lua/lmem.c

80 lines
2.0 KiB
C

/*
** $Id: lmem.c,v 1.55 2002/05/15 18:57:44 roberto Exp roberto $
** Interface to Memory Manager
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#include "lua.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
/*
** definition for realloc function. It must assure that
** l_realloc(block, x, 0) frees the block, and l_realloc(NULL, 0, x)
** allocates a new block (ANSI C assures that).
** (`os' is the old block size; some allocators may use that.)
*/
#ifndef l_realloc
#define l_realloc(b,os,s) realloc(b,s)
#endif
#define MINSIZEARRAY 4
void *luaM_growaux (lua_State *L, void *block, int *size, int size_elems,
int limit, const char *errormsg) {
void *newblock;
int newsize = (*size)*2;
if (newsize < MINSIZEARRAY)
newsize = MINSIZEARRAY; /* minimum size */
else if (*size >= limit/2) { /* cannot double it? */
if (*size < limit - MINSIZEARRAY) /* try something smaller... */
newsize = limit; /* still have at least MINSIZEARRAY free places */
else luaG_runerror(L, errormsg);
}
newblock = luaM_realloc(L, block,
cast(lu_mem, *size)*cast(lu_mem, size_elems),
cast(lu_mem, newsize)*cast(lu_mem, size_elems));
*size = newsize; /* update only when everything else is OK */
return newblock;
}
/*
** generic allocation routine.
*/
void *luaM_realloc (lua_State *L, void *block, lu_mem oldsize, lu_mem size) {
if (size == 0) {
if (block != NULL) {
l_realloc(block, oldsize, size);
block = NULL;
}
}
else if (size >= MAX_SIZET)
luaG_runerror(L, "memory allocation error: block too big");
else {
block = l_realloc(block, oldsize, size);
if (block == NULL) {
if (L)
luaD_error(L, MEMERRMSG, LUA_ERRMEM);
else return NULL; /* error before creating state! */
}
}
if (L && G(L)) {
G(L)->nblocks -= oldsize;
G(L)->nblocks += size;
}
return block;
}