xalloc.c

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	/*
	 * large block
	 */
	/* mmapped malloc */
	/* round up amount */
	amount += SIZE_HEADER + TAIL_SIZE;
	/* round up brutto amount to a multiple of the page size */
	amount = (amount + pagesize-1) & ~(pagesize-1);
#ifdef MMAP_DEV_ZERO
	ptr = (unsigned long *)mmap((caddr_t)0,
					(size_t)amount,
					PROT_READ | PROT_WRITE,
					MAP_PRIVATE,
					devzerofd,
					(off_t)0);
#else
	ptr = (unsigned long *)mmap((caddr_t)0,
					(size_t)amount,
					PROT_READ | PROT_WRITE,
					MAP_ANON | MAP_PRIVATE,
					-1,
					(off_t)0);
#endif
	if (-1!=(long)ptr) {
		ptr[0] = amount - SIZE_HEADER - TAIL_SIZE;
#ifdef XALLOC_DEBUG
		ptr[1] = MAGIC;
#endif /* XALLOC_DEBUG */
#ifdef SIZE_TAIL
# ifdef __hppa__
		/* reserved space for 2 * sizeof(long), so use correct one */
		/* see SIZE_TAIL macro */
		((unsigned long *)((char *)ptr + amount))[-2] = MAGIC2;
# else
		((unsigned long *)((char *)ptr + amount))[-1] = MAGIC2;
# endif /* __hppa__ */
#endif /* SIZE_TAIL */
		ptr = (unsigned long *)((char *)ptr + SIZE_HEADER);
		LOG_ALLOC("Xalloc-L", amount, ptr);
		return ptr;
	} /* else fall through to 'Out of memory' */
#endif /* HAS_MMAP_ANON || MMAP_DEV_ZERO */
    } else {
	/*
	 * medium sized block
	 */
	/* 'normal' malloc() */
	ptr=(unsigned long *)calloc(1,amount+SIZE_HEADER+TAIL_SIZE);
	if (ptr != (unsigned long *)NULL) {
		ptr[0] = amount;
#ifdef XALLOC_DEBUG
		ptr[1] = MAGIC;
#endif /* XALLOC_DEBUG */
#ifdef SIZE_TAIL
		*(unsigned long *)((char *)ptr + amount + SIZE_HEADER) = MAGIC2;
#endif /* SIZE_TAIL */
		ptr = (unsigned long *)((char *)ptr + SIZE_HEADER);
		LOG_ALLOC("Xalloc-M", amount, ptr);
		return ptr;
	}
    }
    if (Must_have_memory)
	FatalError("Out of memory");
    LOG_ALLOC("Xalloc-oom", amount, 0);
    return (unsigned long *)NULL;
}

/*****************
 * XNFalloc 
 * "no failure" realloc, alternate interface to Xalloc w/o Must_have_memory
 *****************/

unsigned long *
XNFalloc (amount)
    unsigned long amount;
{
    register unsigned long *ptr;

    /* zero size requested */
    if (amount == 0) {
	LOG_ALLOC("XNFalloc=0", amount, 0);
	return (unsigned long *)NULL;
    }
    /* negative size (or size > 2GB) - what do we do? */
    if ((long)amount < 0) {
	/* Diagnostic */
#ifdef FATALERRORS
	FatalError("Xalloc: XNFalloc(<0)\n");
#else
	ErrorF("Xalloc warning: XNFalloc(<0) ignored..\n");
#endif
 	LOG_ALLOC("XNFalloc<0", amount, 0);
	return (unsigned long *)NULL;
    }
    ptr = Xalloc(amount);
    if (!ptr)
    {
        FatalError("Out of memory");
    }
    return ptr;
}

/*****************
 * Xcalloc
 *****************/

unsigned long *
Xcalloc (amount)
    unsigned long   amount;
{
    unsigned long   *ret;

    ret = Xalloc (amount);
    if (ret
#if defined(HAS_MMAP_ANON) || defined(MMAP_DEV_ZERO)
	    && (amount < MIN_LARGE)	/* mmaped anonymous mem is already cleared */
#endif
       )
	bzero ((char *) ret, (int) amount);
    return ret;
}

