api: refactor vlibmemory

- separate client/server code for both memory and socket apis
- separate memory api code from generic vlib api code
- move unix_shared_memory_fifo to svm and rename to svm_fifo_t
- overall declutter

Change-Id: I90cdd98ff74d0787d58825b914b0f1eafcfa4dc2
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 905 insertions, 0 deletions

diff --git a/src/vlibmemory/memory_api.c b/src/vlibmemory/memory_api.c
new file mode 100644
index 00000000000..d049a625015
--- /dev/null
+++ b/src/vlibmemory/memory_api.c
@@ -0,0 +1,905 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+#include <signal.h>
+
+#include <vlib/vlib.h>
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibmemory/memory_api.h>
+
+#include <vlibmemory/vl_memory_msg_enum.h>	/* enumerate all vlib messages */
+
+#define vl_typedefs		/* define message structures */
+#include <vlibmemory/vl_memory_api_h.h>
+#undef vl_typedefs
+
+/* instantiate all the print functions we know about */
+#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
+#define vl_printfun
+#include <vlibmemory/vl_memory_api_h.h>
+#undef vl_printfun
+
+/* instantiate all the endian swap functions we know about */
+#define vl_endianfun
+#include <vlibmemory/vl_memory_api_h.h>
+#undef vl_endianfun
+
+static inline void *
+vl_api_memclnt_create_t_print (vl_api_memclnt_create_t * a, void *handle)
+{
+  vl_print (handle, "vl_api_memclnt_create_t:\n");
+  vl_print (handle, "name: %s\n", a->name);
+  vl_print (handle, "input_queue: 0x%wx\n", a->input_queue);
+  vl_print (handle, "context: %u\n", (unsigned) a->context);
+  vl_print (handle, "ctx_quota: %ld\n", (long) a->ctx_quota);
+  return handle;
+}
+
+static inline void *
+vl_api_memclnt_delete_t_print (vl_api_memclnt_delete_t * a, void *handle)
+{
+  vl_print (handle, "vl_api_memclnt_delete_t:\n");
+  vl_print (handle, "index: %u\n", (unsigned) a->index);
+  vl_print (handle, "handle: 0x%wx\n", a->handle);
+  return handle;
+}
+
+volatile int **vl_api_queue_cursizes;
+
+static void
+memclnt_queue_callback (vlib_main_t * vm)
+{
+  int i;
+  api_main_t *am = &api_main;
+
+  if (PREDICT_FALSE (vec_len (vl_api_queue_cursizes) !=
+		     1 + vec_len (am->vlib_private_rps)))
+    {
+      vl_shmem_hdr_t *shmem_hdr = am->shmem_hdr;
+      svm_queue_t *q;
+
+      if (shmem_hdr == 0)
+	return;
+
+      q = shmem_hdr->vl_input_queue;
+      if (q == 0)
+	return;
+
+      vec_add1 (vl_api_queue_cursizes, &q->cursize);
+
+      for (i = 0; i < vec_len (am->vlib_private_rps); i++)
+	{
+	  svm_region_t *vlib_rp = am->vlib_private_rps[i];
+
+	  shmem_hdr = (void *) vlib_rp->user_ctx;
+	  q = shmem_hdr->vl_input_queue;
+	  vec_add1 (vl_api_queue_cursizes, &q->cursize);
+	}
+    }
+
+  for (i = 0; i < vec_len (vl_api_queue_cursizes); i++)
+    {
+      if (*vl_api_queue_cursizes[i])
+	{
+	  vm->queue_signal_pending = 1;
+	  vm->api_queue_nonempty = 1;
+	  vlib_process_signal_event (vm, vl_api_clnt_node.index,
+				     /* event_type */ QUEUE_SIGNAL_EVENT,
+				     /* event_data */ 0);
+	  break;
+	}
+    }
+}
+
+/*
+ * vl_api_memclnt_create_internal
+ */
+u32
+vl_api_memclnt_create_internal (char *name, svm_queue_t * q)
+{
+  vl_api_registration_t **regpp;
+  vl_api_registration_t *regp;
+  svm_region_t *svm;
+  void *oldheap;
+  api_main_t *am = &api_main;
+
+  ASSERT (vlib_get_thread_index () == 0);
+  pool_get (am->vl_clients, regpp);
+
+  svm = am->vlib_rp;
+
+  pthread_mutex_lock (&svm->mutex);
