lua/lmem.c

132 lines
2.9 KiB
C

/*
** $Id: lmem.c,v 1.21 1999/11/29 16:38:48 roberto Exp roberto $
** Interface to Memory Manager
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#define LUA_REENTRANT
#include "lmem.h"
#include "lobject.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
void *luaM_growaux (lua_State *L, void *block, unsigned long nelems,
int inc, int size, const char *errormsg, unsigned long limit) {
unsigned long newn = nelems+inc;
if (newn >= limit) lua_error(L, errormsg);
if ((newn ^ nelems) <= nelems || /* still the same power-of-2 limit? */
(nelems > 0 && newn < MINPOWER2)) /* or block already is MINPOWER2? */
return block; /* do not need to reallocate */
else /* it crossed a power-of-2 boundary; grow to next power */
return luaM_realloc(L, block, luaO_power2(newn)*size);
}
#ifndef DEBUG
/*
** generic allocation routine.
*/
void *luaM_realloc (lua_State *L, void *block, unsigned long size) {
size_t s = (size_t)size;
if (s != size)
lua_error(L, "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(L, memEM);
return block;
}
#else
/* DEBUG */
#include <string.h>
#define HEADER (sizeof(double))
#define MARKSIZE 16
#define MARK 55
#define blocksize(b) ((unsigned long *)((char *)(b) - HEADER))
unsigned long numblocks = 0;
unsigned long totalmem = 0;
static void *checkblock (void *block) {
unsigned long *b = blocksize(block);
unsigned long size = *b;
int i;
for (i=0;i<MARKSIZE;i++)
LUA_ASSERT(L, *(((char *)b)+HEADER+size+i) == MARK+i, "corrupted block");
numblocks--;
totalmem -= size;
return b;
}
static void freeblock (void *block) {
if (block) {
memset(block, -1, *blocksize(block)); /* erase block */
block = checkblock(block);
free(block);
}
}
void *luaM_realloc (lua_State *L, void *block, unsigned long size) {
unsigned long realsize = HEADER+size+MARKSIZE;
if (realsize != (size_t)realsize)
lua_error(L, "memory allocation error: block too big");
if (size == 0) {
freeblock(block);
return NULL;
}
else {
char *newblock = malloc(realsize);
int i;
if (block) {
unsigned long oldsize = *blocksize(block);
if (oldsize > size) oldsize = size;
memcpy(newblock+HEADER, block, oldsize);
freeblock(block); /* erase (and check) old copy */
}
if (newblock == NULL)
lua_error(L, memEM);
totalmem += size;
numblocks++;
*(unsigned long *)newblock = size;
for (i=0;i<MARKSIZE;i++)
*(newblock+HEADER+size+i) = (char)(MARK+i);
return newblock+HEADER;
}
}
#endif