X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Frts%2FItimer.c;h=623839189fb4b3fcd6cf9711a1b6d4433785cb9c;hb=5acd2909936a1e56db8386ebccf66e0347012ad6;hp=60e30e786d649780815d0e8d0d21faabc00118ce;hpb=b9d8ddb91c9360e3165244520f31dcd28c396825;p=ghc-hetmet.git

diff --git a/ghc/rts/Itimer.c b/ghc/rts/Itimer.c
index 60e30e7..6238391 100644
--- a/ghc/rts/Itimer.c
+++ b/ghc/rts/Itimer.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Itimer.c,v 1.13 2000/04/03 15:54:49 simonmar Exp $
+ * $Id: Itimer.c,v 1.19 2000/10/06 11:05:57 rrt Exp $
  *
  * (c) The GHC Team, 1995-1999
  *
@@ -23,6 +23,7 @@
 #endif
 
 #include "Rts.h"
+#include "RtsFlags.h"
 #include "Itimer.h"
 #include "Proftimer.h"
 #include "Schedule.h"
@@ -45,18 +46,23 @@
  
 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(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
 
 /* -----------------------------------------------------------------------------
    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
@@ -67,8 +73,11 @@ 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++;
 
@@ -76,8 +85,16 @@ handle_tick(int unused STG_UNUSED)
   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 */
+  }
 }
 
 
@@ -94,32 +111,8 @@ handle_tick(int unused STG_UNUSED)
 
 #if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
 
-/* 
- * Sigh - to avoid requiring anyone that wants to build ghc to have
- * to augment the Win32 header files that comes with cygwinb20.1,
- * include the missing MM API decls here inline.
- *
- * ToDo: check and remove these once the next version of cygwin is
- * released.
- */
-#define TIMERR_NOERROR   0
-#define TIMERR_NOCANDO   97
-#define TIME_PERIODIC    1
-
-typedef UINT MMRESULT;
-typedef void CALLBACK (*TIMECALLBACK) (UINT, UINT, DWORD, DWORD, DWORD);
-typedef TIMECALLBACK *LPTIMECALLBACK;
-MMRESULT STDCALL  timeSetEvent(UINT, UINT, LPTIMECALLBACK, DWORD, UINT);
-/*
-  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)
 {
@@ -130,23 +123,28 @@ initialize_virtual_timer(nat ms)
      
      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.)
+     (GetTickCount is used for threadDelay)
   */
-  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;
 }
  
@@ -161,6 +159,9 @@ 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;
@@ -179,6 +180,9 @@ 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;
@@ -237,12 +241,22 @@ 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() * 1000;
 }
 #endif