ceph/src/civetweb/src/third_party/lua-5.3.1/src/lmem.c

   1 /*
   2 ** $Id: lmem.c,v 1.91 2015/03/06 19:45:54 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 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   if (*size >= limit/2) {  /* cannot double it? */
  53     if (*size >= limit)  /* cannot grow even a little? */
  54       luaG_runerror(L, "too many %s (limit is %d)", what, limit);
  55     newsize = limit;  /* still have at least one free place */
  56   }
  57   else {
  58     newsize = (*size)*2;
  59     if (newsize < MINSIZEARRAY)
  60       newsize = MINSIZEARRAY;  /* minimum size */
  61   }
  62   newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
  63   *size = newsize;  /* update only when everything else is OK */
  64   return newblock;
  65 }
  66
  67
  68 l_noret luaM_toobig (lua_State *L) {
  69   luaG_runerror(L, "memory allocation error: block too big");
  70 }
  71
  72
  73
  74 /*
  75 ** generic allocation routine.
  76 */
  77 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
  78   void *newblock;
  79   global_State *g = G(L);
  80   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   newblock = (*g->frealloc)(g->ud, block, osize, nsize);
  87   if (newblock == NULL && nsize > 0) {
  88     lua_assert(nsize > realosize);  /* cannot fail when shrinking a block */
  89     if (g->version) {  /* is state fully built? */
  90       luaC_fullgc(L, 1);  /* try to free some memory... */
  91       newblock = (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
  92     }
  93     if (newblock == NULL)
  94       luaD_throw(L, LUA_ERRMEM);
  95   }
  96   lua_assert((nsize == 0) == (newblock == NULL));
  97   g->GCdebt = (g->GCdebt + nsize) - realosize;
  98   return newblock;
  99 }
 100