memory.c

MPEG-4编解码的实现(包括MPEG4视音频编解码)

 * @addr: address
 * @filen: new filename
 * @line: new allocation line
 * 
 * Coerces information in allocation table about allocation file and
 * line to be @filen and @line.  This is used by the evil
 * block_alloc() and should probably not be used anywhere else ever.
 **/
void 
xclaim(void *addr, const char *filen, int line)
{
        alloc_blk *m;
        chk_header *ch;
        
        ch = ((chk_header *)addr) - 1;
        m  = mem_item_find(ch->key); 

        if (chk_header_okay(ch) == FALSE) {
                fprintf(stderr, "xclaim: memory corrupted\n");
                abort();
        }

        if (m == NULL) {
                fprintf(stderr, "xclaim: block not found\n");
                abort();
        }

        free(m->filen);
        m->filen  = strdup(filen);
        m->length = strlen(filen);
        m->line   = line;
        m->est    = tick++;
}

/**
 * xmemdist:
 * @fp: file pointer
 * 
 * Dumps information on existing memory allocations to file.
 **/
void 
xmemdist(FILE *fp)
{
        int i, last_line=-1, cnt=0, entry=0;
        char *last_filen = NULL;

        /* This is painful...I don't actually envisage running beyond this dump :-)
         * 2 sorts are needed, one into order by file, and then back to key order.
         */
        qsort(mem_item, naddr, sizeof(mem_item[0]), alloc_blk_cmp_origin);
        fprintf(fp, "# Distribution of memory allocated\n# <idx> <file> <line> <allocations>\n");
        for(i = 0; i < naddr; i++) {
                if (last_filen == NULL ||
                    last_line  != mem_item[i].line ||
                    strcmp(last_filen, mem_item[i].filen)) {
                        if (last_filen != NULL) {
                                fprintf(fp, "% 3d\n", cnt);
                        }
                        cnt = 0;
                        last_filen = mem_item[i].filen;
                        last_line  = mem_item[i].line;
                        fprintf(fp, "% 3d %20s % 4d ", entry, last_filen, last_line);
                        entry++;
                }
                cnt++;
        }
        fprintf(fp, "% 3d\n", cnt);
        /* Restore order */
        qsort(mem_item, naddr, sizeof(mem_item[0]), mem_key_cmp);
}

/**
 * xfree:
 * @p: pointer to block to freed.
 * 
 * Free block of memory.  Semantically equivalent to free(), but
 * checks for bounds overruns in @p and tidies up state associated
 * additional functionality.
 *
 * Must be used to free memory allocated with xmalloc(), xrealloc(),
 * and xstrdup().
 **/
void 
xfree(void *p)
{
        alloc_blk  *m;
        chk_header *ch;
        uint32_t size, delta, magic, idx;
        
	if (p == NULL) {
		printf("ERROR: Attempt to free NULL pointer!\n");
		abort();
	}
        ch = ((chk_header*)p) - 1;

        printf("free at %p\n", ch);
        /* Validate entry  */
        if (chk_header_okay(ch) == FALSE) {
                printf("ERROR: Freeing corrupted block\n");
                abort();
        }

        /* Locate in table */
        m = mem_item_find(ch->key);
        if (m == NULL) {
                printf("ERROR: Freeing unallocated or already free'd block\n");
                abort();
        }

        /* Trash memory of allocated block, maybe noticed by apps when    
         * deref'ing free'd */
        size  = ch->size + sizeof(chk_header) + MAGIC_MEMORY_SIZE;
        magic = MAGIC_MEMORY;
        p     = (uint8_t*)ch;
        while (size > 0) {
                delta = min(size, 4);
                memcpy(p, &magic, delta);
                (uint8_t*)p += delta;
                size        -= delta;
        }

        /* Free memory     */
        free(ch);
        free(m->filen);

        /* Remove from table */
        idx = m - mem_item;
        if (naddr - idx > 0) {
                memmove(&mem_item[idx], 
                        &mem_item[idx + 1], 
                        (naddr - idx - 1) * sizeof(alloc_blk));
        }
        naddr--;
        xmemchk();
}

void *
_xmalloc(unsigned size, const char *filen, int line)
{
        uint32_t   *data;
        void       *p;
        chk_header *ch;

        p = (void*) malloc (size + sizeof(chk_header) + MAGIC_MEMORY_SIZE);

