embedaddon/libiconv/srclib/malloca.c - diff

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Diff for /embedaddon/libiconv/srclib/malloca.c between versions 1.1.1.1 and 1.1.1.2

version 1.1.1.1, 2012/02/21 22:57:48	version 1.1.1.2, 2012/05/29 09:29:43
Line 1	Line 1
/* Safe automatic memory allocation.	/* Safe automatic memory allocation.
Copyright (C) 2003, 2006-2007 Free Software Foundation, Inc.	Copyright (C) 2003, 2006-2007, 2009-2011 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.	Written by Bruno Haible <bruno@clisp.org>, 2003.

This program is free software; you can redistribute it and/or modify	This program is free software; you can redistribute it and/or modify
Line 16	Line 16
along with this program; if not, write to the Free Software Foundation,	along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */	Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */

	#define _GL_USE_STDLIB_ALLOC 1
#include <config.h>	#include <config.h>

/* Specification. */	/* Specification. */
#include "malloca.h"	#include "malloca.h"

	#include "verify.h"

/* The speed critical point in this file is freea() applied to an alloca()	/* 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	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	mmalloca() and freea() in the other case are not critical, because they
Line 50 struct preliminary_header { void *next; char room[MAGI	Line 53 struct preliminary_header { void *next; char room[MAGI
#define HEADER_SIZE \	#define HEADER_SIZE \
(((sizeof (struct preliminary_header) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max)	(((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]; };	struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; };
/* Verify that HEADER_SIZE == sizeof (struct header). */	verify (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	/* 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	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	table resizable, because when the hash table gets filled so much that the
Line 74 mmalloca (size_t n)	Line 76 mmalloca (size_t n)
char p = (char ) malloc (nplus);	char p = (char ) malloc (nplus);

if (p != NULL)	if (p != NULL)
{	{
size_t slot;	size_t slot;

p += HEADER_SIZE;	p += HEADER_SIZE;

/* Put a magic number into the indicator word. */	/* Put a magic number into the indicator word. */
((int *) p)[-1] = MAGIC_NUMBER;	((int *) p)[-1] = MAGIC_NUMBER;

/* Enter p into the hash table. */	/* Enter p into the hash table. */
slot = (unsigned long) p % HASH_TABLE_SIZE;	slot = (unsigned long) p % HASH_TABLE_SIZE;
((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot];	((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot];
mmalloca_results[slot] = p;	mmalloca_results[slot] = p;

return p;	return p;
}	}
}	}
/* Out of memory. */	/* Out of memory. */
return NULL;	return NULL;
Line 109 freea (void *p)	Line 111 freea (void *p)
if (p != NULL)	if (p != NULL)
{	{
/* Attempt to quickly distinguish the mmalloca() result - which has	/* Attempt to quickly distinguish the mmalloca() result - which has
a magic indicator word - and the alloca() result - which has an	a magic indicator word - and the alloca() result - which has an
uninitialized indicator word. It is for this test that sa_increment	uninitialized indicator word. It is for this test that sa_increment
additional bytes are allocated in the alloca() case. */	additional bytes are allocated in the alloca() case. */
if (((int *) p)[-1] == MAGIC_NUMBER)	if (((int *) p)[-1] == MAGIC_NUMBER)
{	{
/* Looks like a mmalloca() result. To see whether it really is one,	/* Looks like a mmalloca() result. To see whether it really is one,
perform a lookup in the hash table. */	perform a lookup in the hash table. */
size_t slot = (unsigned long) p % HASH_TABLE_SIZE;	size_t slot = (unsigned long) p % HASH_TABLE_SIZE;
void **chain = &mmalloca_results[slot];	void **chain = &mmalloca_results[slot];
for (; *chain != NULL;)	for (; *chain != NULL;)
{	{
if (*chain == p)	if (*chain == p)
{	{
/* Found it. Remove it from the hash table and free it. */	/* Found it. Remove it from the hash table and free it. */
char p_begin = (char ) p - HEADER_SIZE;	char p_begin = (char ) p - HEADER_SIZE;
chain = ((struct header ) p_begin)->next;	chain = ((struct header ) p_begin)->next;
free (p_begin);	free (p_begin);
return;	return;
}	}
chain = &((struct header ) ((char ) *chain - HEADER_SIZE))->next;	chain = &((struct header ) ((char ) *chain - HEADER_SIZE))->next;
}	}
}	}
/* At this point, we know it was not a mmalloca() result. */	/* At this point, we know it was not a mmalloca() result. */
}	}
}	}

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Removed from v.1.1.1.1
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	Added in v.1.1.1.2