alloc.c

DHCP服务器源码

/* alloc.c

   Functions supporting memory allocation for the object management
   protocol... */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1999-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <[e-mail]>
 *   http://www.isc.org/
 *
 * This software has been written for Internet Systems Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about Internet Systems Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#include <omapip/omapip_p.h>

#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
struct dmalloc_preamble *dmalloc_list;
unsigned long dmalloc_outstanding;
unsigned long dmalloc_longterm;
unsigned long dmalloc_generation;
unsigned long dmalloc_cutoff_generation;
#endif

#if defined (DEBUG_RC_HISTORY)
struct rc_history_entry rc_history [RC_HISTORY_MAX];
int rc_history_index;
int rc_history_count;
#endif

#if defined (DEBUG_RC_HISTORY)
static void print_rc_hist_entry (int);
#endif

VOIDPTR dmalloc (size, file, line)
	unsigned size;
	const char *file;
	int line;
{
	unsigned char *foo = malloc (size + DMDSIZE);
	int i;
	VOIDPTR *bar;
#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
	struct dmalloc_preamble *dp;
#endif
	if (!foo)
		return (VOIDPTR)0;
	bar = (VOIDPTR)(foo + DMDOFFSET);
	memset (bar, 0, size);

#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
	dp = (struct dmalloc_preamble *)foo;
	dp -> prev = dmalloc_list;
	if (dmalloc_list)
		dmalloc_list -> next = dp;
	dmalloc_list = dp;
	dp -> next = (struct dmalloc_preamble *)0;
	dp -> size = size;
	dp -> file = file;
	dp -> line = line;
	dp -> generation = dmalloc_generation++;
	dmalloc_outstanding += size;
	for (i = 0; i < DMLFSIZE; i++)
		dp -> low_fence [i] =
			(((unsigned long)
			  (&dp -> low_fence [i])) % 143) + 113;
	for (i = DMDOFFSET; i < DMDSIZE; i++)
		foo [i + size] =
			(((unsigned long)
			  (&foo [i + size])) % 143) + 113;
#if defined (DEBUG_MALLOC_POOL_EXHAUSTIVELY)
	/* Check _every_ entry in the pool!   Very expensive. */
	for (dp = dmalloc_list; dp; dp = dp -> prev) {
		for (i = 0; i < DMLFSIZE; i++) {
			if (dp -> low_fence [i] !=
				(((unsigned long)
				  (&dp -> low_fence [i])) % 143) + 113)
			{
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
		foo = (unsigned char *)dp;
		for (i = DMDOFFSET; i < DMDSIZE; i++) {
			if (foo [i + dp -> size] !=
				(((unsigned long)
				  (&foo [i + dp -> size])) % 143) + 113) {
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
	}
#endif
#endif
#ifdef DEBUG_REFCNT_DMALLOC_FREE
	rc_register (file, line, 0, foo + DMDOFFSET, 1, 0, RC_MALLOC);
#endif
	return bar;
}

void dfree (ptr, file, line)
	VOIDPTR ptr;
	const char *file;
	int line;
{
	if (!ptr) {
		log_error ("dfree %s(%d): free on null pointer.", file, line);
		return;
	}
#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
	{
		unsigned char *bar = ptr;
		struct dmalloc_preamble *dp, *cur;
		int i;
		bar -= DMDOFFSET;
		cur = (struct dmalloc_preamble *)bar;
		for (dp = dmalloc_list; dp; dp = dp -> prev)
			if (dp == cur)
				break;
		if (!dp) {
			log_error ("%s(%d): freeing unknown memory: %lx",
				   file, line, (unsigned long)cur);
			abort ();
		}
		if (dp -> prev)
			dp -> prev -> next = dp -> next;
		if (dp -> next)
			dp -> next -> prev = dp -> prev;
		if (dp == dmalloc_list)
			dmalloc_list = dp -> prev;
		if (dp -> generation >= dmalloc_cutoff_generation)
			dmalloc_outstanding -= dp -> size;
		else
			dmalloc_longterm -= dp -> size;

		for (i = 0; i < DMLFSIZE; i++) {
			if (dp -> low_fence [i] !=
				(((unsigned long)
				  (&dp -> low_fence [i])) % 143) + 113)
			{
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
		for (i = DMDOFFSET; i < DMDSIZE; i++) {
			if (bar [i + dp -> size] !=
				(((unsigned long)
				  (&bar [i + dp -> size])) % 143) + 113) {
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
		ptr = bar;
	}
#endif
#ifdef DEBUG_REFCNT_DMALLOC_FREE
	rc_register (file, line,
		     0, (unsigned char *)ptr + DMDOFFSET, 0, 1, RC_MALLOC);
#endif
	free (ptr);
}

