For #1659, #307, add ffmpeg-4.2-fit for rtc

trunk/3rdparty/ffmpeg-4.2-fit/libavutil/slicethread.c

@@ -0,0 +1,255 @@
+/*
+ * 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
+ */
+
+#include <stdatomic.h>
+#include "slicethread.h"
+#include "mem.h"
+#include "thread.h"
+#include "avassert.h"
+
+#if HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS2THREADS
+
+typedef struct WorkerContext {
+    AVSliceThread   *ctx;
+    pthread_mutex_t mutex;
+    pthread_cond_t  cond;
+    pthread_t       thread;
+    int             done;
+} WorkerContext;
+
+struct AVSliceThread {
+    WorkerContext   *workers;
+    int             nb_threads;
+    int             nb_active_threads;
+    int             nb_jobs;
+
+    atomic_uint     first_job;
+    atomic_uint     current_job;
+    pthread_mutex_t done_mutex;
+    pthread_cond_t  done_cond;
+    int             done;
+    int             finished;
+
+    void            *priv;
+    void            (*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads);
+    void            (*main_func)(void *priv);
+};
+
+static int run_jobs(AVSliceThread *ctx)
+{
+    unsigned nb_jobs    = ctx->nb_jobs;
+    unsigned nb_active_threads = ctx->nb_active_threads;
+    unsigned first_job    = atomic_fetch_add_explicit(&ctx->first_job, 1, memory_order_acq_rel);
+    unsigned current_job  = first_job;
+
+    do {
+        ctx->worker_func(ctx->priv, current_job, first_job, nb_jobs, nb_active_threads);
+    } while ((current_job = atomic_fetch_add_explicit(&ctx->current_job, 1, memory_order_acq_rel)) < nb_jobs);
+
+    return current_job == nb_jobs + nb_active_threads - 1;
+}
+
+static void *attribute_align_arg thread_worker(void *v)
+{
+    WorkerContext *w = v;
+    AVSliceThread *ctx = w->ctx;
+
+    pthread_mutex_lock(&w->mutex);
+    pthread_cond_signal(&w->cond);
+
+    while (1) {
+        w->done = 1;
+        while (w->done)
+            pthread_cond_wait(&w->cond, &w->mutex);
+
+        if (ctx->finished) {
+            pthread_mutex_unlock(&w->mutex);
+            return NULL;
+        }
+
+        if (run_jobs(ctx)) {
+            pthread_mutex_lock(&ctx->done_mutex);
+            ctx->done = 1;
+            pthread_cond_signal(&ctx->done_cond);
+            pthread_mutex_unlock(&ctx->done_mutex);
+        }
+    }
+}
+
+int avpriv_slicethread_create(AVSliceThread **pctx, void *priv,
+                              void (*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads),
+                              void (*main_func)(void *priv),
+                              int nb_threads)
+{
+    AVSliceThread *ctx;
+    int nb_workers, i;
+
+    av_assert0(nb_threads >= 0);
+    if (!nb_threads) {
+        int nb_cpus = av_cpu_count();
+        if (nb_cpus > 1)
+            nb_threads = nb_cpus + 1;
+        else
+            nb_threads = 1;
+    }
+
+    nb_workers = nb_threads;
+    if (!main_func)
+        nb_workers--;
+
+    *pctx = ctx = av_mallocz(sizeof(*ctx));
+    if (!ctx)
+        return AVERROR(ENOMEM);
+
+    if (nb_workers && !(ctx->workers = av_calloc(nb_workers, sizeof(*ctx->workers)))) {
+        av_freep(pctx);
+        return AVERROR(ENOMEM);
+    }
+
+    ctx->priv        = priv;
+    ctx->worker_func = worker_func;
+    ctx->main_func   = main_func;
+    ctx->nb_threads  = nb_threads;
+    ctx->nb_active_threads = 0;
+    ctx->nb_jobs     = 0;
+    ctx->finished    = 0;
+
+    atomic_init(&ctx->first_job, 0);
+    atomic_init(&ctx->current_job, 0);
+    pthread_mutex_init(&ctx->done_mutex, NULL);
