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Diffstat (limited to 'src/lib/lua/lmem.c')
-rw-r--r-- | src/lib/lua/lmem.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/lib/lua/lmem.c b/src/lib/lua/lmem.c new file mode 100644 index 0000000..0a0476c --- /dev/null +++ b/src/lib/lua/lmem.c @@ -0,0 +1,100 @@ +/* +** $Id: lmem.c,v 1.91 2015/03/06 19:45:54 roberto Exp $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#define lmem_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#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; +} + |