mirror of
https://github.com/lua/lua
synced 2024-11-29 16:13:17 +03:00
100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
/*
|
|
** $Id: lmem.c,v 1.72 2006/09/14 12:59:06 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 "lgc.h"
|
|
#include "lmem.h"
|
|
#include "lobject.h"
|
|
#include "lstate.h"
|
|
|
|
|
|
|
|
/*
|
|
** About the realloc function:
|
|
** void * frealloc (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).
|
|
**
|
|
** * frealloc(ud, NULL, 0, x) creates a new block of size `x'
|
|
**
|
|
** * frealloc(ud, p, x, 0) frees the block `p'
|
|
** (in this specific case, frealloc must return NULL).
|
|
** particularly, frealloc(ud, NULL, 0, 0) does nothing
|
|
** (which is equivalent to free(NULL) in ANSI C)
|
|
**
|
|
** frealloc 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, size_t size_elems,
|
|
int limit, const char *what) {
|
|
void *newblock;
|
|
int newsize;
|
|
if (*size >= limit/2) { /* cannot double it? */
|
|
if (*size >= limit) /* cannot grow even a little? */
|
|
luaG_runerror(L, "too many %s (limit is %d)", what, limit);
|
|
newsize = limit; /* still have at least one free place */
|
|
}
|
|
else {
|
|
newsize = (*size)*2;
|
|
if (newsize < MINSIZEARRAY)
|
|
newsize = MINSIZEARRAY; /* minimum size */
|
|
}
|
|
newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
|
|
*size = newsize; /* update only when everything else is OK */
|
|
return newblock;
|
|
}
|
|
|
|
|
|
void *luaM_toobig (lua_State *L) {
|
|
luaG_runerror(L, "memory allocation error: block too big");
|
|
return NULL; /* to avoid warnings */
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
** generic allocation routine.
|
|
*/
|
|
void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
|
|
void *newblock;
|
|
global_State *g = G(L);
|
|
lua_assert((osize == 0) == (block == NULL));
|
|
#if defined(HARDMEMTESTS)
|
|
if (nsize > osize && g->GCthreshold != MAX_LUMEM)
|
|
luaC_fullgc(L, 1); /* force a GC whenever possible */
|
|
#endif
|
|
newblock = (*g->frealloc)(g->ud, block, osize, nsize);
|
|
if (newblock == NULL && nsize > 0) {
|
|
lua_assert(nsize > osize); /* cannot fail when shrinking a block */
|
|
if (g->GCthreshold != MAX_LUMEM) {
|
|
luaC_fullgc(L, 1); /* try to free some memory... */
|
|
newblock = (*g->frealloc)(g->ud, block, osize, nsize); /* try again */
|
|
}
|
|
if (newblock == NULL)
|
|
luaD_throw(L, LUA_ERRMEM);
|
|
}
|
|
lua_assert((nsize == 0) == (newblock == NULL));
|
|
g->totalbytes = (g->totalbytes - osize) + nsize;
|
|
return newblock;
|
|
}
|
|
|