diff --git a/src/svm/message_queue.c b/src/svm/message_queue.c
index 0ebce70..fdf9293 100644
--- a/src/svm/message_queue.c
+++ b/src/svm/message_queue.c
@@ -16,7 +16,9 @@
 #include <svm/message_queue.h>
 #include <vppinfra/mem.h>
 #include <vppinfra/format.h>
+#include <vppinfra/time.h>
 #include <sys/eventfd.h>
+#include <sys/socket.h>
 
 static inline svm_msg_q_ring_t *
 svm_msg_q_ring_inline (svm_msg_q_t * mq, u32 ring_index)
@@ -37,19 +39,51 @@
   return (ring->shr->data + elt_index * ring->elsize);
 }
 
+static void
+svm_msg_q_init_mutex (svm_msg_q_shared_queue_t *sq)
+{
+  pthread_mutexattr_t attr;
+  pthread_condattr_t cattr;
+
+  clib_memset (&attr, 0, sizeof (attr));
+  clib_memset (&cattr, 0, sizeof (cattr));
+
+  if (pthread_mutexattr_init (&attr))
+    clib_unix_warning ("mutexattr_init");
+  if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED))
+    clib_unix_warning ("pthread_mutexattr_setpshared");
+  if (pthread_mutexattr_setrobust (&attr, PTHREAD_MUTEX_ROBUST))
+    clib_unix_warning ("setrobust");
+  if (pthread_mutex_init (&sq->mutex, &attr))
+    clib_unix_warning ("mutex_init");
+  if (pthread_mutexattr_destroy (&attr))
+    clib_unix_warning ("mutexattr_destroy");
+  if (pthread_condattr_init (&cattr))
+    clib_unix_warning ("condattr_init");
+  if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED))
+    clib_unix_warning ("condattr_setpshared");
+  if (pthread_cond_init (&sq->condvar, &cattr))
+    clib_unix_warning ("cond_init1");
+  if (pthread_condattr_destroy (&cattr))
+    clib_unix_warning ("cond_init2");
+}
+
 svm_msg_q_shared_t *
 svm_msg_q_init (void *base, svm_msg_q_cfg_t *cfg)
 {
   svm_msg_q_ring_shared_t *ring;
+  svm_msg_q_shared_queue_t *sq;
   svm_msg_q_shared_t *smq;
   u32 q_sz, offset;
   int i;
 
-  q_sz = sizeof (svm_queue_t) + cfg->q_nitems * sizeof (svm_msg_q_msg_t);
+  q_sz = sizeof (*sq) + cfg->q_nitems * sizeof (svm_msg_q_msg_t);
 
   smq = (svm_msg_q_shared_t *) base;
-  svm_queue_init (&smq->q, cfg->q_nitems, sizeof (svm_msg_q_msg_t));
-  smq->q->consumer_pid = cfg->consumer_pid;
+  sq = smq->q;
+  clib_memset (sq, 0, sizeof (*sq));
+  sq->elsize = sizeof (svm_msg_q_msg_t);
+  sq->maxsize = cfg->q_nitems;
   smq->n_rings = cfg->n_rings;
   ring = (void *) ((u8 *) smq->q + q_sz);
   for (i = 0; i < cfg->n_rings; i++)
@@ -61,6 +95,8 @@
       ring = (void *) ((u8 *) ring + offset);
     }
 
+  svm_msg_q_init_mutex (sq);
+
   return smq;
 }
 
@@ -83,7 +119,8 @@
       rings_sz += (uword) ring_cfg->nitems * ring_cfg->elsize;
     }
 
-  q_sz = sizeof (svm_queue_t) + cfg->q_nitems * sizeof (svm_msg_q_msg_t);
+  q_sz = sizeof (svm_msg_q_shared_queue_t) +
+	 cfg->q_nitems * sizeof (svm_msg_q_msg_t);
   mq_sz = sizeof (svm_msg_q_shared_t) + q_sz + rings_sz;
 
   return mq_sz;
@@ -111,10 +148,12 @@
   u32 i, n_rings, q_sz, offset;
 
   smq = (svm_msg_q_shared_t *) smq_base;
-  mq->q = smq->q;
+  mq->q.shr = smq->q;
+  mq->q.evtfd = -1;
   n_rings = smq->n_rings;
   vec_validate (mq->rings, n_rings - 1);
-  q_sz = sizeof (svm_queue_t) + mq->q->maxsize * sizeof (svm_msg_q_msg_t);
+  q_sz = sizeof (svm_msg_q_shared_queue_t) +
+	 mq->q.shr->maxsize * sizeof (svm_msg_q_msg_t);
   ring = (void *) ((u8 *) smq->q + q_sz);
   for (i = 0; i < n_rings; i++)
     {
@@ -129,10 +168,31 @@
 void
 svm_msg_q_free (svm_msg_q_t * mq)
 {
-  svm_queue_free (mq->q);
+  clib_mem_free (mq->q.shr);
   clib_mem_free (mq);
 }
 