/*****************
 * Xrealloc
 *****************/

unsigned long *
Xrealloc (ptr, amount)
    register pointer ptr;
    unsigned long amount;
{
    register unsigned long *new_ptr;

    /* zero size requested */
    if (amount == 0) {
	if (ptr)
		Xfree(ptr);
	LOG_REALLOC("Xrealloc=0", ptr, amount, 0);
	return (unsigned long *)NULL;
    }
    /* negative size (or size > 2GB) - what do we do? */
    if ((long)amount < 0) {
	/* Diagnostic */
#ifdef FATALERRORS
	FatalError("Xalloc: Xrealloc(<0)\n");
#else
	ErrorF("Xalloc warning: Xrealloc(<0) ignored..\n");
#endif
	if (ptr)
		Xfree(ptr);	/* ?? */
	LOG_REALLOC("Xrealloc<0", ptr, amount, 0);
	return (unsigned long *)NULL;
    }

    new_ptr = Xalloc(amount);
    if ( (new_ptr) && (ptr) ) {
	unsigned long old_size;
	old_size = ((unsigned long *)ptr)[-2];
#ifdef XALLOC_DEBUG
	if (MAGIC != ((unsigned long *)ptr)[-1]) {
#ifdef FATALERRORS
		FatalError("Xalloc error: header corrupt in Xrealloc() :-(\n");
#else
		ErrorF("Xalloc error: header corrupt in Xrealloc() :-(\n");
#endif
		LOG_REALLOC("Xalloc error: header corrupt in Xrealloc() :-(",
			ptr, amount, 0);
		return (unsigned long *)NULL;
	}
#endif /* XALLOC_DEBUG */
	/* copy min(old size, new size) */
	memcpy((char *)new_ptr, (char *)ptr, (amount < old_size ? amount : old_size));
    }
    if (ptr)
	Xfree(ptr);
    if (new_ptr) {
	LOG_REALLOC("Xrealloc", ptr, amount, new_ptr);
	return new_ptr;
    }
    if (Must_have_memory)
	FatalError("Out of memory");
    LOG_REALLOC("Xrealloc", ptr, amount, 0);
    return (unsigned long *)NULL;
}
                    
/*****************
 * XNFrealloc 
 * "no failure" realloc, alternate interface to Xrealloc w/o Must_have_memory
 *****************/

unsigned long *
XNFrealloc (ptr, amount)
    register pointer ptr;
    unsigned long amount;
{
    if (( ptr = (pointer)Xrealloc( ptr, amount ) ) == NULL)
    {
        FatalError( "Out of memory" );
    }
    return ((unsigned long *)ptr);
}

/*****************
 *  Xfree
 *    calls free 
 *****************/    

void
Xfree(ptr)
    register pointer ptr;
{
    unsigned long size;
    unsigned long *pheader;

    /* free(NULL) IS valid :-(  - and widely used throughout the server.. */
    if (!ptr)
	return;

    pheader = (unsigned long *)((char *)ptr - SIZE_HEADER);
#ifdef XALLOC_DEBUG
    if (MAGIC != pheader[1]) {
	/* Diagnostic */
#ifdef FATALERRORS
	FatalError("Xalloc error: Header corrupt in Xfree() :-(\n");
#else
	ErrorF("Xalloc error: Header corrupt in Xfree() :-(\n");
#endif
	LOG_FREE("Xalloc error:  Header corrupt in Xfree() :-(", ptr);
	return;
    }
#endif /* XALLOC_DEBUG */

    size = pheader[0];
    if (size <= MAX_SMALL) {
	int indx;
	/*
	 * small block
	 */
#ifdef SIZE_TAIL
	if (MAGIC2 != *(unsigned long *)((char *)ptr + size)) {
		/* Diagnostic */
#ifdef FATALERRORS
		FatalError("Xalloc error: Tail corrupt in Xfree() for small block (adr=0x%x, val=0x%x)\n",(char *)ptr + size,*(unsigned long *)((char *)ptr + size));
#else
		ErrorF("Xalloc error: Tail corrupt in Xfree() for small block (adr=0x%x, val=0x%x)\n",(char *)ptr + size,*(unsigned long *)((char *)ptr + size));
#endif
		LOG_FREE("Xalloc error: Tail corrupt in Xfree() for small block", ptr);
		return;
	}
#endif /* SIZE_TAIL */

