diff --git a/lib/libthr/pthread.map b/lib/libthr/pthread.map
index a14341e557ff..ec7017d65c60 100644
--- a/lib/libthr/pthread.map
+++ b/lib/libthr/pthread.map
@@ -2,12 +2,14 @@
 LIBTHREAD_1_0 {
 global:
 	___creat;
+	___mq_close;
 	__accept;
 	__close;
 	__connect;
 	__error;
 	__fcntl;
 	__fsync;
+	__mq_notify;
 	__msync;
 	__nanosleep;
 	__open;
@@ -32,6 +34,7 @@ global:
 	_aio_suspend;
 	_execve;
 	_fork;
+	_mq_notify;
 	_nanosleep;
 	_pause;
 	_pselect;
@@ -193,6 +196,7 @@ global:
 	fcntl;
 	fork;
 	fsync;
+	mq_notify;
 	msync;
 	nanosleep;
 	open;
diff --git a/lib/libthr/thread/thr_timer.c b/lib/libthr/thread/thr_timer.c
index 80e4bd0039e8..c5f204e2bd00 100644
--- a/lib/libthr/thread/thr_timer.c
+++ b/lib/libthr/thread/thr_timer.c
@@ -27,72 +27,178 @@
  *
  */
 
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <mqueue.h>
 #include <time.h>
 #include <setjmp.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
 
 #include "thr_private.h"
 
 struct thread_node {
-	struct pthread_attr		attr;
-	TAILQ_ENTRY(thread_node)	link;
-	pthread_t	thread;
-	int		refcount;
-	int		exit;
-	jmp_buf		jbuf;
-	struct timer 	*curtmr;
+	struct pthread_attr	tn_attr;
+	TAILQ_ENTRY(thread_node)tn_link;
+	pthread_t		tn_thread;
+	int			tn_refcount;
+	int			tn_exit;
+	jmp_buf			tn_jbuf;
+	struct rtobj_node *	tn_curobj;
 };
 
-struct timer {
-	union sigval	value;
-	void		(*function)(union sigval, int);
-	int		timerid;
-	long		flags;
-	int		gen;
-	struct thread_node *tn;
+struct rtobj_node {
+	LIST_ENTRY(rtobj_node)	rt_link;
+	int			rt_type;
+	union sigval		rt_value;
+	void *			rt_func;
+	umtx_t			rt_flags;
+	union {
+		int	_timerid;
+		int	_mqd;
+	} _rt_id;
+	int			rt_gen;
+	struct thread_node *	rt_tn;
 };
 
-static struct timer		**timer_list;
-static int			timer_gen;
-static int			timer_max;
-static umtx_t			timer_list_lock;
-static TAILQ_HEAD(,thread_node)	timer_threads;
-static umtx_t			timer_threads_lock;
+#define	rt_timerid		_rt_id._timerid
+#define	rt_mqd			_rt_id._mqd
 
-static void	*service_loop(void *);
-static int	register_timer(struct timer *);
-static struct thread_node	*create_timer_thread(pthread_attr_t);
-static void	release_timer_thread(struct thread_node *);
+LIST_HEAD(rtobj_hash_head, rtobj_node);
+#define HASH_QUEUES		17
+#define	HASH(t, id)		((((id) << 3) + (t)) % HASH_QUEUES)
+static struct rtobj_hash_head	rtobj_hash[HASH_QUEUES];
+static int			generation;
+static umtx_t			hash_lock;
+static TAILQ_HEAD(,thread_node)	threads;
+static umtx_t			threads_lock;
+
+static struct thread_node *thread_create(pthread_attr_t *);
+static void	thread_release(struct thread_node *);
+static struct rtobj_node *rtobj_find(int, int);
+static int	rtobj_register(struct rtobj_node *);
+static int	rtobj_delete(int, int);
+static int	rtobj_delete_obj(struct rtobj_node *);
+static void *	service_loop(void *);
+static void	timer_dispatch(struct rtobj_node *p, int);
 
 extern int __sys_timer_create(clockid_t, struct sigevent *, timer_t *);
 extern int __sys_timer_delete(timer_t);
+extern int __sys_mq_notify(mqd_t mqdes, const struct sigevent *);
+extern int __mq_close(mqd_t mqd);
 
 __weak_reference(__timer_create, timer_create);
 __weak_reference(__timer_create, _timer_create);
 __weak_reference(__timer_delete, timer_delete);
 __weak_reference(__timer_delete, _timer_delete);
+__weak_reference(__mq_notify, mq_notify);
+__weak_reference(__mq_notify, _mq_notify);
+__weak_reference(___mq_close, mq_close);
+__weak_reference(___mq_close, _mq_close);
 