+  oldheap = svm_push_data_heap (svm);
+  *regpp = clib_mem_alloc (sizeof (vl_api_registration_t));
+
+  regp = *regpp;
+  memset (regp, 0, sizeof (*regp));
+  regp->registration_type = REGISTRATION_TYPE_SHMEM;
+  regp->vl_api_registration_pool_index = regpp - am->vl_clients;
+  regp->vlib_rp = svm;
+  regp->shmem_hdr = am->shmem_hdr;
+
+  regp->vl_input_queue = q;
+  regp->name = format (0, "%s%c", name, 0);
+
+  pthread_mutex_unlock (&svm->mutex);
+  svm_pop_heap (oldheap);
+  return vl_msg_api_handle_from_index_and_epoch
+    (regp->vl_api_registration_pool_index,
+     am->shmem_hdr->application_restarts);
+}
+
+/*
+ * vl_api_memclnt_create_t_handler
+ */
+void
+vl_api_memclnt_create_t_handler (vl_api_memclnt_create_t * mp)
+{
+  vl_api_registration_t **regpp;
+  vl_api_registration_t *regp;
+  vl_api_memclnt_create_reply_t *rp;
+  svm_region_t *svm;
+  svm_queue_t *q;
+  int rv = 0;
+  void *oldheap;
+  api_main_t *am = &api_main;
+
+  /*
+   * This is tortured. Maintain a vlib-address-space private
+   * pool of client registrations. We use the shared-memory virtual
+   * address of client structure as a handle, to allow direct
+   * manipulation of context quota vbls from the client library.
+   *
+   * This scheme causes trouble w/ API message trace replay, since
+   * some random VA from clib_mem_alloc() certainly won't
+   * occur in the Linux sim. The (very) few places
+   * that care need to use the pool index.
+   *
+   * Putting the registration object(s) into a pool in shared memory and
+   * using the pool index as a handle seems like a great idea.
+   * Unfortunately, each and every reference to that pool would need
+   * to be protected by a mutex:
+   *
+   *     Client                      VLIB
+   *     ------                      ----
+   *     convert pool index to
+   *     pointer.
+   *     <deschedule>
+   *                                 expand pool
+   *                                 <deschedule>
+   *     kaboom!
+   */
+
+  pool_get (am->vl_clients, regpp);
+
+  svm = am->vlib_rp;
+
+  pthread_mutex_lock (&svm->mutex);
+  oldheap = svm_push_data_heap (svm);
+  *regpp = clib_mem_alloc (sizeof (vl_api_registration_t));
+
+  regp = *regpp;
+  memset (regp, 0, sizeof (*regp));
+  regp->registration_type = REGISTRATION_TYPE_SHMEM;
+  regp->vl_api_registration_pool_index = regpp - am->vl_clients;
+  regp->vlib_rp = svm;
+  regp->shmem_hdr = am->shmem_hdr;
+
+  q = regp->vl_input_queue = (svm_queue_t *) (uword) mp->input_queue;
+
+  regp->name = format (0, "%s", mp->name);
+  vec_add1 (regp->name, 0);
+
+  if (am->serialized_message_table_in_shmem == 0)
+    am->serialized_message_table_in_shmem =
+      vl_api_serialize_message_table (am, 0);
+
+  pthread_mutex_unlock (&svm->mutex);
+  svm_pop_heap (oldheap);
+
+  rp = vl_msg_api_alloc (sizeof (*rp));
+  rp->_vl_msg_id = ntohs (VL_API_MEMCLNT_CREATE_REPLY);
+  rp->handle = (uword) regp;
+  rp->index = vl_msg_api_handle_from_index_and_epoch
+    (regp->vl_api_registration_pool_index,
+     am->shmem_hdr->application_restarts);
+  rp->context = mp->context;
+  rp->response = ntohl (rv);
+  rp->message_table =
+    pointer_to_uword (am->serialized_message_table_in_shmem);
+
+  vl_msg_api_send_shmem (q, (u8 *) & rp);
+}
+
+int
+vl_api_call_reaper_functions (u32 client_index)
+{
+  clib_error_t *error = 0;
+  _vl_msg_api_function_list_elt_t *i;
+
+  i = api_main.reaper_function_registrations;
