Fix a thread race in X264Encoder. Found by GCC TSan.

[nageru] / x264_encoder.cpp

diff --git a/x264_encoder.cpp b/x264_encoder.cpp
index ccf6942e1813ef7aa4748b45b531d108dd06d64f..66c06344f4ce7710919241be4d9dd9e7d449b60c 100644 (file)
--- a/x264_encoder.cpp
+++ b/x264_encoder.cpp
@@ -343,7 +343,12 @@ void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
        }
 
        if (speed_control) {
-               speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
+               float queue_fill_ratio;
+               {
+                       lock_guard<mutex> lock(mu);
+                       queue_fill_ratio = float(free_frames.size()) / X264_QUEUE_LENGTH;
+               }
+               speed_control->before_frame(queue_fill_ratio, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
        }
        dyn.x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
        if (speed_control) {