+    pthread_cond_init(&ctx->done_cond, NULL);
+    ctx->done        = 0;
+
+    for (i = 0; i < nb_workers; i++) {
+        WorkerContext *w = &ctx->workers[i];
+        int ret;
+        w->ctx = ctx;
+        pthread_mutex_init(&w->mutex, NULL);
+        pthread_cond_init(&w->cond, NULL);
+        pthread_mutex_lock(&w->mutex);
+        w->done = 0;
+
+        if (ret = pthread_create(&w->thread, NULL, thread_worker, w)) {
+            ctx->nb_threads = main_func ? i : i + 1;
+            pthread_mutex_unlock(&w->mutex);
+            pthread_cond_destroy(&w->cond);
+            pthread_mutex_destroy(&w->mutex);
+            avpriv_slicethread_free(pctx);
+            return AVERROR(ret);
+        }
+
+        while (!w->done)
+            pthread_cond_wait(&w->cond, &w->mutex);
+        pthread_mutex_unlock(&w->mutex);
+    }
+
+    return nb_threads;
+}
+
+void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
+{
+    int nb_workers, i, is_last = 0;
+
+    av_assert0(nb_jobs > 0);
+    ctx->nb_jobs           = nb_jobs;
+    ctx->nb_active_threads = FFMIN(nb_jobs, ctx->nb_threads);
+    atomic_store_explicit(&ctx->first_job, 0, memory_order_relaxed);
+    atomic_store_explicit(&ctx->current_job, ctx->nb_active_threads, memory_order_relaxed);
+    nb_workers             = ctx->nb_active_threads;
+    if (!ctx->main_func || !execute_main)
+        nb_workers--;
+
+    for (i = 0; i < nb_workers; i++) {
+        WorkerContext *w = &ctx->workers[i];
+        pthread_mutex_lock(&w->mutex);
+        w->done = 0;
+        pthread_cond_signal(&w->cond);
+        pthread_mutex_unlock(&w->mutex);
+    }
+
+    if (ctx->main_func && execute_main)
+        ctx->main_func(ctx->priv);
+    else
+        is_last = run_jobs(ctx);
+
+    if (!is_last) {
+        pthread_mutex_lock(&ctx->done_mutex);
+        while (!ctx->done)
+            pthread_cond_wait(&ctx->done_cond, &ctx->done_mutex);
+        ctx->done = 0;
+        pthread_mutex_unlock(&ctx->done_mutex);
+    }
+}
+
+void avpriv_slicethread_free(AVSliceThread **pctx)
+{
+    AVSliceThread *ctx;
+    int nb_workers, i;
+
+    if (!pctx || !*pctx)
+        return;
+
+    ctx = *pctx;
+    nb_workers = ctx->nb_threads;
+    if (!ctx->main_func)
+        nb_workers--;
+
+    ctx->finished = 1;
+    for (i = 0; i < nb_workers; i++) {
+        WorkerContext *w = &ctx->workers[i];
+        pthread_mutex_lock(&w->mutex);
+        w->done = 0;
+        pthread_cond_signal(&w->cond);
+        pthread_mutex_unlock(&w->mutex);
+    }
+
+    for (i = 0; i < nb_workers; i++) {
+        WorkerContext *w = &ctx->workers[i];
+        pthread_join(w->thread, NULL);
+        pthread_cond_destroy(&w->cond);
+        pthread_mutex_destroy(&w->mutex);
+    }
+
+    pthread_cond_destroy(&ctx->done_cond);
+    pthread_mutex_destroy(&ctx->done_mutex);
+    av_freep(&ctx->workers);
+    av_freep(pctx);
+}
+
+#else /* HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS32THREADS */
+
+int avpriv_slicethread_create(AVSliceThread **pctx, void *priv,
+                              void (*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads),
+                              void (*main_func)(void *priv),
+                              int nb_threads)
+{
+    *pctx = NULL;
+    return AVERROR(EINVAL);
+}
+
+void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
+{
+    av_assert0(0);
+}
+
+void avpriv_slicethread_free(AVSliceThread **pctx)
+{
+    av_assert0(!pctx || !*pctx);
+}
+
+#endif /* HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS32THREADS */