+  while (i)
+    {
+      error = i->f (client_index);
+      if (error)
+	clib_error_report (error);
+      i = i->next_init_function;
+    }
+  return 0;
+}
+
+/*
+ * vl_api_memclnt_delete_t_handler
+ */
+void
+vl_api_memclnt_delete_t_handler (vl_api_memclnt_delete_t * mp)
+{
+  vl_api_registration_t **regpp;
+  vl_api_registration_t *regp;
+  vl_api_memclnt_delete_reply_t *rp;
+  svm_region_t *svm;
+  void *oldheap;
+  api_main_t *am = &api_main;
+  u32 handle, client_index, epoch;
+
+  handle = mp->index;
+
+  if (vl_api_call_reaper_functions (handle))
+    return;
+
+  epoch = vl_msg_api_handle_get_epoch (handle);
+  client_index = vl_msg_api_handle_get_index (handle);
+
+  if (epoch != (am->shmem_hdr->application_restarts & VL_API_EPOCH_MASK))
+    {
+      clib_warning
+	("Stale clnt delete index %d old epoch %d cur epoch %d",
+	 client_index, epoch,
+	 (am->shmem_hdr->application_restarts & VL_API_EPOCH_MASK));
+      return;
+    }
+
+  regpp = am->vl_clients + client_index;
+
+  if (!pool_is_free (am->vl_clients, regpp))
+    {
+      int i;
+      regp = *regpp;
+      svm = am->vlib_rp;
+      int private_registration = 0;
+
+      /*
+       * Note: the API message handling path will set am->vlib_rp
+       * as appropriate for pairwise / private memory segments
+       */
+      rp = vl_msg_api_alloc (sizeof (*rp));
+      rp->_vl_msg_id = ntohs (VL_API_MEMCLNT_DELETE_REPLY);
+      rp->handle = mp->handle;
+      rp->response = 1;
+
+      vl_msg_api_send_shmem (regp->vl_input_queue, (u8 *) & rp);
+
+      if (client_index != regp->vl_api_registration_pool_index)
+	{
+	  clib_warning ("mismatch client_index %d pool_index %d",
+			client_index, regp->vl_api_registration_pool_index);
+	  vl_msg_api_free (rp);
+	  return;
+	}
+
+      /* For horizontal scaling, add a hash table... */
+      for (i = 0; i < vec_len (am->vlib_private_rps); i++)
+	{
+	  /* Is this a pairwise / private API segment? */
+	  if (am->vlib_private_rps[i] == svm)
+	    {
+	      /* Note: account for the memfd header page */
+	      u64 virtual_base = svm->virtual_base - MMAP_PAGESIZE;
+	      u64 virtual_size = svm->virtual_size + MMAP_PAGESIZE;
+
+	      /*
+	       * Kill the registration pool element before we make
+	       * the index vanish forever
+	       */
+	      pool_put_index (am->vl_clients,
+			      regp->vl_api_registration_pool_index);
+
+	      vec_delete (am->vlib_private_rps, 1, i);
+	      /* Kill it, accounting for the memfd header page */
+	      if (munmap ((void *) virtual_base, virtual_size) < 0)
+		clib_unix_warning ("munmap");
+	      /* Reset the queue-length-address cache */
+	      vec_reset_length (vl_api_queue_cursizes);
+	      private_registration = 1;
+	      break;
+	    }
+	}
+
+      /* No dangling references, please */
+      *regpp = 0;
+
+      if (private_registration == 0)
+	{
+	  pool_put_index (am->vl_clients,
+			  regp->vl_api_registration_pool_index);
+	  pthread_mutex_lock (&svm->mutex);
+	  oldheap = svm_push_data_heap (svm);
+	  /* Poison the old registration */
+	  memset (regp, 0xF1, sizeof (*regp));
+	  clib_mem_free (regp);
+	  pthread_mutex_unlock (&svm->mutex);
+	  svm_pop_heap (oldheap);
+	  /*
+	   * These messages must be freed manually, since they're set up
+	   * as "bounce" messages. In the private_registration == 1 case,
+	   * we kill the shared-memory segment which contains the message
+	   * with munmap.
