[FFmpeg-cvslog] pthread: mark lockless thread synchronization variables as volatile
Michael Niedermayer
git at videolan.org
Sun Jul 22 02:58:39 CEST 2012
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Tue Jul 17 16:10:49 2012 +0200| [7c71f8e0ec987863157ad5e53820dd989c37ac01] | committer: Michael Niedermayer
pthread: mark lockless thread synchronization variables as volatile
No speed difference was meassureable
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7c71f8e0ec987863157ad5e53820dd989c37ac01
---
libavcodec/pthread.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c
index 597aeba..8006ae7 100644
--- a/libavcodec/pthread.c
+++ b/libavcodec/pthread.c
@@ -129,8 +129,8 @@ typedef struct PerThreadContext {
/**
* Array of progress values used by ff_thread_get_buffer().
*/
- int progress[MAX_BUFFERS][2];
- uint8_t progress_used[MAX_BUFFERS];
+ volatile int progress[MAX_BUFFERS][2];
+ volatile uint8_t progress_used[MAX_BUFFERS];
AVFrame *requested_frame; ///< AVFrame the codec passed to get_buffer()
} PerThreadContext;
@@ -500,7 +500,7 @@ static int update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
static void free_progress(AVFrame *f)
{
PerThreadContext *p = f->owner->thread_opaque;
- int *progress = f->thread_opaque;
+ volatile int *progress = f->thread_opaque;
p->progress_used[(progress - p->progress[0]) / 2] = 0;
}
@@ -666,7 +666,7 @@ int ff_thread_decode_frame(AVCodecContext *avctx,
void ff_thread_report_progress(AVFrame *f, int n, int field)
{
PerThreadContext *p;
- int *progress = f->thread_opaque;
+ volatile int *progress = f->thread_opaque;
if (!progress || progress[field] >= n) return;
@@ -684,7 +684,7 @@ void ff_thread_report_progress(AVFrame *f, int n, int field)
void ff_thread_await_progress(AVFrame *f, int n, int field)
{
PerThreadContext *p;
- int *progress = f->thread_opaque;
+ volatile int *progress = f->thread_opaque;
if (!progress || progress[field] >= n) return;
@@ -911,7 +911,7 @@ void ff_thread_flush(AVCodecContext *avctx)
}
}
-static int *allocate_progress(PerThreadContext *p)
+static volatile int *allocate_progress(PerThreadContext *p)
{
int i;
@@ -942,7 +942,8 @@ int ff_thread_can_start_frame(AVCodecContext *avctx)
int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
{
PerThreadContext *p = avctx->thread_opaque;
- int *progress, err;
+ int err;
+ volatile int *progress;
f->owner = avctx;
@@ -961,7 +962,7 @@ int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
}
pthread_mutex_lock(&p->parent->buffer_mutex);
- f->thread_opaque = progress = allocate_progress(p);
+ f->thread_opaque = (int*)(progress = allocate_progress(p));
if (!progress) {
pthread_mutex_unlock(&p->parent->buffer_mutex);
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