From 129bb238430ec45a3b5f8f1d384df590ddf7b62f Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Sat, 11 May 2013 20:41:46 +0200 Subject: lavfi: add a slice threading infrastructure Mostly based on libavcodec's --- libavfilter/pthread.c | 229 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 229 insertions(+) create mode 100644 libavfilter/pthread.c (limited to 'libavfilter/pthread.c') diff --git a/libavfilter/pthread.c b/libavfilter/pthread.c new file mode 100644 index 0000000000..374c1c32c3 --- /dev/null +++ b/libavfilter/pthread.c @@ -0,0 +1,229 @@ +/* + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Libavfilter multithreading support + */ + +#include "config.h" + +#include "libavutil/common.h" +#include "libavutil/cpu.h" +#include "libavutil/mem.h" + +#include "avfilter.h" +#include "internal.h" +#include "thread.h" + +#if HAVE_PTHREADS +#include +#elif HAVE_W32THREADS +#include "compat/w32pthreads.h" +#endif + +typedef struct ThreadContext { + AVFilterGraph *graph; + + int nb_threads; + pthread_t *workers; + action_func *func; + + /* per-execute perameters */ + AVFilterContext *ctx; + void *arg; + int *rets; + int nb_rets; + int nb_jobs; + + pthread_cond_t last_job_cond; + pthread_cond_t current_job_cond; + pthread_mutex_t current_job_lock; + int current_job; + int done; +} ThreadContext; + +static void* attribute_align_arg worker(void *v) +{ + ThreadContext *c = v; + int our_job = c->nb_jobs; + int nb_threads = c->nb_threads; + int self_id; + + pthread_mutex_lock(&c->current_job_lock); + self_id = c->current_job++; + for (;;) { + while (our_job >= c->nb_jobs) { + if (c->current_job == nb_threads + c->nb_jobs) + pthread_cond_signal(&c->last_job_cond); + + pthread_cond_wait(&c->current_job_cond, &c->current_job_lock); + our_job = self_id; + + if (c->done) { + pthread_mutex_unlock(&c->current_job_lock); + return NULL; + } + } + pthread_mutex_unlock(&c->current_job_lock); + + c->rets[our_job % c->nb_rets] = c->func(c->ctx, c->arg, our_job, c->nb_jobs); + + pthread_mutex_lock(&c->current_job_lock); + our_job = c->current_job++; + } +} + +static void slice_thread_uninit(ThreadContext *c) +{ + int i; + + pthread_mutex_lock(&c->current_job_lock); + c->done = 1; + pthread_cond_broadcast(&c->current_job_cond); + pthread_mutex_unlock(&c->current_job_lock); + + for (i = 0; i < c->nb_threads; i++) + pthread_join(c->workers[i], NULL); + + pthread_mutex_destroy(&c->current_job_lock); + pthread_cond_destroy(&c->current_job_cond); + pthread_cond_destroy(&c->last_job_cond); + av_freep(&c->workers); +} + +static void slice_thread_park_workers(ThreadContext *c) +{ + pthread_cond_wait(&c->last_job_cond, &c->current_job_lock); + pthread_mutex_unlock(&c->current_job_lock); +} + +static int thread_execute(AVFilterContext *ctx, action_func *func, + void *arg, int *ret, int nb_jobs) +{ + ThreadContext *c = ctx->graph->internal->thread; + int dummy_ret; + + if (nb_jobs <= 0) + return 0; + + pthread_mutex_lock(&c->current_job_lock); + + c->current_job = c->nb_threads; + c->nb_jobs = nb_jobs; + c->ctx = ctx; + c->arg = arg; + c->func = func; + if (ret) { + c->rets = ret; + c->nb_rets = nb_jobs; + } else { + c->rets = &dummy_ret; + c->nb_rets = 1; + } + pthread_cond_broadcast(&c->current_job_cond); + + slice_thread_park_workers(c); + + return 0; +} + +static int thread_init(ThreadContext *c, int nb_threads) +{ + int i, ret; + + if (!nb_threads) { + int nb_cpus = av_cpu_count(); + av_log(c->graph, AV_LOG_DEBUG, "Detected %d logical cores.\n", nb_cpus); + // use number of cores + 1 as thread count if there is more than one + if (nb_cpus > 1) + nb_threads = nb_cpus + 1; + else + nb_threads = 1; + } + + if (nb_threads <= 1) + return 1; + + c->nb_threads = nb_threads; + c->workers = av_mallocz(sizeof(*c->workers) * nb_threads); + if (!c->workers) + return AVERROR(ENOMEM); + + c->current_job = 0; + c->nb_jobs = 0; + c->done = 0; + + pthread_cond_init(&c->current_job_cond, NULL); + pthread_cond_init(&c->last_job_cond, NULL); + + pthread_mutex_init(&c->current_job_lock, NULL); + pthread_mutex_lock(&c->current_job_lock); + for (i = 0; i < nb_threads; i++) { + ret = pthread_create(&c->workers[i], NULL, worker, c); + if (ret) { + pthread_mutex_unlock(&c->current_job_lock); + c->nb_threads = i; + slice_thread_uninit(c); + return AVERROR(ret); + } + } + + slice_thread_park_workers(c); + + return c->nb_threads; +} + +int ff_graph_thread_init(AVFilterGraph *graph) +{ + int ret; + +#if HAVE_W32THREADS + w32thread_init(); +#endif + + if (graph->nb_threads == 1) { + graph->thread_type = 0; + return 0; + } + + graph->internal->thread = av_mallocz(sizeof(ThreadContext)); + if (!graph->internal->thread) + return AVERROR(ENOMEM); + + ret = thread_init(graph->internal->thread, graph->nb_threads); + if (ret <= 1) { + av_freep(&graph->internal->thread); + graph->thread_type = 0; + graph->nb_threads = 1; + return (ret < 0) ? ret : 0; + } + graph->nb_threads = ret; + + graph->internal->thread_execute = thread_execute; + + return 0; +} + +void ff_graph_thread_free(AVFilterGraph *graph) +{ + if (graph->internal->thread) + slice_thread_uninit(graph->internal->thread); + av_freep(&graph->internal->thread); +} -- cgit v1.2.3