rts: Eliminate shutdown data race on task counters

2 files changed, 5 insertions, 0 deletions

diff --git a/rts/Stats.c b/rts/Stats.c
index 80fca509ad..fcf48c3720 100644
--- a/rts/Stats.c
+++ b/rts/Stats.c
@@ -1230,6 +1230,8 @@ stat_exit (void)
 {
     RTSSummaryStats sum;
     init_RTSSummaryStats(&sum);
+    // We'll need to refer to task counters later
+    ACQUIRE_LOCK(&all_tasks_mutex);
 
     if (RtsFlags.GcFlags.giveStats != NO_GC_STATS) {
         // First we tidy the times in stats, and populate the times in sum.
@@ -1446,6 +1448,8 @@ stat_exit (void)
       stgFree(GC_coll_max_pause);
       GC_coll_max_pause = NULL;
     }
+
+    RELEASE_LOCK(&all_tasks_mutex);
 }
 
 /* Note [Work Balance]
diff --git a/rts/Task.c b/rts/Task.c
index 5fc2331827..c471d4afee 100644
--- a/rts/Task.c
+++ b/rts/Task.c
@@ -30,6 +30,7 @@
 Task *all_tasks = NULL;
 
 // current number of bound tasks + total number of worker tasks.
+// Locks required: all_tasks_mutex.
 uint32_t taskCount;
 uint32_t workerCount;
 uint32_t currentWorkerCount;