From: Chris Hanson <org/chris-hanson/cph>
Date: Fri, 5 Jul 1991 23:30:46 +0000 (+0000)
Subject: Eliminate use of CATCH and THROW macros.  Use position in `struct
X-Git-Tag: 20090517-FFI~10483
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=d05b6ca8eb9fefff8dfcd47191eeb2de15eb3e4f;p=mit-scheme.git

Eliminate use of CATCH and THROW macros.  Use position in `struct
interruptable_extent' to set the dstack after a throw.  Guarantee that
signal mask is restored last when interrupting.
---

diff --git a/v7/src/microcode/intext.c b/v7/src/microcode/intext.c
index e4fc9c11f..a045c2390 100644
--- a/v7/src/microcode/intext.c
+++ b/v7/src/microcode/intext.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/intext.c,v 1.2 1991/06/22 19:29:02 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/intext.c,v 1.3 1991/07/05 23:30:46 cph Exp $
 
 Copyright (c) 1990-91 Massachusetts Institute of Technology
 
@@ -56,14 +56,19 @@ struct interruptable_extent *
 DEFUN_VOID (enter_interruptable_extent)
 {
   PTR position = dstack_position;
-  struct interruptable_extent * frame =
-    (dstack_alloc (sizeof (struct interruptable_extent)));
+  struct interruptable_extent * frame;
+  /* Inside the interrupt handler, the signal mask will be different.
+     Push a winding frame that will restore it to its current value.
+     Do this before any other changes so that the other changes are
+     undone before the signal mask is restored (possibly causing
+     another interrupt).  */
+  preserve_signal_mask ();
+  frame = (dstack_alloc (sizeof (struct interruptable_extent)));
   (frame -> position) = position;
   (frame -> interrupted) = 0;
   /* Create a dynamic binding frame but don't assign the new frame to
-     it until the CATCH has been done. */
+     it until the setjmp has been done. */
   dstack_bind ((&current_interruptable_extent), current_interruptable_extent);
-  preserve_signal_mask ();
   return (frame);
 }
 
@@ -87,5 +92,5 @@ DEFUN_VOID (enter_interruption_extent)
 void
 DEFUN_VOID (exit_interruption_extent)
 {
-  THROW ((current_interruptable_extent -> control_point), 1);
+  longjmp ((current_interruptable_extent -> control_point), 1);
 }
diff --git a/v7/src/microcode/intext.h b/v7/src/microcode/intext.h
index cb1284bed..383abec6a 100644
--- a/v7/src/microcode/intext.h
+++ b/v7/src/microcode/intext.h
@@ -1,8 +1,8 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/intext.h,v 1.1 1990/06/20 19:35:53 cph Rel $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/intext.h,v 1.2 1991/07/05 23:30:34 cph Exp $
 
-Copyright (c) 1990 Massachusetts Institute of Technology
+Copyright (c) 1990-91 Massachusetts Institute of Technology
 
 This material was developed by the Scheme project at the Massachusetts
 Institute of Technology, Department of Electrical Engineering and
@@ -41,7 +41,7 @@ MIT in each case. */
 struct interruptable_extent
 {
   PTR position;
-  Tcatch_tag control_point;
+  jmp_buf control_point;
   int interrupted;
 };
 
@@ -57,7 +57,7 @@ extern void EXFUN (exit_interruption_extent, (void));
 {									\
   struct interruptable_extent * INTERRUPTABLE_EXTENT_frame =		\
     (enter_interruptable_extent ());					\
-  if ((CATCH (INTERRUPTABLE_EXTENT_frame -> control_point)) == 0)	\
+  if ((setjmp (INTERRUPTABLE_EXTENT_frame -> control_point)) == 0)	\
     {									\
       current_interruptable_extent = INTERRUPTABLE_EXTENT_frame;	\
       (result) = (expression);						\