mem.c

bind-3.2.

/*
 * Perform a malloc, doing memory filling and overrun detection as necessary.
 */
static inline void *
mem_get(isc_mem_t *ctx, size_t size) {
	char *ret;

#if ISC_MEM_CHECKOVERRUN
	size += 1;
#endif

	ret = (ctx->memalloc)(ctx->arg, size);
	if (ret == NULL)
		ctx->memalloc_failures++;	

#if ISC_MEM_FILL
	if (ret != NULL)
		memset(ret, 0xbe, size); /* Mnemonic for "beef". */
#else
#  if ISC_MEM_CHECKOVERRUN
	if (ret != NULL)
		ret[size-1] = 0xbe;
#  endif
#endif

	return (ret);
}

/*
 * Perform a free, doing memory filling and overrun detection as necessary.
 */
static inline void
mem_put(isc_mem_t *ctx, void *mem, size_t size) {
#if ISC_MEM_CHECKOVERRUN
	INSIST(((unsigned char *)mem)[size] == 0xbe);
#endif
#if ISC_MEM_FILL
	memset(mem, 0xde, size); /* Mnemonic for "dead". */
#else
	UNUSED(size);
#endif
	(ctx->memfree)(ctx->arg, mem);
}

/*
 * Update internal counters after a memory get.
 */
static inline void
mem_getstats(isc_mem_t *ctx, size_t size) {
	ctx->total += size;
	ctx->inuse += size;

	if (size > ctx->max_size) {
		ctx->stats[ctx->max_size].gets++;
		ctx->stats[ctx->max_size].totalgets++;
	} else {
		ctx->stats[size].gets++;
		ctx->stats[size].totalgets++;
	}
}

/*
 * Update internal counters after a memory put.
 */
static inline void
mem_putstats(isc_mem_t *ctx, void *ptr, size_t size) {
	UNUSED(ptr);

	INSIST(ctx->inuse >= size);
	ctx->inuse -= size;

	if (size > ctx->max_size) {
		INSIST(ctx->stats[ctx->max_size].gets > 0U);
		ctx->stats[ctx->max_size].gets--;
	} else {
		INSIST(ctx->stats[size].gets > 0U);
		ctx->stats[size].gets--;
	}
}

#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

/*
 * Private.
 */

static void *
default_memalloc(void *arg, size_t size) {
	UNUSED(arg);
	if (size == 0U)
		size = 1;
	return (malloc(size));
}

static void
default_memfree(void *arg, void *ptr) {
	UNUSED(arg);
	free(ptr);
}

/*
 * Public.
 */

isc_result_t
isc_mem_createx(size_t init_max_size, size_t target_size,
		isc_memalloc_t memalloc, isc_memfree_t memfree, void *arg,
		isc_mem_t **ctxp)
{
	isc_mem_t *ctx;
	isc_result_t result;

	REQUIRE(ctxp != NULL && *ctxp == NULL);
	REQUIRE(memalloc != NULL);
	REQUIRE(memfree != NULL);

	INSIST((ALIGNMENT_SIZE & (ALIGNMENT_SIZE - 1)) == 0);

#if !ISC_MEM_USE_INTERNAL_MALLOC
	UNUSED(target_size);
#endif

	ctx = (memalloc)(arg, sizeof *ctx);
	if (ctx == NULL)
		return (ISC_R_NOMEMORY);

	if (init_max_size == 0U)
		ctx->max_size = DEF_MAX_SIZE;
	else
		ctx->max_size = init_max_size;
	ctx->references = 1;
	ctx->quota = 0;
	ctx->total = 0;
	ctx->inuse = 0;
	ctx->maxinuse = 0;
	ctx->hi_water = 0;
	ctx->lo_water = 0;
	ctx->hi_called = ISC_FALSE;
	ctx->water = NULL;
	ctx->water_arg = NULL;
	ctx->magic = MEM_MAGIC;
	isc_ondestroy_init(&ctx->ondestroy);
	ctx->memalloc = memalloc;
	ctx->memfree = memfree;
	ctx->arg = arg;
	ctx->stats = NULL;
	ctx->checkfree = ISC_TRUE;
	ISC_LIST_INIT(ctx->pools);

#if ISC_MEM_USE_INTERNAL_MALLOC
	ctx->freelists = NULL;
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	ctx->stats = (memalloc)(arg,
				(ctx->max_size+1) * sizeof (struct stats));
	if (ctx->stats == NULL) {
		result = ISC_R_NOMEMORY;
		goto error;
	}
	memset(ctx->stats, 0, (ctx->max_size + 1) * sizeof (struct stats));