+static void
+svm_msg_q_send_signal (svm_msg_q_t *mq)
+{
+  if (mq->q.evtfd == -1)
+    {
+      (void) pthread_cond_broadcast (&mq->q.shr->condvar);
+    }
+  else
+    {
+      int __clib_unused rv;
+      u64 data = 1;
+
+      if (mq->q.evtfd < 0)
+	return;
+
+      rv = write (mq->q.evtfd, &data, sizeof (data));
+      if (PREDICT_FALSE (rv < 0))
+	clib_unix_warning ("signal write on %d returned %d", mq->q.evtfd, rv);
+    }
+}
+
 svm_msg_q_msg_t
 svm_msg_q_alloc_msg_w_ring (svm_msg_q_t * mq, u32 ring_index)
 {
@@ -147,7 +207,7 @@
   msg.ring_index = ring - mq->rings;
   msg.elt_index = sr->tail;
   sr->tail = (sr->tail + 1) % ring->nitems;
-  clib_atomic_fetch_add (&sr->cursize, 1);
+  clib_atomic_fetch_add_rel (&sr->cursize, 1);
   return msg;
 }
 
@@ -193,7 +253,7 @@
     msg.ring_index = ring - mq->rings;
     msg.elt_index = sr->tail;
     sr->tail = (sr->tail + 1) % ring->nitems;
-    clib_atomic_fetch_add (&sr->cursize, 1);
+    clib_atomic_fetch_add_rel (&sr->cursize, 1);
     break;
   }
   return msg;
@@ -228,10 +288,10 @@
     }
 
   need_signal = sr->cursize == ring->nitems;
-  clib_atomic_fetch_sub (&sr->cursize, 1);
+  clib_atomic_fetch_sub_rel (&sr->cursize, 1);
 
   if (PREDICT_FALSE (need_signal))
-    svm_queue_send_signal (mq->q, 0);
+    svm_msg_q_send_signal (mq);
 }
 
 static int
@@ -257,71 +317,216 @@
   return (dist1 < dist2);
 }
 
+static void
+svm_msg_q_add_raw (svm_msg_q_t *mq, u8 *elem)
+{
+  svm_msg_q_shared_queue_t *sq = mq->q.shr;
+  i8 *tailp;
+  u32 sz;
+
+  tailp = (i8 *) (&sq->data[0] + sq->elsize * sq->tail);
+  clib_memcpy_fast (tailp, elem, sq->elsize);
+
+  sq->tail = (sq->tail + 1) % sq->maxsize;
+
+  sz = clib_atomic_fetch_add_rel (&sq->cursize, 1);
+  if (!sz)
+    svm_msg_q_send_signal (mq);
+}
+
 int
 svm_msg_q_add (svm_msg_q_t * mq, svm_msg_q_msg_t * msg, int nowait)
 {
   ASSERT (svm_msq_q_msg_is_valid (mq, msg));
-  return svm_queue_add (mq->q, (u8 *) msg, nowait);
+
+  if (nowait)
+    {
+      /* zero on success */
+      if (svm_msg_q_try_lock (mq))
+	{
+	  return (-1);
+	}
+    }
+  else
+    svm_msg_q_lock (mq);
+
+  if (PREDICT_FALSE (svm_msg_q_is_full (mq)))
+    {
+      if (nowait)
+	return (-2);
+      while (svm_msg_q_is_full (mq))
+	svm_msg_q_wait (mq);
+    }
+
+  svm_msg_q_add_raw (mq, (u8 *) msg);
+
+  svm_msg_q_unlock (mq);
+
+  return 0;
 }
 
 void
 svm_msg_q_add_and_unlock (svm_msg_q_t * mq, svm_msg_q_msg_t * msg)
 {
   ASSERT (svm_msq_q_msg_is_valid (mq, msg));
-  svm_queue_add_raw (mq->q, (u8 *) msg);
+  svm_msg_q_add_raw (mq, (u8 *) msg);
   svm_msg_q_unlock (mq);
 }
 
+static int
+svm_msg_q_sub_raw (svm_msg_q_t *mq, u8 *elem)
+{
+  svm_msg_q_shared_queue_t *sq = mq->q.shr;
+  i8 *headp;
+  u32 sz;
+
+  ASSERT (!svm_msg_q_is_empty (mq));
+
+  headp = (i8 *) (&sq->data[0] + sq->elsize * sq->head);
+  clib_memcpy_fast (elem, headp, sq->elsize);
+
+  sq->head = (sq->head + 1) % sq->maxsize;
+
+  sz = clib_atomic_fetch_sub_rel (&sq->cursize, 1);
+  if (PREDICT_FALSE (sz == sq->maxsize))
+    svm_msg_q_send_signal (mq);
+
+  return 0;
+}
+
 int
 svm_msg_q_sub (svm_msg_q_t * mq, svm_msg_q_msg_t * msg,
 	       svm_q_conditional_wait_t cond, u32 time)
 {
-  return svm_queue_sub (mq->q, (u8 *) msg, cond, time);
+  int rc = 0;
+
+  if (cond == SVM_Q_NOWAIT)
+    {
+      /* zero on success */
+      if (svm_msg_q_try_lock (mq))
+	{
+	  return (-1);
+	}
+    }
+  else
+    svm_msg_q_lock (mq);
+
+  if (PREDICT_FALSE (svm_msg_q_is_empty (mq)))
+    {
+      if (cond == SVM_Q_NOWAIT)
+	{
+	  svm_msg_q_unlock (mq);
+	  return (-2);
+	}
+      else if (cond == SVM_Q_TIMEDWAIT)
+	{
+	  while (svm_msg_q_is_empty (mq) && rc == 0)
+	    rc = svm_msg_q_timedwait (mq, time);
+
+	  if (rc == ETIMEDOUT)
+	    {
+	      svm_msg_q_unlock (mq);
+	      return ETIMEDOUT;
+	    }
+	}
+      else
+	{
+	  while (svm_msg_q_is_empty (mq))
+	    svm_msg_q_wait (mq);
+	}
+    }
+
+  svm_msg_q_sub_raw (mq, (u8 *) msg);
+
+  svm_msg_q_unlock (mq);
+
+  return 0;
 }
 
