X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FItimer.c;h=5b10a5bbbc3f34cb1c65ad5f6196fa3e3214adf0;hb=92b67d724a648d1a2ddb371c8ecd3333b0a2ba18;hp=c327528e1295903c4b57b1eec81ce5190fc0121c;hpb=66f7a41dfbf02a000ef3fb2a2b84c89f5dd53177;p=ghc-hetmet.git

diff --git a/ghc/rts/Itimer.c b/ghc/rts/Itimer.c
index c327528..5b10a5b 100644
--- a/ghc/rts/Itimer.c
+++ b/ghc/rts/Itimer.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Itimer.c,v 1.16 2000/08/03 11:28:35 simonmar Exp $
+ * $Id: Itimer.c,v 1.22 2001/03/02 10:52:15 simonmar Exp $
  *
  * (c) The GHC Team, 1995-1999
  *
@@ -49,18 +49,10 @@ lnat total_ticks = 0;
 /* 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.
+   We use the ticker for 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
@@ -71,8 +63,11 @@ static
 void
 #if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
 CALLBACK
-#endif
+handle_tick(UINT uID STG_UNUSED, UINT uMsg STG_UNUSED, DWORD dwUser STG_UNUSED,
+	    DWORD dw1 STG_UNUSED, DWORD d STG_UNUSED)
+#else
 handle_tick(int unused STG_UNUSED)
+#endif
 {
   total_ticks++;
 
@@ -80,13 +75,17 @@ handle_tick(int unused STG_UNUSED)
   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 */
+  /* 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++;
+
+  if (RtsFlags.ConcFlags.ctxtSwitchTicks > 0) {
+      ticks_to_ctxt_switch--;
+      if (ticks_to_ctxt_switch <= 0) {
+	  ticks_to_ctxt_switch = RtsFlags.ConcFlags.ctxtSwitchTicks;
+	  context_switch = 1;	/* schedule a context switch */
+      }
   }
 }
 
@@ -104,43 +103,35 @@ handle_tick(int unused STG_UNUSED)
 
 #if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
 
-/*
-  vtalrm_handler is assigned and set up in Signals.c
-
-  vtalrm_id (defined in Signals.c) holds
-  the system id for the current timer (used to 
-  later block/kill it.)
-*/
-extern nat vtalrm_id;
-TIMECALLBACK *vtalrm_cback;
- 
+LPTIMECALLBACK vtalrm_cback;
+
 nat
 initialize_virtual_timer(nat ms)
 {
-# 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.)
+     The delivery of ticks isn't free; the performance hit should be checked.
   */
-  unsigned int delay,vtalrm_id;
+  unsigned int delay;
+  static unsigned int vtalrm_id;
  
-  delay = timeBeginPeriod(1);
-  if (delay == TIMERR_NOCANDO) { /* error of some sort. */
-     return delay;
+  if (ms) {
+    delay = timeBeginPeriod(1);
+    if (delay == TIMERR_NOCANDO) { /* error of some sort. */
+      return delay;
+    }
+    vtalrm_id =
+      timeSetEvent(ms,      /* event every `delay' milliseconds. */
+		   1,       /* precision is within 1 ms */
+		   vtalrm_cback,
+		   TIME_CALLBACK_FUNCTION,     /* ordinary callback */
+		   TIME_PERIODIC);
+  } else {
+    timeKillEvent(vtalrm_id);
+    timeEndPeriod(1);
   }
-  vtalrm_id =
-    timeSetEvent(ms,     /* event every `delay' milliseconds. */
- 	        1,       /* precision is within 5 millisecs. */
- 	        (LPTIMECALLBACK)vtalrm_cback,
- 		0,
- 		TIME_PERIODIC);
-# endif
 
   return 0;
 }
@@ -156,6 +147,9 @@ initialize_virtual_timer(nat ms)
 # 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;
@@ -174,6 +168,9 @@ 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;
@@ -232,12 +229,22 @@ unblock_vtalrm_signal(void)
 }
 #endif
 
-#if !defined(HAVE_SETITIMER) && !defined(mingw32_TARGET_OS)
+/* gettimeofday() takes around 1us on our 500MHz PIII.  Since we're
+ * only calling it 50 times/s, it shouldn't have any great impact.
+ */
+#if !defined(mingw32_TARGET_OS)
 unsigned int 
 getourtimeofday(void)
 {
   struct timeval tv;
   gettimeofday(&tv, (struct timezone *) NULL);
-  return (tv.tv_sec * 1000000 + tv.tv_usec);
+  return (tv.tv_sec * TICK_FREQUENCY +
+	  tv.tv_usec * TICK_FREQUENCY / 1000000);
+}
+#else
+unsigned int
+getourtimeofday(void)
+{
+  return ((unsigned int)GetTickCount() * TICK_FREQUENCY) / 1000;
 }
 #endif