diff options
Diffstat (limited to 'lib/malloca.c')
| -rw-r--r-- | lib/malloca.c | 44 |
1 files changed, 16 insertions, 28 deletions
diff --git a/lib/malloca.c b/lib/malloca.c index ef07acd7..39baa5e2 100644 --- a/lib/malloca.c +++ b/lib/malloca.c @@ -1,5 +1,5 @@ /* Safe automatic memory allocation. - Copyright (C) 2003, 2006-2007, 2009-2015 Free Software Foundation, Inc. + Copyright (C) 2003, 2006-2007, 2009-2010 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2003. This program is free software; you can redistribute it and/or modify @@ -13,18 +13,14 @@ GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License - along with this program; if not, see <http://www.gnu.org/licenses/>. */ + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ -#define _GL_USE_STDLIB_ALLOC 1 #include <config.h> /* Specification. */ #include "malloca.h" -#include <stdint.h> - -#include "verify.h" - /* The speed critical point in this file is freea() applied to an alloca() result: it must be fast, to match the speed of alloca(). The speed of mmalloca() and freea() in the other case are not critical, because they @@ -49,18 +45,13 @@ #define MAGIC_SIZE sizeof (int) /* This is how the header info would look like without any alignment considerations. */ -struct preliminary_header { void *next; int magic; }; +struct preliminary_header { void *next; char room[MAGIC_SIZE]; }; /* 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) -union header { - void *next; - struct { - char room[HEADER_SIZE - MAGIC_SIZE]; - int word; - } magic; -}; -verify (HEADER_SIZE == sizeof (union header)); +struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; }; +/* Verify that HEADER_SIZE == sizeof (struct header). */ +typedef int verify1[2 * (HEADER_SIZE == sizeof (struct header)) - 1]; /* 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 @@ -80,21 +71,20 @@ mmalloca (size_t n) if (nplus >= n) { - void *p = malloc (nplus); + char *p = (char *) malloc (nplus); if (p != NULL) { size_t slot; - union header *h = p; - p = h + 1; + p += HEADER_SIZE; /* Put a magic number into the indicator word. */ - h->magic.word = MAGIC_NUMBER; + ((int *) p)[-1] = MAGIC_NUMBER; /* Enter p into the hash table. */ - slot = (uintptr_t) p % HASH_TABLE_SIZE; - h->next = mmalloca_results[slot]; + slot = (unsigned long) p % HASH_TABLE_SIZE; + ((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot]; mmalloca_results[slot] = p; return p; @@ -126,21 +116,19 @@ freea (void *p) { /* Looks like a mmalloca() result. To see whether it really is one, perform a lookup in the hash table. */ - size_t slot = (uintptr_t) p % HASH_TABLE_SIZE; + size_t slot = (unsigned long) p % HASH_TABLE_SIZE; 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. */ - union header *p_begin = h - 1; - *chain = p_begin->next; + char *p_begin = (char *) p - HEADER_SIZE; + *chain = ((struct header *) p_begin)->next; free (p_begin); return; } - h = *chain; - chain = &h[-1].next; + chain = &((struct header *) ((char *) *chain - HEADER_SIZE))->next; } } /* At this point, we know it was not a mmalloca() result. */ |