/* ** $Id: lmem.c,v 1.91.1.1 2017/04/19 17:20:42 roberto Exp $ ** Interface to Memory Manager ** See Copyright Notice in lua.h */ #define lmem_c #define LUA_CORE #include "lprefix.h" #include #include "lua.h" #include "ldebug.h" #include "ldo.h" #include "lgc.h" #include "lmem.h" #include "lobject.h" #include "lstate.h" /* ** About the realloc function: ** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize); ** ('osize' is the old size, 'nsize' is the new size) ** ** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no ** matter 'x'). ** ** * frealloc(ud, p, x, 0) frees the block 'p' ** (in this specific case, frealloc must return NULL); ** particularly, frealloc(ud, NULL, 0, 0) does nothing ** (which is equivalent to free(NULL) in ISO C) ** ** frealloc returns NULL if it cannot create or reallocate the area ** (any reallocation to an equal or smaller size cannot fail!) */ #define MINSIZEARRAY 4 void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems, int limit, const char *what) { void *newblock; int newsize; if (*size >= limit/2) { /* cannot double it? */ if (*size >= limit) /* cannot grow even a little? */ luaG_runerror(L, "too many %s (limit is %d)", what, limit); newsize = limit; /* still have at least one free place */ } else { newsize = (*size)*2; if (newsize < MINSIZEARRAY) newsize = MINSIZEARRAY; /* minimum size */ } newblock = luaM_reallocv(L, block, *size, newsize, size_elems); *size = newsize; /* update only when everything else is OK */ return newblock; } l_noret luaM_toobig (lua_State *L) { luaG_runerror(L, "memory allocation error: block too big"); } /* ** generic allocation routine. */ void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) { void *newblock; global_State *g = G(L); size_t realosize = (block) ? osize : 0; lua_assert((realosize == 0) == (block == NULL)); #if defined(HARDMEMTESTS) if (nsize > realosize && g->gcrunning) luaC_fullgc(L, 1); /* force a GC whenever possible */ #endif newblock = (*g->frealloc)(g->ud, block, osize, nsize); if (newblock == NULL && nsize > 0) { lua_assert(nsize > realosize); /* cannot fail when shrinking a block */ if (g->version) { /* is state fully built? */ luaC_fullgc(L, 1); /* try to free some memory... */ newblock = (*g->frealloc)(g->ud, block, osize, nsize); /* try again */ } if (newblock == NULL) luaD_throw(L, LUA_ERRMEM); } lua_assert((nsize == 0) == (newblock == NULL)); g->GCdebt = (g->GCdebt + nsize) - realosize; return newblock; }