threads: limit the number of automatic threads to MAX_AUTO_THREADS

[ffmpeg] / libavcodec / pthread.c

diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c
index 3364376a6675567850f33254de18dbb6889e521c..58c5fcd638c7e574f18a540752fe630b384d9383 100644 (file)
--- a/libavcodec/pthread.c
+++ b/libavcodec/pthread.c
@@ -30,6 +30,25 @@
  */
 
 #include "config.h"
+
+#if HAVE_SCHED_GETAFFINITY
+#define _GNU_SOURCE
+#include <sched.h>
+#endif
+#if HAVE_GETSYSTEMINFO
+#include <windows.h>
+#endif
+#if HAVE_SYSCTL
+#if HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#endif
+#if HAVE_SYSCONF
+#include <unistd.h>
+#endif
+
 #include "avcodec.h"
 #include "internal.h"
 #include "thread.h"
@@ -70,6 +89,7 @@ typedef struct PerThreadContext {
     struct FrameThreadContext *parent;
 
     pthread_t      thread;
+    int            thread_init;
     pthread_cond_t input_cond;      ///< Used to wait for a new packet from the main thread.
     pthread_cond_t progress_cond;   ///< Used by child threads to wait for progress to change.
     pthread_cond_t output_cond;     ///< Used by the main thread to wait for frames to finish.
@@ -132,6 +152,44 @@ typedef struct FrameThreadContext {
     int die;                       ///< Set when threads should exit.
 } FrameThreadContext;
 
+
+/* H264 slice threading seems to be buggy with more than 16 threads,
+ * limit the number of threads to 16 for automatic detection */
+#define MAX_AUTO_THREADS 16
+
+static int get_logical_cpus(AVCodecContext *avctx)
+{
+    int ret, nb_cpus = 1;
+#if HAVE_SCHED_GETAFFINITY && defined(CPU_COUNT)
+    cpu_set_t cpuset;
+
+    CPU_ZERO(&cpuset);
+
+    ret = sched_getaffinity(0, sizeof(cpuset), &cpuset);
+    if (!ret) {
+        nb_cpus = CPU_COUNT(&cpuset);
+    }
+#elif HAVE_GETSYSTEMINFO
+    SYSTEM_INFO sysinfo;
+    GetSystemInfo(&sysinfo);
+    nb_cpus = sysinfo.dwNumberOfProcessors;
+#elif HAVE_SYSCTL && defined(HW_NCPU)
+    int mib[2] = { CTL_HW, HW_NCPU };
+    size_t len = sizeof(nb_cpus);
+
+    ret = sysctl(mib, 2, &nb_cpus, &len, NULL, 0);
+    if (ret == -1)
+        nb_cpus = 0;
+#elif HAVE_SYSCONF && defined(_SC_NPROC_ONLN)
+    nb_cpus = sysconf(_SC_NPROC_ONLN);
+#elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
+    nb_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+    av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
+    return nb_cpus;
+}
+
+
 static void* attribute_align_arg worker(void *v)
 {
     AVCodecContext *avctx = v;
@@ -236,8 +294,19 @@ static int thread_init(AVCodecContext *avctx)
     ThreadContext *c;
     int thread_count = avctx->thread_count;
 
-    if (thread_count <= 1)
+    if (!thread_count) {
+        int nb_cpus = get_logical_cpus(avctx);
+        // use number of cores + 1 as thread count if there is more than one
+        if (nb_cpus > 1)
+            thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
+        else
+            thread_count = avctx->thread_count = 1;
+    }
+
+    if (thread_count <= 1) {
+        avctx->active_thread_type = 0;
         return 0;
+    }
 
     c = av_mallocz(sizeof(ThreadContext));
     if (!c)
@@ -321,7 +390,7 @@ static attribute_align_arg void *frame_worker_thread(void *arg)
 }
 
 /**
- * Updates the next thread's AVCodecContext with values from the reference thread's context.
+ * Update the next thread's AVCodecContext with values from the reference thread's context.
  *
  * @param dst The destination context.
  * @param src The source context.
@@ -490,6 +559,7 @@ static int submit_packet(PerThreadContext *p, AVPacket *avpkt)
     }
 
     fctx->prev_thread = p;
+    fctx->next_decoding++;
 
     return 0;
 }
@@ -512,8 +582,6 @@ int ff_thread_decode_frame(AVCodecContext *avctx,
     err = submit_packet(p, avpkt);
     if (err) return err;
 
-    fctx->next_decoding++;
-
     /*
      * If we're still receiving the initial packets, don't return a frame.
      */
@@ -545,6 +613,10 @@ int ff_thread_decode_frame(AVCodecContext *avctx,
         *picture = p->frame;
         *got_picture_ptr = p->got_frame;
         picture->pkt_dts = p->avpkt.dts;
+        picture->sample_aspect_ratio = avctx->sample_aspect_ratio;
+        picture->width  = avctx->width;
+        picture->height = avctx->height;
+        picture->format = avctx->pix_fmt;
 
         /*
          * A later call with avkpt->size == 0 may loop over all threads,
@@ -651,7 +723,8 @@ static void frame_thread_free(AVCodecContext *avctx, int thread_count)
         pthread_cond_signal(&p->input_cond);
         pthread_mutex_unlock(&p->mutex);
 
-        pthread_join(p->thread, NULL);
+        if (p->thread_init)
+            pthread_join(p->thread, NULL);
 
         if (codec->close)
             codec->close(p->avctx);
@@ -694,6 +767,15 @@ static int frame_thread_init(AVCodecContext *avctx)
     FrameThreadContext *fctx;
     int i, err = 0;
 
+    if (!thread_count) {
+        int nb_cpus = get_logical_cpus(avctx);
+        // use number of cores + 1 as thread count if there is more than one
+        if (nb_cpus > 1)
+            thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
+        else
+            thread_count = avctx->thread_count = 1;
+    }
+
     if (thread_count <= 1) {
         avctx->active_thread_type = 0;
         return 0;
@@ -755,7 +837,8 @@ static int frame_thread_init(AVCodecContext *avctx)
 
         if (err) goto error;
 
-        pthread_create(&p->thread, NULL, frame_worker_thread, p);
+        if (!pthread_create(&p->thread, NULL, frame_worker_thread, p))
+            p->thread_init = 1;
     }
 
     return 0;
@@ -853,13 +936,6 @@ int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
 
     pthread_mutex_unlock(&p->parent->buffer_mutex);
 
-    /*
-     * Buffer age is difficult to keep track of between
-     * multiple threads, and the optimizations it allows
-     * are not worth the effort. It is disabled for now.
-     */
-    f->age = INT_MAX;
-
     return err;
 }
 
@@ -910,6 +986,9 @@ static void validate_thread_parameters(AVCodecContext *avctx)
     } else if (avctx->codec->capabilities & CODEC_CAP_SLICE_THREADS &&
                avctx->thread_type & FF_THREAD_SLICE) {
         avctx->active_thread_type = FF_THREAD_SLICE;
+    } else if (!(avctx->codec->capabilities & CODEC_CAP_AUTO_THREADS)) {
+        avctx->thread_count       = 1;
+        avctx->active_thread_type = 0;
     }
 }