+	   */
+	  vl_msg_api_free (mp);
+	}
+    }
+  else
+    {
+      clib_warning ("unknown client ID %d", mp->index);
+    }
+}
+
+/**
+ * client answered a ping, stave off the grim reaper...
+ */
+void
+  vl_api_memclnt_keepalive_reply_t_handler
+  (vl_api_memclnt_keepalive_reply_t * mp)
+{
+  vl_api_registration_t *regp;
+  vlib_main_t *vm = vlib_get_main ();
+
+  regp = vl_api_client_index_to_registration (mp->context);
+  if (regp)
+    {
+      regp->last_heard = vlib_time_now (vm);
+      regp->unanswered_pings = 0;
+    }
+  else
+    clib_warning ("BUG: anonymous memclnt_keepalive_reply");
+}
+
+/**
+ * We can send ourselves these messages if someone uses the
+ * builtin binary api test tool...
+ */
+static void
+vl_api_memclnt_keepalive_t_handler (vl_api_memclnt_keepalive_t * mp)
+{
+  vl_api_memclnt_keepalive_reply_t *rmp;
+  api_main_t *am;
+  vl_shmem_hdr_t *shmem_hdr;
+
+  am = &api_main;
+  shmem_hdr = am->shmem_hdr;
+
+  rmp = vl_msg_api_alloc_as_if_client (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_MEMCLNT_KEEPALIVE_REPLY);
+  rmp->context = mp->context;
+  vl_msg_api_send_shmem (shmem_hdr->vl_input_queue, (u8 *) & rmp);
+}
+
+#define foreach_vlib_api_msg                            \
+_(MEMCLNT_CREATE, memclnt_create)                       \
+_(MEMCLNT_DELETE, memclnt_delete)                       \
+_(MEMCLNT_KEEPALIVE, memclnt_keepalive)                 \
+_(MEMCLNT_KEEPALIVE_REPLY, memclnt_keepalive_reply)	\
+
+/*
+ * memory_api_init
+ */
+int
+vl_mem_api_init (const char *region_name)
+{
+  int rv;
+  api_main_t *am = &api_main;
+  vl_msg_api_msg_config_t cfg;
+  vl_msg_api_msg_config_t *c = &cfg;
+  vl_shmem_hdr_t *shm;
+  vlib_main_t *vm = vlib_get_main ();
+
+  memset (c, 0, sizeof (*c));
+
+  if ((rv = vl_map_shmem (region_name, 1 /* is_vlib */ )) < 0)
+    return rv;
+
+#define _(N,n) do {                                             \
+    c->id = VL_API_##N;                                         \
+    c->name = #n;                                               \
+    c->handler = vl_api_##n##_t_handler;                        \
+    c->cleanup = vl_noop_handler;                               \
+    c->endian = vl_api_##n##_t_endian;                          \
+    c->print = vl_api_##n##_t_print;                            \
+    c->size = sizeof(vl_api_##n##_t);                           \
+    c->traced = 1; /* trace, so these msgs print */             \
+    c->replay = 0; /* don't replay client create/delete msgs */ \
+    c->message_bounce = 0; /* don't bounce this message */	\
+    vl_msg_api_config(c);} while (0);
+
+  foreach_vlib_api_msg;
+#undef _
+
+  /*
+   * special-case freeing of memclnt_delete messages, so we can
+   * simply munmap pairwise / private API segments...
