[project @ 2000-08-03 11:28:35 by simonmar]

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

diff --git a/ghc/rts/Itimer.c b/ghc/rts/Itimer.c
index bbbb3ad..c327528 100644 (file)
--- a/ghc/rts/Itimer.c
+++ b/ghc/rts/Itimer.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Itimer.c,v 1.5 1999/08/25 16:11:48 simonmar Exp $
+ * $Id: Itimer.c,v 1.16 2000/08/03 11:28:35 simonmar Exp $
  *
  * (c) The GHC Team, 1995-1999
  *
@@ -23,7 +23,9 @@
 #endif
 
 #include "Rts.h"
+#include "RtsFlags.h"
 #include "Itimer.h"
+#include "Proftimer.h"
 #include "Schedule.h"
 
 /* As recommended in the autoconf manual */
@@ -43,30 +45,49 @@
 #endif
  
 lnat total_ticks = 0;
-rtsBool do_prof_ticks = rtsFalse;
 
-static void handle_tick(int unused STG_UNUSED);
+/* ticks left before next pre-emptive context switch */
+int ticks_to_ctxt_switch = 0;
+
+static
+void
+#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
+CALLBACK
+#endif
+handle_tick(int unused STG_UNUSED);
 
 /* -----------------------------------------------------------------------------
    Tick handler
 
    We use the ticker for two things: supporting threadDelay, and time
    profiling.
+
+   SMP note: this signal could be delivered to *any* thread.  We have
+   to ensure that it doesn't matter which thread actually runs the
+   signal handler.
    -------------------------------------------------------------------------- */
 
-static void
+static
+void
+#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
+CALLBACK
+#endif
 handle_tick(int unused STG_UNUSED)
 {
   total_ticks++;
 
 #ifdef PROFILING
-  if (do_prof_ticks = rtsTrue) {
-    CCS_TICK(CCCS);
-  }
+  handleProfTick();
 #endif
 
   /* For threadDelay etc., see Select.c */
   ticks_since_select++;
+
+  ticks_to_ctxt_switch--;
+  if (ticks_to_ctxt_switch <= 0) {
+      ticks_to_ctxt_switch = RtsFlags.ConcFlags.ctxtSwitchTicks;
+      context_switch = 1;      /* schedule a context switch */
+  }
 }
 
 
@@ -96,10 +117,16 @@ TIMECALLBACK *vtalrm_cback;
 nat
 initialize_virtual_timer(nat ms)
 {
-  /* VTALRM is currently not supported by  cygwin32, 
-     so we use the Timer support provided by the
-     MultiMedia API that is part of Win32. The
-     parameters to timeSetEvent may require some tweaking.
+# ifdef PROFILING
+  /* On Win32 setups that don't have support for
+     setitimer(), we use the MultiMedia API's timer
+     support.
+     
+     As the delivery of ticks isn't free, we only
+     enable it if we really needed, i.e., when profiling.
+     (the RTS now also needs timer ticks to implement
+     threadDelay in non-profiling mode, but the pure
+     Win32 port doesn't support that.....yet.)
   */
   unsigned int delay,vtalrm_id;
  
@@ -113,6 +140,8 @@ initialize_virtual_timer(nat ms)
                (LPTIMECALLBACK)vtalrm_cback,
                0,
                TIME_PERIODIC);
+# endif
+
   return 0;
 }
  
@@ -122,7 +151,7 @@ nat
 initialize_virtual_timer(nat ms)
 {
 # ifndef HAVE_SETITIMER
-    fprintf(stderr, "No virtual timer on this system\n");
+  /*    fprintf(stderr, "No virtual timer on this system\n"); */
     return -1;
 # else
     struct itimerval it;
@@ -149,8 +178,7 @@ initialize_virtual_timer(nat ms)
     se.sigev_signo = SIGVTALRM;
     se.sigev_value.sival_int = SIGVTALRM;
     if (timer_create(CLOCK_VIRTUAL, &se, &tid)) {
-       fprintf(stderr, "Can't create virtual timer.\n");
-       EXIT(EXIT_FAILURE);
+       barf("can't create virtual timer");
     }
     it.it_value.tv_sec = ms / 1000;
     it.it_value.tv_nsec = 1000000 * (ms - 1000 * it.it_value.tv_sec);
@@ -203,3 +231,13 @@ unblock_vtalrm_signal(void)
     (void) sigprocmask(SIG_UNBLOCK, &signals, NULL);
 }
 #endif
+
+#if !defined(HAVE_SETITIMER) && !defined(mingw32_TARGET_OS)
+unsigned int 
+getourtimeofday(void)
+{
+  struct timeval tv;
+  gettimeofday(&tv, (struct timezone *) NULL);
+  return (tv.tv_sec * 1000000 + tv.tv_usec);
+}
+#endif