ref: de5fd00ec53cd1aaec8b709424d19ea3108632e2
dir: /vpx_util/vpx_thread.h/
// Copyright 2013 Google Inc. All Rights Reserved. // // Use of this source code is governed by a BSD-style license // that can be found in the COPYING file in the root of the source // tree. An additional intellectual property rights grant can be found // in the file PATENTS. All contributing project authors may // be found in the AUTHORS file in the root of the source tree. // ----------------------------------------------------------------------------- // // Multi-threaded worker // // Original source: // https://chromium.googlesource.com/webm/libwebp #ifndef VPX_THREAD_H_ #define VPX_THREAD_H_ #include "./vpx_config.h" #ifdef __cplusplus extern "C" { #endif // Set maximum decode threads to be 8 due to the limit of frame buffers // and not enough semaphores in the emulation layer on windows. #define MAX_DECODE_THREADS 8 #if CONFIG_MULTITHREAD #if defined(_WIN32) && !HAVE_PTHREAD_H #include <errno.h> // NOLINT #include <process.h> // NOLINT #include <windows.h> // NOLINT typedef HANDLE pthread_t; typedef CRITICAL_SECTION pthread_mutex_t; #if _WIN32_WINNT >= 0x0600 // Windows Vista / Server 2008 or greater #define USE_WINDOWS_CONDITION_VARIABLE typedef CONDITION_VARIABLE pthread_cond_t; #else typedef struct { HANDLE waiting_sem_; HANDLE received_sem_; HANDLE signal_event_; } pthread_cond_t; #endif // _WIN32_WINNT >= 0x600 #ifndef WINAPI_FAMILY_PARTITION #define WINAPI_PARTITION_DESKTOP 1 #define WINAPI_FAMILY_PARTITION(x) x #endif #if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) #define USE_CREATE_THREAD #endif //------------------------------------------------------------------------------ // simplistic pthread emulation layer // _beginthreadex requires __stdcall #if defined(__GNUC__) && \ (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2)) #define THREADFN __attribute__((force_align_arg_pointer)) unsigned int __stdcall #else #define THREADFN unsigned int __stdcall #endif #define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val) #if _WIN32_WINNT >= 0x0501 // Windows XP or greater #define WaitForSingleObject(obj, timeout) \ WaitForSingleObjectEx(obj, timeout, FALSE /*bAlertable*/) #endif static INLINE int pthread_create(pthread_t *const thread, const void *attr, unsigned int(__stdcall *start)(void *), void *arg) { (void)attr; #ifdef USE_CREATE_THREAD *thread = CreateThread(NULL, /* lpThreadAttributes */ 0, /* dwStackSize */ start, arg, 0, /* dwStackSize */ NULL); /* lpThreadId */ #else *thread = (pthread_t)_beginthreadex(NULL, /* void *security */ 0, /* unsigned stack_size */ start, arg, 0, /* unsigned initflag */ NULL); /* unsigned *thrdaddr */ #endif if (*thread == NULL) return 1; SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL); return 0; } static INLINE int pthread_join(pthread_t thread, void **value_ptr) { (void)value_ptr; return (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0 || CloseHandle(thread) == 0); } // Mutex static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex, void *mutexattr) { (void)mutexattr; #if _WIN32_WINNT >= 0x0600 // Windows Vista / Server 2008 or greater InitializeCriticalSectionEx(mutex, 0 /*dwSpinCount*/, 0 /*Flags*/); #else InitializeCriticalSection(mutex); #endif return 0; } static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) { return TryEnterCriticalSection(mutex) ? 0 : EBUSY; } static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) { EnterCriticalSection(mutex); return 0; } static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) { LeaveCriticalSection(mutex); return 0; } static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) { DeleteCriticalSection(mutex); return 0; } // Condition static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) { int ok = 1; #ifdef USE_WINDOWS_CONDITION_VARIABLE (void)condition; #else ok &= (CloseHandle(condition->waiting_sem_) != 0); ok &= (CloseHandle(condition->received_sem_) != 0); ok &= (CloseHandle(condition->signal_event_) != 0); #endif return !ok; } static INLINE int pthread_cond_init(pthread_cond_t *const condition, void *cond_attr) { (void)cond_attr; #ifdef USE_WINDOWS_CONDITION_VARIABLE InitializeConditionVariable(condition); #else condition->waiting_sem_ = CreateSemaphore(NULL, 0, MAX_DECODE_THREADS, NULL); condition->received_sem_ = CreateSemaphore(NULL, 0, MAX_DECODE_THREADS, NULL); condition->signal_event_ = CreateEvent(NULL, FALSE, FALSE, NULL); if (condition->waiting_sem_ == NULL || condition->received_sem_ == NULL || condition->signal_event_ == NULL) { pthread_cond_destroy(condition); return 1; } #endif return 0; } static INLINE int pthread_cond_signal(pthread_cond_t *const condition) { int ok = 1; #ifdef USE_WINDOWS_CONDITION_VARIABLE WakeConditionVariable(condition); #else if (WaitForSingleObject(condition->waiting_sem_, 0) == WAIT_OBJECT_0) { // a thread is waiting in pthread_cond_wait: allow it to be notified ok = SetEvent(condition->signal_event_); // wait until the event is consumed so the signaler cannot consume // the event via its own pthread_cond_wait. ok &= (WaitForSingleObject(condition->received_sem_, INFINITE) != WAIT_OBJECT_0); } #endif return !ok; } static INLINE int pthread_cond_wait(pthread_cond_t *const condition, pthread_mutex_t *const mutex) { int ok; #ifdef USE_WINDOWS_CONDITION_VARIABLE ok = SleepConditionVariableCS(condition, mutex, INFINITE); #else // note that there is a consumer available so the signal isn't dropped in // pthread_cond_signal if (!ReleaseSemaphore(condition->waiting_sem_, 1, NULL)) return 1; // now unlock the mutex so pthread_cond_signal may be issued pthread_mutex_unlock(mutex); ok = (WaitForSingleObject(condition->signal_event_, INFINITE) == WAIT_OBJECT_0); ok &= ReleaseSemaphore(condition->received_sem_, 1, NULL); pthread_mutex_lock(mutex); #endif return !ok; } #elif defined(__OS2__) #define INCL_DOS #include <os2.h> // NOLINT #include <errno.h> // NOLINT #include <stdlib.h> // NOLINT #include <sys/builtin.h> // NOLINT #define pthread_t TID #define pthread_mutex_t HMTX typedef struct { HEV event_sem_; HEV ack_sem_; volatile unsigned wait_count_; } pthread_cond_t; //------------------------------------------------------------------------------ // simplistic pthread emulation layer #define THREADFN void * #define THREAD_RETURN(val) (val) typedef struct { void *(*start_)(void *); void *arg_; } thread_arg; static void thread_start(void *arg) { thread_arg targ = *(thread_arg *)arg; free(arg); targ.start_(targ.arg_); } static INLINE int pthread_create(pthread_t *const thread, const void *attr, void *(*start)(void *), void *arg) { int tid; thread_arg *targ = (thread_arg *)malloc(sizeof(*targ)); if (targ == NULL) return 1; (void)attr; targ->start_ = start; targ->arg_ = arg; tid = (pthread_t)_beginthread(thread_start, NULL, 1024 * 1024, targ); if (tid == -1) { free(targ); return 1; } *thread = tid; return 0; } static INLINE int pthread_join(pthread_t thread, void **value_ptr) { (void)value_ptr; return DosWaitThread(&thread, DCWW_WAIT) != 0; } // Mutex static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex, void *mutexattr) { (void)mutexattr; return DosCreateMutexSem(NULL, mutex, 0, FALSE) != 0; } static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) { return DosRequestMutexSem(*mutex, SEM_IMMEDIATE_RETURN) == 0 ? 0 : EBUSY; } static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) { return DosRequestMutexSem(*mutex, SEM_INDEFINITE_WAIT) != 0; } static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) { return DosReleaseMutexSem(*mutex) != 0; } static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) { return DosCloseMutexSem(*mutex) != 0; } // Condition static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) { int ok = 1; ok &= DosCloseEventSem(condition->event_sem_) == 0; ok &= DosCloseEventSem(condition->ack_sem_) == 0; return !ok; } static INLINE int pthread_cond_init(pthread_cond_t *const condition, void *cond_attr) { int ok = 1; (void)cond_attr; ok &= DosCreateEventSem(NULL, &condition->event_sem_, DCE_POSTONE, FALSE) == 0; ok &= DosCreateEventSem(NULL, &condition->ack_sem_, DCE_POSTONE, FALSE) == 0; if (!ok) { pthread_cond_destroy(condition); return 1; } condition->wait_count_ = 0; return 0; } static INLINE int pthread_cond_signal(pthread_cond_t *const condition) { int ok = 1; if (!