+   */
+  am->message_bounce[VL_API_MEMCLNT_DELETE] = 1;
+  am->is_mp_safe[VL_API_MEMCLNT_KEEPALIVE_REPLY] = 1;
+
+  vlib_set_queue_signal_callback (vm, memclnt_queue_callback);
+
+  shm = am->shmem_hdr;
+  ASSERT (shm && shm->vl_input_queue);
+
+  /* Make a note so we can always find the primary region easily */
+  am->vlib_primary_rp = am->vlib_rp;
+
+  return 0;
+}
+
+static void
+send_memclnt_keepalive (vl_api_registration_t * regp, f64 now)
+{
+  vl_api_memclnt_keepalive_t *mp;
+  svm_queue_t *q;
+  api_main_t *am = &api_main;
+  svm_region_t *save_vlib_rp = am->vlib_rp;
+  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
+
+  q = regp->vl_input_queue;
+
+  /*
+   * If the queue head is moving, assume that the client is processing
+   * messages and skip the ping. This heuristic may fail if the queue
+   * is in the same position as last time, net of wrapping; in which
+   * case, the client will receive a keepalive.
+   */
+  if (regp->last_queue_head != q->head)
+    {
+      regp->last_heard = now;
+      regp->unanswered_pings = 0;
+      regp->last_queue_head = q->head;
+      return;
+    }
+
+  /*
+   * push/pop shared memory segment, so this routine
+   * will work with "normal" as well as "private segment"
+   * memory clients..
+   */
+
+  am->vlib_rp = regp->vlib_rp;
+  am->shmem_hdr = regp->shmem_hdr;
+
+  mp = vl_msg_api_alloc (sizeof (*mp));
+  memset (mp, 0, sizeof (*mp));
+  mp->_vl_msg_id = clib_host_to_net_u16 (VL_API_MEMCLNT_KEEPALIVE);
+  mp->context = mp->client_index =
+    vl_msg_api_handle_from_index_and_epoch
+    (regp->vl_api_registration_pool_index,
+     am->shmem_hdr->application_restarts);
+
+  regp->unanswered_pings++;
+
+  /* Failure-to-send due to a stuffed queue is absolutely expected */
+  if (svm_queue_add (q, (u8 *) & mp, 1 /* nowait */ ))
+    vl_msg_api_free (mp);
+
+  am->vlib_rp = save_vlib_rp;
+  am->shmem_hdr = save_shmem_hdr;
+}
+
+void
+vl_mem_api_dead_client_scan (api_main_t * am, vl_shmem_hdr_t * shm, f64 now)
+{
+  vl_api_registration_t **regpp;
+  vl_api_registration_t *regp;
+  static u32 *dead_indices;
+  static u32 *confused_indices;
+
+  vec_reset_length (dead_indices);
+  vec_reset_length (confused_indices);
+
+  /* *INDENT-OFF* */
+  pool_foreach (regpp, am->vl_clients,
+  ({
+    regp = *regpp;
+    if (regp)
+      {
+        /* If we haven't heard from this client recently... */
+        if (regp->last_heard < (now - 10.0))
+          {
+            if (regp->unanswered_pings == 2)
+              {
+                svm_queue_t *q;
+                q = regp->vl_input_queue;
+                if (kill (q->consumer_pid, 0) >=0)
+                  {
+                    clib_warning ("REAPER: lazy binary API client '%s'",
+                                  regp->name);
+                    regp->unanswered_pings = 0;
+                    regp->last_heard = now;
+                  }
+                else
+                  {
+                    clib_warning ("REAPER: binary API client '%s' died",
+                                  regp->name);
+                    vec_add1(dead_indices, regpp - am->vl_clients);