	ASSERT(p     != NULL);
	ASSERT(filen != NULL);

        /* Fix block header */
        ch = (chk_header*)p;
        ch->key   = tick++;
        ch->size  = size;
        ch->magic = MAGIC_MEMORY;

	data = (uint32_t*)((chk_header *)p + 1);
#if 0
	memset((void*)data, 0xf0, size);
#else
	memset((void*)data, 0, size);
#endif
        
        /* Fix block tail */
        memcpy(((uint8_t*)data) + size, &ch->magic, MAGIC_MEMORY_SIZE);

        /* Check set up okay */
        if (chk_header_okay(ch) == FALSE) {
                fprintf(stderr, "Implementation Error\n");
                abort();
        }

        /* Add table entry */
        mem_item[naddr].key    = ch->key;
	mem_item[naddr].addr   = p;
	mem_item[naddr].filen  = (char *)strdup(filen);
	mem_item[naddr].line   = line;
	mem_item[naddr].length = strlen(filen);
        mem_item[naddr].blen   = 0;        /* block_alloc'ed len when appropriate     */
        mem_item[naddr].est    = ch->key;  /* changes when block_alloc recycles block */
        naddr ++;

	if (naddr >= MAX_ADDRS) {
		fprintf(stderr, "ERROR: Allocated too much! Table overflow in xmalloc()\n");
		fprintf(stderr, "       Do you really need to allocate more than %d items?\n", MAX_ADDRS);
		abort();
	}
        
        if (chk_header_okay(ch) == FALSE) {
                fprintf(stderr, "Implementation Error\n");
                abort();
        }

        printf("malloc at %p\n", p);
        return (uint8_t*)p + sizeof(chk_header);
}

void *
_xrealloc(void *p, unsigned size, const char *filen, int line)
{
        alloc_blk  *m;
        chk_header *ch;
        uint8_t    *t;
       
        ASSERT(p     != NULL);
        ASSERT(filen != NULL);
	
        ch = ((chk_header*) p) - 1;
        m  = mem_item_find(ch->key);
        if (m != NULL) {
                /* Attempt reallocation */
                m->addr = realloc((void*)ch, size + sizeof(chk_header) + MAGIC_MEMORY_SIZE);
                if (m->addr == NULL) {
                        debug_msg("realloc failed\n");
                        return NULL;
                }
                /* Update table */
                free(m->filen);
                m->filen  = (char *) strdup(filen);
                m->line   = line;
                m->length = strlen(filen);
                m->est    = tick++;
                /* Fix chunk header */
                ch->size  = size;
                /* Fix trailer */
                t = (uint8_t*)p + size;
                memcpy(t, &ch->magic, MAGIC_MEMORY_SIZE);
                /* Check block is okay */
                if (chk_header_okay(ch) == FALSE) {
                        fprintf(stderr, "Implementation Error\n");
                        abort();
                }
                return p;
	}
	debug_msg("Trying to xrealloc() memory not which is not allocated\n");
	abort();
        return 0;
}

char *_xstrdup(const char *s1, const char *filen, int line)
{
	char 	*s2;
  
	s2 = (char *) _xmalloc(strlen(s1)+1, filen, line);
	if (s2 != NULL) {
		strcpy(s2, s1);
        }
	return (s2);
}
#else

void xdoneinit (void) { return; }
void xmemchk   (void) { return; }
void xmemdmp   (void) { return; }

void xclaim    (void *p, const char *filen, int line)
{
        UNUSED(p);
        UNUSED(filen);
        UNUSED(line);
        return;
}

void xmemdist (FILE *f) { UNUSED(f); }

void xfree    (void *x) { free(x); }

void *_xmalloc(unsigned int size, const char *filen, int line) {
	void	*m;

	m = malloc(size);

#ifdef DEBUG
	/* This is just to check initialization errors in allocated structs */
	memset(m, 0xf0, size);
#endif
	UNUSED(filen);
	UNUSED(line);

	return m;
}

void *_xrealloc(void *p, unsigned int size,const char *filen,int line) {
        UNUSED(filen);
        UNUSED(line);
        return realloc(p, size);
}
char *_xstrdup(const char *s1, const char *filen, int line) {
        UNUSED(filen);
        UNUSED(line);
        return strdup(s1);
}

#endif /* DEBUG_MEM */