#ifdef XFREE_ERASES
	memset(ptr,0xF0,size);
#endif /* XFREE_ERASES */

	/* put this small block at the head of the list */
	indx = (size-1) / SIZE_STEPS;
	*(unsigned long **)(ptr) = free_lists[indx];
	free_lists[indx] = (unsigned long *)ptr;
	LOG_FREE("Xfree", ptr);
	return;

#if defined(HAS_MMAP_ANON) || defined(MMAP_DEV_ZERO)
    } else if (size >= MIN_LARGE) {
	/*
	 * large block
	 */
#ifdef SIZE_TAIL
	if (MAGIC2 != ((unsigned long *)((char *)ptr + size))[0]) {
		/* Diagnostic */
#ifdef FATALERRORS
		FatalError("Xalloc error: Tail corrupt in Xfree() for big block (adr=0x%x, val=0x%x)\n",(char *)ptr+size,((unsigned long *)((char *)ptr + size))[0]);
#else
		ErrorF("Xalloc error: Tail corrupt in Xfree() for big block (adr=0x%x, val=0x%x)\n",(char *)ptr+size,((unsigned long *)((char *)ptr + size))[0]);
#endif
		LOG_FREE("Xalloc error: Tail corrupt in Xfree() for big block", ptr);
		return;
	}
	size += SIZE_TAIL;
#endif /* SIZE_TAIL */

	LOG_FREE("Xfree", ptr);
	size += SIZE_HEADER;
	munmap((caddr_t)pheader, (size_t)size);
	/* no need to clear - mem is inaccessible after munmap.. */
#endif /* HAS_MMAP_ANON */

    } else {
	/*
	 * medium sized block
	 */
#ifdef SIZE_TAIL
	if (MAGIC2 != *(unsigned long *)((char *)ptr + size)) {
		/* Diagnostic */
#ifdef FATALERRORS
		FatalError("Xalloc error: Tail corrupt in Xfree() for medium block (adr=0x%x, val=0x%x)\n",(char *)ptr + size,*(unsigned long *)((char *)ptr + size));
#else
		ErrorF("Xalloc error: Tail corrupt in Xfree() for medium block (adr=0x%x, val=0x%x)\n",(char *)ptr + size,*(unsigned long *)((char *)ptr + size));
#endif
		LOG_FREE("Xalloc error: Tail corrupt in Xfree() for medium block", ptr);
		return;
	}
#endif /* SIZE_TAIL */

#ifdef XFREE_ERASES
	memset(pheader,0xF0,size+SIZE_HEADER);
#endif /* XFREE_ERASES */

	LOG_FREE("Xfree", ptr);
	free((char *)pheader);
    }
}

void
OsInitAllocator ()
{
    static Bool beenhere = FALSE;

    if (beenhere)
	return;
    beenhere = TRUE;

#if defined(HAS_MMAP_ANON) || defined (MMAP_DEV_ZERO)
#if defined(_SC_PAGESIZE) /* || defined(linux) */
    pagesize = sysconf(_SC_PAGESIZE);
#else
#ifdef HAS_GETPAGESIZE
    pagesize = getpagesize();
#else
    pagesize = PAGE_SIZE;
#endif
#endif
#endif

    /* set up linked lists of free blocks */
    bzero ((char *) free_lists, MAX_SMALL/SIZE_STEPS*sizeof(unsigned long *));

#ifdef MMAP_DEV_ZERO
    /* open /dev/zero on systems that have mmap, but not MAP_ANON */
    if (devzerofd < 0) {
	if ((devzerofd = open("/dev/zero", O_RDWR, 0)) < 0)
	    FatalError("OsInitAllocator: Cannot open /dev/zero (errno=%d)\n",
			errno);
    }
#endif

#ifdef XALLOC_LOG
    /* reset the log file to zero length */
    {
	FILE *f;
	f = fopen(XALLOC_LOG_FILE, "w");
	if (NULL!=f)
		fclose(f);
    }
#endif
}

#else /* !INTERNAL_MALLOC */
/* This is to avoid an empty .o */
static int no_internal_xalloc;
#endif /* INTERNAL_MALLOC */