-#define	SIGTIMER	SIGCANCEL	/* Reuse SIGCANCEL */
+#define	SIGSERVICE		SIGCANCEL	/* Reuse SIGCANCEL */
 
-#define	WORKING		0x01
-#define	WANTED		0x02
+#define	RT_WORKING		0x01
+#define	RT_WANTED		0x02
 
-#define	TIMERS_LOCK(t)		THR_UMTX_LOCK((t), &timer_list_lock)
-#define	TIMERS_UNLOCK(t)	THR_UMTX_UNLOCK((t), &timer_list_lock)
+#define	HASH_LOCK(t)		THR_LOCK_ACQUIRE((t), &hash_lock)
+#define	HASH_UNLOCK(t)		THR_LOCK_RELEASE((t), &hash_lock)
 
-#define	THREADS_LOCK(t)		THR_UMTX_LOCK((t), &timer_threads_lock)
-#define	THREADS_UNLOCK(t)	THR_UMTX_UNLOCK((t), &timer_threads_lock)
+#define	THREADS_LOCK(t)		THR_LOCK_ACQUIRE((t), &threads_lock)
+#define	THREADS_UNLOCK(t)	THR_LOCK_RELEASE((t), &threads_lock)
 
 void
 _thr_timer_init(void)
 {
-	_thr_umtx_init(&timer_list_lock);
-	_thr_umtx_init(&timer_threads_lock);
-	TAILQ_INIT(&timer_threads);
-	timer_list = NULL;
-	timer_max = 0;
+	int i;
+
+	_thr_umtx_init(&hash_lock);
+	_thr_umtx_init(&threads_lock);
+	for (i = 0; i < HASH_QUEUES; ++i)
+		LIST_INIT(&rtobj_hash[i]);
+	TAILQ_INIT(&threads);
+}
+
+static struct rtobj_node *
+rtobj_alloc(int type, const struct sigevent *evp)
+{
+	struct rtobj_node *obj;
+
+	obj = calloc(1, sizeof(*obj));
+	if (obj != NULL) {
+		obj->rt_value = evp->sigev_value;
+		obj->rt_func = evp->sigev_notify_function;
+		obj->rt_gen = atomic_fetchadd_int(&generation, 1);
+		obj->rt_type = type;
+	}
+
+	return (obj);
+}
+
+static __inline void
+rtobj_free(struct rtobj_node *obj)
+{
+	free(obj);
+}
+
+static struct rtobj_node *
+rtobj_find(int type, int id)
+{
+	struct rtobj_node *obj;
+	int chain = HASH(type, id);
+
+	LIST_FOREACH(obj, &rtobj_hash[chain], rt_link) {
+		if (obj->rt_type == type && obj->rt_mqd == id)
+			break;
+	}
+	return (obj);
+}
+
+static int
+rtobj_register(struct rtobj_node *obj)
+{
+	int chain = HASH(obj->rt_type, obj->rt_mqd);
+
+	LIST_INSERT_HEAD(&rtobj_hash[chain], obj, rt_link);
+	return (0);
+}
+
+static int
+rtobj_delete(int type, int id)
+{
+	struct rtobj_node *obj;
+
+	obj = rtobj_find(type, id);
+	if (obj != NULL)
+		return (rtobj_delete_obj(obj));
+	return (0);
+}
+
+static int
+rtobj_delete_obj(struct rtobj_node *obj)
+{
+	struct pthread *curthread = _get_curthread();
+	umtx_t flags;
+
+	LIST_REMOVE(obj, rt_link);
+	/* If the timer is servicing, allow it to complete. */
+	while ((flags = obj->rt_flags) & RT_WORKING) {
+		obj->rt_flags |= RT_WANTED;
+		HASH_UNLOCK(curthread);
+		_thr_umtx_wait(&obj->rt_flags, flags, NULL);
+		HASH_LOCK(curthread);
+	}
+	HASH_UNLOCK(curthread);
+	/*
+	 * Drop reference count of servicing thread,
+	 * may free the thread.
+	 */
+	thread_release(obj->rt_tn);
+	rtobj_free(obj);
+
+	HASH_LOCK(curthread);
+	return (0);
 }
 
