Line data    Source code

       1              : /*
       2              : ** $Id: lmem.c,v 1.91.1.1 2017/04/19 17:20:42 roberto Exp $
       3              : ** Interface to Memory Manager
       4              : ** See Copyright Notice in lua.h
       5              : */
       6              : 
       7              : #define lmem_c
       8              : #define LUA_CORE
       9              : 
      10              : #include "lprefix.h"
      11              : 
      12              : 
      13              : #include <stddef.h>
      14              : 
      15              : #include "lua.h"
      16              : 
      17              : #include "ldebug.h"
      18              : #include "ldo.h"
      19              : #include "lgc.h"
      20              : #include "lmem.h"
      21              : #include "lobject.h"
      22              : #include "lstate.h"
      23              : 
      24              : 
      25              : 
      26              : /*
      27              : ** About the realloc function:
      28              : ** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
      29              : ** ('osize' is the old size, 'nsize' is the new size)
      30              : **
      31              : ** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no
      32              : ** matter 'x').
      33              : **
      34              : ** * frealloc(ud, p, x, 0) frees the block 'p'
      35              : ** (in this specific case, frealloc must return NULL);
      36              : ** particularly, frealloc(ud, NULL, 0, 0) does nothing
      37              : ** (which is equivalent to free(NULL) in ISO C)
      38              : **
      39              : ** frealloc returns NULL if it cannot create or reallocate the area
      40              : ** (any reallocation to an equal or smaller size cannot fail!)
      41              : */
      42              : 
      43              : 
      44              : 
      45              : #define MINSIZEARRAY    4
      46              : 
      47              : 
      48        21625 : void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
      49              :                      int limit, const char *what) {
      50              :   void *newblock;
      51              :   int newsize;
      52        21625 :   if (*size >= limit/2) {  /* cannot double it? */
      53            0 :     if (*size >= limit)  /* cannot grow even a little? */
      54            0 :       luaG_runerror(L, "too many %s (limit is %d)", what, limit);
      55            0 :     newsize = limit;  /* still have at least one free place */
      56              :   }
      57              :   else {
      58        21625 :     newsize = (*size)*2;
      59        21625 :     if (newsize < MINSIZEARRAY)
      60        11005 :       newsize = MINSIZEARRAY;  /* minimum size */
      61              :   }
      62        21625 :   newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
      63        21625 :   *size = newsize;  /* update only when everything else is OK */
      64        21625 :   return newblock;
      65              : }
      66              : 
      67              : 
      68            0 : l_noret luaM_toobig (lua_State *L) {
      69            0 :   luaG_runerror(L, "memory allocation error: block too big");
      70              : }
      71              : 
      72              : 
      73              : 
      74              : /*
      75              : ** generic allocation routine.
      76              : */
      77       238965 : void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
      78              :   void *newblock;
      79       238965 :   global_State *g = G(L);
      80       238965 :   size_t realosize = (block) ? osize : 0;
      81              :   lua_assert((realosize == 0) == (block == NULL));
      82              : #if defined(HARDMEMTESTS)
      83              :   if (nsize > realosize && g->gcrunning)
      84              :     luaC_fullgc(L, 1);  /* force a GC whenever possible */
      85              : #endif
      86       238965 :   newblock = (*g->frealloc)(g->ud, block, osize, nsize);
      87       238965 :   if (newblock == NULL && nsize > 0) {
      88              :     lua_assert(nsize > realosize);  /* cannot fail when shrinking a block */
      89            0 :     if (g->version) {  /* is state fully built? */
      90            0 :       luaC_fullgc(L, 1);  /* try to free some memory... */
      91            0 :       newblock = (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
      92              :     }
      93            0 :     if (newblock == NULL)
      94            0 :       luaD_throw(L, LUA_ERRMEM);
      95              :   }
      96              :   lua_assert((nsize == 0) == (newblock == NULL));
      97       238965 :   g->GCdebt = (g->GCdebt + nsize) - realosize;
      98       238965 :   return newblock;
      99              : }
     100              :