gcc is getting smarter, so we need to hit it with a bigger stick

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

diff --git a/ghc/rts/Timer.c b/ghc/rts/Timer.c
index da4c852..0bfea2d 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.
  *
@@ -19,17 +19,17 @@
 #include "Proftimer.h"
 #include "Schedule.h"
 #include "Timer.h"
+#include "Ticker.h"
 #include "Capability.h"
 
-#if !defined(mingw32_HOST_OS)
-#include "Itimer.h"
-#else
-#include "win32/Ticker.h"
-#endif
-
 /* 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()
  *
@@ -48,32 +48,41 @@ 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(RTS_SUPPORTS_THREADS)
-         /* 
-          * If we've been inactive for a whole time slice, tell the
-          * scheduler to wake up and do a GC, to check for threads
-          * that are deadlocked.
+#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?
           */
-         switch (recent_activity) {
-         case ACTIVITY_YES:
-             recent_activity = ACTIVITY_MAYBE_NO;
-             break;
-         case ACTIVITY_MAYBE_NO:
-             recent_activity = ACTIVITY_INACTIVE;
-             blackholes_need_checking = rtsTrue;
-             /* hack: re-use the blackholes_need_checking flag */
-             threadRunnable();
-             /* ToDo: this threadRunnable only works if there's
-              * another thread (not this one) waiting to be woken up
-              */
-             break;
-         default:
-             break;
-         }
-#endif
+         prodOneCapability();
       }
+      break;
+  default:
+      break;
   }
+#endif
 }
 
 int