[project @ 2005-10-21 14:47:36 by simonmar]

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

diff --git a/ghc/rts/Timer.c b/ghc/rts/Timer.c
index 5425116..b6414f8 100644 (file)
--- a/ghc/rts/Timer.c
+++ b/ghc/rts/Timer.c
@@ -1,6 +1,6 @@
 /* -----------------------------------------------------------------------------
  *
- * (c) The GHC Team, 1995-2003
+ * (c) The GHC Team, 1995-2005
  *
  * Interval timer service for profiling and pre-emptive scheduling.
  *
@@ -19,22 +19,24 @@
 #include "Proftimer.h"
 #include "Schedule.h"
 #include "Timer.h"
-
-#if !defined(mingw32_TARGET_OS)
-#include "Itimer.h"
-#else
-#include "win32/Ticker.h"
-#endif
+#include "Ticker.h"
+#include "Capability.h"
 
 /* ticks left before next pre-emptive context switch */
 static int ticks_to_ctxt_switch = 0;
 
+#if defined(THREADED_RTS)
+/* idle ticks left before we perform a GC */
+static int ticks_to_gc = 0;
+#endif
+
 /*
  * Function: handle_tick()
  *
  * At each occurrence of a tick, the OS timer will invoke
  * handle_tick().
  */
+static
 void
 handle_tick(int unused STG_UNUSED)
 {
@@ -46,6 +48,39 @@ handle_tick(int unused STG_UNUSED)
       if (ticks_to_ctxt_switch <= 0) {
          ticks_to_ctxt_switch = RtsFlags.ConcFlags.ctxtSwitchTicks;
          context_switch = 1;   /* schedule a context switch */
+
+#if defined(THREADED_RTS)
+         /* 
+          * If we've been inactive for idleGCDelayTicks (set by +RTS
+          * -I), tell the scheduler to wake up and do a GC, to check
+          * for threads that are deadlocked.
+          */
+         switch (recent_activity) {
+         case ACTIVITY_YES:
+             recent_activity = ACTIVITY_MAYBE_NO;
+             ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTicks;
+             break;
+         case ACTIVITY_MAYBE_NO:
+             if (ticks_to_gc == 0) break; /* 0 ==> no idle GC */
+             ticks_to_gc--;
+             if (ticks_to_gc == 0) {
+                 ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTicks;
+                 recent_activity = ACTIVITY_INACTIVE;
+                 blackholes_need_checking = rtsTrue;
+                 /* hack: re-use the blackholes_need_checking flag */
+
+                 /* ToDo: this doesn't work.  Can't invoke
+                  * pthread_cond_signal from a signal handler.
+                  * Furthermore, we can't prod a capability that we
+                  * might be holding.  What can we do?
+                  */
+                 prodOneCapability();
+             }
+             break;
+         default:
+             break;
+         }
+#endif
       }
   }
 }
@@ -57,7 +92,7 @@ startTimer(nat ms)
   initProfTimer();
 #endif
 
-  return startTicker(ms);
+  return startTicker(ms, handle_tick);
 }
 
 int