#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
/* For allocation functions that keep their own free lists, we want to
   account for the reuse of the memory. */

void dmalloc_reuse (foo, file, line, justref)
	VOIDPTR foo;
	const char *file;
	int line;
	int justref;
{
	struct dmalloc_preamble *dp;

	/* Get the pointer to the dmalloc header. */
	dp = foo;
	dp--;

	/* If we just allocated this and are now referencing it, this
	   function would almost be a no-op, except that it would
	   increment the generation count needlessly.  So just return
	   in this case. */
	if (dp -> generation == dmalloc_generation)
		return;

	/* If this is longterm data, and we just made reference to it,
	   don't put it on the short-term list or change its name -
	   we don't need to know about this. */
	if (dp -> generation < dmalloc_cutoff_generation && justref)
		return;

	/* Take it out of the place in the allocated list where it was. */
	if (dp -> prev)
		dp -> prev -> next = dp -> next;
	if (dp -> next)
		dp -> next -> prev = dp -> prev;
	if (dp == dmalloc_list)
		dmalloc_list = dp -> prev;

	/* Account for its removal. */
	if (dp -> generation >= dmalloc_cutoff_generation)
		dmalloc_outstanding -= dp -> size;
	else
		dmalloc_longterm -= dp -> size;

	/* Now put it at the head of the list. */
	dp -> prev = dmalloc_list;
	if (dmalloc_list)
		dmalloc_list -> next = dp;
	dmalloc_list = dp;
	dp -> next = (struct dmalloc_preamble *)0;

	/* Change the reference location information. */
	dp -> file = file;
	dp -> line = line;

	/* Increment the generation. */
	dp -> generation = dmalloc_generation++;

	/* Account for it. */
	dmalloc_outstanding += dp -> size;
}

void dmalloc_dump_outstanding ()
{
	static unsigned long dmalloc_cutoff_point;
	struct dmalloc_preamble *dp;
	unsigned char *foo;
	int i;

	if (!dmalloc_cutoff_point)
		dmalloc_cutoff_point = dmalloc_cutoff_generation;
	for (dp = dmalloc_list; dp; dp = dp -> prev) {
		if (dp -> generation <= dmalloc_cutoff_point)
			break;
#if defined (DEBUG_MALLOC_POOL)
		for (i = 0; i < DMLFSIZE; i++) {
			if (dp -> low_fence [i] !=
				(((unsigned long)
				  (&dp -> low_fence [i])) % 143) + 113)
			{
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
		foo = (unsigned char *)dp;
		for (i = DMDOFFSET; i < DMDSIZE; i++) {
			if (foo [i + dp -> size] !=
				(((unsigned long)
				  (&foo [i + dp -> size])) % 143) + 113) {
				log_error ("malloc fence modified: %s(%d)",
					   dp -> file, dp -> line);
				abort ();
			}
		}
#endif
#if defined (DEBUG_MEMORY_LEAKAGE) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
		/* Don't count data that's actually on a free list
                   somewhere. */
		if (dp -> file) {
#if defined (DEBUG_RC_HISTORY)
			int i, count, inhistory = 0, noted = 0;

