mirror of
https://github.com/lua/lua
synced 2024-11-25 22:29:39 +03:00
85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
/*
|
|
** $Id: lmem.c,v 1.63 2003/11/27 18:18:37 roberto Exp roberto $
|
|
** Interface to Memory Manager
|
|
** See Copyright Notice in lua.h
|
|
*/
|
|
|
|
|
|
#include <stddef.h>
|
|
|
|
#define lmem_c
|
|
#define LUA_CORE
|
|
|
|
#include "lua.h"
|
|
|
|
#include "ldebug.h"
|
|
#include "ldo.h"
|
|
#include "lmem.h"
|
|
#include "lobject.h"
|
|
#include "lstate.h"
|
|
|
|
|
|
|
|
/*
|
|
** About the realloc function:
|
|
** void * realloc (void *ud, void *ptr, size_t osize, size_t nsize);
|
|
** (`osize' is the old size, `nsize' is the new size)
|
|
**
|
|
** Lua ensures that (ptr == NULL) iff (osize == 0).
|
|
**
|
|
** * realloc(ud, NULL, 0, x) creates a new block of size `x'
|
|
**
|
|
** * realloc(ud, p, x, 0) frees the block `p'
|
|
** (in this specific case, realloc must return NULL).
|
|
** particularly, realloc(ud, NULL, 0, 0) does nothing
|
|
** (which is equivalent to free(NULL) in ANSI C)
|
|
**
|
|
** realloc returns NULL if it cannot create or reallocate the area
|
|
** (any reallocation to an equal or smaller size cannot fail!)
|
|
*/
|
|
|
|
|
|
|
|
#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;
|
|
if (*size >= limit/2) { /* cannot double it? */
|
|
if (*size >= limit - MINSIZEARRAY) /* try something smaller... */
|
|
luaG_runerror(L, errormsg);
|
|
newsize = limit; /* still have at least MINSIZEARRAY free places */
|
|
}
|
|
else {
|
|
newsize = (*size)*2;
|
|
if (newsize < MINSIZEARRAY)
|
|
newsize = MINSIZEARRAY; /* minimum size */
|
|
}
|
|
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 osize, lu_mem nsize) {
|
|
global_State *g = G(L);
|
|
lua_assert((osize == 0) == (block == NULL));
|
|
if (nsize >= MAX_SIZET)
|
|
luaG_runerror(L, "memory allocation error: block too big");
|
|
block = (*g->realloc)(g->ud, block, osize, nsize);
|
|
if (block == NULL && nsize > 0)
|
|
luaD_throw(L, LUA_ERRMEM);
|
|
lua_assert((nsize == 0) == (block == NULL));
|
|
g->nblocks -= osize;
|
|
g->nblocks += nsize;
|
|
return block;
|
|
}
|
|
|