[FFmpeg-devel] [PATCH v3 1/3] avcodec: make a local copy of executor
Nuo Mi
nuomi2021 at gmail.com
Tue Oct 1 16:54:36 EEST 2024
We still need several refactors to improve the current VVC decoder's performance,
which will frequently break the API/ABI. To mitigate this, we've copied the executor from
avutil to avcodec. Once the API/ABI is stable, we will move this class back to avutil
---
libavcodec/Makefile | 1 +
libavcodec/executor.c | 221 ++++++++++++++++++++++++++++++++++++++++
libavcodec/executor.h | 73 +++++++++++++
libavcodec/vvc/thread.c | 8 +-
4 files changed, 299 insertions(+), 4 deletions(-)
create mode 100644 libavcodec/executor.c
create mode 100644 libavcodec/executor.h
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index a4fcce3b42..da1a1aa945 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -43,6 +43,7 @@ OBJS = ac3_parser.o \
dirac.o \
dv_profile.o \
encode.o \
+ executor.o \
get_buffer.o \
imgconvert.o \
jni.o \
diff --git a/libavcodec/executor.c b/libavcodec/executor.c
new file mode 100644
index 0000000000..f8fc7c33ab
--- /dev/null
+++ b/libavcodec/executor.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2024 Nuo Mi
+ *
+ * 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 "config.h"
+
+#include <stdbool.h>
+
+#include "libavutil/mem.h"
+#include "libavutil/thread.h"
+
+#include "executor.h"
+
+#if !HAVE_THREADS
+
+#define ExecutorThread char
+
+#define executor_thread_create(t, a, s, ar) 0
+#define executor_thread_join(t, r) do {} while(0)
+
+#else
+
+#define ExecutorThread pthread_t
+
+#define executor_thread_create(t, a, s, ar) pthread_create(t, a, s, ar)
+#define executor_thread_join(t, r) pthread_join(t, r)
+
+#endif //!HAVE_THREADS
+
+typedef struct ThreadInfo {
+ AVExecutor *e;
+ ExecutorThread thread;
+} ThreadInfo;
+
+struct AVExecutor {
+ AVTaskCallbacks cb;
+ int thread_count;
+ bool recursive;
+
+ ThreadInfo *threads;
+ uint8_t *local_contexts;
+
+ AVMutex lock;
+ AVCond cond;
+ int die;
+
+ AVTask *tasks;
+};
+
+static AVTask* remove_task(AVTask **prev, AVTask *t)
+{
+ *prev = t->next;
+ t->next = NULL;
+ return t;
+}
+
+static void add_task(AVTask **prev, AVTask *t)
+{
+ t->next = *prev;
+ *prev = t;
+}
+
+static int run_one_task(AVExecutor *e, void *lc)
+{
+ AVTaskCallbacks *cb = &e->cb;
+ AVTask **prev;
+
+ for (prev = &e->tasks; *prev && !cb->ready(*prev, cb->user_data); prev = &(*prev)->next)
+ /* nothing */;
+ if (*prev) {
+ AVTask *t = remove_task(prev, *prev);
+ if (e->thread_count > 0)
+ ff_mutex_unlock(&e->lock);
+ cb->run(t, lc, cb->user_data);
+ if (e->thread_count > 0)
+ ff_mutex_lock(&e->lock);
+ return 1;
+ }
+ return 0;
+}
+
+#if HAVE_THREADS
+static void *executor_worker_task(void *data)
+{
+ ThreadInfo *ti = (ThreadInfo*)data;
+ AVExecutor *e = ti->e;
+ void *lc = e->local_contexts + (ti - e->threads) * e->cb.local_context_size;
+
+ ff_mutex_lock(&e->lock);
+ while (1) {
+ if (e->die) break;
+
+ if (!run_one_task(e, lc)) {
+ //no task in one loop
+ ff_cond_wait(&e->cond, &e->lock);
+ }
+ }
+ ff_mutex_unlock(&e->lock);
+ return NULL;
+}
+#endif
+
+static void executor_free(AVExecutor *e, const int has_lock, const int has_cond)
+{
+ if (e->thread_count) {
+ //signal die
+ ff_mutex_lock(&e->lock);
+ e->die = 1;
+ ff_cond_broadcast(&e->cond);
+ ff_mutex_unlock(&e->lock);
+
+ for (int i = 0; i < e->thread_count; i++)
+ executor_thread_join(e->threads[i].thread, NULL);
+ }
+ if (has_cond)
+ ff_cond_destroy(&e->cond);
+ if (has_lock)
+ ff_mutex_destroy(&e->lock);
+
+ av_free(e->threads);
+ av_free(e->local_contexts);
+
+ av_free(e);
+}
+
+AVExecutor* ff_executor_alloc(const AVTaskCallbacks *cb, int thread_count)
+{
+ AVExecutor *e;
+ int has_lock = 0, has_cond = 0;
+ if (!cb || !cb->user_data || !cb->ready || !cb->run || !cb->priority_higher)
+ return NULL;
+
+ e = av_mallocz(sizeof(*e));
+ if (!e)
+ return NULL;
+ e->cb = *cb;
+
+ e->local_contexts = av_calloc(FFMAX(thread_count, 1), e->cb.local_context_size);
+ if (!e->local_contexts)
+ goto free_executor;
+
+ e->threads = av_calloc(FFMAX(thread_count, 1), sizeof(*e->threads));
+ if (!e->threads)
+ goto free_executor;
+
+ if (!thread_count)
+ return e;
+