			/* If we have the info, see if this is actually
			   new garbage. */
			if (rc_history_count < RC_HISTORY_MAX) {
			    count = rc_history_count;
			} else
			    count = RC_HISTORY_MAX;
			i = rc_history_index - 1;
			if (i < 0)
				i += RC_HISTORY_MAX;

			do {
			    if (rc_history [i].addr == dp + 1) {
				inhistory = 1;
				if (!noted) {
				    log_info ("  %s(%d): %d", dp -> file,
					      dp -> line, dp -> size);
				    noted = 1;
				}
				print_rc_hist_entry (i);
				if (!rc_history [i].refcnt)
				    break;
			    }
			    if (--i < 0)
				i = RC_HISTORY_MAX - 1;
			} while (count--);
			if (!inhistory)
#endif
				log_info ("  %s(%d): %d",
					  dp -> file, dp -> line, dp -> size);
		}
#endif
	}
	if (dmalloc_list)
		dmalloc_cutoff_point = dmalloc_list -> generation;
}
#endif /* DEBUG_MEMORY_LEAKAGE || DEBUG_MALLOC_POOL */

#if defined (DEBUG_RC_HISTORY)
static void print_rc_hist_entry (int i)
{
	log_info ("   referenced by %s(%d)[%lx]: addr = %lx  refcnt = %x",
		  rc_history [i].file, rc_history [i].line,
		  (unsigned long)rc_history [i].reference,
		  (unsigned long)rc_history [i].addr,
		  rc_history [i].refcnt);
}

void dump_rc_history (void *addr)
{
	int i;

	i = rc_history_index;
	if (!rc_history [i].file)
		i = 0;
	else if (rc_history_count < RC_HISTORY_MAX) {
		i -= rc_history_count;
		if (i < 0)
			i += RC_HISTORY_MAX;
	}
	rc_history_count = 0;
		
	while (rc_history [i].file) {
		if (!addr || addr == rc_history [i].addr)
			print_rc_hist_entry (i);
		++i;
		if (i == RC_HISTORY_MAX)
			i = 0;
		if (i == rc_history_index)
			break;
	}
}
void rc_history_next (int d)
{
#if defined (RC_HISTORY_COMPRESSION)
	int i, j = 0, m, n = 0;
	void *ap, *rp;

	/* If we are decreasing the reference count, try to find the
	   entry where the reference was made and eliminate it; then
	   we can also eliminate this reference. */
	if (d) {
	    m = rc_history_index - 1000;
	    if (m < -1)
		m = -1;
	    ap = rc_history [rc_history_index].addr;
	    rp = rc_history [rc_history_index].reference;
	    for (i = rc_history_index - 1; i > m; i--) {
		if (rc_history [i].addr == ap) {
		    if (rc_history [i].reference == rp) {
			if (n > 10) {
			    for (n = i; n <= rc_history_index; n++)
				    print_rc_hist_entry (n);
			    n = 11;
			}
			memmove (&rc_history [i],
				 &rc_history [i + 1],
				 (unsigned)((rc_history_index - i) *
					    sizeof (struct rc_history_entry)));
			--rc_history_count;
			--rc_history_index;
			for (j = i; j < rc_history_count; j++) {
			    if (rc_history [j].addr == ap)
				--rc_history [j].refcnt;
			}
			if (n > 10) {
			    for (n = i; n <= rc_history_index; n++)
				    print_rc_hist_entry (n);
			    n = 11;
			    exit (0);
			}
			return;
		    }
		}
	    }
	}
#endif
	if (++rc_history_index == RC_HISTORY_MAX)
		rc_history_index = 0;
	++rc_history_count;
}
#endif

#if defined (DEBUG_MEMORY_LEAKAGE) || defined (DEBUG_MALLOC_POOL) || \
		defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
struct caller {
	struct dmalloc_preamble *dp;
	int count;
};

static int dmalloc_find_entry (struct dmalloc_preamble *dp,
			       struct caller *array,
			       int min, int max)
{
	int middle;
	int cmp;

	middle = (min + max) / 2;
	if (middle == min)
		return middle;
	if (array [middle].dp -> file == dp -> file) {
		if (array [middle].dp -> line == dp -> line)
			return middle;
		else if (array [middle].dp -> line < dp -> line)
			return dmalloc_find_entry (dp, array, middle, max);
		else
			return dmalloc_find_entry (dp, array, 0, middle);
	} else if (array [middle].dp -> file < dp -> file)
		return dmalloc_find_entry (dp, array, middle, max);
	else
		return dmalloc_find_entry (dp, array, 0, middle);
}

