mem.c

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/*!
 * 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--;
	}
}

/*
 * 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);
}

static void
initialize_action(void) {
        RUNTIME_CHECK(isc_mutex_init(&lock) == ISC_R_SUCCESS);
}

/*
 * 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)
{
	return (isc_mem_createx2(init_max_size, target_size, memalloc, memfree,
				 arg, ctxp, ISC_MEMFLAG_DEFAULT));
				 
}

isc_result_t
isc_mem_createx2(size_t init_max_size, size_t target_size,
		 isc_memalloc_t memalloc, isc_memfree_t memfree, void *arg,
		 isc_mem_t **ctxp, unsigned int flags)
{
	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);

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

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

	if ((flags & ISC_MEMFLAG_NOLOCK) == 0) {
		result = isc_mutex_init(&ctx->lock);
		if (result != ISC_R_SUCCESS) {
			(memfree)(arg, ctx);
			return (result);
		}
	}

	if (init_max_size == 0U)
		ctx->max_size = DEF_MAX_SIZE;
	else
		ctx->max_size = init_max_size;
	ctx->flags = flags;
	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;
#if ISC_MEM_TRACKLINES
	ctx->debuglist = NULL;
#endif
	ISC_LIST_INIT(ctx->pools);
	ctx->freelists = NULL;
	ctx->basic_blocks = NULL;
	ctx->basic_table = NULL;
	ctx->basic_table_count = 0;
	ctx->basic_table_size = 0;
	ctx->lowest = NULL;
	ctx->highest = NULL;

	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 ((flags & ISC_MEMFLAG_INTERNAL) != 0) {
		if (target_size == 0U)
			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 *));
	}

#if ISC_MEM_TRACKLINES
	if ((isc_mem_debugging & ISC_MEM_DEBUGRECORD) != 0) {
		unsigned int i;

		ctx->debuglist = (memalloc)(arg,
				      (ctx->max_size+1) * sizeof(debuglist_t));
		if (ctx->debuglist == NULL) {
			result = ISC_R_NOMEMORY;
			goto error;
		}
		for (i = 0; i <= ctx->max_size; i++)
			ISC_LIST_INIT(ctx->debuglist[i]);
	}
#endif

	ctx->memalloc_failures = 0;

	LOCK(&lock);
	ISC_LIST_INITANDAPPEND(contexts, ctx, link);
	UNLOCK(&lock);

	*ctxp = ctx;
	return (ISC_R_SUCCESS);

  error:
	if (ctx != NULL) {
		if (ctx->stats != NULL)
			(memfree)(arg, ctx->stats);
		if (ctx->freelists != NULL)
			(memfree)(arg, ctx->freelists);
#if ISC_MEM_TRACKLINES
		if (ctx->debuglist != NULL)
			(ctx->memfree)(ctx->arg, ctx->debuglist);
#endif /* ISC_MEM_TRACKLINES */
		if ((ctx->flags & ISC_MEMFLAG_NOLOCK) == 0)
			DESTROYLOCK(&ctx->lock);
		(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_createx2(init_max_size, target_size,
				 default_memalloc, default_memfree, NULL,
				 ctxp, ISC_MEMFLAG_DEFAULT));
}

isc_result_t
isc_mem_create2(size_t init_max_size, size_t target_size,
		isc_mem_t **ctxp, unsigned int flags)
{
	return (isc_mem_createx2(init_max_size, target_size,
				 default_memalloc, default_memfree, NULL,
				 ctxp, flags));
}

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

	ctx->magic = 0;

	LOCK(&lock);
	ISC_LIST_UNLINK(contexts, ctx, link);
	UNLOCK(&lock);

	INSIST(ISC_LIST_EMPTY(ctx->pools));

#if ISC_MEM_TRACKLINES
	if (ctx->debuglist != NULL) {
		if (ctx->checkfree) {
			for (i = 0; i <= ctx->max_size; i++) {
				if (!ISC_LIST_EMPTY(ctx->debuglist[i]))
					print_active(ctx, stderr);
				INSIST(ISC_LIST_EMPTY(ctx->debuglist[i]));
			}
		} else {
			debuglink_t *dl;

			for (i = 0; i <= ctx->max_size; i++)
				for (dl = ISC_LIST_HEAD(ctx->debuglist[i]);
				     dl != NULL;
				     dl = ISC_LIST_HEAD(ctx->debuglist[i])) {
					ISC_LIST_UNLINK(ctx->debuglist[i],
						 	dl, link);
					free(dl);
				}
		}
		(ctx->memfree)(ctx->arg, ctx->debuglist);
	}
#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 != 0U)
				print_active(ctx, stderr);
#endif
			INSIST(ctx->stats[i].gets == 0U);
		}
	}

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

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		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);
	}

	ondest = ctx->ondestroy;

	if ((ctx->flags & ISC_MEMFLAG_NOLOCK) == 0)
		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);

	MCTXLOCK(source, &source->lock);
	source->references++;
	MCTXUNLOCK(source, &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));