 /*
@@ -102,61 +208,49 @@ _thr_timer_init(void)
 int
 __timer_create(clockid_t clockid, struct sigevent *evp, timer_t *timerid)
 {
-	pthread_attr_t attr;
 	struct sigevent ev;
-	struct timer *tmr;
-	int ret;
+	struct rtobj_node *obj;
+	struct pthread *curthread;
+	int ret, err;
 
 	/* Call syscall directly if it is not SIGEV_THREAD */
 	if (evp == NULL || evp->sigev_notify != SIGEV_THREAD)
 		return (__sys_timer_create(clockid, evp, timerid));
 
 	/* Otherwise, do all magical things. */
-	tmr = malloc(sizeof(*tmr));
-	if (__predict_false(tmr == NULL)) {
+	obj = rtobj_alloc(SI_TIMER, evp);
+	if (obj == NULL) {
 		errno = EAGAIN;
 		return (-1);
 	}
-	tmr->value = evp->sigev_value;
-	/* XXX
-	 * Here we pass second parameter an overrun count, this is
-	 * not required by POSIX.
-	 */
-	tmr->function = (void (*)(union sigval, int))
-		evp->sigev_notify_function;
-	tmr->flags = 0;
-	tmr->timerid = -1;
-	pthread_attr_init(&attr);
-	if (evp->sigev_notify_attributes != NULL) {
-		*attr = **(pthread_attr_t *)(evp->sigev_notify_attributes);
-		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-	}
-
-	tmr->gen = atomic_fetchadd_int(&timer_gen, 1);
-	tmr->tn = create_timer_thread(attr);
-	if (__predict_false(tmr->tn == NULL)) {
-		free(tmr);
+	obj->rt_tn = thread_create(evp->sigev_notify_attributes);
+	if (obj->rt_tn == NULL) {
+		rtobj_free(obj);
 		errno = EAGAIN;
 		return (-1);
 	}
 
 	/*
-	 * Build a new sigevent, and tell kernel to deliver
-	 * SIGTIMER signal to the new thread.
+	 * Build a new sigevent, and tell kernel to deliver SIGSERVICE
+	 * signal to the new thread.
 	 */
 	ev.sigev_notify = SIGEV_THREAD_ID;
-	ev.sigev_signo = SIGTIMER;
-	ev.sigev_notify_thread_id = (lwpid_t)tmr->tn->thread->tid;
-	ev.sigev_value.sival_int = tmr->gen;
-	ret = __sys_timer_create(clockid, &ev, &tmr->timerid);
-	if (__predict_false(ret != 0 || register_timer(tmr) != 0)) {
-		ret = errno;
-		release_timer_thread(tmr->tn);
-		free(tmr);
-		errno = ret;
+	ev.sigev_signo = SIGSERVICE;
+	ev.sigev_notify_thread_id = (lwpid_t)obj->rt_tn->tn_thread->tid;
+	ev.sigev_value.sival_int = obj->rt_gen;
+	ret = __sys_timer_create(clockid, &ev, &obj->rt_timerid);
+	if (ret != 0) {
+		err = errno;
+		thread_release(obj->rt_tn);
+		rtobj_free(obj);
+		errno = err;
 		return (-1);
 	}
-	*timerid = tmr->timerid;
+	curthread = _get_curthread();
+	HASH_LOCK(curthread);
+	rtobj_register(obj);
+	HASH_UNLOCK(curthread);
+	*timerid = obj->rt_timerid;
 	return (0);
 }
 
@@ -164,209 +258,256 @@ int
 __timer_delete(timer_t timerid)
 {
 	struct pthread *curthread = _get_curthread();
-	struct timer *tmr = NULL;
-	long flags;
 
-	TIMERS_LOCK(curthread);
-	/*
-	 * Check if this is a SIGEV_THREAD timer by looking up
-	 * it in the registered list.
-	 */
-	if (timerid >= 0 && timerid < timer_max && 
-	    (tmr = timer_list[timerid]) != NULL) {
-		/* Take it from timer list */
-		timer_list[timerid] = NULL;
-		/* If the timer is servicing, allow it to complete. */
-		while ((flags = tmr->flags) & WORKING) {
-			tmr->flags |= WANTED;
-			TIMERS_UNLOCK(curthread);
-			_thr_umtx_wait(&tmr->flags, flags, NULL);
-			TIMERS_LOCK(curthread);
-		}
-		TIMERS_UNLOCK(curthread);
-		/*
-		 * Drop reference count of servicing thread,
-		 * may free the thread.
-		 */
-		release_timer_thread(tmr->tn);
-	} else
-		TIMERS_UNLOCK(curthread);
-	if (tmr != NULL)
-		free(tmr);
+	HASH_LOCK(curthread);
+	rtobj_delete(SI_TIMER, timerid);
+	HASH_UNLOCK(curthread);
 	return (__sys_timer_delete(timerid));
 }
 
