mirror of https://github.com/lua/lua
156 lines
3.8 KiB
C
156 lines
3.8 KiB
C
/*
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** $Id: lmem.c,v 1.40 2000/11/24 17:39:56 roberto Exp roberto $
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** Interface to Memory Manager
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** See Copyright Notice in lua.h
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*/
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#include <stdlib.h>
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#include "lua.h"
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#include "ldo.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lstate.h"
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#ifdef LUA_DEBUG
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/*
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** {======================================================================
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** Controlled version for realloc.
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** =======================================================================
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*/
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#include <assert.h>
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#include <limits.h>
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#include <string.h>
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#define realloc(b, s) debug_realloc(b, s)
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#define malloc(b) debug_realloc(NULL, b)
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#define free(b) debug_realloc(b, 0)
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/* ensures maximum alignment for HEADER */
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#define HEADER (sizeof(union L_Umaxalign))
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#define MARKSIZE 16
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#define MARK 0x55 /* 01010101 (a nice pattern) */
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#define blocksize(b) ((size_t *)((char *)(b) - HEADER))
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mem_int memdebug_numblocks = 0;
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mem_int memdebug_total = 0;
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mem_int memdebug_maxmem = 0;
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mem_int memdebug_memlimit = LONG_MAX;
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static void *checkblock (void *block) {
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size_t *b = blocksize(block);
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size_t size = *b;
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int i;
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for (i=0;i<MARKSIZE;i++)
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assert(*(((char *)b)+HEADER+size+i) == MARK+i); /* corrupted block? */
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memdebug_numblocks--;
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memdebug_total -= size;
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return b;
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}
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static void freeblock (void *block) {
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if (block) {
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size_t size = *blocksize(block);
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block = checkblock(block);
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memset(block, -1, size+HEADER+MARKSIZE); /* erase block */
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(free)(block); /* free original block */
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}
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}
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static void *debug_realloc (void *block, size_t size) {
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if (size == 0) {
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freeblock(block);
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return NULL;
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}
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else if (memdebug_total+size > memdebug_memlimit)
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return NULL; /* to test memory allocation errors */
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else {
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size_t realsize = HEADER+size+MARKSIZE;
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char *newblock = (char *)(malloc)(realsize); /* alloc a new block */
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int i;
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if (realsize < size) return NULL; /* overflow! */
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if (newblock == NULL) return NULL;
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if (block) {
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size_t oldsize = *blocksize(block);
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if (oldsize > size) oldsize = size;
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memcpy(newblock+HEADER, block, oldsize);
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freeblock(block); /* erase (and check) old copy */
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}
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memdebug_total += size;
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if (memdebug_total > memdebug_maxmem) memdebug_maxmem = memdebug_total;
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memdebug_numblocks++;
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*(size_t *)newblock = size;
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for (i=0;i<MARKSIZE;i++)
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*(newblock+HEADER+size+i) = (char)(MARK+i);
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return newblock+HEADER;
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}
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}
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/* }====================================================================== */
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#endif
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/*
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** Real ISO (ANSI) systems do not need these tests;
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** but some systems (Sun OS) are not that ISO...
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*/
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#ifdef OLD_ANSI
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#define realloc(b,s) ((b) == NULL ? malloc(s) : (realloc)(b, s))
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#define free(b) if (b) (free)(b)
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#endif
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void *luaM_growaux (lua_State *L, void *block, int *size, int size_elems,
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int limit, const char *errormsg) {
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void *newblock;
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int newsize = (*size)*2;
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if (newsize < MINPOWER2)
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newsize = MINPOWER2; /* minimum size */
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else if (*size >= limit/2) { /* cannot double it? */
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if (*size < limit - MINPOWER2) /* try something smaller... */
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newsize = limit; /* still have at least MINPOWER2 free places */
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else lua_error(L, errormsg);
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}
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newblock = luaM_realloc(L, block, (luint32)newsize*(luint32)size_elems);
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*size = newsize; /* update only when everything else is OK */
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return newblock;
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}
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/*
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** generic allocation routine.
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*/
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void *luaM_realloc (lua_State *L, void *block, luint32 size) {
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if (size == 0) {
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free(block); /* block may be NULL; that is OK for free */
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return NULL;
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}
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else if (size >= MAX_SIZET)
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lua_error(L, "memory allocation error: block too big");
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block = realloc(block, size);
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if (block == NULL) {
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if (L)
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luaD_breakrun(L, LUA_ERRMEM); /* break run without error message */
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else return NULL; /* error before creating state! */
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}
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return block;
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}
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