tracker/pt: protect get_n_points()

There's a race here since further accesses to the points array aren't
protected by a mutex in the extractor class.

There's no race in "get_points()" in the extractor since it's only used
in same thread where updates take place.

1 files changed, 1 insertions, 0 deletions

diff --git a/tracker-pt/point_extractor.h b/tracker-pt/point_extractor.h
index 030251ff..8bcc2437 100644
--- a/tracker-pt/point_extractor.h
+++ b/tracker-pt/point_extractor.h
@@ -23,6 +23,7 @@ public:
     // WARNING: returned reference is valid as long as object
     const std::vector<cv::Vec2f> &extract_points(cv::Mat &frame);
     const std::vector<cv::Vec2f>& get_points() { QMutexLocker l(&mtx); return points; }
+    int get_n_points() const { QMutexLocker l(&mtx); return points.size(); }
     PointExtractor();
     
     settings_pt s;