ref: 55834d42cc7d2a5cdcfec8472fd4b88a1f720102
dir: /vp9/decoder/vp9_thread.c/
// 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: // http://git.chromium.org/webm/libwebp.git // 100644 blob eff8f2a8c20095aade3c292b0e9292dac6cb3587 src/utils/thread.c #include <assert.h> #include <string.h> // for memset() #include "./vp9_thread.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif #if CONFIG_MULTITHREAD //------------------------------------------------------------------------------ static THREADFN thread_loop(void *ptr) { // thread loop VP9Worker* const worker = (VP9Worker*)ptr; int done = 0; while (!done) { pthread_mutex_lock(&worker->mutex_); while (worker->status_ == OK) { // wait in idling mode pthread_cond_wait(&worker->condition_, &worker->mutex_); } if (worker->status_ == WORK) { vp9_worker_execute(worker); worker->status_ = OK; } else if (worker->status_ == NOT_OK) { // finish the worker done = 1; } // signal to the main thread that we're done (for Sync()) pthread_cond_signal(&worker->condition_); pthread_mutex_unlock(&worker->mutex_); } return THREAD_RETURN(NULL); // Thread is finished } // main thread state control static void change_state(VP9Worker* const worker, VP9WorkerStatus new_status) { // no-op when attempting to change state on a thread that didn't come up if (worker->status_ < OK) return; pthread_mutex_lock(&worker->mutex_); // wait for the worker to finish while (worker->status_ != OK) { pthread_cond_wait(&worker->condition_, &worker->mutex_); } // assign new status and release the working thread if needed if (new_status != OK) { worker->status_ = new_status; pthread_cond_signal(&worker->condition_); } pthread_mutex_unlock(&worker->mutex_); } #endif // CONFIG_MULTITHREAD //------------------------------------------------------------------------------ void vp9_worker_init(VP9Worker* const worker) { memset(worker, 0, sizeof(*worker)); worker->status_ = NOT_OK; } int vp9_worker_sync(VP9Worker* const worker) { #if CONFIG_MULTITHREAD change_state(worker, OK); #endif assert(worker->status_ <= OK); return !worker->had_error; } int vp9_worker_reset(VP9Worker* const worker) { int ok = 1; worker->had_error = 0; if (worker->status_ < OK) { #if CONFIG_MULTITHREAD if (pthread_mutex_init(&worker->mutex_, NULL) || pthread_cond_init(&worker->condition_, NULL)) { return 0; } pthread_mutex_lock(&worker->mutex_); ok = !pthread_create(&worker->thread_, NULL, thread_loop, worker); if (ok) worker->status_ = OK; pthread_mutex_unlock(&worker->mutex_); #else worker->status_ = OK; #endif } else if (worker->status_ > OK) { ok = vp9_worker_sync(worker); } assert(!ok || (worker->status_ == OK)); return ok; } void vp9_worker_execute(VP9Worker* const worker) { if (worker->hook != NULL) { worker->had_error |= !worker->hook(worker->data1, worker->data2); } } void vp9_worker_launch(VP9Worker* const worker) { #if CONFIG_MULTITHREAD change_state(worker, WORK); #else vp9_worker_execute(worker); #endif } void vp9_worker_end(VP9Worker* const worker) { if (worker->status_ >= OK) { #if CONFIG_MULTITHREAD change_state(worker, NOT_OK); pthread_join(worker->thread_, NULL); pthread_mutex_destroy(&worker->mutex_); pthread_cond_destroy(&worker->condition_); #else worker->status_ = NOT_OK; #endif } assert(worker->status_ == NOT_OK); } //------------------------------------------------------------------------------ #if defined(__cplusplus) || defined(c_plusplus) } // extern "C" #endif