-static struct thread_node *
-create_timer_thread(pthread_attr_t attr)
+typedef void (*timer_func)(union sigval val, int timerid, int overrun);
+
+static void
+timer_dispatch(struct rtobj_node *obj, int overrun)
 {
-	struct pthread *curthread = _get_curthread();
+	timer_func f = obj->rt_func;
+
+	f(obj->rt_value, obj->rt_timerid, overrun);
+}
+
+int
+___mq_close(mqd_t mqd)
+{
+	struct pthread *curthread;
+	int ret;
+
+	curthread = _get_curthread();
+	HASH_LOCK(curthread);
+	rtobj_delete(SI_MESGQ, mqd);
+	ret = __mq_close(mqd);
+	HASH_UNLOCK(curthread);
+	return (ret);
+}
+
+int
+__mq_notify(mqd_t mqd, const struct sigevent *evp)
+{
+	struct sigevent ev;
+	struct rtobj_node *obj;
+	struct pthread *curthread;
+	int ret, err;
+
+	curthread = _get_curthread();
+
+	HASH_LOCK(curthread);
+	rtobj_delete(SI_MESGQ, mqd);
+	if (evp == NULL || evp->sigev_notify != SIGEV_THREAD) {
+		ret = __sys_mq_notify(mqd, evp);
+		HASH_UNLOCK(curthread);
+		return (ret);
+	}
+	HASH_UNLOCK(curthread);
+
+	obj = rtobj_alloc(SI_MESGQ, evp);
+	if (obj == NULL) {
+		errno = EAGAIN;
+		return (-1);
+	}
+	obj->rt_tn = thread_create(evp->sigev_notify_attributes);
+	if (obj->rt_tn == NULL) {
+		rtobj_free(obj);
+		errno = EAGAIN;
+		return (-1);
+	}
+	obj->rt_mqd = mqd;
+	/*
+	 * Build a new sigevent, and tell kernel to deliver SIGSERVICE
+	 * signal to the new thread.
+	 */
+	ev.sigev_notify = SIGEV_THREAD_ID;
+	ev.sigev_signo = SIGSERVICE;
+	ev.sigev_notify_thread_id = (lwpid_t)obj->rt_tn->tn_thread->tid;
+	ev.sigev_value.sival_int = obj->rt_gen;
+	HASH_LOCK(curthread);
+	ret = __sys_mq_notify(mqd, &ev);
+	if (ret != 0) {
+		err = errno;
+		HASH_UNLOCK(curthread);
+		thread_release(obj->rt_tn);
+		rtobj_free(obj);
+		errno = err;
+		return (-1);
+	}
+	rtobj_register(obj);
+	HASH_UNLOCK(curthread);
+	return (0);
+}
+
+typedef void (*mq_func)(union sigval val, int mqd);
+
+static void
+mq_dispatch(struct rtobj_node *obj)
+{
+	mq_func f = obj->rt_func;
+
+	f(obj->rt_value, obj->rt_mqd);
+}
+
+static struct thread_node *
+thread_create(pthread_attr_t *pattr)
+{
+	pthread_attr_t attr;
+	struct pthread *curthread;
 	struct thread_node *tn;
 	int ret;
 
