update submodules for GHC.HetMet.GArrow -> Control.GArrow renaming

[ghc-hetmet.git] / rts / Timer.c

diff --git a/rts/Timer.c b/rts/Timer.c
index 8c178a0..02d106f 100644 (file)
--- a/rts/Timer.c
+++ b/rts/Timer.c
@@ -76,8 +76,6 @@ handle_tick(int unused STG_UNUSED)
               ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTime /
                   RtsFlags.MiscFlags.tickInterval;
               recent_activity = ACTIVITY_INACTIVE;
-              blackholes_need_checking = rtsTrue;
-              /* hack: re-use the blackholes_need_checking flag */
               wakeUpRts();
           }
       }
@@ -88,6 +86,15 @@ handle_tick(int unused STG_UNUSED)
 #endif
 }
 
+// This global counter is used to allow multiple threads to stop the
+// timer temporarily with a stopTimer()/startTimer() pair.  If 
+//      timer_enabled  == 0          timer is enabled
+//      timer_disabled == N, N > 0   timer is disabled by N threads
+// When timer_enabled makes a transition to 0, we enable the timer,
+// and when it makes a transition to non-0 we disable it.
+
+static StgWord timer_disabled;
+
 void
 initTimer(void)
 {
@@ -95,28 +102,33 @@ initTimer(void)
     if (RtsFlags.MiscFlags.tickInterval != 0) {
         initTicker(RtsFlags.MiscFlags.tickInterval, handle_tick);
     }
+    timer_disabled = 1;
 }
 
 void
 startTimer(void)
 {
-    if (RtsFlags.MiscFlags.tickInterval != 0) {
-        startTicker();
+    if (atomic_dec(&timer_disabled) == 0) {
+        if (RtsFlags.MiscFlags.tickInterval != 0) {
+            startTicker();
+        }
     }
 }
 
 void
 stopTimer(void)
 {
-    if (RtsFlags.MiscFlags.tickInterval != 0) {
-        stopTicker();
+    if (atomic_inc(&timer_disabled) == 1) {
+        if (RtsFlags.MiscFlags.tickInterval != 0) {
+            stopTicker();
+        }
     }
 }
 
 void
-exitTimer(void)
+exitTimer (rtsBool wait)
 {
     if (RtsFlags.MiscFlags.tickInterval != 0) {
-        exitTicker();
+        exitTicker(wait);
     }
 }