/* * 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 = 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 = 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 = 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 = 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 = 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 = 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 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"); initonce_begin = (void*)GetProcAddress(kernel_dll, "InitOnceBeginInitialize"); initonce_complete = (void*)GetProcAddress(kernel_dll, "InitOnceComplete"); #endif } #endif /* COMPAT_W32PTHREADS_H */