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Diffstat (limited to 'src/lua/lmem.c')
-rw-r--r-- | src/lua/lmem.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/src/lua/lmem.c b/src/lua/lmem.c new file mode 100644 index 00000000..8fdecef3 --- /dev/null +++ b/src/lua/lmem.c @@ -0,0 +1,150 @@ +/* +** $Id: lmem.c,v 1.3 2001/11/26 23:00:24 darkgod Exp $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + + +#include <stdlib.h> + +#include "lua.h" + +#include "ldo.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + + + +#ifdef LUA_DEBUG +/* +** {====================================================================== +** Controlled version for realloc. +** ======================================================================= +*/ + + +#include <assert.h> +#include <limits.h> +#include <string.h> + +#define realloc(b, s) debug_realloc(b, s) +#define malloc(b) debug_realloc(NULL, b) +#define free(b) debug_realloc(b, 0) + + +/* ensures maximum alignment for HEADER */ +#define HEADER (sizeof(union L_Umaxalign)) + +#define MARKSIZE 16 +#define MARK 0x55 /* 01010101 (a nice pattern) */ + + +#define blocksize(b) ((unsigned long *)((char *)(b) - HEADER)) + +unsigned long memdebug_numblocks = 0; +unsigned long memdebug_total = 0; +unsigned long memdebug_maxmem = 0; +unsigned long memdebug_memlimit = LONG_MAX; + + +static void *checkblock (void *block) { + unsigned long *b = blocksize(block); + unsigned long size = *b; + int i; + for (i=0;i<MARKSIZE;i++) + assert(*(((char *)b)+HEADER+size+i) == MARK+i); /* corrupted block? */ + memdebug_numblocks--; + memdebug_total -= size; + return b; +} + + +static void freeblock (void *block) { + if (block) { + size_t size = *blocksize(block); + block = checkblock(block); + memset(block, -1, size+HEADER+MARKSIZE); /* erase block */ + (free)(block); /* free original block */ + } +} + + +static void *debug_realloc (void *block, size_t size) { + if (size == 0) { + freeblock(block); + return NULL; + } + else if (memdebug_total+size > memdebug_memlimit) + return NULL; /* to test memory allocation errors */ + else { + size_t realsize = HEADER+size+MARKSIZE; + char *newblock = (char *)(malloc)(realsize); /* alloc a new block */ + int i; + if (realsize < size) return NULL; /* overflow! */ + if (newblock == NULL) return NULL; + if (block) { + size_t oldsize = *blocksize(block); + if (oldsize > size) oldsize = size; + memcpy(newblock+HEADER, block, oldsize); + freeblock(block); /* erase (and check) old copy */ + } + memdebug_total += size; + if (memdebug_total > memdebug_maxmem) memdebug_maxmem = memdebug_total; + memdebug_numblocks++; + *(unsigned long *)newblock = size; + for (i=0;i<MARKSIZE;i++) + *(newblock+HEADER+size+i) = (char)(MARK+i); + return newblock+HEADER; + } +} + + +/* }====================================================================== */ +#endif + + + +/* +** Real ISO (ANSI) systems do not need these tests; +** but some systems (Sun OS) are not that ISO... +*/ +#ifdef OLD_ANSI +#define realloc(b,s) ((b) == NULL ? malloc(s) : (realloc)(b, s)) +#define free(b) if (b) (free)(b) +#endif + + +void *luaM_growaux (lua_State *L, void *block, size_t nelems, + int inc, size_t size, const char *errormsg, size_t limit) { + size_t newn = nelems+inc; + if (nelems >= limit-inc) lua_error(L, errormsg); + if ((newn ^ nelems) <= nelems || /* still the same power-of-2 limit? */ + (nelems > 0 && newn < MINPOWER2)) /* or block already is MINPOWER2? */ + return block; /* do not need to reallocate */ + else /* it crossed a power-of-2 boundary; grow to next power */ + return luaM_realloc(L, block, luaO_power2(newn)*size); +} + + +/* +** generic allocation routine. +*/ +void *luaM_realloc (lua_State *L, void *block, lint32 size) { + if (size == 0) { + free(block); /* block may be NULL; that is OK for free */ + return NULL; + } + else if (size >= MAX_SIZET) + lua_error(L, "memory allocation error: block too big"); + block = realloc(block, size); + if (block == NULL) { + if (L) + luaD_breakrun(L, LUA_ERRMEM); /* break run without error message */ + else return NULL; /* error before creating state! */ + } + return block; +} + + |