 void
-svm_msg_q_sub_w_lock (svm_msg_q_t * mq, svm_msg_q_msg_t * msg)
+svm_msg_q_sub_w_lock (svm_msg_q_t *mq, svm_msg_q_msg_t *msg)
 {
-  svm_queue_sub_raw (mq->q, (u8 *) msg);
+  svm_msg_q_sub_raw (mq, (u8 *) msg);
 }
 
 void
-svm_msg_q_set_consumer_eventfd (svm_msg_q_t * mq, int fd)
+svm_msg_q_set_eventfd (svm_msg_q_t *mq, int fd)
 {
-  mq->q->consumer_evtfd = fd;
-}
-
-void
-svm_msg_q_set_producer_eventfd (svm_msg_q_t * mq, int fd)
-{
-  mq->q->producer_evtfd = fd;
+  mq->q.evtfd = fd;
 }
 
 int
-svm_msg_q_alloc_consumer_eventfd (svm_msg_q_t * mq)
+svm_msg_q_alloc_eventfd (svm_msg_q_t *mq)
 {
   int fd;
   if ((fd = eventfd (0, EFD_NONBLOCK)) < 0)
     return -1;
-  svm_msg_q_set_consumer_eventfd (mq, fd);
+  svm_msg_q_set_eventfd (mq, fd);
   return 0;
 }
 
-int
-svm_msg_q_alloc_producer_eventfd (svm_msg_q_t * mq)
+void
+svm_msg_q_wait (svm_msg_q_t *mq)
 {
-  int fd;
-  if ((fd = eventfd (0, EFD_NONBLOCK)) < 0)
-    return -1;
-  svm_msg_q_set_producer_eventfd (mq, fd);
-  return 0;
+  if (mq->q.evtfd == -1)
+    {
+      pthread_cond_wait (&mq->q.shr->condvar, &mq->q.shr->mutex);
+    }
+  else
+    {
+      u64 buf;
+      int rv;
+
+      svm_msg_q_unlock (mq);
+      while ((rv = read (mq->q.evtfd, &buf, sizeof (buf))) < 0)
+	{
+	  if (errno != EAGAIN)
+	    {
+	      clib_unix_warning ("read error");
+	      return;
+	    }
+	}
+      svm_msg_q_lock (mq);
+    }
+}
+
+int
+svm_msg_q_timedwait (svm_msg_q_t *mq, double timeout)
+{
+  if (mq->q.evtfd == -1)
+    {
+      struct timespec ts;
+      ts.tv_sec = unix_time_now () + (u32) timeout;
+      ts.tv_nsec = (timeout - (u32) timeout) * 1e9;
+      return pthread_cond_timedwait (&mq->q.shr->condvar, &mq->q.shr->mutex,
+				     &ts);
+    }
+  else
+    {
+      struct timeval tv;
+      u64 buf;
+      int rv;
+
+      tv.tv_sec = (u64) timeout;
+      tv.tv_usec = ((u64) timeout - (u64) timeout) * 1e9;
+      setsockopt (mq->q.evtfd, SOL_SOCKET, SO_RCVTIMEO, (const char *) &tv,
+		  sizeof tv);
+
+      svm_msg_q_unlock (mq);
+      rv = read (mq->q.evtfd, &buf, sizeof (buf));
+      if (rv < 0)
+	clib_warning ("read %u", errno);
+      svm_msg_q_lock (mq);
+
+      return rv < 0 ? errno : 0;
+    }
 }
 
 u8 *
 format_svm_msg_q (u8 * s, va_list * args)
 {
   svm_msg_q_t *mq = va_arg (*args, svm_msg_q_t *);
-  s = format (s, " [Q:%d/%d]", mq->q->cursize, mq->q->maxsize);
+  s = format (s, " [Q:%d/%d]", mq->q.shr->cursize, mq->q.shr->maxsize);
   for (u32 i = 0; i < vec_len (mq->rings); i++)
     {
       s = format (s, " [R%d:%d/%d]", i, mq->rings[i].shr->cursize,