Do not store any metadata where the user (was) legitimate to write

[simgrid.git] / src / xbt / mmalloc / mrealloc.c

diff --git a/src/xbt/mmalloc/mrealloc.c b/src/xbt/mmalloc/mrealloc.c
index 7b803fe..b9deaff 100644 (file)
--- a/src/xbt/mmalloc/mrealloc.c
+++ b/src/xbt/mmalloc/mrealloc.c
@@ -1,6 +1,6 @@
 /* Change the size of a block allocated by `mmalloc'.
    Copyright 1990, 1991 Free Software Foundation
-      Written May 1989 by Mike Haertel. */
+   Written May 1989 by Mike Haertel. */
 
 /* Copyright (c) 2010. The SimGrid Team.
  * All rights reserved.                                                     */
@@ -38,7 +38,7 @@ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size)
 
   if ((char *) ptr < (char *) mdp->heapbase || BLOCK(ptr) > mdp->heapsize) {
     printf
-        ("FIXME. Ouch, this pointer is not mine, refusing to proceed (another solution would be to malloc it instead of reallocing it, see source code)\n");
+      ("FIXME. Ouch, this pointer is not mine, refusing to proceed (another solution would be to malloc it instead of reallocing it, see source code)\n");
     result = mmalloc(mdp, size);
     abort();
     return result;
@@ -83,10 +83,10 @@ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size)
       /* The new size is smaller; return excess memory to the free list. */
       //printf("(%s) return excess memory...",xbt_thread_self_name());
       for (it= block+blocks; it< mdp->heapinfo[block].busy_block.size ; it++)
-  mdp->heapinfo[it].type = 0; // FIXME that should be useless, type should already be 0 here
+        mdp->heapinfo[it].type = 0; // FIXME that should be useless, type should already be 0 here
 
       mdp->heapinfo[block + blocks].busy_block.size
-          = mdp->heapinfo[block].busy_block.size - blocks;
+        = mdp->heapinfo[block].busy_block.size - blocks;
       mfree(mdp, ADDRESS(block + blocks));
 
       mdp->heapinfo[block].busy_block.size = blocks;
@@ -101,8 +101,9 @@ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size)
 
     } else {
       /* Won't fit, so allocate a new region that will.
-         Free the old region first in case there is sufficient
-         adjacent free space to grow without moving. */
+         Free the old region first in case there is sufficient adjacent free space to grow without moving.
+         This trick mandates using a specific version of mmalloc that does not memset the memory to 0 after
+           action for obvious reasons. */
       blocks = mdp->heapinfo[block].busy_block.size;
       /* Prevent free from actually returning memory to the system.  */
       oldlimit = mdp->heaplimit;
@@ -110,9 +111,12 @@ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size)
       mfree(mdp, ptr);
       mdp->heaplimit = oldlimit;
 
-      result = mmalloc(mdp, requested_size);
+      result = mmalloc_no_memset(mdp, requested_size);
+      //fprintf(stderr,"remalloc(%zu)~>%p\n",requested_size,result);
+
       if (ptr != result)
         memmove(result, ptr, blocks * BLOCKSIZE);
+      /* FIXME: we should memset the end of the recently area */
     }
     break;