	MCTXLOCK(ctx, &ctx->lock);
	INSIST(ctx->references > 0);
	ctx->references--;
	if (ctx->references == 0)
		want_destroy = ISC_TRUE;
	MCTXUNLOCK(ctx, &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;
	size_info *si;
	size_t oldsize;

	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_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0) {
		if ((isc_mem_debugging & ISC_MEM_DEBUGSIZE) != 0) {
			si = &(((size_info *)ptr)[-1]);
			oldsize = si->u.size - ALIGNMENT_SIZE;
			if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
				oldsize -= ALIGNMENT_SIZE;
			INSIST(oldsize == size);
		}
		isc__mem_free(ctx, ptr FLARG_PASS);

		MCTXLOCK(ctx, &ctx->lock);
		ctx->references--;
		if (ctx->references == 0)
			want_destroy = ISC_TRUE;
		MCTXUNLOCK(ctx, &ctx->lock);
		if (want_destroy)
			destroy(ctx);

		return;
	}

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		MCTXLOCK(ctx, &ctx->lock);
		mem_putunlocked(ctx, ptr, size);
	} else {
		mem_put(ctx, ptr, size);
		MCTXLOCK(ctx, &ctx->lock);
		mem_putstats(ctx, ptr, size);
	}

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

	MCTXUNLOCK(ctx, &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));

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

	MCTXLOCK(ctx, &ctx->lock);
	res = isc_ondestroy_register(&ctx->ondestroy, task, event);
	MCTXUNLOCK(ctx, &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_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0)
		return (isc__mem_allocate(ctx, size FLARG_PASS));

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		MCTXLOCK(ctx, &ctx->lock);
		ptr = mem_getunlocked(ctx, size);
	} else {
		ptr = mem_get(ctx, size);
		MCTXLOCK(ctx, &ctx->lock);
		if (ptr != NULL)
			mem_getstats(ctx, size);
	}

	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);
	}
	MCTXUNLOCK(ctx, &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;
	size_info *si;
	size_t oldsize;

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

	if ((isc_mem_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0) {
		if ((isc_mem_debugging & ISC_MEM_DEBUGSIZE) != 0) {
			si = &(((size_info *)ptr)[-1]);
			oldsize = si->u.size - ALIGNMENT_SIZE;
			if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
				oldsize -= ALIGNMENT_SIZE;
			INSIST(oldsize == size);
		}
		isc__mem_free(ctx, ptr FLARG_PASS);
		return;
	}

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		MCTXLOCK(ctx, &ctx->lock);
		mem_putunlocked(ctx, ptr, size);
	} else {
		mem_put(ctx, ptr, size);
		MCTXLOCK(ctx, &ctx->lock);
		mem_putstats(ctx, ptr, size);
	}

	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;
	}
	MCTXUNLOCK(ctx, &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 (mctx->debuglist != NULL) {
		debuglink_t *dl;
		unsigned int i, j;
		const char *format;
		isc_boolean_t found;

		fprintf(out, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					    ISC_MSG_DUMPALLOC,
					    "Dump of all outstanding "
					    "memory allocations:\n"));
		found = ISC_FALSE;
		format = isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				        ISC_MSG_PTRFILELINE,
					"\tptr %p size %u file %s line %u\n");
		for (i = 0; i <= mctx->max_size; i++) {
			dl = ISC_LIST_HEAD(mctx->debuglist[i]);
			
			if (dl != NULL)
				found = ISC_TRUE;

			while (dl != NULL) {
				for (j = 0; j < DEBUGLIST_COUNT; j++)
					if (dl->ptr[j] != NULL)
						fprintf(out, format,
							dl->ptr[j],
							dl->size[j],
							dl->file[j],
							dl->line[j]);
				dl = ISC_LIST_NEXT(dl, link);
			}
		}
		if (!found)
			fprintf(out, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
						    ISC_MSG_NONE, "\tNone.\n"));
	}
}
#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));
	MCTXLOCK(ctx, &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 ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0 &&
		    (s->blocks != 0U || s->freefrags != 0U))
			fprintf(out, " (%lu bl, %lu ff)",
				s->blocks, s->freefrags);
		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"));
		pool = ISC_LIST_NEXT(pool, link);
	}

#if ISC_MEM_TRACKLINES
	print_active(ctx, out);
#endif

	MCTXUNLOCK(ctx, &ctx->lock);
}

/*
 * Replacements for malloc() and free() -- they implicitly remember the
 * size of the object allocated (with some additional overhead).
 */

static void *
isc__mem_allocateunlocked(isc_mem_t *ctx, size_t size) {
	size_info *si;

	size += ALIGNMENT_SIZE;
	if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
		size += ALIGNMENT_SIZE;

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0)
		si = mem_getunlocked(ctx, size);
	else
		si = mem_get(ctx, size);

	if (si == NULL)
		return (NULL);
	if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0) {
		si->u.ctx = ctx;
		si++;
	}
	si->u.size = size;
	return (&si[1]);
}

void *
isc__mem_allocate(isc_mem_t *ctx, size_t size FLARG) {
	size_info *si;
	isc_boolean_t call_water = ISC_FALSE;

	REQUIRE(VALID_CONTEXT(ctx));