tracker/pt: reduce mutex contention

1 files changed, 4 insertions, 3 deletions

diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index dd36c57f..6eb255a5 100644
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -147,12 +147,13 @@ std::vector<cv::Vec2f> PointExtractor::extract_points(cv::Mat& frame)
         blobs.push_back(blob(radius, pos, confid, area));
     }
     
-    // clear old points
-	points.clear();
-
     using b = const blob;
     std::sort(blobs.begin(), blobs.end(), [](b& b1, b& b2) {return b1.confid > b2.confid;});
     
+    QMutexLocker l(&mtx);
+    
+	points.clear();
+    
     for (auto& b : blobs)
     {
         cv::Vec2f p((b.pos[0] - W/2)/W, -(b.pos[1] - H/2)/W);