[Mesa-dev] [PATCH 7/8] st/vdpau: Fix multithreading

[Thomas Hellstrom]

The vdpau state tracker allows multiple threads access to the same gallium
context simultaneously. We can fix this either by locking the same mutex
each time the context is used or by using a different gallium context for
each mutex domain. Here we do the latter, although I'm not sure that's really
the best option.

Signed-off-by: Thomas Hellstrom <thellstrom at vmware.com>
Acked-by: Sinclair Yeh <syeh at vmware.com>
---
 src/gallium/state_trackers/vdpau/decode.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/gallium/state_trackers/vdpau/decode.c b/src/gallium/state_trackers/vdpau/decode.c
index f85bce8..2a07d17 100644
--- a/src/gallium/state_trackers/vdpau/decode.c
+++ b/src/gallium/state_trackers/vdpau/decode.c
@@ -68,7 +68,6 @@ vlVdpDecoderCreate(VdpDevice device,
    if (!dev)
       return VDP_STATUS_INVALID_HANDLE;
 
-   pipe = dev->context;
    screen = dev->vscreen->pscreen;
 
    pipe_mutex_lock(dev->mutex);
@@ -123,6 +122,12 @@ vlVdpDecoderCreate(VdpDevice device,
       templat.level = u_get_h264_level(templat.width, templat.height,
                             &templat.max_references);
 
+   pipe = screen->context_create(screen, dev->vscreen, 0);
+   if (!pipe) {
+      ret = VDP_STATUS_RESOURCES;
+      goto error_context;
+   }
+
    vldecoder->decoder = pipe->create_video_codec(pipe, &templat);
 
    if (!vldecoder->decoder) {
@@ -145,6 +150,8 @@ error_handle:
    vldecoder->decoder->destroy(vldecoder->decoder);
 
 error_decoder:
+   pipe->destroy(pipe);
+error_context:
    pipe_mutex_unlock(dev->mutex);
    DeviceReference(&vldecoder->device, NULL);
    FREE(vldecoder);
@@ -158,15 +165,18 @@ VdpStatus
 vlVdpDecoderDestroy(VdpDecoder decoder)
 {
    vlVdpDecoder *vldecoder;
+   struct pipe_context *pipe;
 
    vldecoder = (vlVdpDecoder *)vlGetDataHTAB(decoder);
    if (!vldecoder)
       return VDP_STATUS_INVALID_HANDLE;
 
+   pipe = vldecoder->decoder->context;
    pipe_mutex_lock(vldecoder->mutex);
    vldecoder->decoder->destroy(vldecoder->decoder);
    pipe_mutex_unlock(vldecoder->mutex);
    pipe_mutex_destroy(vldecoder->mutex);
+   pipe->destroy(pipe);
 
    vlRemoveDataHTAB(decoder);
    DeviceReference(&vldecoder->device, NULL);
@@ -674,10 +684,20 @@ vlVdpDecoderRender(VdpDecoder decoder,
    if (ret != VDP_STATUS_OK)
       return ret;
 
+   /*
+    * Since we use separate contexts for the two mutex domains, we need
+    * to flush to make sure rendering operations happen in order.
+    * In particular, so that a frame is rendered before it is presented.
+    */
+   pipe_mutex_lock(vldecoder->device->mutex);
+   vldecoder->device->context->flush(vldecoder->device->context, NULL, 0);
+   pipe_mutex_unlock(vldecoder->device->mutex);
+
    pipe_mutex_lock(vldecoder->mutex);
    dec->begin_frame(dec, vlsurf->video_buffer, &desc.base);
    dec->decode_bitstream(dec, vlsurf->video_buffer, &desc.base, bitstream_buffer_count, buffers, sizes);
    dec->end_frame(dec, vlsurf->video_buffer, &desc.base);
+   dec->flush(dec);
    pipe_mutex_unlock(vldecoder->mutex);
    return ret;
 }
-- 
2.5.0