1 /* 2 ** $Id: lmem.c,v 1.84.1.1 2013/04/12 18:48:47 roberto Exp $ 3 ** Interface to Memory Manager 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #include <sys/zfs_context.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 } 99 100