+	curthread = _get_curthread();
+	pthread_attr_init(&attr);
+	if (pattr != NULL) {
+		*attr = **(pthread_attr_t *)pattr;
+		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+	}
+
 	THREADS_LOCK(curthread);
 	/* Search a thread matching the required pthread_attr. */
-	TAILQ_FOREACH(tn, &timer_threads, link) {
+	TAILQ_FOREACH(tn, &threads, tn_link) {
 		if (attr->stackaddr_attr == NULL) {
-			if (attr->sched_policy == tn->attr.sched_policy &&
-			    attr->sched_inherit == tn->attr.sched_inherit &&
-			    attr->prio == tn->attr.prio &&
-			    attr->stacksize_attr == tn->attr.stacksize_attr &&
-			    attr->guardsize_attr == tn->attr.guardsize_attr &&
+			if (attr->sched_policy == tn->tn_attr.sched_policy &&
+			    attr->sched_inherit == tn->tn_attr.sched_inherit &&
+			    attr->prio == tn->tn_attr.prio &&
+			    attr->stacksize_attr == tn->tn_attr.stacksize_attr &&
+			    attr->guardsize_attr == tn->tn_attr.guardsize_attr &&
 			    ((attr->flags & PTHREAD_SCOPE_SYSTEM) ==
-			     (tn->attr.flags & PTHREAD_SCOPE_SYSTEM)))
+			     (tn->tn_attr.flags & PTHREAD_SCOPE_SYSTEM)))
 				break;
 		} else {
 			/*
 			 * Reuse the thread if it has same stack address,
 			 * because two threads can not run on same stack.
 			 */
-			if (attr->stackaddr_attr == tn->attr.stackaddr_attr)
+			if (attr->stackaddr_attr == tn->tn_attr.stackaddr_attr)
 				break;
 		}
 	}
 	if (tn != NULL) {
-		tn->refcount++;
+		tn->tn_refcount++;
 		THREADS_UNLOCK(curthread);
+		pthread_attr_destroy(&attr);
 		return (tn);
 	}
 	tn = malloc(sizeof(*tn));
-	tn->refcount = 1;
-	tn->exit = 0;
-	tn->attr = *attr;
-	tn->curtmr = NULL;
-	_thr_signal_block(curthread); /* SIGTIMER is also blocked. */
-	TAILQ_INSERT_TAIL(&timer_threads, tn, link);
-	ret = _pthread_create(&tn->thread, &attr, service_loop, tn);
+	tn->tn_refcount = 1;
+	tn->tn_exit = 0;
+	tn->tn_attr = *attr;
+	tn->tn_curobj = NULL;
+	_thr_signal_block(curthread); /* SIGSERVICE is also blocked. */
+	TAILQ_INSERT_TAIL(&threads, tn, tn_link);
+	ret = _pthread_create(&tn->tn_thread, &attr, service_loop, tn);
 	_thr_signal_unblock(curthread);
 	if (ret != 0) {
-		TAILQ_REMOVE(&timer_threads, tn, link);
+		TAILQ_REMOVE(&threads, tn, tn_link);
 		free(tn);
 		tn = NULL;
 	}
 	THREADS_UNLOCK(curthread);
+	pthread_attr_destroy(&attr);
 	return (tn);
 }
 
 static void
-release_timer_thread(struct thread_node *tn)
+thread_release(struct thread_node *tn)
 {
 	struct pthread *curthread = _get_curthread();
-	struct pthread *th;
 
 	THREADS_LOCK(curthread);
-	if (--tn->refcount == 0) {
-		/*
-		 * If I am the last user, current implement kills the
-		 * service thread, is this allowed by POSIX ? does
-		 * this hurt performance ?
-		 */ 
-		tn->exit = 1;
-		th = tn->thread;
-		_thr_send_sig(th, SIGTIMER);
-		pthread_join(th, NULL);
-		TAILQ_REMOVE(&timer_threads, tn, link);
+	tn->tn_refcount--;
+#if 0
+	if (tn->tn_refcount == 0) {
+		struct pthread *th;
+		tn->tn_exit = 1;
+		th = tn->tn_thread;
+		_thr_send_sig(th, SIGSERVICE);
+		TAILQ_REMOVE(&threads, tn, tn_link);
 	} else
+#endif
 		tn = NULL;
 	THREADS_UNLOCK(curthread);
 	if (tn != NULL)
 		free(tn);
 }
 
-/* Register a SIGEV_THREAD timer. */
-static int
-register_timer(struct timer *tmr)
-{
-	struct pthread *curthread = _get_curthread();
-	struct timer **list;
-	int count;
-
-	while ((count = timer_max) <= tmr->timerid) {
-		if (count < 32)
-			count = 32;
-		while (count <= tmr->timerid)
-			count <<= 1;
-		list = malloc(count * sizeof(void *));
-		memset(list, 0, count * sizeof(void *));
-		if (list == NULL)
-			return (-1);
-		TIMERS_LOCK(curthread);
-		if (timer_max >= count) {
-			TIMERS_UNLOCK(curthread);
-			free(list);
-			continue;
-		}
-		memcpy(timer_list, list, timer_max * sizeof(void *));
-		timer_list = list;
-		timer_max = count;
-		TIMERS_UNLOCK(curthread);
-	}
-	TIMERS_LOCK(curthread);
-	timer_list[tmr->timerid] = tmr;
-	TIMERS_UNLOCK(curthread);
-	return (0);
-}
-
 /*
  * This function is called if user callback calls
  * pthread_exit() or pthread_cancel() for the thread.
  */
 static void
-cleanup_thread(void *arg)
+thread_cleanup(void *arg)
 {
 	struct pthread *curthread = _get_curthread();
 	struct thread_node *tn = arg;
 
