lua/lmem.c

133 lines
3.0 KiB
C

/*
** $Id: lmem.c,v 1.15 1999/05/11 14:18:40 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 these tests;
** 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
#define MINSIZE 8 /* minimum size for "growing" vectors */
#ifndef DEBUG
static unsigned long power2 (unsigned long n) {
unsigned long p = MINSIZE;
while (p<=n) p<<=1;
return p;
}
void *luaM_growaux (void *block, unsigned long nelems, int inc, int size,
char *errormsg, unsigned long limit) {
unsigned long newn = nelems+inc;
if (newn >= limit) lua_error(errormsg);
if ((newn ^ nelems) <= nelems || /* still the same power of 2 limit? */
(nelems > 0 && newn < MINSIZE)) /* or block already is MINSIZE? */
return block; /* do not need to reallocate */
else /* it crossed a power of 2 boundary; grow to next power */
return luaM_realloc(block, power2(newn)*size);
}
/*
** generic allocation routine.
*/
void *luaM_realloc (void *block, unsigned long size) {
size_t s = (size_t)size;
if (s != size)
lua_error("memory 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>
void *luaM_growaux (void *block, unsigned long nelems, int inc, int size,
char *errormsg, unsigned long limit) {
unsigned long newn = nelems+inc;
if (newn >= limit)
lua_error(errormsg);
return luaM_realloc(block, newn*size);
}
#define HEADER (sizeof(double))
#define MARKSIZE 32
#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;
int i;
for (i=0;i<MARKSIZE;i++)
LUA_ASSERT(*(((char *)b)+size+HEADER+i) == MARK+i, "corrupted block");
numblocks--;
totalmem -= size;
return b;
}
void *luaM_realloc (void *block, unsigned long size) {
unsigned long realsize = HEADER+size+MARKSIZE;
if (realsize != (size_t)realsize)
lua_error("memory 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;
{ int i; for (i=0;i<MARKSIZE;i++) *(((char *)block)+size+HEADER+i) = MARK+i; }
return (unsigned long *)((char *)block+HEADER);
}
#endif