#if ISC_MEM_USE_INTERNAL_MALLOC
	if (target_size == 0)
		ctx->mem_target = DEF_MEM_TARGET;
	else
		ctx->mem_target = target_size;
	ctx->freelists = (memalloc)(arg, ctx->max_size * sizeof (element *));
	if (ctx->freelists == NULL) {
		result = ISC_R_NOMEMORY;
		goto error;
	}
	memset(ctx->freelists, 0,
	       ctx->max_size * sizeof (element *));
	ctx->basic_blocks = NULL;
	ctx->basic_table = NULL;
	ctx->basic_table_count = 0;
	ctx->basic_table_size = 0;
	ctx->lowest = NULL;
	ctx->highest = NULL;
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	if (isc_mutex_init(&ctx->lock) != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init() %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
		result = ISC_R_UNEXPECTED;
		goto error;
	}

#if ISC_MEM_TRACKLINES
	ISC_LIST_INIT(ctx->debuglist);
	ctx->debugging = isc_mem_debugging;
#endif

	ctx->memalloc_failures = 0;

	*ctxp = ctx;
	return (ISC_R_SUCCESS);

  error:
	if (ctx) {
		if (ctx->stats)
			(memfree)(arg, ctx->stats);
#if ISC_MEM_USE_INTERNAL_MALLOC
		if (ctx->freelists)
			(memfree)(arg, ctx->freelists);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */
		(memfree)(arg, ctx);
	}

	return (result);
}

isc_result_t
isc_mem_create(size_t init_max_size, size_t target_size,
	       isc_mem_t **ctxp)
{
	return (isc_mem_createx(init_max_size, target_size,
				default_memalloc, default_memfree, NULL,
				ctxp));
}

static void
destroy(isc_mem_t *ctx) {
	unsigned int i;
	isc_ondestroy_t ondest;

	ctx->magic = 0;

#if ISC_MEM_USE_INTERNAL_MALLOC
	INSIST(ISC_LIST_EMPTY(ctx->pools));
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

#if ISC_MEM_TRACKLINES
	if (ctx->checkfree) {
		if (!ISC_LIST_EMPTY(ctx->debuglist))
			print_active(ctx, stderr);
		INSIST(ISC_LIST_EMPTY(ctx->debuglist));
	} else {
		debuglink_t *dl;

		for (dl = ISC_LIST_HEAD(ctx->debuglist);
		     dl != NULL;
		     dl = ISC_LIST_HEAD(ctx->debuglist)) {
			ISC_LIST_UNLINK(ctx->debuglist, dl, link);
			free(dl);
		}
	}
#endif
	INSIST(ctx->references == 0);

	if (ctx->checkfree) {
		for (i = 0; i <= ctx->max_size; i++) {
#if ISC_MEM_TRACKLINES
			if (ctx->stats[i].gets != 0)
				print_active(ctx, stderr);
#endif
			INSIST(ctx->stats[i].gets == 0U);
		}
	}

	(ctx->memfree)(ctx->arg, ctx->stats);

#if ISC_MEM_USE_INTERNAL_MALLOC
	for (i = 0; i < ctx->basic_table_count; i++)
		(ctx->memfree)(ctx->arg, ctx->basic_table[i]);
	(ctx->memfree)(ctx->arg, ctx->freelists);
	(ctx->memfree)(ctx->arg, ctx->basic_table);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	ondest = ctx->ondestroy;

	DESTROYLOCK(&ctx->lock);
	(ctx->memfree)(ctx->arg, ctx);

	isc_ondestroy_notify(&ondest, ctx);
}

void
isc_mem_attach(isc_mem_t *source, isc_mem_t **targetp) {
	REQUIRE(VALID_CONTEXT(source));
	REQUIRE(targetp != NULL && *targetp == NULL);

	LOCK(&source->lock);
	source->references++;
	UNLOCK(&source->lock);

	*targetp = source;
}

void
isc_mem_detach(isc_mem_t **ctxp) {
	isc_mem_t *ctx;
	isc_boolean_t want_destroy = ISC_FALSE;

	REQUIRE(ctxp != NULL);
	ctx = *ctxp;
	REQUIRE(VALID_CONTEXT(ctx));

