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Diffstat (limited to 'media/ffvpx/compat/w32pthreads.h')
| -rw-r--r-- | media/ffvpx/compat/w32pthreads.h | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/media/ffvpx/compat/w32pthreads.h b/media/ffvpx/compat/w32pthreads.h new file mode 100644 index 000000000..4ac2a995b --- /dev/null +++ b/media/ffvpx/compat/w32pthreads.h @@ -0,0 +1,418 @@ +/* + * 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 */ |