Rearrange the code that sets memtop to trigger an interrupt. I have a

strong suspicion that these timer interrupts run in a separate thread
under NT.  If so, this is a really dangerous thing to be doing without
synchronization.  This rearrangement will minimize the window in which
problems can occur.

diff --git a/v7/src/microcode/ntutl/scheme16.c b/v7/src/microcode/ntutl/scheme16.c
index b248c2ee1ac392c636cbaf1ddff254df2378ce4c..c935cb50fab23aa596d406bf331ba8a87b5dab3e 100644 (file)
--- a/v7/src/microcode/ntutl/scheme16.c
+++ b/v7/src/microcode/ntutl/scheme16.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Id: scheme16.c,v 1.9 1997/01/01 22:58:15 cph Exp $
+$Id: scheme16.c,v 1.10 1997/01/02 07:07:13 cph Exp $
 
 Copyright (c) 1993-97 Massachusetts Institute of Technology
 
@@ -355,11 +355,11 @@ scheme_asynctimer (void)
       if (((INTERRUPT_CODE (scm_timer)) & (INTERRUPT_MASK (scm_timer)))
          != 0L)
        {
+         (MEMTOP (scm_timer)) = ((unsigned long) -1L);
          PostMessage ((scm_timer -> window),
                       (scm_timer -> interrupt_message),
                       ((WPARAM) 0),
                       ((LPARAM) 0));
-         (MEMTOP (scm_timer)) = ((unsigned long) -1L);
        }
       (CATATONIA_COUNTER (scm_timer)) += 1L;
       if (((CATATONIA_COUNTER (scm_timer)) > (CATATONIA_LIMIT (scm_timer)))
@@ -367,11 +367,11 @@ scheme_asynctimer (void)
        {
          if ((CATATONIA_FLAG (scm_timer)) == 0L)
            {
+             (CATATONIA_FLAG (scm_timer)) = 1L;
              PostMessage ((scm_timer -> window),
                           (scm_timer -> catatonia_message),
                           ((WPARAM) 0),
                           ((LPARAM) 0));
-             (CATATONIA_FLAG (scm_timer)) = 1L;
            }
          (CATATONIA_COUNTER (scm_timer)) = 0L;
        }

diff --git a/v7/src/microcode/ntutl/scheme32.c b/v7/src/microcode/ntutl/scheme32.c
index d75d1d3bbaef566cadaf43526cb2e8d658e4a004..8490ffacc701aa889e4dbbdee1523ce56cb451b8 100644 (file)
--- a/v7/src/microcode/ntutl/scheme32.c
+++ b/v7/src/microcode/ntutl/scheme32.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Id: scheme32.c,v 1.12 1997/01/01 22:58:18 cph Exp $
+$Id: scheme32.c,v 1.13 1997/01/02 07:07:19 cph Exp $
 
 Copyright (c) 1993-97 Massachusetts Institute of Technology
 
@@ -160,13 +160,13 @@ win32_nt_timer_tick (UINT wID, UINT wMsg, DWORD dwUser, DWORD dw1, DWORD dw2)
   (INTERRUPT_CODE (scm_timer)) |= (scm_timer -> bit_mask);
   if (((INTERRUPT_CODE (scm_timer)) & (INTERRUPT_MASK (scm_timer))) != 0L)
     {
+      (MEMTOP (scm_timer)) = ((unsigned long) -1L);
       /* Post an interrupt message to the window.  This forces it to
         wake up and exit MsgWaitForMultipleObjects if needed.  */
       PostMessage ((scm_timer -> window),
                   (scm_timer -> interrupt_message),
                   ((WPARAM) 0),
                   ((LPARAM) 0));
-      (MEMTOP (scm_timer)) = ((unsigned long) -1L);
     }
   (CATATONIA_COUNTER (scm_timer)) += 1L;
   if (((CATATONIA_COUNTER (scm_timer)) > (CATATONIA_LIMIT (scm_timer)))
@@ -174,11 +174,11 @@ win32_nt_timer_tick (UINT wID, UINT wMsg, DWORD dwUser, DWORD dw1, DWORD dw2)
     {
       if ((CATATONIA_FLAG (scm_timer)) == 0L)
        {
+         (CATATONIA_FLAG (scm_timer)) = 1L;
          PostMessage ((scm_timer -> window),
                       (scm_timer -> catatonia_message),
                       ((WPARAM) 0),
                       ((LPARAM) 0));
-         (CATATONIA_FLAG (scm_timer)) = 1L;
        }
       (CATATONIA_COUNTER (scm_timer)) = 0L;
     }