lua/lmem.c
1999-01-22 16:08:57 -02:00

113 lines
2.3 KiB
C

/*
** $Id: lmem.c,v 1.8 1999/01/22 17:28:00 roberto Exp roberto $
** Interface to Memory Manager
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#include "lmem.h"
#include "lstate.h"
#include "lua.h"
/*
** real ANSI systems do not need some of these tests,
** since realloc(NULL, s)==malloc(s).
** But some systems (Sun OS) are not that ANSI...
*/
#ifdef OLD_ANSI
#define realloc(b,s) ((b) == NULL ? malloc(s) : (realloc)(b, s))
#define free(b) if (b) (free)(b)
#endif
int luaM_growaux (void **block, unsigned long nelems, int size,
char *errormsg, unsigned long limit) {
if (nelems >= limit)
lua_error(errormsg);
nelems = (nelems == 0) ? 32 : nelems*2;
if (nelems > limit)
nelems = limit;
*block = luaM_realloc(*block, nelems*size);
return (int)nelems;
}
#ifndef DEBUG
/*
** generic allocation routine.
*/
void *luaM_realloc (void *block, unsigned long size) {
size_t s = (size_t)size;
if (s != size)
lua_error("Allocation Error: Block too big");
if (size == 0) {
free(block); /* block may be NULL, that is OK for free */
return NULL;
}
block = realloc(block, s);
if (block == NULL)
lua_error(memEM);
return block;
}
#else
/* DEBUG */
#include <string.h>
#define HEADER (sizeof(double))
#define MARK 55
unsigned long numblocks = 0;
unsigned long totalmem = 0;
static void *checkblock (void *block) {
unsigned long *b = (unsigned long *)((char *)block - HEADER);
unsigned long size = *b;
LUA_ASSERT(*(((char *)b)+size+HEADER) == MARK,
"corrupted block");
numblocks--;
totalmem -= size;
return b;
}
void *luaM_realloc (void *block, unsigned long size) {
unsigned long realsize = HEADER+size+1;
if (realsize != (size_t)realsize)
lua_error("Allocation Error: Block too big");
if (size == 0) {
if (block) {
unsigned long *b = (unsigned long *)((char *)block - HEADER);
memset(block, -1, *b); /* erase block */
block = checkblock(block);
}
free(block);
return NULL;
}
if (block)
block = checkblock(block);
block = (unsigned long *)realloc(block, realsize);
if (block == NULL)
lua_error(memEM);
totalmem += size;
numblocks++;
*(unsigned long *)block = size;
*(((char *)block)+size+HEADER) = MARK;
return (unsigned long *)((char *)block+HEADER);
}
#endif