	LOCK(&ctx->lock);
	INSIST(ctx->references > 0);
	ctx->references--;
	if (ctx->references == 0)
		want_destroy = ISC_TRUE;
	UNLOCK(&ctx->lock);

	if (want_destroy)
		destroy(ctx);

	*ctxp = NULL;
}

/*
 * isc_mem_putanddetach() is the equivalent of:
 *
 * mctx = NULL;
 * isc_mem_attach(ptr->mctx, &mctx);
 * isc_mem_detach(&ptr->mctx);
 * isc_mem_put(mctx, ptr, sizeof(*ptr);
 * isc_mem_detach(&mctx);
 */

void
isc__mem_putanddetach(isc_mem_t **ctxp, void *ptr, size_t size FLARG) {
	isc_mem_t *ctx;
	isc_boolean_t want_destroy = ISC_FALSE;

	REQUIRE(ctxp != NULL);
	ctx = *ctxp;
	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(ptr != NULL);

	/*
	 * Must be before mem_putunlocked() as ctxp is usually within
	 * [ptr..ptr+size).
	 */
	*ctxp = NULL;

#if ISC_MEM_USE_INTERNAL_MALLOC
	LOCK(&ctx->lock);
	mem_putunlocked(ctx, ptr, size);
#else /* ISC_MEM_USE_INTERNAL_MALLOC */
	mem_put(ctx, ptr, size);
	LOCK(&ctx->lock);
	mem_putstats(ctx, ptr, size);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	DELETE_TRACE(ctx, ptr, size, file, line);
	INSIST(ctx->references > 0);
	ctx->references--;
	if (ctx->references == 0)
		want_destroy = ISC_TRUE;

	UNLOCK(&ctx->lock);

	if (want_destroy)
		destroy(ctx);
}

void
isc_mem_destroy(isc_mem_t **ctxp) {
	isc_mem_t *ctx;

	/*
	 * This routine provides legacy support for callers who use mctxs
	 * without attaching/detaching.
	 */

	REQUIRE(ctxp != NULL);
	ctx = *ctxp;
	REQUIRE(VALID_CONTEXT(ctx));

	LOCK(&ctx->lock);
#if ISC_MEM_TRACKLINES
	if (ctx->references != 1)
		print_active(ctx, stderr);
#endif
	REQUIRE(ctx->references == 1);
	ctx->references--;
	UNLOCK(&ctx->lock);

	destroy(ctx);

	*ctxp = NULL;
}

isc_result_t
isc_mem_ondestroy(isc_mem_t *ctx, isc_task_t *task, isc_event_t **event) {
	isc_result_t res;

	LOCK(&ctx->lock);
	res = isc_ondestroy_register(&ctx->ondestroy, task, event);
	UNLOCK(&ctx->lock);

	return (res);
}


void *
isc__mem_get(isc_mem_t *ctx, size_t size FLARG) {
	void *ptr;
	isc_boolean_t call_water = ISC_FALSE;

	REQUIRE(VALID_CONTEXT(ctx));

#if ISC_MEM_USE_INTERNAL_MALLOC
	LOCK(&ctx->lock);
	ptr = mem_getunlocked(ctx, size);
#else /* ISC_MEM_USE_INTERNAL_MALLOC */
	ptr = mem_get(ctx, size);
	LOCK(&ctx->lock);
	if (ptr)
		mem_getstats(ctx, size);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	ADD_TRACE(ctx, ptr, size, file, line);
	if (ctx->hi_water != 0U && !ctx->hi_called &&
	    ctx->inuse > ctx->hi_water) {
		ctx->hi_called = ISC_TRUE;
		call_water = ISC_TRUE;
	}
	if (ctx->inuse > ctx->maxinuse) {
		ctx->maxinuse = ctx->inuse;
		if (ctx->hi_water != 0U && ctx->inuse > ctx->hi_water &&
		    (isc_mem_debugging & ISC_MEM_DEBUGUSAGE) != 0)
			fprintf(stderr, "maxinuse = %lu\n",
				(unsigned long)ctx->inuse);
	}
	UNLOCK(&ctx->lock);

	if (call_water) {
		(ctx->water)(ctx->water_arg, ISC_MEM_HIWATER);
	}

	return (ptr);
}

void
isc__mem_put(isc_mem_t *ctx, void *ptr, size_t size FLARG)
{
	isc_boolean_t call_water = ISC_FALSE;

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(ptr != NULL);