+                  }
+              }
+            else
+              send_memclnt_keepalive (regp, now);
+          }
+        else
+          regp->unanswered_pings = 0;
+      }
+    else
+      {
+        clib_warning ("NULL client registration index %d",
+                      regpp - am->vl_clients);
+        vec_add1 (confused_indices, regpp - am->vl_clients);
+      }
+  }));
+  /* *INDENT-ON* */
+  /* This should "never happen," but if it does, fix it... */
+  if (PREDICT_FALSE (vec_len (confused_indices) > 0))
+    {
+      int i;
+      for (i = 0; i < vec_len (confused_indices); i++)
+	{
+	  pool_put_index (am->vl_clients, confused_indices[i]);
+	}
+    }
+
+  if (PREDICT_FALSE (vec_len (dead_indices) > 0))
+    {
+      int i;
+      svm_region_t *svm;
+      void *oldheap;
+
+      /* Allow the application to clean up its registrations */
+      for (i = 0; i < vec_len (dead_indices); i++)
+	{
+	  regpp = pool_elt_at_index (am->vl_clients, dead_indices[i]);
+	  if (regpp)
+	    {
+	      u32 handle;
+
+	      handle = vl_msg_api_handle_from_index_and_epoch
+		(dead_indices[i], shm->application_restarts);
+	      (void) vl_api_call_reaper_functions (handle);
+	    }
+	}
+
+      svm = am->vlib_rp;
+      pthread_mutex_lock (&svm->mutex);
+      oldheap = svm_push_data_heap (svm);
+
+      for (i = 0; i < vec_len (dead_indices); i++)
+	{
+	  regpp = pool_elt_at_index (am->vl_clients, dead_indices[i]);
+	  if (regpp)
+	    {
+	      /* Is this a pairwise SVM segment? */
+	      if ((*regpp)->vlib_rp != svm)
+		{
+		  int i;
+		  svm_region_t *dead_rp = (*regpp)->vlib_rp;
+		  /* Note: account for the memfd header page */
+		  u64 virtual_base = dead_rp->virtual_base - MMAP_PAGESIZE;
+		  u64 virtual_size = dead_rp->virtual_size + MMAP_PAGESIZE;
+
+		  /* For horizontal scaling, add a hash table... */
+		  for (i = 0; i < vec_len (am->vlib_private_rps); i++)
+		    if (am->vlib_private_rps[i] == dead_rp)
+		      {
+			vec_delete (am->vlib_private_rps, 1, i);
+			goto found;
+		      }
+		  clib_warning ("private rp %llx AWOL", dead_rp);
+
+		found:
+		  /* Kill it, accounting for the memfd header page */
+		  if (munmap ((void *) virtual_base, virtual_size) < 0)
+		    clib_unix_warning ("munmap");
+		  /* Reset the queue-length-address cache */
+		  vec_reset_length (vl_api_queue_cursizes);
+		}
+	      else
+		{
+		  /* Poison the old registration */
+		  memset (*regpp, 0xF3, sizeof (**regpp));
+		  clib_mem_free (*regpp);
+		}
+	      /* no dangling references, please */
+	      *regpp = 0;
+	    }
+	  else
+	    {
+	      svm_pop_heap (oldheap);
+	      clib_warning ("Duplicate free, client index %d",
+			    regpp - am->vl_clients);
+	      oldheap = svm_push_data_heap (svm);
+	    }
+	}
+
+      svm_client_scan_this_region_nolock (am->vlib_rp);
+
+      pthread_mutex_unlock (&svm->mutex);
+      svm_pop_heap (oldheap);
+      for (i = 0; i < vec_len (dead_indices); i++)
+	pool_put_index (am->vl_clients, dead_indices[i]);
+    }
+}
+
+static inline int
+void_mem_api_handle_msg_i (api_main_t * am, vlib_main_t * vm,
+			   vlib_node_runtime_t * node, svm_queue_t * q)