+ has_lock = !ff_mutex_init(&e->lock, NULL);
+ has_cond = !ff_cond_init(&e->cond, NULL);
+
+ if (!has_lock || !has_cond)
+ goto free_executor;
+
+ for (/* nothing */; e->thread_count < thread_count; e->thread_count++) {
+ ThreadInfo *ti = e->threads + e->thread_count;
+ ti->e = e;
+ if (executor_thread_create(&ti->thread, NULL, executor_worker_task, ti))
+ goto free_executor;
+ }
+ return e;
+
+free_executor:
+ executor_free(e, has_lock, has_cond);
+ return NULL;
+}
+
+void ff_executor_free(AVExecutor **executor)
+{
+ int thread_count;
+
+ if (!executor || !*executor)
+ return;
+ thread_count = (*executor)->thread_count;
+ executor_free(*executor, thread_count, thread_count);
+ *executor = NULL;
+}
+
+void ff_executor_execute(AVExecutor *e, AVTask *t)
+{
+ AVTaskCallbacks *cb = &e->cb;
+ AVTask **prev;
+
+ if (e->thread_count)
+ ff_mutex_lock(&e->lock);
+ if (t) {
+ for (prev = &e->tasks; *prev && cb->priority_higher(*prev, t); prev = &(*prev)->next)
+ /* nothing */;
+ add_task(prev, t);
+ }
+ if (e->thread_count) {
+ ff_cond_signal(&e->cond);
+ ff_mutex_unlock(&e->lock);
+ }
+
+ if (!e->thread_count || !HAVE_THREADS) {
+ if (e->recursive)
+ return;
+ e->recursive = true;
+ // We are running in a single-threaded environment, so we must handle all tasks ourselves
+ while (run_one_task(e, e->local_contexts))
+ /* nothing */;
+ e->recursive = false;
+ }
+}
diff --git a/libavcodec/executor.h b/libavcodec/executor.h
new file mode 100644
index 0000000000..05d4b1e189
--- /dev/null
+++ b/libavcodec/executor.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2024 Nuo Mi
+ *
+ * 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
+ */
+
+/*
+ * We still need several refactors to improve the current VVC decoder's performance,
+ * which will frequently break the API/ABI. To mitigate this, we've copied the executor from
+ * avutil to avcodec. Once the API/ABI is stable, we will move this class back to avutil
+ */
+
+#ifndef AVCODEC_EXECUTOR_H
+#define AVCODEC_EXECUTOR_H
+
+typedef struct AVExecutor AVExecutor;
+typedef struct AVTask AVTask;
+
+struct AVTask {
+ AVTask *next;
+};
+
+typedef struct AVTaskCallbacks {
+ void *user_data;
+
+ int local_context_size;
+
+ // return 1 if a's priority > b's priority
+ int (*priority_higher)(const AVTask *a, const AVTask *b);
+
+ // task is ready for run
+ int (*ready)(const AVTask *t, void *user_data);
+
+ // run the task
+ int (*run)(AVTask *t, void *local_context, void *user_data);
+} AVTaskCallbacks;
+
+/**
+ * Alloc executor
+ * @param callbacks callback structure for executor
+ * @param thread_count worker thread number, 0 for run on caller's thread directly
+ * @return return the executor
+ */
+AVExecutor* ff_executor_alloc(const AVTaskCallbacks *callbacks, int thread_count);
+
+/**
+ * Free executor
+ * @param e pointer to executor
+ */
+void ff_executor_free(AVExecutor **e);
+
+/**
+ * Add task to executor
+ * @param e pointer to executor
+ * @param t pointer to task. If NULL, it will wakeup one work thread
+ */
+void ff_executor_execute(AVExecutor *e, AVTask *t);
+
+#endif //AVCODEC_EXECUTOR_H
diff --git a/libavcodec/vvc/thread.c b/libavcodec/vvc/thread.c
index 86a7753c6a..72f5c51382 100644
--- a/libavcodec/vvc/thread.c
+++ b/libavcodec/vvc/thread.c
@@ -22,7 +22,7 @@
#include <stdatomic.h>
-#include "libavutil/executor.h"
+#include "libavcodec/executor.h"
#include "libavutil/mem.h"
#include "libavutil/thread.h"
@@ -109,7 +109,7 @@ static void add_task(VVCContext *s, VVCTask *t)
atomic_fetch_add(&ft->nb_scheduled_tasks, 1);
- av_executor_execute(s->executor, &t->u.task);
+ ff_executor_execute(s->executor, &t->u.task);
}
static void task_init(VVCTask *t, VVCTaskStage stage, VVCFrameContext *fc, const int rx, const int ry)
@@ -692,12 +692,12 @@ AVExecutor* ff_vvc_executor_alloc(VVCContext *s, const int thread_count)
task_ready,
task_run,
};
- return av_executor_alloc(&callbacks, thread_count);
+ return ff_executor_alloc(&callbacks, thread_count);
}
void ff_vvc_executor_free(AVExecutor **e)
{
- av_executor_free(e);
+ ff_executor_free(e);
}
void ff_vvc_frame_thread_free(VVCFrameContext *fc)
--
2.34.1
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