#if ISC_MEM_USE_INTERNAL_MALLOC
	LOCK(&ctx->lock);
	mem_putunlocked(ctx, ptr, size);
#else /* ISC_MEM_USE_INTERNAL_MALLOC */
	mem_put(ctx, ptr, size);
	LOCK(&ctx->lock);
	mem_putstats(ctx, ptr, size);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */

	DELETE_TRACE(ctx, ptr, size, file, line);

	/*
	 * The check against ctx->lo_water == 0 is for the condition
	 * when the context was pushed over hi_water but then had
	 * isc_mem_setwater() called with 0 for hi_water and lo_water.
	 */
	if (ctx->hi_called && 
	    (ctx->inuse < ctx->lo_water || ctx->lo_water == 0U)) {
		ctx->hi_called = ISC_FALSE;

		if (ctx->water != NULL)
			call_water = ISC_TRUE;
	}
	UNLOCK(&ctx->lock);

	if (call_water) {
		(ctx->water)(ctx->water_arg, ISC_MEM_LOWATER);
	}
}

#if ISC_MEM_TRACKLINES
static void
print_active(isc_mem_t *mctx, FILE *out) {
	if (MEM_RECORD) {
		debuglink_t *dl;
		unsigned int i;

		fprintf(out, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					    ISC_MSG_DUMPALLOC,
					    "Dump of all outstanding "
					    "memory allocations:\n"));
		dl = ISC_LIST_HEAD(mctx->debuglist);
		if (dl == NULL)
			fprintf(out, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
						    ISC_MSG_NONE,
						    "\tNone.\n"));
		while (dl != NULL) {
			for (i = 0 ; i < DEBUGLIST_COUNT ; i++)
				if (dl->ptr[i] != NULL)
					fprintf(out,
						isc_msgcat_get(isc_msgcat,
							   ISC_MSGSET_MEM,
							   ISC_MSG_PTRFILELINE,
							   "\tptr %p "
							   "file %s "
							   "line %u\n"),
						dl->ptr[i], dl->file[i],
						dl->line[i]);
			dl = ISC_LIST_NEXT(dl, link);
		}
	}
}
#endif

/*
 * Print the stats[] on the stream "out" with suitable formatting.
 */
void
isc_mem_stats(isc_mem_t *ctx, FILE *out) {
	size_t i;
	const struct stats *s;
	const isc_mempool_t *pool;

	REQUIRE(VALID_CONTEXT(ctx));
	LOCK(&ctx->lock);

	for (i = 0; i <= ctx->max_size; i++) {
		s = &ctx->stats[i];

		if (s->totalgets == 0U && s->gets == 0U)
			continue;
		fprintf(out, "%s%5lu: %11lu gets, %11lu rem",
			(i == ctx->max_size) ? ">=" : "  ",
			(unsigned long) i, s->totalgets, s->gets);
#if ISC_MEM_USE_INTERNAL_MALLOC
		if (s->blocks != 0 || s->freefrags != 0)
			fprintf(out, " (%lu bl, %lu ff)",
				s->blocks, s->freefrags);
#endif /* ISC_MEM_USE_INTERNAL_MALLOC */
		fputc('\n', out);
	}

	/*
	 * Note that since a pool can be locked now, these stats might be
	 * somewhat off if the pool is in active use at the time the stats
	 * are dumped.  The link fields are protected by the isc_mem_t's
	 * lock, however, so walking this list and extracting integers from
	 * stats fields is always safe.
	 */
	pool = ISC_LIST_HEAD(ctx->pools);
	if (pool != NULL) {
		fprintf(out, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					    ISC_MSG_POOLSTATS,
					    "[Pool statistics]\n"));
		fprintf(out, "%15s %10s %10s %10s %10s %10s %10s %10s %1s\n",
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLNAME, "name"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLSIZE, "size"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLMAXALLOC, "maxalloc"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLALLOCATED, "allocated"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFREECOUNT, "freecount"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFREEMAX, "freemax"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFILLCOUNT, "fillcount"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLGETS, "gets"),
			"L");
	}
	while (pool != NULL) {
		fprintf(out, "%15s %10lu %10u %10u %10u %10u %10u %10u %s\n",
			pool->name, (unsigned long) pool->size, pool->maxalloc,
			pool->allocated, pool->freecount, pool->freemax,
			pool->fillcount, pool->gets,
			(pool->lock == NULL ? "N" : "Y"));