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comparison lib/lua/lua-5.2.2/lmem.c @ 1866:41cc4dd3c122

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Lua 5.2.2 added.
author Nomad
date Wed, 16 Oct 2013 13:34:26 +0200
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1848:3b39b70e8e93 1866:41cc4dd3c122
1 /*
2 ** $Id: lmem.c,v 1.84 2012/05/23 15:41:53 roberto Exp $
3 ** Interface to Memory Manager
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <stddef.h>
9
10 #define lmem_c
11 #define LUA_CORE
12
13 #include "lua.h"
14
15 #include "ldebug.h"
16 #include "ldo.h"
17 #include "lgc.h"
18 #include "lmem.h"
19 #include "lobject.h"
20 #include "lstate.h"
21
22
23
24 /*
25 ** About the realloc function:
26 ** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
27 ** (`osize' is the old size, `nsize' is the new size)
28 **
29 ** * frealloc(ud, NULL, x, s) creates a new block of size `s' (no
30 ** matter 'x').
31 **
32 ** * frealloc(ud, p, x, 0) frees the block `p'
33 ** (in this specific case, frealloc must return NULL);
34 ** particularly, frealloc(ud, NULL, 0, 0) does nothing
35 ** (which is equivalent to free(NULL) in ANSI C)
36 **
37 ** frealloc returns NULL if it cannot create or reallocate the area
38 ** (any reallocation to an equal or smaller size cannot fail!)
39 */
40
41
42
43 #define MINSIZEARRAY 4
44
45
46 void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
47 int limit, const char *what) {
48 void *newblock;
49 int newsize;
50 if (*size >= limit/2) { /* cannot double it? */
51 if (*size >= limit) /* cannot grow even a little? */
52 luaG_runerror(L, "too many %s (limit is %d)", what, limit);
53 newsize = limit; /* still have at least one free place */
54 }
55 else {
56 newsize = (*size)*2;
57 if (newsize < MINSIZEARRAY)
58 newsize = MINSIZEARRAY; /* minimum size */
59 }
60 newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
61 *size = newsize; /* update only when everything else is OK */
62 return newblock;
63 }
64
65
66 l_noret luaM_toobig (lua_State *L) {
67 luaG_runerror(L, "memory allocation error: block too big");
68 }
69
70
71
72 /*
73 ** generic allocation routine.
74 */
75 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
76 void *newblock;
77 global_State *g = G(L);
78 size_t realosize = (block) ? osize : 0;
79 lua_assert((realosize == 0) == (block == NULL));
80 #if defined(HARDMEMTESTS)
81 if (nsize > realosize && g->gcrunning)
82 luaC_fullgc(L, 1); /* force a GC whenever possible */
83 #endif
84 newblock = (*g->frealloc)(g->ud, block, osize, nsize);
85 if (newblock == NULL && nsize > 0) {
86 api_check(L, nsize > realosize,
87 "realloc cannot fail when shrinking a block");
88 if (g->gcrunning) {
89 luaC_fullgc(L, 1); /* try to free some memory... */
90 newblock = (*g->frealloc)(g->ud, block, osize, nsize); /* try again */
91 }
92 if (newblock == NULL)
93 luaD_throw(L, LUA_ERRMEM);
94 }
95 lua_assert((nsize == 0) == (newblock == NULL));
96 g->GCdebt = (g->GCdebt + nsize) - realosize;
97 return newblock;
98 }
99