1 files changed, 11 insertions, 0 deletions
diff --git a/courses.go b/courses.go
index e38e2dc..454ee1c 100644
--- a/courses.go
+++ b/courses.go
@@ -34,6 +34,10 @@ type (
 
 type courseT struct {
 	ID           int
+	/*
+	 * TODO: There will be a lot of lock contention over Selected. It is
+	 * probably more appropriate to directly use atomics.
+	 */
 	Selected     int
 	SelectedLock sync.RWMutex
 	Max          int
@@ -210,3 +214,10 @@ func getCourseGroupFromCourseID(ctx context.Context, courseID int) (courseGroupT
 	}
 	return ret, nil
 }
+
+func (course *courseT) decrementSelectedAndPropagate() {
+	course.SelectedLock.Lock()
+	defer course.SelectedLock.Unlock()
+	course.Selected--
+	propagateIgnoreFailures(fmt.Sprintf("M %d %d", course.ID, course.Selected))
+}