-	if (tn->exit == 0) {
-		/* broken usercode is killing us. */
-		if (tn->curtmr) {
-			TIMERS_LOCK(curthread);
-			tn->curtmr->flags &= ~WORKING;
-			if (tn->curtmr->flags & WANTED)
-				_thr_umtx_wake(&tn->curtmr->flags, INT_MAX);
-			TIMERS_UNLOCK(curthread);
+	if (tn->tn_exit == 0) {
+		/* broken user code is killing us. */
+		if (tn->tn_curobj != NULL) {
+			HASH_LOCK(curthread);
+			tn->tn_curobj->rt_flags &= ~RT_WORKING;
+			if (tn->tn_curobj->rt_flags & RT_WANTED)
+				_thr_umtx_wake(&tn->tn_curobj->rt_flags, INT_MAX);
+			HASH_UNLOCK(curthread);
 		}
 		atomic_clear_int(&curthread->cancelflags, THR_CANCEL_EXITING);
-		longjmp(tn->jbuf, 1);
+		longjmp(tn->tn_jbuf, 1);
 	}
 }
 
 static void *
 service_loop(void *arg)
 {
-	struct pthread *curthread = _get_curthread();
-	struct thread_node *tn = arg;
-	struct timer *tmr;
 	siginfo_t si;
 	sigset_t set;
+	struct thread_node *tn;
+	struct pthread *curthread;
+	struct rtobj_node *obj;
 
+	tn = arg;
+	curthread = _get_curthread();
 	/*
 	 * Service thread should not be killed by callback, if user
 	 * tries to do so, the thread will be restarted.
 	 */
-	setjmp(tn->jbuf);
+	setjmp(tn->tn_jbuf);
 	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 	sigemptyset(&set);
-	sigaddset(&set, SIGTIMER);
-	THR_CLEANUP_PUSH(curthread, cleanup_thread, tn);
-	while (tn->exit == 0) {
+	sigaddset(&set, SIGSERVICE);
+	THR_CLEANUP_PUSH(curthread, thread_cleanup, tn);
+	while (tn->tn_exit == 0) {
 		if (__predict_false(__sys_sigwaitinfo(&set, &si) == -1 ||
-			si.si_code != SI_TIMER))
+			(si.si_code != SI_TIMER && si.si_code != SI_MESGQ)))
 			continue;
-		TIMERS_LOCK(curthread);
-		if (si.si_timerid >= 0 && si.si_timerid < timer_max &&
-		    (tmr = timer_list[si.si_timerid]) != NULL &&
-		    si.si_value.sival_int == tmr->gen) {
-			tmr->flags |= WORKING;
-			TIMERS_UNLOCK(curthread);
-			tn->curtmr = tmr;
-			tmr->function(tmr->value, si.si_overrun);
-			tn->curtmr = NULL;
-			TIMERS_LOCK(curthread);
-			tmr->flags &= ~WORKING;
-			if (tmr->flags & WANTED)
-				_thr_umtx_wake(&tmr->flags, INT_MAX);
+		HASH_LOCK(curthread);
+		obj = rtobj_find(si.si_code, si.si_timerid);
+		if (obj && (obj->rt_gen == si.si_value.sival_int)) {
+			obj->rt_flags |= RT_WORKING;
+			HASH_UNLOCK(curthread);
+			tn->tn_curobj = obj;
+			if (si.si_code == SI_TIMER)
+				timer_dispatch(obj, si.si_overrun);
+			else if (si.si_code == SI_MESGQ)
+				mq_dispatch(obj);
+			tn->tn_curobj = NULL;
+			HASH_LOCK(curthread);
+			obj->rt_flags &= ~RT_WORKING;
+			if (obj->rt_flags & RT_WANTED)
+				_thr_umtx_wake(&obj->rt_flags, INT_MAX);
+			else if (si.si_code == SI_MESGQ) {
+				/*
+				 * mq_notify is oneshot event, should remove
+				 * atomatically by the thread.
+				 */
+				rtobj_delete_obj(obj);
+			}
 		}
-		TIMERS_UNLOCK(curthread);
+		HASH_UNLOCK(curthread);
 	}
 	THR_CLEANUP_POP(curthread, 0);
 	return (0);