void omapi_print_dmalloc_usage_by_caller ()
{
	struct dmalloc_preamble *dp;
	unsigned char *foo;
	int ccur, cmax, i, j;
	struct caller cp [1024];

	cmax = 1024;
	ccur = 0;

	memset (cp, 0, sizeof cp);
	for (dp = dmalloc_list; dp; dp = dp -> prev) {
		i = dmalloc_find_entry (dp, cp, 0, ccur);
		if ((i == ccur ||
		     cp [i].dp -> file != dp -> file ||
		     cp [i].dp -> line != dp -> line) &&
		    ccur == cmax) {
			log_error ("no space for memory usage summary.");
			return;
		}
		if (i == ccur) {
			cp [ccur++].dp = dp;
			cp [i].count = 1;
		} else if (cp [i].dp -> file < dp -> file ||
			   (cp [i].dp -> file == dp -> file &&
			    cp [i].dp -> line < dp -> line)) {
			if (i + 1 != ccur)
				memmove (cp + i + 2, cp + i + 1,
					 (ccur - i) * sizeof *cp);
			cp [i + 1].dp = dp;
			cp [i + 1].count = 1;
			ccur++;
		} else if (cp [i].dp -> file != dp -> file ||
			   cp [i].dp -> line != dp -> line) {
			memmove (cp + i + 1,
				 cp + i, (ccur - i) * sizeof *cp);
			cp [i].dp = dp;
			cp [i].count = 1;
			ccur++;
		} else
			cp [i].count++;
#if 0
		printf ("%d\t%s:%d\n", i, dp -> file, dp -> line);
		dump_rc_history (dp + 1);
#endif
	}
	for (i = 0; i < ccur; i++) {
		printf ("%d\t%s:%d\t%d\n", i,
			cp [i].dp -> file, cp [i].dp -> line, cp [i].count);
		dump_rc_history (cp [i].dp + 1);
	}
}
#endif /* DEBUG_MEMORY_LEAKAGE || DEBUG_MALLOC_POOL */

isc_result_t omapi_object_allocate (omapi_object_t **o,
				    omapi_object_type_t *type,
				    size_t size,
				    const char *file, int line)
{
	size_t tsize;
	omapi_object_t *foo;
	isc_result_t status;

	if (type -> allocator) {
		foo = (omapi_object_t *)0;
		status = (*type -> allocator) (&foo, file, line);
		tsize = type -> size;
	} else
		status = ISC_R_NOMEMORY;
	if (status == ISC_R_NOMEMORY) {
		if (type -> sizer)
			tsize = (*type -> sizer) (size);
		else
			tsize = type -> size;
		
		/* Sanity check. */
		if (tsize < sizeof (omapi_object_t))
			return ISC_R_INVALIDARG;
		
		foo = dmalloc (tsize, file, line);
		if (!foo)
			return ISC_R_NOMEMORY;
	}

	status = omapi_object_initialize (foo, type, size, tsize, file, line);
	if (status != ISC_R_SUCCESS) {
		if (type -> freer)
			(*type -> freer) (foo, file, line);
		else
			dfree (foo, file, line);
		return status;
	}
	return omapi_object_reference (o, foo, file, line);
}

isc_result_t omapi_object_initialize (omapi_object_t *o,
				      omapi_object_type_t *type,
				      size_t usize, size_t psize,
				      const char *file, int line)
{
	memset (o, 0, psize);
	o -> type = type;
	if (type -> initialize)
		(*type -> initialize) (o, file, line);
	return ISC_R_SUCCESS;
}

isc_result_t omapi_object_reference (omapi_object_t **r,
				     omapi_object_t *h,
				     const char *file, int line)
{
	if (!h || !r)
		return ISC_R_INVALIDARG;

	if (*r) {
#if defined (POINTER_DEBUG)
		log_error ("%s(%d): reference store into non-null pointer!",
			   file, line);
		abort ();
#else
		return ISC_R_INVALIDARG;
#endif
	}
	*r = h;
	h -> refcnt++;
	rc_register (file, line, r, h, h -> refcnt, 0, h -> type -> rc_flag);