond);
static void (WINAPI *cond_signal)(pthread_cond_t *cond);
static BOOL (WINAPI *cond_wait)(pthread_cond_t *cond, pthread_mutex_t *mutex,
DWORD milliseconds);
static av_unused int pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
{
win32_cond_t *win32_cond = NULL;
w32thread_once_fallback(&w32thread_init_state, w32thread_init);
if (cond_init) {
cond_init(cond);
return 0;
}
/* non native condition variables */
win32_cond = (win32_cond_t*)av_mallocz(sizeof(win32_cond_t));
if (!win32_cond)
return ENOMEM;
cond->Ptr = win32_cond;
win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
if (!win32_cond->semaphore)
return ENOMEM;
win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!win32_cond->waiters_done)
return ENOMEM;
pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL);
pthread_mutex_init(&win32_cond->mtx_broadcast, NULL);
return 0;
}
static av_unused int pthread_cond_destroy(pthread_cond_t *cond)
{
win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
/* native condition variables do not destroy */
if (cond_init)
return 0;
/* non native condition variables */
CloseHandle(win32_cond->semaphore);
CloseHandle(win32_cond->waiters_done);
pthread_mutex_destroy(&win32_cond->mtx_waiter_count);
pthread_mutex_destroy(&win32_cond->mtx_broadcast);
av_freep(&win32_cond);
cond->Ptr = NULL;
return 0;
}
static av_unused int pthread_cond_broadcast(pthread_cond_t *cond)
{
win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
int have_waiter;
if (cond_broadcast) {
cond_broadcast(cond);
return 0;
}
/* non native condition variables */
pthread_mutex_lock(&win32_cond->mtx_broadcast);
pthread_mutex_lock(&win32_cond->mtx_waiter_count);
have_waiter = 0;
if (win32_cond->waiter_count) {
win32_cond->is_broadcast = 1;
have_waiter = 1;
}
if (have_waiter) {
ReleaseSemaphore(win32_cond->semaphore, win32_cond->waiter_count, NULL);
pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
WaitForSingleObject(win32_cond->waiters_done, INFINITE);
ResetEvent(win32_cond->waiters_done);
win32_cond->is_broadcast = 0;
} else
pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
pthread_mutex_unlock(&win32_cond->mtx_broadcast);
return 0;
}
static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
int last_waiter;
if (cond_wait) {
cond_wait(cond, mutex, INFINITE);
return 0;
}
/* non native condition variables */
pthread_mutex_lock(&win32_cond->mtx_broadcast);
pthread_mutex_lock(&win32_cond->mtx_waiter_count);
win32_cond->waiter_count++;
pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
pthread_mutex_unlock(&win32_cond->mtx_broadcast);
// unlock the external mutex
pthread_mutex_unlock(mutex);
WaitForSingleObject(win32_cond->semaphore, INFINITE);
pthread_mutex_lock(&win32_cond->mtx_waiter_count);
win32_cond->waiter_count--;
last_waiter = !win32_cond->waiter_count || !win32_cond->is_broadcast;
pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
if (last_waiter)
SetEvent(win32_cond->waiters_done);
// lock the external mutex
return pthread_mutex_lock(mutex);
}
static av_unused int pthread_cond_signal(pthread_cond_t *cond)
{
win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
int have_waiter;
if (cond_signal) {
cond_signal(cond);
return 0;
}
pthread_mutex_lock(&win32_cond->mtx_broadcast);
/* non-native condition variables */
pthread_mutex_lock(&win32_cond->mtx_waiter_count);
have_waiter = win32_cond->waiter_count;
pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
if (have_waiter) {
ReleaseSemaphore(win32_cond->semaphore, 1, NULL);
WaitForSingleObject(win32_cond->waiters_done, INFINITE);
ResetEvent(win32_cond->waiters_done);
}
pthread_mutex_unlock(&win32_cond->mtx_broadcast);
return 0;
}
#endif
static av_unused void w32thread_init(void)
{
#if _WIN32_WINNT < 0x0600
HMODULE kernel_dll = GetModuleHandle(TEXT("kernel32.dll"));
/* if one is available, then they should all be available */
cond_init = (void (WINAPI*)(pthread_cond_t *))
GetProcAddress(kernel_dll, "InitializeConditionVariable");
cond_broadcast = (void (WINAPI*)(pthread_cond_t *))
GetProcAddress(kernel_dll, "WakeAllConditionVariable");
cond_signal = (void (WINAPI*)(pthread_cond_t *))
GetProcAddress(kernel_dll, "WakeConditionVariable");
cond_wait = (BOOL (WINAPI*)(pthread_cond_t *, pthread_mutex_t *, DWORD))
GetProcAddress(kernel_dll, "SleepConditionVariableCS");
initonce_begin = (BOOL (WINAPI*)(pthread_once_t *, DWORD, BOOL *, void **))
GetProcAddress(kernel_dll, "InitOnceBeginInitialize");
initonce_complete = (BOOL (WINAPI*)(pthread_once_t *, DWORD, void *))
GetProcAddress(kernel_dll, "InitOnceComplete");
#endif
}
#endif /* COMPAT_W32PTHREADS_H */