lua/lmem.c
1997-12-17 18:48:58 -02:00

111 lines
2.3 KiB
C

/*
** $Id: lmem.c,v 1.3 1997/12/01 20:30:44 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"
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.
** real ANSI systems do not need some of these tests,
** since realloc(NULL, s)==malloc(s) and realloc(b, 0)==free(b).
** But some systems (e.g. Sun OS) are not that ANSI...
*/
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) {
if (block) {
free(block);
}
return NULL;
}
block = block ? realloc(block, s) : malloc(s);
if (block == NULL)
lua_error(memEM);
return block;
}
#else
/* DEBUG */
#include <assert.h>
#include <string.h>
#define MARK 55
unsigned long numblocks = 0;
unsigned long totalmem = 0;
static void *checkblock (void *block)
{
unsigned long *b = (unsigned long *)block - 1;
unsigned long size = *b;
assert(*(((char *)b)+size+sizeof(unsigned long)) == MARK);
numblocks--;
totalmem -= size;
return b;
}
void *luaM_realloc (void *block, unsigned long size)
{
unsigned long realsize = sizeof(unsigned long)+size+sizeof(char);
if (realsize != (size_t)realsize)
lua_error("Allocation Error: Block too big");
if (size == 0) { /* ANSI doen't need this, but some machines... */
if (block) {
memset(block, -1, *((unsigned long *)block-1)); /* erase block */
block = checkblock(block);
free(block);
}
return NULL;
}
if (block) {
block = checkblock(block);
block = (unsigned long *)realloc(block, realsize);
}
else
block = (unsigned long *)malloc(realsize);
if (block == NULL)
lua_error(memEM);
totalmem += size;
numblocks++;
*(unsigned long *)block = size;
*(((char *)block)+size+sizeof(unsigned long)) = MARK;
return (unsigned long *)block+1;
}
#endif