X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FItimer.c;h=07d6dcd6fe80e572df9bb10ddf7189aebc15cf0c;hb=67a402e25d3707ce4e031e809b874f8341032d23;hp=1bdd2bb4a4294634cc8a9d7b7570206e5d1005f2;hpb=bbe3617e46aa95ecb2519285d824a64bca17d228;p=ghc-hetmet.git

diff --git a/ghc/rts/Itimer.c b/ghc/rts/Itimer.c
index 1bdd2bb..07d6dcd 100644
--- a/ghc/rts/Itimer.c
+++ b/ghc/rts/Itimer.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Itimer.c,v 1.9 2000/02/28 10:57:44 simonmar Exp $
+ * $Id: Itimer.c,v 1.17 2000/08/25 13:12:07 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 */
@@ -43,9 +45,16 @@
 #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
@@ -58,19 +67,29 @@ static void handle_tick(int unused STG_UNUSED);
    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++;
+  /* so we can get a rough indication of the current time at any point
+   * without having to call gettimeofday() (see Select.c):
+   */
+  ticks_since_timestamp++;
+
+  ticks_to_ctxt_switch--;
+  if (ticks_to_ctxt_switch <= 0) {
+      ticks_to_ctxt_switch = RtsFlags.ConcFlags.ctxtSwitchTicks;
+      context_switch = 1;	/* schedule a context switch */
+  }
 }
 
 
@@ -124,6 +143,7 @@ initialize_virtual_timer(nat ms)
  		0,
  		TIME_PERIODIC);
 # endif
+
   return 0;
 }
  
@@ -133,11 +153,14 @@ 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;
 
+    timestamp = getourtimeofday();
+    ticks_since_timestamp = 0;
+
     it.it_value.tv_sec = ms / 1000;
     it.it_value.tv_usec = 1000 * (ms - (1000 * it.it_value.tv_sec));
     it.it_interval = it.it_value;
@@ -156,6 +179,9 @@ initialize_virtual_timer(nat ms)
     struct itimerspec it;
     timer_t tid;
 
+    timestamp = getourtimeofday();
+    ticks_since_timestamp = 0;
+
     se.sigev_notify = SIGEV_SIGNAL;
     se.sigev_signo = SIGVTALRM;
     se.sigev_value.sival_int = SIGVTALRM;
@@ -213,3 +239,15 @@ unblock_vtalrm_signal(void)
     (void) sigprocmask(SIG_UNBLOCK, &signals, NULL);
 }
 #endif
+
+/* gettimeofday() takes around 1us on our 500MHz PIII.  Since we're
+ * only calling it 50 times/s, it shouldn't have any great impact.
+ */
+unsigned int 
+getourtimeofday(void)
+{
+  struct timeval tv;
+  gettimeofday(&tv, (struct timezone *) NULL);
+  return (tv.tv_sec * TICK_FREQUENCY +
+	  tv.tv_usec * TICK_FREQUENCY / 1000000);
+}