rlm@1: /*
rlm@1: ** $Id: lmem.c,v 1.70.1.1 2007/12/27 13:02:25 roberto Exp $
rlm@1: ** Interface to Memory Manager
rlm@1: ** See Copyright Notice in lua.h
rlm@1: */
rlm@1: 
rlm@1: 
rlm@1: #include <stddef.h>
rlm@1: 
rlm@1: #define lmem_c
rlm@1: #define LUA_CORE
rlm@1: 
rlm@1: #include "lua.h"
rlm@1: 
rlm@1: #include "ldebug.h"
rlm@1: #include "ldo.h"
rlm@1: #include "lmem.h"
rlm@1: #include "lobject.h"
rlm@1: #include "lstate.h"
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** About the realloc function:
rlm@1: ** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
rlm@1: ** (`osize' is the old size, `nsize' is the new size)
rlm@1: **
rlm@1: ** Lua ensures that (ptr == NULL) iff (osize == 0).
rlm@1: **
rlm@1: ** * frealloc(ud, NULL, 0, x) creates a new block of size `x'
rlm@1: **
rlm@1: ** * frealloc(ud, p, x, 0) frees the block `p'
rlm@1: ** (in this specific case, frealloc must return NULL).
rlm@1: ** particularly, frealloc(ud, NULL, 0, 0) does nothing
rlm@1: ** (which is equivalent to free(NULL) in ANSI C)
rlm@1: **
rlm@1: ** frealloc returns NULL if it cannot create or reallocate the area
rlm@1: ** (any reallocation to an equal or smaller size cannot fail!)
rlm@1: */
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: #define MINSIZEARRAY	4
rlm@1: 
rlm@1: 
rlm@1: void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
rlm@1:                      int limit, const char *errormsg) {
rlm@1:   void *newblock;
rlm@1:   int newsize;
rlm@1:   if (*size >= limit/2) {  /* cannot double it? */
rlm@1:     if (*size >= limit)  /* cannot grow even a little? */
rlm@1:       luaG_runerror(L, errormsg);
rlm@1:     newsize = limit;  /* still have at least one free place */
rlm@1:   }
rlm@1:   else {
rlm@1:     newsize = (*size)*2;
rlm@1:     if (newsize < MINSIZEARRAY)
rlm@1:       newsize = MINSIZEARRAY;  /* minimum size */
rlm@1:   }
rlm@1:   newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
rlm@1:   *size = newsize;  /* update only when everything else is OK */
rlm@1:   return newblock;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: void *luaM_toobig (lua_State *L) {
rlm@1:   luaG_runerror(L, "memory allocation error: block too big");
rlm@1:   return NULL;  /* to avoid warnings */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** generic allocation routine.
rlm@1: */
rlm@1: void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
rlm@1:   global_State *g = G(L);
rlm@1:   lua_assert((osize == 0) == (block == NULL));
rlm@1:   block = (*g->frealloc)(g->ud, block, osize, nsize);
rlm@1:   if (block == NULL && nsize > 0)
rlm@1:     luaD_throw(L, LUA_ERRMEM);
rlm@1:   lua_assert((nsize == 0) == (block == NULL));
rlm@1:   g->totalbytes = (g->totalbytes - osize) + nsize;
rlm@1:   return block;
rlm@1: }
rlm@1: