This is the mail archive of the
cygwin-patches@cygwin.com
mailing list for the Cygwin project.
[Patch] cygheap.cc: Allow _crealloc to shrink memory-block.
- From: Bas van Gompel <cygwin-patches dot buzz at bavag dot tmfweb dot nl>
- To: cygwin-patches at cygwin dot com
- Date: Wed, 13 Oct 2004 00:11:24 +0200 (MET DST)
- Subject: [Patch] cygheap.cc: Allow _crealloc to shrink memory-block.
- Organisation: Ehm...
- Reply-to: cygwin-patches mailing-list <cygwin-patches at cygwin dot com>
Hi,
Following (trivial IMO) patch, allows memory blocks on the cygheap to
be shrunk.
There are some issues with this:
- The code is slightly slower.
- This change is in a block of code marked ``copyright D. J. Delorie''.
- I'm not sure _crealloc is ever called with a smaller size. (If it
isn't, this patch is useless.)
(I did test this, and it WJFFM.)
ChangeLog-entry:
20040-10-13 Bas van Gompel <cygwin-patch.buzz@bavag.tmfweb.nl>
* cygheap.cc (_crealloc): Allow memory-block to shrink.
--- src/winsup/cygwin/cygheap.cc 2 Jun 2004 21:20:53 -0000 1.103
+++ src/winsup/cygwin/cygheap.cc 12 Oct 2004 02:43:30 -0000
@@ -324,16 +324,22 @@ _cfree (void *ptr)
static void *__stdcall
_crealloc (void *ptr, unsigned size)
{
+ unsigned sz;
void *newptr;
if (ptr == NULL)
newptr = _cmalloc (size);
else
{
unsigned oldsize = 1 << to_cmalloc (ptr)->b;
- if (size <= oldsize)
+
+ /* Calculate size as a power of two. */
+ for (sz = 8; sz && sz < size; sz <<= 1)
+ continue;
+
+ if (sz == oldsize)
return ptr;
newptr = _cmalloc (size);
- memcpy (newptr, ptr, oldsize);
+ memcpy (newptr, ptr, min(sz, oldsize));
_cfree (ptr);
}
return newptr;
Buzz.
--
) | | ---/ ---/ Yes, this | This message consists of true | I do not
-- | | / / really is | and false bits entirely. | mail for
) | | / / a 72 by 4 +-------------------------------+ any1 but
-- \--| /--- /--- .sigfile. | |perl -pe "s.u(z)\1.as." | me. 4^re