+{
+  uword mp;
+  if (!svm_queue_sub2 (q, (u8 *) & mp))
+    {
+      vl_msg_api_handler_with_vm_node (am, (void *) mp, vm, node);
+      return 0;
+    }
+  return -1;
+}
+
+int
+vl_mem_api_handle_msg_main (vlib_main_t * vm, vlib_node_runtime_t * node)
+{
+  api_main_t *am = &api_main;
+  return void_mem_api_handle_msg_i (am, vm, node,
+				    am->shmem_hdr->vl_input_queue);
+}
+
+int
+vl_mem_api_handle_msg_private (vlib_main_t * vm, vlib_node_runtime_t * node,
+			       u32 reg_index)
+{
+  api_main_t *am = &api_main;
+  vl_shmem_hdr_t *save_shmem_hdr = am->shmem_hdr;
+  svm_region_t *vlib_rp, *save_vlib_rp = am->vlib_rp;
+  svm_queue_t *q;
+  int rv;
+
+  vlib_rp = am->vlib_rp = am->vlib_private_rps[reg_index];
+
+  am->shmem_hdr = (void *) vlib_rp->user_ctx;
+  q = am->shmem_hdr->vl_input_queue;
+
+  rv = void_mem_api_handle_msg_i (am, vm, node, q);
+
+  am->shmem_hdr = save_shmem_hdr;
+  am->vlib_rp = save_vlib_rp;
+
+  return rv;
+}
+
+vl_api_registration_t *
+vl_mem_api_client_index_to_registration (u32 handle)
+{
+  vl_api_registration_t **regpp;
+  vl_api_registration_t *regp;
+  api_main_t *am = &api_main;
+  u32 index;
+
+  index = vl_msg_api_handle_get_index (handle);
+  if ((am->shmem_hdr->application_restarts & VL_API_EPOCH_MASK)
+      != vl_msg_api_handle_get_epoch (handle))
+    {
+      vl_msg_api_increment_missing_client_counter ();
+      return 0;
+    }
+
+  regpp = am->vl_clients + index;
+
+  if (pool_is_free (am->vl_clients, regpp))
+    {
+      vl_msg_api_increment_missing_client_counter ();
+      return 0;
+    }
+  regp = *regpp;
+  return (regp);
+}
+
+svm_queue_t *
+vl_api_client_index_to_input_queue (u32 index)
+{
+  vl_api_registration_t *regp;
+  api_main_t *am = &api_main;
+
+  /* Special case: vlib trying to send itself a message */
+  if (index == (u32) ~ 0)
+    return (am->shmem_hdr->vl_input_queue);
+
+  regp = vl_mem_api_client_index_to_registration (index);
+  if (!regp)
+    return 0;
+  return (regp->vl_input_queue);
+}
+
+static clib_error_t *
+setup_memclnt_exit (vlib_main_t * vm)
+{
+  atexit (vl_unmap_shmem);
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (setup_memclnt_exit);
+
+u8 *
+format_api_message_rings (u8 * s, va_list * args)
+{
+  api_main_t *am = va_arg (*args, api_main_t *);
+  vl_shmem_hdr_t *shmem_hdr = va_arg (*args, vl_shmem_hdr_t *);
+  int main_segment = va_arg (*args, int);
+  ring_alloc_t *ap;
+  int i;
+
+  if (shmem_hdr == 0)
+    return format (s, "%8s %8s %8s %8s %8s\n",
+		   "Owner", "Size", "Nitems", "Hits", "Misses");
+
+  ap = shmem_hdr->vl_rings;
+
+  for (i = 0; i < vec_len (shmem_hdr->vl_rings); i++)
+    {
+      s = format (s, "%8s %8d %8d %8d %8d\n",
+		  "vlib", ap->size, ap->nitems, ap->hits, ap->misses);
+      ap++;
+    }
+
+  ap = shmem_hdr->client_rings;
+
+  for (i = 0; i < vec_len (shmem_hdr->client_rings); i++)
+    {
+      s = format (s, "%8s %8d %8d %8d %8d\n",
+		  "clnt", ap->size, ap->nitems, ap->hits, ap->misses);
+      ap++;
+    }
+
+  if (main_segment)
+    {
+      s = format (s, "%d ring miss fallback allocations\n", am->ring_misses);
+      s = format
+	(s,
