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authorMark H Weaver <mhw@netris.org>2014-02-03 21:04:39 -0500
committerMark H Weaver <mhw@netris.org>2014-02-03 21:05:52 -0500
commit5e69ceb7a667377a61cb0c31d7ac20e245b3fafd (patch)
treeef1e4fe569392fd4630dfcfc26d9948b7e6ffac5 /lib/malloca.c
parent866af5da3d11ac4a9df44ee8c5b1781a0073c288 (diff)
Update Gnulib to v0.1-77-gd9361da
Diffstat (limited to 'lib/malloca.c')
-rw-r--r--lib/malloca.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/lib/malloca.c b/lib/malloca.c
index 04ddc236e..3e95f2333 100644
--- a/lib/malloca.c
+++ b/lib/malloca.c
@@ -1,5 +1,5 @@
/* Safe automatic memory allocation.
- Copyright (C) 2003, 2006-2007, 2009-2013 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2006-2007, 2009-2014 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
This program is free software; you can redistribute it and/or modify
@@ -49,12 +49,18 @@
#define MAGIC_SIZE sizeof (int)
/* This is how the header info would look like without any alignment
considerations. */
-struct preliminary_header { void *next; char room[MAGIC_SIZE]; };
+struct preliminary_header { void *next; int magic; };
/* But the header's size must be a multiple of sa_alignment_max. */
#define HEADER_SIZE \
(((sizeof (struct preliminary_header) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max)
-struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; };
-verify (HEADER_SIZE == sizeof (struct header));
+union header {
+ void *next;
+ struct {
+ char room[HEADER_SIZE - MAGIC_SIZE];
+ int word;
+ } magic;
+};
+verify (HEADER_SIZE == sizeof (union header));
/* We make the hash table quite big, so that during lookups the probability
of empty hash buckets is quite high. There is no need to make the hash
table resizable, because when the hash table gets filled so much that the
@@ -74,20 +80,21 @@ mmalloca (size_t n)
if (nplus >= n)
{
- char *p = (char *) malloc (nplus);
+ void *p = malloc (nplus);
if (p != NULL)
{
size_t slot;
+ union header *h = p;
- p += HEADER_SIZE;
+ p = h + 1;
/* Put a magic number into the indicator word. */
- ((int *) p)[-1] = MAGIC_NUMBER;
+ h->magic.word = MAGIC_NUMBER;
/* Enter p into the hash table. */
slot = (uintptr_t) p % HASH_TABLE_SIZE;
- ((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot];
+ h->next = mmalloca_results[slot];
mmalloca_results[slot] = p;
return p;
@@ -123,15 +130,17 @@ freea (void *p)
void **chain = &mmalloca_results[slot];
for (; *chain != NULL;)
{
+ union header *h = p;
if (*chain == p)
{
/* Found it. Remove it from the hash table and free it. */
- char *p_begin = (char *) p - HEADER_SIZE;
- *chain = ((struct header *) p_begin)->next;
+ union header *p_begin = h - 1;
+ *chain = p_begin->next;
free (p_begin);
return;
}
- chain = &((struct header *) ((char *) *chain - HEADER_SIZE))->next;
+ h = *chain;
+ chain = &h[-1].next;
}
}
/* At this point, we know it was not a mmalloca() result. */