[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 d40ab4e..c327528 100644 (file)
--- a/ghc/rts/Itimer.c
+++ b/ghc/rts/Itimer.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Itimer.c,v 1.3 1999/02/05 16:02:44 simonm Exp $
+ * $Id: Itimer.c,v 1.16 2000/08/03 11:28:35 simonmar Exp $
  *
  * (c) The GHC Team, 1995-1999
  *
@@ -23,7 +23,10 @@
 #endif
 
 #include "Rts.h"
+#include "RtsFlags.h"
 #include "Itimer.h"
+#include "Proftimer.h"
+#include "Schedule.h"
 
 /* As recommended in the autoconf manual */
 # ifdef TIME_WITH_SYS_TIME
@@ -36,7 +39,58 @@
 #   include <time.h>
 #  endif
 # endif
+
+#if HAVE_WINDOWS_H
+# include <windows.h>
+#endif
  
+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.
+
+   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
+#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
+CALLBACK
+#endif
+handle_tick(int unused STG_UNUSED)
+{
+  total_ticks++;
+
+#ifdef PROFILING
+  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 */
+  }
+}
+
+
 /*
  * Handling timer events under cygwin32 is not done with signal/setitimer.
  * Instead of the two steps of first registering a signal handler to handle
@@ -48,28 +102,31 @@
  * 11/98: if the cygwin DLL supports setitimer(), then use it instead.
  */
 
-#if defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER)
-
-#include <windows.h>  /* OK, bring it all in... */
+#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
 
 /*
-  vtalrm_handler is assigned and set up in
-  main/Signals.lc.
+  vtalrm_handler is assigned and set up in Signals.c
 
-  vtalrm_id (defined in main/Signals.lc) holds
+  vtalrm_id (defined in Signals.c) holds
   the system id for the current timer (used to 
-  later block/kill the timer)
+  later block/kill it.)
 */
 extern nat vtalrm_id;
-extern TIMECALLBACK *vtalrm_cback;
+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;
  
@@ -83,6 +140,8 @@ initialize_virtual_timer(nat ms)
                (LPTIMECALLBACK)vtalrm_cback,
                0,
                TIME_PERIODIC);
+# endif
+
   return 0;
 }
  
@@ -92,7 +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;
@@ -119,8 +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);
@@ -129,12 +187,21 @@ initialize_virtual_timer(nat ms)
 }
 # endif
 
+#if defined(mingw32_TARGET_OS) || (defined(cygwin32_TARGET_OS) && !defined(HAVE_SETITIMER))
+int
+install_vtalrm_handler(void)
+{
+  vtalrm_cback = handle_tick;
+  return 0;
+}
+
+#else
 int
-install_vtalrm_handler(void (*handler)(int))
+install_vtalrm_handler(void)
 {
     struct sigaction action;
 
-    action.sa_handler = handler;
+    action.sa_handler = handle_tick;
 
     sigemptyset(&action.sa_mask);
     action.sa_flags = 0;
@@ -163,3 +230,14 @@ 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