diff options
Diffstat (limited to 'media/libvpx/libvpx/vpx_util/vpx_thread.c')
| -rw-r--r-- | media/libvpx/libvpx/vpx_util/vpx_thread.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vpx_util/vpx_thread.c b/media/libvpx/libvpx/vpx_util/vpx_thread.c new file mode 100644 index 0000000000..04c5fb6f26 --- /dev/null +++ b/media/libvpx/libvpx/vpx_util/vpx_thread.c @@ -0,0 +1,181 @@ +// 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 + +#include <assert.h> +#include <string.h> // for memset() +#include "./vpx_thread.h" +#include "vpx_mem/vpx_mem.h" + +#if CONFIG_MULTITHREAD + +struct VPxWorkerImpl { + pthread_mutex_t mutex_; + pthread_cond_t condition_; + pthread_t thread_; +}; + +//------------------------------------------------------------------------------ + +static void execute(VPxWorker *const worker); // Forward declaration. + +static THREADFN thread_loop(void *ptr) { + VPxWorker *const worker = (VPxWorker *)ptr; + int done = 0; + while (!done) { + pthread_mutex_lock(&worker->impl_->mutex_); + while (worker->status_ == OK) { // wait in idling mode + pthread_cond_wait(&worker->impl_->condition_, &worker->impl_->mutex_); + } + if (worker->status_ == WORK) { + 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->impl_->condition_); + pthread_mutex_unlock(&worker->impl_->mutex_); + } + return THREAD_RETURN(NULL); // Thread is finished +} + +// main thread state control +static void change_state(VPxWorker *const worker, VPxWorkerStatus new_status) { + // No-op when attempting to change state on a thread that didn't come up. + // Checking status_ without acquiring the lock first would result in a data + // race. + if (worker->impl_ == NULL) return; + + pthread_mutex_lock(&worker->impl_->mutex_); + if (worker->status_ >= OK) { + // wait for the worker to finish + while (worker->status_ != OK) { + pthread_cond_wait(&worker->impl_->condition_, &worker->impl_->mutex_); + } + // assign new status and release the working thread if needed + if (new_status != OK) { + worker->status_ = new_status; + pthread_cond_signal(&worker->impl_->condition_); + } + } + pthread_mutex_unlock(&worker->impl_->mutex_); +} + +#endif // CONFIG_MULTITHREAD + +//------------------------------------------------------------------------------ + +static void init(VPxWorker *const worker) { + memset(worker, 0, sizeof(*worker)); + worker->status_ = NOT_OK; +} + +static int sync(VPxWorker *const worker) { +#if CONFIG_MULTITHREAD + change_state(worker, OK); +#endif + assert(worker->status_ <= OK); + return !worker->had_error; +} + +static int reset(VPxWorker *const worker) { + int ok = 1; + worker->had_error = 0; + if (worker->status_ < OK) { +#if CONFIG_MULTITHREAD + worker->impl_ = (VPxWorkerImpl *)vpx_calloc(1, sizeof(*worker->impl_)); + if (worker->impl_ == NULL) { + return 0; + } + if (pthread_mutex_init(&worker->impl_->mutex_, NULL)) { + goto Error; + } + if (pthread_cond_init(&worker->impl_->condition_, NULL)) { + pthread_mutex_destroy(&worker->impl_->mutex_); + goto Error; + } + pthread_mutex_lock(&worker->impl_->mutex_); + ok = !pthread_create(&worker->impl_->thread_, NULL, thread_loop, worker); + if (ok) worker->status_ = OK; + pthread_mutex_unlock(&worker->impl_->mutex_); + if (!ok) { + pthread_mutex_destroy(&worker->impl_->mutex_); + pthread_cond_destroy(&worker->impl_->condition_); + Error: + vpx_free(worker->impl_); + worker->impl_ = NULL; + return 0; + } +#else + worker->status_ = OK; +#endif + } else if (worker->status_ > OK) { + ok = sync(worker); + } + assert(!ok || (worker->status_ == OK)); + return ok; +} + +static void execute(VPxWorker *const worker) { + if (worker->hook != NULL) { + worker->had_error |= !worker->hook(worker->data1, worker->data2); + } +} + +static void launch(VPxWorker *const worker) { +#if CONFIG_MULTITHREAD + change_state(worker, WORK); +#else + execute(worker); +#endif +} + +static void end(VPxWorker *const worker) { +#if CONFIG_MULTITHREAD + if (worker->impl_ != NULL) { + change_state(worker, NOT_OK); + pthread_join(worker->impl_->thread_, NULL); + pthread_mutex_destroy(&worker->impl_->mutex_); + pthread_cond_destroy(&worker->impl_->condition_); + vpx_free(worker->impl_); + worker->impl_ = NULL; + } +#else + worker->status_ = NOT_OK; + assert(worker->impl_ == NULL); +#endif + assert(worker->status_ == NOT_OK); +} + +//------------------------------------------------------------------------------ + +static VPxWorkerInterface g_worker_interface = { init, reset, sync, + launch, execute, end }; + +int vpx_set_worker_interface(const VPxWorkerInterface *const winterface) { + if (winterface == NULL || winterface->init == NULL || + winterface->reset == NULL || winterface->sync == NULL || + winterface->launch == NULL || winterface->execute == NULL || + winterface->end == NULL) { + return 0; + } + g_worker_interface = *winterface; + return 1; +} + +const VPxWorkerInterface *vpx_get_worker_interface(void) { + return &g_worker_interface; +} + +//------------------------------------------------------------------------------ |