__atomic_cmpxchg32(&condition->wait_count_, 0, 0)) { ok &= DosPostEventSem(condition->event_sem_) == 0; ok &= DosWaitEventSem(condition->ack_sem_, SEM_INDEFINITE_WAIT) == 0; } return !ok; } static INLINE int pthread_cond_broadcast(pthread_cond_t *const condition) { int ok = 1; while (!__atomic_cmpxchg32(&condition->wait_count_, 0, 0)) ok &= pthread_cond_signal(condition) == 0; return !ok; } static INLINE int pthread_cond_wait(pthread_cond_t *const condition, pthread_mutex_t *const mutex) { int ok = 1; __atomic_increment(&condition->wait_count_); ok &= pthread_mutex_unlock(mutex) == 0; ok &= DosWaitEventSem(condition->event_sem_, SEM_INDEFINITE_WAIT) == 0; __atomic_decrement(&condition->wait_count_); ok &= DosPostEventSem(condition->ack_sem_) == 0; pthread_mutex_lock(mutex); return !ok; } #else // _WIN32 #include <pthread.h> // NOLINT #define THREADFN void * #define THREAD_RETURN(val) val #endif #endif // CONFIG_MULTITHREAD // State of the worker thread object typedef enum { NOT_OK = 0, // object is unusable OK, // ready to work WORK // busy finishing the current task } VPxWorkerStatus; // Function to be called by the worker thread. Takes two opaque pointers as // arguments (data1 and data2), and should return false in case of error. typedef int (*VPxWorkerHook)(void *, void *); // Platform-dependent implementation details for the worker. typedef struct VPxWorkerImpl VPxWorkerImpl; // Synchronization object used to launch job in the worker thread typedef struct { VPxWorkerImpl *impl_; VPxWorkerStatus status_; VPxWorkerHook hook; // hook to call void *data1; // first argument passed to 'hook' void *data2; // second argument passed to 'hook' int had_error; // return value of the last call to 'hook' } VPxWorker; // The interface for all thread-worker related functions. All these functions // must be implemented. typedef struct { // Must be called first, before any other method. void (*init)(VPxWorker *const worker); // Must be called to initialize the object and spawn the thread. Re-entrant. // Will potentially launch the thread. Returns false in case of error. int (*reset)(VPxWorker *const worker); // Makes sure the previous work is finished. Returns true if worker->had_error // was not set and no error condition was triggered by the working thread. int (*sync)(VPxWorker *const worker); // Triggers the thread to call hook() with data1 and data2 arguments. These // hook/data1/data2 values can be changed at any time before calling this // function, but not be changed afterward until the next call to Sync(). void (*launch)(VPxWorker *const worker); // This function is similar to launch() except that it calls the // hook directly instead of using a thread. Convenient to bypass the thread // mechanism while still using the VPxWorker structs. sync() must // still be called afterward (for error reporting). void (*execute)(VPxWorker *const worker); // Kill the thread and terminate the object. To use the object again, one // must call reset() again. void (*end)(VPxWorker *const worker); } VPxWorkerInterface; // Install a new set of threading functions, overriding the defaults. This // should be done before any workers are started, i.e., before any encoding or // decoding takes place. The contents of the interface struct are copied, it // is safe to free the corresponding memory after this call. This function is // not thread-safe. Return false in case of invalid pointer or methods. int vpx_set_worker_interface(const VPxWorkerInterface *const winterface); // Retrieve the currently set thread worker interface. const VPxWorkerInterface *vpx_get_worker_interface(void); //------------------------------------------------------------------------------ #ifdef __cplusplus } // extern "C" #endif #endif // VPX_THREAD_H_