Mouse-wheel scrolling for DocView Continuous mode. (Bug#4896)

[bpt/emacs.git] / src / ralloc.c

diff --git a/src/ralloc.c b/src/ralloc.c
index 7b31955..6faee2c 100644 (file)
--- a/src/ralloc.c
+++ b/src/ralloc.c
@@ -1,13 +1,13 @@
 /* Block-relocating memory allocator.
    Copyright (C) 1993, 1995, 2000, 2001, 2002, 2003, 2004,
 /* Block-relocating memory allocator.
    Copyright (C) 1993, 1995, 2000, 2001, 2002, 2003, 2004,

-                 2005, 2006, 2007  Free Software Foundation, Inc.
+                 2005, 2006, 2007, 2008, 2009  Free Software Foundation, Inc.

 
 This file is part of GNU Emacs.
 
 
 This file is part of GNU Emacs.
 

-GNU Emacs is free software; you can redistribute it and/or modify
+GNU Emacs is free software: you can redistribute it and/or modify

 it under the terms of the GNU General Public License as published by
 it under the terms of the GNU General Public License as published by

-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.

 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of


@@ -15,9 +15,7 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License

-along with GNU Emacs; see the file COPYING.  If not, write to
-the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA.  */
+along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

 
 /* NOTES:
 
 
 /* NOTES:
 


@@ -28,6 +26,7 @@ Boston, MA 02110-1301, USA.  */
 #ifdef emacs
 
 #include <config.h>
 #ifdef emacs
 
 #include <config.h>

+#include <setjmp.h>

 #include "lisp.h"              /* Needed for VALBITS.  */
 #include "blockinput.h"
 
 #include "lisp.h"              /* Needed for VALBITS.  */
 #include "blockinput.h"
 


@@ -179,9 +178,9 @@ static heap_ptr first_heap, last_heap;
    b->data + b->size == b->next->data.
 
    An element with variable==NIL denotes a freed block, which has not yet
    b->data + b->size == b->next->data.
 
    An element with variable==NIL denotes a freed block, which has not yet

-   been collected.  They may only appear while r_alloc_freeze > 0, and will be
-   freed when the arena is thawed.  Currently, these blocs are not reusable,
-   while the arena is frozen.  Very inefficient.  */
+   been collected.  They may only appear while r_alloc_freeze_level > 0,
+   and will be freed when the arena is thawed.  Currently, these blocs are
+   not reusable, while the arena is frozen.  Very inefficient.  */

 
 typedef struct bp
 {
 
 typedef struct bp
 {


@@ -404,6 +403,11 @@ find_bloc (ptr)
 
   while (p != NIL_BLOC)
     {
 
   while (p != NIL_BLOC)
     {

+      /* Consistency check. Don't return inconsistent blocs.
+        Don't abort here, as callers might be expecting this,  but
+        callers that always expect a bloc to be returned should abort
+        if one isn't to avoid a memory corruption bug that is
+        difficult to track down.  */

       if (p->variable == ptr && p->data == *ptr)
        return p;
 
       if (p->variable == ptr && p->data == *ptr)
        return p;
 


@@ -427,8 +431,7 @@ get_bloc (size)
   if (! (new_bloc = (bloc_ptr) malloc (BLOC_PTR_SIZE))
       || ! (new_bloc->data = obtain (break_value, size)))
     {
   if (! (new_bloc = (bloc_ptr) malloc (BLOC_PTR_SIZE))
       || ! (new_bloc->data = obtain (break_value, size)))
     {

-      if (new_bloc)
-       free (new_bloc);
+      free (new_bloc);

 
       return 0;
     }
 
       return 0;
     }


@@ -942,8 +945,8 @@ r_alloc_sbrk (size)
    which will use the data area.
 
    The allocation of 0 bytes is valid.
    which will use the data area.
 
    The allocation of 0 bytes is valid.

-   In case r_alloc_freeze is set, a best fit of unused blocs could be done
-   before allocating a new area.  Not yet done.
+   In case r_alloc_freeze_level is set, a best fit of unused blocs could be
+   done before allocating a new area.  Not yet done.

 
    If we can't allocate the necessary memory, set *PTR to zero, and
    return zero.  */
 
    If we can't allocate the necessary memory, set *PTR to zero, and
    return zero.  */


@@ -984,7 +987,7 @@ r_alloc_free (ptr)
 
   dead_bloc = find_bloc (ptr);
   if (dead_bloc == NIL_BLOC)
 
   dead_bloc = find_bloc (ptr);
   if (dead_bloc == NIL_BLOC)

-    abort ();
+    abort (); /* Double free? PTR not originally used to allocate?  */

 
   free_bloc (dead_bloc);
   *ptr = 0;
 
   free_bloc (dead_bloc);
   *ptr = 0;


@@ -999,7 +1002,7 @@ r_alloc_free (ptr)
    SIZE is less than or equal to the current bloc size, in which case
    do nothing.
 
    SIZE is less than or equal to the current bloc size, in which case
    do nothing.
 

-   In case r_alloc_freeze is set, a new bloc is allocated, and the
+   In case r_alloc_freeze_level is set, a new bloc is allocated, and the

    memory copied to it.  Not very efficient.  We could traverse the
    bloc_list for a best fit of free blocs first.
 
    memory copied to it.  Not very efficient.  We could traverse the
    bloc_list for a best fit of free blocs first.
 


@@ -1028,7 +1031,7 @@ r_re_alloc (ptr, size)
 
   bloc = find_bloc (ptr);
   if (bloc == NIL_BLOC)
 
   bloc = find_bloc (ptr);
   if (bloc == NIL_BLOC)

-    abort ();
+    abort (); /* Already freed? PTR not originally used to allocate?  */

 
   if (size < bloc->size)
     {
 
   if (size < bloc->size)
     {


@@ -1226,6 +1229,34 @@ r_alloc_check ()
 
 #endif /* DEBUG */
 
 
 #endif /* DEBUG */
 

+/* Update the internal record of which variable points to some data to NEW.
+   Used by buffer-swap-text in Emacs to restore consistency after it
+   swaps the buffer text between two buffer objects.  The OLD pointer
+   is checked to ensure that memory corruption does not occur due to
+   misuse.  */
+void
+r_alloc_reset_variable (old, new)
+     POINTER *old, *new;
+{
+  bloc_ptr bloc = first_bloc;
+
+  /* Find the bloc that corresponds to the data pointed to by pointer.
+     find_bloc cannot be used, as it has internal consistency checks
+     which fail when the variable needs reseting.  */
+  while (bloc != NIL_BLOC)
+    {
+      if (bloc->data == *new)
+       break;
+
+      bloc = bloc->next;
+    }
+
+  if (bloc == NIL_BLOC || bloc->variable != old)
+    abort (); /* Already freed? OLD not originally used to allocate?  */
+
+  /* Update variable to point to the new location.  */
+  bloc->variable = new;
+}

 
 \f
 /***********************************************************************
 
 \f
 /***********************************************************************