From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 2 Jan 1997 07:07:19 +0000 (+0000)
Subject: Rearrange the code that sets memtop to trigger an interrupt.  I have a
X-Git-Tag: 20090517-FFI~5280
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=aad6a1660f5fa31cf76c4dba940622eccaa121be;p=mit-scheme.git

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 b248c2ee1..c935cb50f 100644
--- 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 d75d1d3bb..8490ffacc 100644
--- 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;
     }