1 files changed, 6 insertions, 0 deletions

diff --git a/mps/code/trace.c b/mps/code/trace.c
index 3614f3157df..69ff0018404 100644
--- a/mps/code/trace.c
+++ b/mps/code/trace.c
@@ -1056,6 +1056,9 @@ static void tracePostMessage(Trace trace)
     message->notCondemnedSize = trace->notCondemned;
     MessagePost(arena, TraceMessageMessage(message));
   }
+  if(arena->alertCollection) {
+    (*arena->alertCollection)(MPS_ALERT_COLLECTION_STOP, trace->why);
+  }
 
   return;
 }
@@ -1859,6 +1862,9 @@ void TraceStart(Trace trace, double mortality, double finishingTime)
   if(!MessageOnQueue(message)) {
     MessagePost(arena, message);
   }
+  if(arena->alertCollection) {
+    (*arena->alertCollection)(MPS_ALERT_COLLECTION_START, trace->why);
+  }
 
   /* From the already set up white set, derive a grey set. */