| /* |
| * Copyright (C) 2010-2011 x264 project |
| * |
| * Authors: Steven Walters <kemuri9@gmail.com> |
| * Pegasys Inc. <http://www.pegasys-inc.com> |
| * |
| * This file is part of Libav. |
| * |
| * Libav 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. |
| * |
| * Libav 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 Libav; 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 AVCODEC_W32PTHREADS_H |
| #define AVCODEC_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> |
| |
| typedef struct { |
| 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 CONDITIONAL_VARIABLE typedef for using Window's native |
| * conditional variables on kernels 6.0+. |
| * MinGW does not currently have this typedef. */ |
| typedef struct { |
| void *ptr; |
| } pthread_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 unsigned __stdcall attribute_align_arg win32thread_worker(void *arg) |
| { |
| pthread_t *h = arg; |
| h->ret = h->func(h->arg); |
| return 0; |
| } |
| |
| static int pthread_create(pthread_t *thread, const void *unused_attr, |
| void *(*start_routine)(void*), void *arg) |
| { |
| thread->func = start_routine; |
| thread->arg = arg; |
| thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread, |
| 0, NULL); |
| return !thread->handle; |
| } |
| |
| static void pthread_join(pthread_t thread, void **value_ptr) |
| { |
| DWORD ret = WaitForSingleObject(thread.handle, INFINITE); |
| if (ret != WAIT_OBJECT_0) |
| return; |
| if (value_ptr) |
| *value_ptr = thread.ret; |
| CloseHandle(thread.handle); |
| } |
| |
| 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; |
| } |
| |
| /* for pre-Windows 6.0 platforms we need to define and use our own condition |
| * variable and api */ |
| typedef struct { |
| 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; |
| |
| static void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr) |
| { |
| win32_cond_t *win32_cond = NULL; |
| if (cond_init) { |
| cond_init(cond); |
| return; |
| } |
| |
| /* non native condition variables */ |
| win32_cond = av_mallocz(sizeof(win32_cond_t)); |
| if (!win32_cond) |
| return; |
| cond->ptr = win32_cond; |
| win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL); |
| if (!win32_cond->semaphore) |
| return; |
| win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL); |
| if (!win32_cond->waiters_done) |
| return; |
| |
| pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL); |
| pthread_mutex_init(&win32_cond->mtx_broadcast, NULL); |
| } |
| |
| static void pthread_cond_destroy(pthread_cond_t *cond) |
| { |
| win32_cond_t *win32_cond = cond->ptr; |
| /* native condition variables do not destroy */ |
| if (cond_init) |
| return; |
| |
| /* 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; |
| } |
| |
| static void pthread_cond_broadcast(pthread_cond_t *cond) |
| { |
| win32_cond_t *win32_cond = cond->ptr; |
| int have_waiter; |
| |
| if (cond_broadcast) { |
| cond_broadcast(cond); |
| return; |
| } |
| |
| /* 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); |
| } |
| |
| static int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) |
| { |
| win32_cond_t *win32_cond = 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 void pthread_cond_signal(pthread_cond_t *cond) |
| { |
| win32_cond_t *win32_cond = cond->ptr; |
| int have_waiter; |
| if (cond_signal) { |
| cond_signal(cond); |
| return; |
| } |
| |
| 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); |
| } |
| |
| static void w32thread_init(void) |
| { |
| HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll")); |
| /* if one is available, then they should all be available */ |
| cond_init = |
| (void*)GetProcAddress(kernel_dll, "InitializeConditionVariable"); |
| cond_broadcast = |
| (void*)GetProcAddress(kernel_dll, "WakeAllConditionVariable"); |
| cond_signal = |
| (void*)GetProcAddress(kernel_dll, "WakeConditionVariable"); |
| cond_wait = |
| (void*)GetProcAddress(kernel_dll, "SleepConditionVariableCS"); |
| } |
| |
| #endif /* AVCODEC_W32PTHREADS_H */ |