+	 "%d application restarts, %d reclaimed msgs, %d garbage collects\n",
+	 shmem_hdr->application_restarts, shmem_hdr->restart_reclaims,
+	 shmem_hdr->garbage_collects);
+    }
+  return s;
+}
+
+static clib_error_t *
+vl_api_ring_command (vlib_main_t * vm,
+		     unformat_input_t * input, vlib_cli_command_t * cli_cmd)
+{
+  int i;
+  vl_shmem_hdr_t *shmem_hdr;
+  api_main_t *am = &api_main;
+
+  /* First, dump the primary region rings.. */
+
+  if (am->vlib_primary_rp == 0 || am->vlib_primary_rp->user_ctx == 0)
+    {
+      vlib_cli_output (vm, "Shared memory segment not initialized...\n");
+      return 0;
+    }
+
+  shmem_hdr = (void *) am->vlib_primary_rp->user_ctx;
+
+  vlib_cli_output (vm, "Main API segment rings:");
+
+  vlib_cli_output (vm, "%U", format_api_message_rings, am,
+		   0 /* print header */ , 0 /* notused */ );
+
+  vlib_cli_output (vm, "%U", format_api_message_rings, am,
+		   shmem_hdr, 1 /* main segment */ );
+
+  for (i = 0; i < vec_len (am->vlib_private_rps); i++)
+    {
+      svm_region_t *vlib_rp = am->vlib_private_rps[i];
+      shmem_hdr = (void *) vlib_rp->user_ctx;
+      vl_api_registration_t **regpp;
+      vl_api_registration_t *regp = 0;
+
+      /* For horizontal scaling, add a hash table... */
+      /* *INDENT-OFF* */
+      pool_foreach (regpp, am->vl_clients,
+      ({
+        regp = *regpp;
+        if (regp && regp->vlib_rp == vlib_rp)
+          {
+            vlib_cli_output (vm, "%s segment rings:", regp->name);
+            goto found;
+          }
+      }));
+      vlib_cli_output (vm, "regp %llx not found?", regp);
+      continue;
+      /* *INDENT-ON* */
+    found:
+      vlib_cli_output (vm, "%U", format_api_message_rings, am,
+		       0 /* print header */ , 0 /* notused */ );
+      vlib_cli_output (vm, "%U", format_api_message_rings, am,
+		       shmem_hdr, 0 /* main segment */ );
+    }
+
+  return 0;
+}
+
+/*?
+ * Display binary api message allocation ring statistics
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (cli_show_api_ring_command, static) =
+{
+  .path = "show api ring-stats",
+  .short_help = "Message ring statistics",
+  .function = vl_api_ring_command,
+};
+/* *INDENT-ON* */
+
+clib_error_t *
+vlibmemory_init (vlib_main_t * vm)
+{
+  api_main_t *am = &api_main;
+  svm_map_region_args_t _a, *a = &_a;
+  clib_error_t *error;
+
+  memset (a, 0, sizeof (*a));
+  a->root_path = am->root_path;
+  a->name = SVM_GLOBAL_REGION_NAME;
+  a->baseva = (am->global_baseva != 0) ?
+    am->global_baseva : SVM_GLOBAL_REGION_BASEVA;
+  a->size = (am->global_size != 0) ? am->global_size : SVM_GLOBAL_REGION_SIZE;
+  a->flags = SVM_FLAGS_NODATA;
+  a->uid = am->api_uid;
+  a->gid = am->api_gid;
+  a->pvt_heap_size =
+    (am->global_pvt_heap_size !=
+     0) ? am->global_pvt_heap_size : SVM_PVT_MHEAP_SIZE;
+
+  svm_region_init_args (a);
+
+  error = vlib_call_init_function (vm, vlibsocket_init);
+
+  return error;
+}
+
+VLIB_INIT_FUNCTION (vlibmemory_init);
+
+void
+vl_set_memory_region_name (const char *name)
+{
+  api_main_t *am = &api_main;
+  am->region_name = name;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */