paragraph for gnunet devs that don't know how to use the web
[oweals/gnunet.git] / src / testbed / testbed_api.c
index 564637caaeb157a28ce037d00a4f6d1cf53853d5..a643aacdd4ab34ad9565a83ef2d239ba652741f9 100644 (file)
@@ -1,21 +1,19 @@
 /*
       This file is part of GNUnet
-      (C) 2008--2013 Christian Grothoff (and other contributing authors)
+      Copyright (C) 2008--2013 GNUnet e.V.
 
-      GNUnet is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published
-      by the Free Software Foundation; either version 3, or (at your
-      option) any later version.
+      GNUnet is free software: you can redistribute it and/or modify it
+      under the terms of the GNU Affero General Public License as published
+      by the Free Software Foundation, either version 3 of the License,
+      or (at your option) any later version.
 
       GNUnet is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-      General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with GNUnet; see the file COPYING.  If not, write to the
-      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-      Boston, MA 02111-1307, USA.
+      Affero General Public License for more details.
+     
+      You should have received a copy of the GNU Affero General Public License
+      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
@@ -26,8 +24,6 @@
  * @author Christian Grothoff
  * @author Sree Harsha Totakura
  */
-
-
 #include "platform.h"
 #include "gnunet_testbed_service.h"
 #include "gnunet_core_service.h"
 #define TIMEOUT_REL TIME_REL_SECS(1)
 
 
-/**
- * The message queue for sending messages to the controller service
- */
-struct MessageQueue
-{
-  /**
-   * The message to be sent
-   */
-  struct GNUNET_MessageHeader *msg;
-
-  /**
-   * next pointer for DLL
-   */
-  struct MessageQueue *next;
-
-  /**
-   * prev pointer for DLL
-   */
-  struct MessageQueue *prev;
-};
-
-
 /**
  * Context data for forwarded Operation
  */
@@ -99,7 +73,7 @@ struct ForwardedOperationData
   /**
    * The callback to call when reply is available
    */
-  GNUNET_CLIENT_MessageHandler cc;
+  GNUNET_MQ_MessageCallback cc;
 
   /**
    * The closure for the above callback
@@ -200,9 +174,9 @@ exop_insert (struct GNUNET_TESTBED_Operation *op)
 {
   struct ExpireOperationEntry *entry;
 
-  entry = GNUNET_malloc (sizeof (struct ExpireOperationEntry));
+  entry = GNUNET_new (struct ExpireOperationEntry);
   entry->op = op;
-  GNUNET_CONTAINER_DLL_insert_tail (exop_head, exop_tail, entry);  
+  GNUNET_CONTAINER_DLL_insert_tail (exop_head, exop_tail, entry);
 }
 
 
@@ -241,7 +215,9 @@ exop_check (const struct GNUNET_TESTBED_Operation *const op)
   while (NULL != entry)
   {
     entry2 = entry->next;
-    GNUNET_CONTAINER_DLL_remove (exop_head, exop_tail, entry);
+    GNUNET_CONTAINER_DLL_remove (exop_head,
+                                 exop_tail,
+                                 entry);
     GNUNET_free (entry);
     entry = entry2;
   }
@@ -249,25 +225,192 @@ exop_check (const struct GNUNET_TESTBED_Operation *const op)
 }
 
 
+/**
+ * Context information to be used while searching for operation contexts
+ */
+struct SearchContext
+{
+  /**
+   * The result of the search
+   */
+  struct OperationContext *opc;
+
+  /**
+   * The id of the operation context we are searching for
+   */
+  uint64_t id;
+};
+
+
+/**
+ * Search iterator for searching an operation context
+ *
+ * @param cls the serach context
+ * @param key current key code
+ * @param value value in the hash map
+ * @return #GNUNET_YES if we should continue to iterate,
+ *         #GNUNET_NO if not.
+ */
+static int
+opc_search_iterator (void *cls,
+                     uint32_t key,
+                     void *value)
+{
+  struct SearchContext *sc = cls;
+  struct OperationContext *opc = value;
+
+  GNUNET_assert (NULL != opc);
+  GNUNET_assert (NULL == sc->opc);
+  if (opc->id != sc->id)
+    return GNUNET_YES;
+  sc->opc = opc;
+  return GNUNET_NO;
+}
+
+
 /**
  * Returns the operation context with the given id if found in the Operation
  * context queues of the controller
  *
- * @param c the controller whose queues are searched
+ * @param c the controller whose operation context map is searched
  * @param id the id which has to be checked
  * @return the matching operation context; NULL if no match found
  */
 static struct OperationContext *
 find_opc (const struct GNUNET_TESTBED_Controller *c, const uint64_t id)
 {
-  struct OperationContext *opc;
+  struct SearchContext sc;
+
+  sc.id = id;
+  sc.opc = NULL;
+  GNUNET_assert (NULL != c->opc_map);
+  if (GNUNET_SYSERR !=
+      GNUNET_CONTAINER_multihashmap32_get_multiple (c->opc_map, (uint32_t) id,
+                                                    &opc_search_iterator, &sc))
+    return NULL;
+  return sc.opc;
+}
+
+
+/**
+ * Inserts the given operation context into the operation context map of the
+ * given controller.  Creates the operation context map if one does not exist
+ * for the controller
+ *
+ * @param c the controller
+ * @param opc the operation context to be inserted
+ */
+void
+GNUNET_TESTBED_insert_opc_ (struct GNUNET_TESTBED_Controller *c,
+                            struct OperationContext *opc)
+{
+  if (NULL == c->opc_map)
+    c->opc_map = GNUNET_CONTAINER_multihashmap32_create (256);
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONTAINER_multihashmap32_put (c->opc_map,
+                                                      (uint32_t) opc->id, opc,
+                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
+}
+
+
+/**
+ * Removes the given operation context from the operation context map of the
+ * given controller
+ *
+ * @param c the controller
+ * @param opc the operation context to remove
+ */
+void
+GNUNET_TESTBED_remove_opc_ (const struct GNUNET_TESTBED_Controller *c,
+                            struct OperationContext *opc)
+{
+  GNUNET_assert (NULL != c->opc_map);
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_CONTAINER_multihashmap32_remove (c->opc_map,
+                                                         (uint32_t) opc->id,
+                                                         opc));
+  if ( (0 == GNUNET_CONTAINER_multihashmap32_size (c->opc_map))
+       && (NULL != c->opcq_empty_cb) )
+    c->opcq_empty_cb (c->opcq_empty_cls);
+}
+
+
+
+/**
+ * Check #GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM message is well-formed.
+ *
+ * @param cls the controller handler
+ * @param msg message received
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_add_host_confirm (void *cls,
+                        const struct GNUNET_TESTBED_HostConfirmedMessage *msg)
+{
+  const char *emsg;
+  uint16_t msg_size;
+
+  msg_size = ntohs (msg->header.size) - sizeof (*msg);
+  if (0 == msg_size)
+    return GNUNET_OK;
+  /* We have an error message */
+  emsg = (const char *) &msg[1];
+  if ('\0' != emsg[msg_size - 1])
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM message from
+ * controller (testbed service)
+ *
+ * @param cls the controller handler
+ * @param msg message received
+ */
+static void
+handle_add_host_confirm (void *cls,
+                         const struct GNUNET_TESTBED_HostConfirmedMessage *msg)
+{
+  struct GNUNET_TESTBED_Controller *c = cls;
+  struct GNUNET_TESTBED_HostRegistrationHandle *rh = c->rh;
+  const char *emsg;
+  uint16_t msg_size;
 
-  for (opc = c->ocq_head; NULL != opc; opc = opc->next)
+  if (NULL == rh)
+    return;
+  if (GNUNET_TESTBED_host_get_id_ (rh->host) != ntohl (msg->host_id))
+  {
+    LOG_DEBUG ("Mismatch in host id's %u, %u of host confirm msg\n",
+               GNUNET_TESTBED_host_get_id_ (rh->host),
+               ntohl (msg->host_id));
+    return;
+  }
+  c->rh = NULL;
+  msg_size = ntohs (msg->header.size) - sizeof (*msg);
+  if (0 == msg_size)
   {
-    if (id == opc->id)
-      return opc;
+    LOG_DEBUG ("Host %u successfully registered\n",
+               ntohl (msg->host_id));
+    GNUNET_TESTBED_mark_host_registered_at_ (rh->host,
+                                             c);
+    rh->cc (rh->cc_cls,
+            NULL);
+    GNUNET_free (rh);
+    return;
   }
-  return NULL;
+  /* We have an error message */
+  emsg = (const char *) &msg[1];
+  LOG (GNUNET_ERROR_TYPE_ERROR,
+       _("Adding host %u failed with error: %s\n"),
+       ntohl (msg->host_id),
+       emsg);
+  rh->cc (rh->cc_cls,
+          emsg);
+  GNUNET_free (rh);
 }
 
 
@@ -279,35 +422,34 @@ find_opc (const struct GNUNET_TESTBED_Controller *c, const uint64_t id)
  * @param msg the message
  */
 static void
-handle_forwarded_operation_msg (struct GNUNET_TESTBED_Controller *c,
+handle_forwarded_operation_msg (void *cls,
                                 struct OperationContext *opc,
                                 const struct GNUNET_MessageHeader *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct ForwardedOperationData *fo_data;
 
   fo_data = opc->data;
   if (NULL != fo_data->cc)
     fo_data->cc (fo_data->cc_cls, msg);
-  GNUNET_CONTAINER_DLL_remove (c->ocq_head, c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (c, opc);
   GNUNET_free (fo_data);
   GNUNET_free (opc);
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM message from
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_ADD_HOST_SUCCESS message from
  * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
-static int
-handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
-                  const struct
-                  GNUNET_TESTBED_GenericOperationSuccessEventMessage *msg)
+static void
+handle_opsuccess (void *cls,
+                  const struct GNUNET_TESTBED_GenericOperationSuccessEventMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   GNUNET_TESTBED_OperationCompletionCallback op_comp_cb;
   void *op_comp_cb_cls;
@@ -319,7 +461,7 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;
   event.op = opc->op;
@@ -331,11 +473,11 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
   switch (opc->type)
   {
   case OP_FORWARDED:
-  {
-    handle_forwarded_operation_msg (c, opc,
-                                    (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
-  }
+    {
+      handle_forwarded_operation_msg (c, opc,
+                                      (const struct GNUNET_MessageHeader *) msg);
+      return;
+    }
     break;
   case OP_PEER_DESTROY:
   {
@@ -371,18 +513,20 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
     opc->data = NULL;
   }
     break;
+  case OP_PEER_RECONFIGURE:
+    break;
   default:
     GNUNET_assert (0);
   }
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
-  exop_insert (event.op);  
+  exop_insert (event.op);
   if (0 != (c->event_mask & (1L << GNUNET_TESTBED_ET_OPERATION_FINISHED)))
   {
     if (NULL != c->cc)
       c->cc (c->cc_cls, &event);
     if (GNUNET_NO == exop_check (event.op))
-      return GNUNET_YES;
+      return;
   }
   else
     LOG_DEBUG ("Not calling callback\n");
@@ -390,30 +534,27 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
     op_comp_cb (op_comp_cb_cls, event.op, NULL);
    /* You could have marked the operation as done by now */
   GNUNET_break (GNUNET_NO == exop_check (event.op));
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCREATESUCCESS message from
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_CREATE_PEER_SUCCESS message from
  * controller (testbed service)
  *
  * @param c the controller handle
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
-static int
-handle_peer_create_success (struct GNUNET_TESTBED_Controller *c,
-                            const struct
-                            GNUNET_TESTBED_PeerCreateSuccessEventMessage *msg)
+static void
+handle_peer_create_success (void *cls,
+                            const struct GNUNET_TESTBED_PeerCreateSuccessEventMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   struct PeerCreateData *data;
   struct GNUNET_TESTBED_Peer *peer;
   struct GNUNET_TESTBED_Operation *op;
   GNUNET_TESTBED_PeerCreateCallback cb;
-  void *cls;
+  void *cb_cls;
   uint64_t op_id;
 
   GNUNET_assert (sizeof (struct GNUNET_TESTBED_PeerCreateSuccessEventMessage) ==
@@ -422,13 +563,13 @@ handle_peer_create_success (struct GNUNET_TESTBED_Controller *c,
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation context for PeerCreateSuccessEvent not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
     handle_forwarded_operation_msg (c, opc,
                                     (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    return;
   }
   GNUNET_assert (OP_PEER_CREATE == opc->type);
   GNUNET_assert (NULL != opc->data);
@@ -436,36 +577,34 @@ handle_peer_create_success (struct GNUNET_TESTBED_Controller *c,
   GNUNET_assert (NULL != data->peer);
   peer = data->peer;
   GNUNET_assert (peer->unique_id == ntohl (msg->peer_id));
-  peer->state = PS_CREATED;
+  peer->state = TESTBED_PS_CREATED;
   GNUNET_TESTBED_peer_register_ (peer);
   cb = data->cb;
-  cls = data->cls;
+  cb_cls = data->cls;
   op = opc->op;
   GNUNET_free (opc->data);
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
   exop_insert (op);
   if (NULL != cb)
-    cb (cls, peer, NULL);
+    cb (cb_cls, peer, NULL);
    /* You could have marked the operation as done by now */
   GNUNET_break (GNUNET_NO == exop_check (op));
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEEREVENT message from
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_PEER_EVENT message from
  * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
-static int
-handle_peer_event (struct GNUNET_TESTBED_Controller *c,
+static void
+handle_peer_event (void *cls,
                    const struct GNUNET_TESTBED_PeerEventMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   struct GNUNET_TESTBED_Peer *peer;
   struct PeerEventData *data;
@@ -473,6 +612,7 @@ handle_peer_event (struct GNUNET_TESTBED_Controller *c,
   void *pcc_cls;
   struct GNUNET_TESTBED_EventInformation event;
   uint64_t op_id;
+  uint64_t mask;
 
   GNUNET_assert (sizeof (struct GNUNET_TESTBED_PeerEventMessage) ==
                  ntohs (msg->header.size));
@@ -480,13 +620,13 @@ handle_peer_event (struct GNUNET_TESTBED_Controller *c,
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
     handle_forwarded_operation_msg (c, opc,
                                     (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    return;
   }
   GNUNET_assert ((OP_PEER_START == opc->type) || (OP_PEER_STOP == opc->type));
   data = opc->data;
@@ -499,12 +639,12 @@ handle_peer_event (struct GNUNET_TESTBED_Controller *c,
   switch (event.type)
   {
   case GNUNET_TESTBED_ET_PEER_START:
-    peer->state = PS_STARTED;
+    peer->state = TESTBED_PS_STARTED;
     event.details.peer_start.host = peer->host;
     event.details.peer_start.peer = peer;
     break;
   case GNUNET_TESTBED_ET_PEER_STOP:
-    peer->state = PS_STOPPED;
+    peer->state = TESTBED_PS_STOPPED;
     event.details.peer_stop.peer = peer;
     break;
   default:
@@ -513,57 +653,56 @@ handle_peer_event (struct GNUNET_TESTBED_Controller *c,
   pcc = data->pcc;
   pcc_cls = data->pcc_cls;
   GNUNET_free (data);
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
   exop_insert (event.op);
-  if (0 !=
-      ((GNUNET_TESTBED_ET_PEER_START | GNUNET_TESTBED_ET_PEER_STOP) &
-       c->event_mask))
+  mask = 1LL << GNUNET_TESTBED_ET_PEER_START;
+  mask |= 1LL << GNUNET_TESTBED_ET_PEER_STOP;
+  if (0 != (mask & c->event_mask))
   {
     if (NULL != c->cc)
-      c->cc (c->cc_cls, &event);    
+      c->cc (c->cc_cls, &event);
     if (GNUNET_NO == exop_check (event.op))
-      return GNUNET_YES;
+      return;
   }
   if (NULL != pcc)
     pcc (pcc_cls, NULL);
    /* You could have marked the operation as done by now */
   GNUNET_break (GNUNET_NO == exop_check (event.op));
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCONEVENT message from
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONNECT_EVENT message from
  * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
-static int
-handle_peer_conevent (struct GNUNET_TESTBED_Controller *c,
+static void
+handle_peer_conevent (void *cls,
                       const struct GNUNET_TESTBED_ConnectionEventMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   struct OverlayConnectData *data;
   GNUNET_TESTBED_OperationCompletionCallback cb;
   void *cb_cls;
   struct GNUNET_TESTBED_EventInformation event;
   uint64_t op_id;
+  uint64_t mask;
 
   op_id = GNUNET_ntohll (msg->operation_id);
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
     handle_forwarded_operation_msg (c, opc,
                                     (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    return;
   }
   GNUNET_assert (OP_OVERLAY_CONNECT == opc->type);
   GNUNET_assert (NULL != (data = opc->data));
@@ -587,40 +726,53 @@ handle_peer_conevent (struct GNUNET_TESTBED_Controller *c,
   }
   cb = data->cb;
   cb_cls = data->cb_cls;
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
   exop_insert (event.op);
-  if (0 !=
-      ((GNUNET_TESTBED_ET_CONNECT | GNUNET_TESTBED_ET_DISCONNECT) &
-       c->event_mask))
+  mask = 1LL << GNUNET_TESTBED_ET_CONNECT;
+  mask |= 1LL << GNUNET_TESTBED_ET_DISCONNECT;
+  if (0 != (mask & c->event_mask))
   {
     if (NULL != c->cc)
       c->cc (c->cc_cls, &event);
     if (GNUNET_NO == exop_check (event.op))
-      return GNUNET_YES;
-  }  
+      return;
+  }
   if (NULL != cb)
     cb (cb_cls, opc->op, NULL);
    /* You could have marked the operation as done by now */
   GNUNET_break (GNUNET_NO == exop_check (event.op));
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCONFIG message from
+ * Validate #GNUNET_MESSAGE_TYPE_TESTBED_PEER_INFORMATION message from
  * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
 static int
-handle_peer_config (struct GNUNET_TESTBED_Controller *c,
-                    const struct
-                    GNUNET_TESTBED_PeerConfigurationInformationMessage *msg)
+check_peer_config (void *cls,
+                   const struct GNUNET_TESTBED_PeerConfigurationInformationMessage *msg)
+{
+  /* anything goes? */
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_PEER_INFORMATION message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ */
+static void
+handle_peer_config (void *cls,
+                    const struct GNUNET_TESTBED_PeerConfigurationInformationMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   struct GNUNET_TESTBED_Peer *peer;
   struct PeerInfoData *data;
@@ -633,31 +785,33 @@ handle_peer_config (struct GNUNET_TESTBED_Controller *c,
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
-    handle_forwarded_operation_msg (c, opc,
-                                    (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    handle_forwarded_operation_msg (c,
+                                    opc,
+                                    &msg->header);
+    return;
   }
   data = opc->data;
   GNUNET_assert (NULL != data);
   peer = data->peer;
   GNUNET_assert (NULL != peer);
   GNUNET_assert (ntohl (msg->peer_id) == peer->unique_id);
-  pinfo = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_PeerInformation));
-  pinfo->pit = data->pit;  
+  pinfo = GNUNET_new (struct GNUNET_TESTBED_PeerInformation);
+  pinfo->pit = data->pit;
   cb = data->cb;
   cb_cls = data->cb_cls;
   GNUNET_assert (NULL != cb);
   GNUNET_free (data);
-  opc->data = NULL;  
+  opc->data = NULL;
   switch (pinfo->pit)
   {
   case GNUNET_TESTBED_PIT_IDENTITY:
-    pinfo->result.id = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
-    (void) memcpy (pinfo->result.id, &msg->peer_identity,
+    pinfo->result.id = GNUNET_new (struct GNUNET_PeerIdentity);
+    GNUNET_memcpy (pinfo->result.id,
+                   &msg->peer_identity,
                    sizeof (struct GNUNET_PeerIdentity));
     break;
   case GNUNET_TESTBED_PIT_CONFIGURATION:
@@ -669,48 +823,63 @@ handle_peer_config (struct GNUNET_TESTBED_Controller *c,
     break;
   }
   opc->data = pinfo;
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
   cb (cb_cls, opc->op, pinfo, NULL);
   /* We dont check whether the operation is marked as done here as the
      operation contains data (cfg/identify) which will be freed at a later point
   */
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_OPERATIONFAILEVENT message from
+ * Validate #GNUNET_MESSAGE_TYPE_TESTBED_OPERATION_FAIL_EVENT message from
  * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
+ * @return #GNUNET_OK if message is well-formed
  */
 static int
-handle_op_fail_event (struct GNUNET_TESTBED_Controller *c,
-                      const struct GNUNET_TESTBED_OperationFailureEventMessage
-                      *msg)
+check_op_fail_event (void *cls,
+                     const struct GNUNET_TESTBED_OperationFailureEventMessage *msg)
+{
+  /* we accept anything as a valid error message */
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_OPERATION_FAIL_EVENT message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ */
+static void
+handle_op_fail_event (void *cls,
+                      const struct GNUNET_TESTBED_OperationFailureEventMessage *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   const char *emsg;
   uint64_t op_id;
+  uint64_t mask;
   struct GNUNET_TESTBED_EventInformation event;
 
   op_id = GNUNET_ntohll (msg->operation_id);
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
     handle_forwarded_operation_msg (c, opc,
                                     (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    return;
   }
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   opc->state = OPC_STATE_FINISHED;
   emsg = GNUNET_TESTBED_parse_error_string_ (msg);
   if (NULL == emsg)
@@ -723,94 +892,93 @@ handle_op_fail_event (struct GNUNET_TESTBED_Controller *c,
     if (NULL != data->cb)
       data->cb (data->cb_cls, opc->op, NULL, emsg);
     GNUNET_free (data);
-    return GNUNET_YES;          /* We do not call controller callback for peer info */
+    return;          /* We do not call controller callback for peer info */
   }
   event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;
   event.op = opc->op;
   event.op_cls = opc->op_cls;
   event.details.operation_finished.emsg = emsg;
   event.details.operation_finished.generic = NULL;
-  if ((0 != (GNUNET_TESTBED_ET_OPERATION_FINISHED & c->event_mask)) &&
-      (NULL != c->cc))
+  mask = (1LL << GNUNET_TESTBED_ET_OPERATION_FINISHED);
+  if ((0 != (mask & c->event_mask)) && (NULL != c->cc))
   {
     exop_insert (event.op);
     c->cc (c->cc_cls, &event);
     if (GNUNET_NO == exop_check (event.op))
-      return GNUNET_YES;
+      return;
   }
   switch (opc->type)
   {
   case OP_PEER_CREATE:
-  {
-    struct PeerCreateData *data;
+    {
+      struct PeerCreateData *data;
 
-    data = opc->data;
-    GNUNET_free (data->peer);
-    if (NULL != data->cb)
-      data->cb (data->cls, NULL, emsg);
-    GNUNET_free (data);
-  }
+      data = opc->data;
+      GNUNET_free (data->peer);
+      if (NULL != data->cb)
+        data->cb (data->cls, NULL, emsg);
+      GNUNET_free (data);
+    }
     break;
   case OP_PEER_START:
   case OP_PEER_STOP:
-  {
-    struct PeerEventData *data;
+    {
+      struct PeerEventData *data;
 
-    data = opc->data;
-    if (NULL != data->pcc)
-      data->pcc (data->pcc_cls, emsg);
-    GNUNET_free (data);
-  }
+      data = opc->data;
+      if (NULL != data->pcc)
+        data->pcc (data->pcc_cls, emsg);
+      GNUNET_free (data);
+    }
     break;
   case OP_PEER_DESTROY:
     break;
   case OP_PEER_INFO:
     GNUNET_assert (0);
   case OP_OVERLAY_CONNECT:
-  {
-    struct OverlayConnectData *data;
+    {
+      struct OverlayConnectData *data;
 
-    data = opc->data;
-    data->failed = GNUNET_YES;
-    if (NULL != data->cb)
-      data->cb (data->cb_cls, opc->op, emsg);
-  }
+      data = opc->data;
+      GNUNET_TESTBED_operation_mark_failed (opc->op);
+      if (NULL != data->cb)
+        data->cb (data->cb_cls, opc->op, emsg);
+    }
     break;
   case OP_FORWARDED:
     GNUNET_assert (0);
   case OP_LINK_CONTROLLERS:    /* No secondary callback */
-    break;    
+    break;
   case OP_SHUTDOWN_PEERS:
-  {
-    struct ShutdownPeersData *data;
+    {
+      struct ShutdownPeersData *data;
 
-    data = opc->data;
-    GNUNET_free (data);         /* FIXME: Decide whether we call data->op_cb */
-    opc->data = NULL;
-  }
+      data = opc->data;
+      GNUNET_free (data);         /* FIXME: Decide whether we call data->op_cb */
+      opc->data = NULL;
+    }
     break;
   case OP_MANAGE_SERVICE:
-  {
-    struct ManageServiceData *data = opc->data;
+    {
+      struct ManageServiceData *data = opc->data;
       GNUNET_TESTBED_OperationCompletionCallback cb;
-    void *cb_cls;
-
-    GNUNET_assert (NULL != data);
-    cb = data->cb;
-    cb_cls = data->cb_cls;
-    GNUNET_free (data);
-    opc->data = NULL;
-    exop_insert (event.op);
-    if (NULL != cb)
-      cb (cb_cls, opc->op, emsg);
-    /* You could have marked the operation as done by now */
-    GNUNET_break (GNUNET_NO == exop_check (event.op));
-  }
+      void *cb_cls;
+
+      GNUNET_assert (NULL != data);
+      cb = data->cb;
+      cb_cls = data->cb_cls;
+      GNUNET_free (data);
+      opc->data = NULL;
+      exop_insert (event.op);
+      if (NULL != cb)
+        cb (cb_cls, opc->op, emsg);
+      /* You could have marked the operation as done by now */
+      GNUNET_break (GNUNET_NO == exop_check (event.op));
+    }
     break;
   default:
     GNUNET_break (0);
   }
-  return GNUNET_YES;
 }
 
 
@@ -838,37 +1006,55 @@ GNUNET_TESTBED_generate_slavegetconfig_msg_ (uint64_t op_id, uint32_t slave_id)
 }
 
 
+
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG message from controller
- * (testbed service)
+ * Validate #GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_INFORMATION message from
+ * controller (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
  */
 static int
-handle_slave_config (struct GNUNET_TESTBED_Controller *c,
+check_slave_config (void *cls,
+                    const struct GNUNET_TESTBED_SlaveConfiguration *msg)
+{
+  /* anything goes? */
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_CONFIGURATION message from controller
+ * (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ */
+static void
+handle_slave_config (void *cls,
                      const struct GNUNET_TESTBED_SlaveConfiguration *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   uint64_t op_id;
+  uint64_t mask;
   struct GNUNET_TESTBED_EventInformation event;
 
   op_id = GNUNET_ntohll (msg->operation_id);
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_GET_SLAVE_CONFIG != opc->type)
   {
     GNUNET_break (0);
-    return GNUNET_YES;
+    return;
   }
   opc->state = OPC_STATE_FINISHED;
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
-  if ((0 != (GNUNET_TESTBED_ET_OPERATION_FINISHED & c->event_mask)) &&
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
+  mask = 1LL << GNUNET_TESTBED_ET_OPERATION_FINISHED;
+  if ((0 != (mask & c->event_mask)) &&
       (NULL != c->cc))
   {
     opc->data = GNUNET_TESTBED_extract_config_ (&msg->header);
@@ -879,24 +1065,38 @@ handle_slave_config (struct GNUNET_TESTBED_Controller *c,
     event.details.operation_finished.emsg = NULL;
     c->cc (c->cc_cls, &event);
   }
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG message from controller
+ * Check #GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT message from controller
  * (testbed service)
  *
  * @param c the controller handler
  * @param msg message received
- * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
- *           not
+ * @return #GNUNET_OK if @a msg is well-formed
  */
 static int
-handle_link_controllers_result (struct GNUNET_TESTBED_Controller *c,
-                                const struct
-                                GNUNET_TESTBED_ControllerLinkResponse *msg)
+check_link_controllers_result (void *cls,
+                                const struct GNUNET_TESTBED_ControllerLinkResponse *msg)
+{
+  /* actual check to be implemented */
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT message from controller
+ * (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ */
+static void
+handle_link_controllers_result (void *cls,
+                                const struct GNUNET_TESTBED_ControllerLinkResponse *msg)
 {
+  struct GNUNET_TESTBED_Controller *c = cls;
   struct OperationContext *opc;
   struct ControllerLinkData *data;
   struct GNUNET_CONFIGURATION_Handle *cfg;
@@ -909,18 +1109,18 @@ handle_link_controllers_result (struct GNUNET_TESTBED_Controller *c,
   if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
-    return GNUNET_YES;
+    return;
   }
   if (OP_FORWARDED == opc->type)
   {
     handle_forwarded_operation_msg (c, opc,
                                     (const struct GNUNET_MessageHeader *) msg);
-    return GNUNET_YES;
+    return;
   }
   if (OP_LINK_CONTROLLERS != opc->type)
   {
     GNUNET_break (0);
-    return GNUNET_YES;
+    return;
   }
   GNUNET_assert (NULL != (data = opc->data));
   host = GNUNET_TESTBED_host_lookup_by_id_ (data->host_id);
@@ -928,7 +1128,7 @@ handle_link_controllers_result (struct GNUNET_TESTBED_Controller *c,
   GNUNET_free (data);
   opc->data = NULL;
   opc->state = OPC_STATE_FINISHED;
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c, opc);
   event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;
   event.op = opc->op;
   event.op_cls = opc->op_cls;
@@ -941,9 +1141,9 @@ handle_link_controllers_result (struct GNUNET_TESTBED_Controller *c,
     emsg = GNUNET_malloc (ntohs (msg->header.size)
                           - sizeof (struct
                                     GNUNET_TESTBED_ControllerLinkResponse) + 1);
-    memcpy (emsg, &msg[1], ntohs (msg->header.size)
-                          - sizeof (struct
-                                    GNUNET_TESTBED_ControllerLinkResponse));
+    GNUNET_memcpy (emsg,
+                   &msg[1],
+                   ntohs (msg->header.size)- sizeof (struct GNUNET_TESTBED_ControllerLinkResponse));
     event.details.operation_finished.emsg = emsg;
   }
   else
@@ -965,173 +1165,157 @@ handle_link_controllers_result (struct GNUNET_TESTBED_Controller *c,
   if (NULL != cfg)
     GNUNET_CONFIGURATION_destroy (cfg);
   GNUNET_free_non_null (emsg);
-  return GNUNET_YES;
 }
 
 
 /**
- * Handler for messages from controller (testbed service)
+ * Validate #GNUNET_MESSAGE_TYPE_TESTBED_BARRIER_STATUS message.
  *
- * @param cls the controller handler
- * @param msg message received, NULL on timeout or fatal error
+ * @param cls the controller handle to determine the connection this message
+ *   belongs to
+ * @param msg the barrier status message
+ * @return #GNUNET_OK if the message is valid; #GNUNET_SYSERR to tear it
+ *   down signalling an error (message malformed)
  */
-static void
-message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+static int
+check_barrier_status (void *cls,
+                      const struct GNUNET_TESTBED_BarrierStatusMsg *msg)
 {
-  struct GNUNET_TESTBED_Controller *c = cls;
-  int status;
   uint16_t msize;
+  uint16_t name_len;
+  int status;
+  const char *name;
+  size_t emsg_len;
 
-  c->in_receive = GNUNET_NO;
-  /* FIXME: Add checks for message integrity */
-  if (NULL == msg)
+  msize = ntohs (msg->header.size);
+  name = msg->data;
+  name_len = ntohs (msg->name_len);
+
+  if (sizeof (struct GNUNET_TESTBED_BarrierStatusMsg) + name_len + 1 > msize)
   {
-    LOG_DEBUG ("Receive timed out or connection to service dropped\n");
-    return;
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
   }
-  status = GNUNET_OK;
-  msize = ntohs (msg->size);
-  switch (ntohs (msg->type))
+  if ('\0' != name[name_len])
   {
-  case GNUNET_MESSAGE_TYPE_TESTBED_ADD_HOST_SUCCESS:
-    GNUNET_assert (msize >=
-                   sizeof (struct GNUNET_TESTBED_HostConfirmedMessage));
-    status =
-        GNUNET_TESTBED_host_handle_addhostconfirm_
-        (c, (const struct GNUNET_TESTBED_HostConfirmedMessage*) msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_GENERIC_OPERATION_SUCCESS:
-    GNUNET_assert (msize ==
-                   sizeof (struct
-                           GNUNET_TESTBED_GenericOperationSuccessEventMessage));
-    status =
-        handle_opsuccess (c,
-                          (const struct
-                           GNUNET_TESTBED_GenericOperationSuccessEventMessage *)
-                          msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_OPERATION_FAIL_EVENT:
-    GNUNET_assert (msize >=
-                   sizeof (struct GNUNET_TESTBED_OperationFailureEventMessage));
-    status =
-        handle_op_fail_event (c,
-                              (const struct
-                               GNUNET_TESTBED_OperationFailureEventMessage *)
-                              msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_CREATE_PEER_SUCCESS:
-    GNUNET_assert (msize ==
-                   sizeof (struct
-                           GNUNET_TESTBED_PeerCreateSuccessEventMessage));
-    status =
-        handle_peer_create_success (c,
-                                    (const struct
-                                     GNUNET_TESTBED_PeerCreateSuccessEventMessage
-                                     *) msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_PEER_EVENT:
-    GNUNET_assert (msize == sizeof (struct GNUNET_TESTBED_PeerEventMessage));
-    status =
-        handle_peer_event (c,
-                           (const struct GNUNET_TESTBED_PeerEventMessage *)
-                           msg);
-
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONFIGURATION:
-    GNUNET_assert (msize >=
-                   sizeof (struct
-                           GNUNET_TESTBED_PeerConfigurationInformationMessage));
-    status =
-        handle_peer_config (c,
-                            (const struct
-                             GNUNET_TESTBED_PeerConfigurationInformationMessage
-                             *) msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONNECT_EVENT:
-    GNUNET_assert (msize ==
-                   sizeof (struct GNUNET_TESTBED_ConnectionEventMessage));
-    status =
-        handle_peer_conevent (c,
-                              (const struct
-                               GNUNET_TESTBED_ConnectionEventMessage *) msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_CONFIGURATION:
-    GNUNET_assert (msize > sizeof (struct GNUNET_TESTBED_SlaveConfiguration));
-    status =
-        handle_slave_config (c,
-                             (const struct GNUNET_TESTBED_SlaveConfiguration *)
-                             msg);
-    break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT:
-    status = 
-        handle_link_controllers_result (c,
-                                        (const struct
-                                         GNUNET_TESTBED_ControllerLinkResponse
-                                         *) msg);
-    break;
-  default:
-    GNUNET_assert (0);
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
   }
-  if ((GNUNET_OK == status) && (GNUNET_NO == c->in_receive))
+  status = ntohs (msg->status);
+  if (GNUNET_TESTBED_BARRIERSTATUS_ERROR == status)
   {
-    c->in_receive = GNUNET_YES;
-    GNUNET_CLIENT_receive (c->client, &message_handler, c,
-                           GNUNET_TIME_UNIT_FOREVER_REL);
+    emsg_len = msize - (sizeof (struct GNUNET_TESTBED_BarrierStatusMsg) + name_len
+                        + 1); /* +1!? */
+    if (0 == emsg_len)
+    {
+      GNUNET_break_op (0);
+      return GNUNET_SYSERR;
+    }
   }
+  return GNUNET_OK;
 }
 
 
 /**
- * Function called to notify a client about the connection begin ready to queue
- * more data.  "buf" will be NULL and "size" zero if the connection was closed
- * for writing in the meantime.
+ * Handler for #GNUNET_MESSAGE_TYPE_TESTBED_BARRIER_STATUS messages
  *
- * @param cls closure
- * @param size number of bytes available in buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
+ * @param cls the controller handle to determine the connection this message
+ *   belongs to
+ * @param msg the barrier status message
  */
-static size_t
-transmit_ready_notify (void *cls, size_t size, void *buf)
+static void
+handle_barrier_status (void *cls,
+                       const struct GNUNET_TESTBED_BarrierStatusMsg *msg)
 {
   struct GNUNET_TESTBED_Controller *c = cls;
-  struct MessageQueue *mq_entry;
-
-  c->th = NULL;
-  mq_entry = c->mq_head;
-  GNUNET_assert (NULL != mq_entry);
-  if ((0 == size) && (NULL == buf))     /* Timeout */
-  {
-    LOG_DEBUG ("Message sending timed out -- retrying\n");
-    c->th =
-        GNUNET_CLIENT_notify_transmit_ready (c->client,
-                                             ntohs (mq_entry->msg->size),
-                                             TIMEOUT_REL, GNUNET_YES,
-                                             &transmit_ready_notify, c);
-    return 0;
-  }
-  GNUNET_assert (ntohs (mq_entry->msg->size) <= size);
-  size = ntohs (mq_entry->msg->size);
-  memcpy (buf, mq_entry->msg, size);
-  LOG_DEBUG ("Message of type: %u and size: %u sent\n",
-             ntohs (mq_entry->msg->type), size);
-  GNUNET_free (mq_entry->msg);
-  GNUNET_CONTAINER_DLL_remove (c->mq_head, c->mq_tail, mq_entry);
-  GNUNET_free (mq_entry);
-  mq_entry = c->mq_head;
-  if (NULL != mq_entry)
-    c->th =
-        GNUNET_CLIENT_notify_transmit_ready (c->client,
-                                             ntohs (mq_entry->msg->size),
-                                             TIMEOUT_REL, GNUNET_YES,
-                                             &transmit_ready_notify, c);
-  if (GNUNET_NO == c->in_receive)
-  {
-    c->in_receive = GNUNET_YES;
-    GNUNET_CLIENT_receive (c->client, &message_handler, c,
-                           GNUNET_TIME_UNIT_FOREVER_REL);
-  }
-  return size;
+  struct GNUNET_TESTBED_Barrier *barrier;
+  char *emsg;
+  const char *name;
+  struct GNUNET_HashCode key;
+  size_t emsg_len;
+  int status;
+  uint16_t msize;
+  uint16_t name_len;
+
+  emsg = NULL;
+  barrier = NULL;
+  msize = ntohs (msg->header.size);
+  if (msize <= sizeof (struct GNUNET_TESTBED_BarrierStatusMsg))
+  {
+    GNUNET_break_op (0);
+    goto cleanup;
+  }
+  name = msg->data;
+  name_len = ntohs (msg->name_len);
+  if (name_len >=  //name_len is strlen(barrier_name)
+      (msize - ((sizeof msg->header) + sizeof (msg->status)) )   )
+  {
+    GNUNET_break_op (0);
+    goto cleanup;
+  }
+  if ('\0' != name[name_len])
+  {
+    GNUNET_break_op (0);
+    goto cleanup;
+  }
+  LOG_DEBUG ("Received BARRIER_STATUS msg\n");
+  status = ntohs (msg->status);
+  if (GNUNET_TESTBED_BARRIERSTATUS_ERROR == status)
+  {
+    status = -1;
+    //unlike name_len, emsg_len includes the trailing zero
+    emsg_len = msize - (sizeof (struct GNUNET_TESTBED_BarrierStatusMsg)
+                        + (name_len + 1));
+    if (0 == emsg_len)
+    {
+      GNUNET_break_op (0);
+      goto cleanup;
+    }
+    if ('\0' != (msg->data[(name_len + 1) + (emsg_len - 1)]))
+    {
+      GNUNET_break_op (0);
+      goto cleanup;
+    }
+    emsg = GNUNET_malloc (emsg_len);
+    GNUNET_memcpy (emsg,
+                   msg->data + name_len + 1,
+                   emsg_len);
+  }
+  if (NULL == c->barrier_map)
+  {
+    GNUNET_break_op (0);
+    goto cleanup;
+  }
+  GNUNET_CRYPTO_hash (name, name_len, &key);
+  barrier = GNUNET_CONTAINER_multihashmap_get (c->barrier_map, &key);
+  if (NULL == barrier)
+  {
+    GNUNET_break_op (0);
+    goto cleanup;
+  }
+  GNUNET_assert (NULL != barrier->cb);
+  if ((GNUNET_YES == barrier->echo) &&
+      (GNUNET_TESTBED_BARRIERSTATUS_CROSSED == status))
+    GNUNET_TESTBED_queue_message_ (c,
+                                   GNUNET_copy_message (&msg->header));
+  barrier->cb (barrier->cls,
+               name,
+               barrier,
+               status,
+               emsg);
+  if (GNUNET_TESTBED_BARRIERSTATUS_INITIALISED == status)
+    return;           /* just initialised; skip cleanup */
+
+ cleanup:
+  GNUNET_free_non_null (emsg);
+  /**
+   * Do not remove the barrier if we did not echo the status back; this is
+   * required at the chained testbed controller setup to ensure the only the
+   * test-driver echos the status and the controller hierarchy properly
+   * propagates the status.
+   */
+  if ((NULL != barrier) && (GNUNET_YES == barrier->echo))
+    GNUNET_TESTBED_barrier_remove_ (barrier);
 }
 
 
@@ -1145,7 +1329,8 @@ void
 GNUNET_TESTBED_queue_message_ (struct GNUNET_TESTBED_Controller *controller,
                                struct GNUNET_MessageHeader *msg)
 {
-  struct MessageQueue *mq_entry;
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_MessageHeader *m2;
   uint16_t type;
   uint16_t size;
 
@@ -1153,19 +1338,13 @@ GNUNET_TESTBED_queue_message_ (struct GNUNET_TESTBED_Controller *controller,
   size = ntohs (msg->size);
   GNUNET_assert ((GNUNET_MESSAGE_TYPE_TESTBED_INIT <= type) &&
                  (GNUNET_MESSAGE_TYPE_TESTBED_MAX > type));
-  mq_entry = GNUNET_malloc (sizeof (struct MessageQueue));
-  mq_entry->msg = msg;
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Queueing message of type %u, size %u for sending\n", type,
-       ntohs (msg->size));
-  GNUNET_CONTAINER_DLL_insert_tail (controller->mq_head, controller->mq_tail,
-                                    mq_entry);
-  if (NULL == controller->th)
-    controller->th =
-        GNUNET_CLIENT_notify_transmit_ready (controller->client, size,
-                                             TIMEOUT_REL, GNUNET_YES,
-                                             &transmit_ready_notify,
-                                             controller);
+  env = GNUNET_MQ_msg_extra (m2,
+                             size - sizeof (*m2),
+                             type);
+  GNUNET_memcpy (m2, msg, size);
+  GNUNET_free (msg);
+  GNUNET_MQ_send (controller->mq,
+                  env);
 }
 
 
@@ -1184,31 +1363,37 @@ GNUNET_TESTBED_queue_message_ (struct GNUNET_TESTBED_Controller *controller,
  *           operation
  */
 struct OperationContext *
-GNUNET_TESTBED_forward_operation_msg_ (struct GNUNET_TESTBED_Controller
-                                       *controller, uint64_t operation_id,
+GNUNET_TESTBED_forward_operation_msg_ (struct GNUNET_TESTBED_Controller *controller,
+                                       uint64_t operation_id,
                                        const struct GNUNET_MessageHeader *msg,
-                                       GNUNET_CLIENT_MessageHandler cc,
+                                       GNUNET_MQ_MessageCallback cc,
                                        void *cc_cls)
 {
   struct OperationContext *opc;
   struct ForwardedOperationData *data;
-  struct GNUNET_MessageHeader *dup_msg;
-  uint16_t msize;
-
-  data = GNUNET_malloc (sizeof (struct ForwardedOperationData));
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_MessageHeader *m2;
+  uint16_t type = ntohs (msg->type);
+  uint16_t size = ntohs (msg->size);
+
+  env = GNUNET_MQ_msg_extra (m2,
+                             size - sizeof (*m2),
+                             type);
+  GNUNET_memcpy (m2,
+                 msg,
+                 size);
+  GNUNET_MQ_send (controller->mq,
+                  env);
+  data = GNUNET_new (struct ForwardedOperationData);
   data->cc = cc;
   data->cc_cls = cc_cls;
-  opc = GNUNET_malloc (sizeof (struct OperationContext));
+  opc = GNUNET_new (struct OperationContext);
   opc->c = controller;
   opc->type = OP_FORWARDED;
   opc->data = data;
   opc->id = operation_id;
-  msize = ntohs (msg->size);
-  dup_msg = GNUNET_malloc (msize);
-  (void) memcpy (dup_msg, msg, msize);
-  GNUNET_TESTBED_queue_message_ (opc->c, dup_msg);
-  GNUNET_CONTAINER_DLL_insert_tail (controller->ocq_head, controller->ocq_tail,
-                                    opc);
+  GNUNET_TESTBED_insert_opc_ (controller,
+                              opc);
   return opc;
 }
 
@@ -1222,7 +1407,8 @@ GNUNET_TESTBED_forward_operation_msg_ (struct GNUNET_TESTBED_Controller
 void
 GNUNET_TESTBED_forward_operation_msg_cancel_ (struct OperationContext *opc)
 {
-  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_remove_opc_ (opc->c,
+                              opc);
   GNUNET_free (opc->data);
   GNUNET_free (opc);
 }
@@ -1246,7 +1432,7 @@ opstart_link_controllers (void *cls)
   msg = data->msg;
   data->msg = NULL;
   opc->state = OPC_STATE_STARTED;
-  GNUNET_CONTAINER_DLL_insert_tail (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_insert_opc_ (opc->c, opc);
   GNUNET_TESTBED_queue_message_ (opc->c, &msg->header);
 }
 
@@ -1266,10 +1452,10 @@ oprelease_link_controllers (void *cls)
   switch (opc->state)
   {
   case OPC_STATE_INIT:
-    GNUNET_free (data->msg);    
+    GNUNET_free (data->msg);
     break;
   case OPC_STATE_STARTED:
-    GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+    GNUNET_TESTBED_remove_opc_ (opc->c, opc);
     break;
   case OPC_STATE_FINISHED:
     break;
@@ -1296,7 +1482,7 @@ opstart_get_slave_config (void *cls)
   GNUNET_free (opc->data);
   data = NULL;
   opc->data = NULL;
-  GNUNET_CONTAINER_DLL_insert_tail (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_insert_opc_ (opc->c, opc);
   GNUNET_TESTBED_queue_message_ (opc->c, &msg->header);
   opc->state = OPC_STATE_STARTED;
 }
@@ -1318,7 +1504,7 @@ oprelease_get_slave_config (void *cls)
     GNUNET_free (opc->data);
     break;
   case OPC_STATE_STARTED:
-    GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+    GNUNET_TESTBED_remove_opc_ (opc->c, opc);
     break;
   case OPC_STATE_FINISHED:
     if (NULL != opc->data)
@@ -1329,14 +1515,35 @@ oprelease_get_slave_config (void *cls)
 }
 
 
+/**
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure, a `struct GNUNET_TESTBED_Controller *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
+{
+  /* struct GNUNET_TESTBED_Controller *c = cls; */
+
+  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+              "Encountered MQ error: %d\n",
+              error);
+  /* now what? */
+  GNUNET_SCHEDULER_shutdown (); /* seems most reasonable */
+}
+
+
 /**
  * Start a controller process using the given configuration at the
  * given host.
  *
- * @param cfg configuration to use
  * @param host host to run the controller on; This should be the same host if
  *          the controller was previously started with
- *          GNUNET_TESTBED_controller_start; NULL for localhost
+ *          GNUNET_TESTBED_controller_start()
  * @param event_mask bit mask with set of events to call 'cc' for;
  *                   or-ed values of "1LL" shifted by the
  *                   respective 'enum GNUNET_TESTBED_EventType'
@@ -1351,13 +1558,59 @@ GNUNET_TESTBED_controller_connect (struct GNUNET_TESTBED_Host *host,
                                    GNUNET_TESTBED_ControllerCallback cc,
                                    void *cc_cls)
 {
-  struct GNUNET_TESTBED_Controller *controller;
+  struct GNUNET_TESTBED_Controller *controller
+    = GNUNET_new (struct GNUNET_TESTBED_Controller);
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (add_host_confirm,
+                           GNUNET_MESSAGE_TYPE_TESTBED_ADD_HOST_SUCCESS,
+                           struct GNUNET_TESTBED_HostConfirmedMessage,
+                           controller),
+    GNUNET_MQ_hd_fixed_size (peer_conevent,
+                             GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONNECT_EVENT,
+                             struct GNUNET_TESTBED_ConnectionEventMessage,
+                             controller),
+    GNUNET_MQ_hd_fixed_size (opsuccess,
+                             GNUNET_MESSAGE_TYPE_TESTBED_GENERIC_OPERATION_SUCCESS,
+                             struct GNUNET_TESTBED_GenericOperationSuccessEventMessage,
+                             controller),
+    GNUNET_MQ_hd_var_size (op_fail_event,
+                           GNUNET_MESSAGE_TYPE_TESTBED_OPERATION_FAIL_EVENT,
+                           struct GNUNET_TESTBED_OperationFailureEventMessage,
+                           controller),
+    GNUNET_MQ_hd_fixed_size (peer_create_success,
+                             GNUNET_MESSAGE_TYPE_TESTBED_CREATE_PEER_SUCCESS,
+                             struct GNUNET_TESTBED_PeerCreateSuccessEventMessage,
+                             controller),
+    GNUNET_MQ_hd_fixed_size (peer_event,
+                             GNUNET_MESSAGE_TYPE_TESTBED_PEER_EVENT,
+                             struct GNUNET_TESTBED_PeerEventMessage,
+                             controller),
+    GNUNET_MQ_hd_var_size (peer_config,
+                           GNUNET_MESSAGE_TYPE_TESTBED_PEER_INFORMATION,
+                           struct GNUNET_TESTBED_PeerConfigurationInformationMessage,
+                           controller),
+    GNUNET_MQ_hd_var_size (slave_config,
+                           GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_CONFIGURATION,
+                           struct GNUNET_TESTBED_SlaveConfiguration,
+                           controller),
+    GNUNET_MQ_hd_var_size (link_controllers_result,
+                           GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT,
+                           struct GNUNET_TESTBED_ControllerLinkResponse,
+                           controller),
+    GNUNET_MQ_hd_var_size (barrier_status,
+                           GNUNET_MESSAGE_TYPE_TESTBED_BARRIER_STATUS,
+                           struct GNUNET_TESTBED_BarrierStatusMsg,
+                           controller),
+    GNUNET_MQ_handler_end ()
+  };
   struct GNUNET_TESTBED_InitMessage *msg;
+  struct GNUNET_MQ_Envelope *env;
   const struct GNUNET_CONFIGURATION_Handle *cfg;
   const char *controller_hostname;
   unsigned long long max_parallel_operations;
   unsigned long long max_parallel_service_connections;
   unsigned long long max_parallel_topology_config_operations;
+  size_t slen;
 
   GNUNET_assert (NULL != (cfg = GNUNET_TESTBED_host_get_cfg_ (host)));
   if (GNUNET_OK !=
@@ -1366,6 +1619,7 @@ GNUNET_TESTBED_controller_connect (struct GNUNET_TESTBED_Host *host,
                                              &max_parallel_operations))
   {
     GNUNET_break (0);
+    GNUNET_free (controller);
     return NULL;
   }
   if (GNUNET_OK !=
@@ -1374,6 +1628,7 @@ GNUNET_TESTBED_controller_connect (struct GNUNET_TESTBED_Host *host,
                                              &max_parallel_service_connections))
   {
     GNUNET_break (0);
+    GNUNET_free (controller);
     return NULL;
   }
   if (GNUNET_OK !=
@@ -1382,244 +1637,112 @@ GNUNET_TESTBED_controller_connect (struct GNUNET_TESTBED_Host *host,
                                              &max_parallel_topology_config_operations))
   {
     GNUNET_break (0);
+    GNUNET_free (controller);
     return NULL;
   }
-  controller = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_Controller));
   controller->cc = cc;
   controller->cc_cls = cc_cls;
   controller->event_mask = event_mask;
   controller->cfg = GNUNET_CONFIGURATION_dup (cfg);
-  controller->client = GNUNET_CLIENT_connect ("testbed", controller->cfg);
-  if (NULL == controller->client)
+  controller->mq = GNUNET_CLIENT_connect (controller->cfg,
+                                          "testbed",
+                                          handlers,
+                                          &mq_error_handler,
+                                          controller);
+  if (NULL == controller->mq)
   {
+    GNUNET_break (0);
     GNUNET_TESTBED_controller_disconnect (controller);
     return NULL;
   }
-  if (NULL == host)
-  {
-    host = GNUNET_TESTBED_host_create_by_id_ (0, controller->cfg);
-    if (NULL == host)           /* If the above host create fails */
-    {
-      LOG (GNUNET_ERROR_TYPE_WARNING,
-           "Treating NULL host as localhost. Multiple references to localhost "
-           "may break when localhost freed before calling disconnect \n");
-      host = GNUNET_TESTBED_host_lookup_by_id_ (0);
-    }
-    else
-    {
-      controller->aux_host = GNUNET_YES;
-    }
-  }
-  GNUNET_assert (NULL != host);
   GNUNET_TESTBED_mark_host_registered_at_ (host, controller);
   controller->host = host;
   controller->opq_parallel_operations =
-      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
-                                              max_parallel_operations);
+      GNUNET_TESTBED_operation_queue_create_ (OPERATION_QUEUE_TYPE_FIXED,
+                                              (unsigned int) max_parallel_operations);
   controller->opq_parallel_service_connections =
-      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+      GNUNET_TESTBED_operation_queue_create_ (OPERATION_QUEUE_TYPE_FIXED,
+                                              (unsigned int)
                                               max_parallel_service_connections);
   controller->opq_parallel_topology_config_operations =
-      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+      GNUNET_TESTBED_operation_queue_create_ (OPERATION_QUEUE_TYPE_FIXED,
+                                              (unsigned int)
                                               max_parallel_topology_config_operations);
   controller_hostname = GNUNET_TESTBED_host_get_hostname (host);
   if (NULL == controller_hostname)
     controller_hostname = "127.0.0.1";
-  msg =
-      GNUNET_malloc (sizeof (struct GNUNET_TESTBED_InitMessage) +
-                     strlen (controller_hostname) + 1);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_INIT);
-  msg->header.size =
-      htons (sizeof (struct GNUNET_TESTBED_InitMessage) +
-             strlen (controller_hostname) + 1);
+  slen = strlen (controller_hostname) + 1;
+  env = GNUNET_MQ_msg_extra (msg,
+                             slen,
+                             GNUNET_MESSAGE_TYPE_TESTBED_INIT);
   msg->host_id = htonl (GNUNET_TESTBED_host_get_id_ (host));
   msg->event_mask = GNUNET_htonll (controller->event_mask);
-  strcpy ((char *) &msg[1], controller_hostname);
-  GNUNET_TESTBED_queue_message_ (controller,
-                                 (struct GNUNET_MessageHeader *) msg);
+  GNUNET_memcpy (&msg[1],
+                 controller_hostname,
+                 slen);
+  GNUNET_MQ_send (controller->mq,
+                  env);
   return controller;
 }
 
 
 /**
- * Configure shared services at a controller.  Using this function,
- * you can specify that certain services (such as "resolver")
- * should not be run for each peer but instead be shared
- * across N peers on the specified host.  This function
- * must be called before any peers are created at the host.
+ * Iterator to free opc map entries
  *
- * @param controller controller to configure
- * @param service_name name of the service to share
- * @param num_peers number of peers that should share one instance
- *        of the specified service (1 for no sharing is the default),
- *        use 0 to disable the service
+ * @param cls closure
+ * @param key current key code
+ * @param value value in the hash map
+ * @return #GNUNET_YES if we should continue to iterate,
+ *         #GNUNET_NO if not.
  */
-void
-GNUNET_TESTBED_controller_configure_sharing (struct GNUNET_TESTBED_Controller
-                                             *controller,
-                                             const char *service_name,
-                                             uint32_t num_peers)
+static int
+opc_free_iterator (void *cls, uint32_t key, void *value)
 {
-  struct GNUNET_TESTBED_ConfigureSharedServiceMessage *msg;
-  uint16_t service_name_size;
-  uint16_t msg_size;
+  struct GNUNET_CONTAINER_MultiHashMap32 *map = cls;
+  struct OperationContext *opc = value;
 
-  service_name_size = strlen (service_name) + 1;
-  msg_size =
-      sizeof (struct GNUNET_TESTBED_ConfigureSharedServiceMessage) +
-      service_name_size;
-  msg = GNUNET_malloc (msg_size);
-  msg->header.size = htons (msg_size);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_SHARE_SERVICE);
-  msg->host_id = htonl (GNUNET_TESTBED_host_get_id_ (controller->host));
-  msg->num_peers = htonl (num_peers);
-  memcpy (&msg[1], service_name, service_name_size);
-  GNUNET_TESTBED_queue_message_ (controller,
-                                 (struct GNUNET_MessageHeader *) msg);
-  GNUNET_break (0);             /* This function is not yet implemented on the
-                                 * testbed service */
+  GNUNET_assert (NULL != opc);
+  GNUNET_break (0);
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_CONTAINER_multihashmap32_remove (map, key, value));
+  GNUNET_free (opc);
+  return GNUNET_YES;
 }
 
 
 /**
- * disconnects from the controller.
+ * Stop the given controller (also will terminate all peers and
+ * controllers dependent on this controller).  This function
+ * blocks until the testbed has been fully terminated (!).
  *
- * @param controller handle to controller to stop
+ * @param c handle to controller to stop
  */
 void
-GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller
-                                      *controller)
+GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller *c)
 {
-  struct MessageQueue *mq_entry;
-
-  if (NULL != controller->th)
-    GNUNET_CLIENT_notify_transmit_ready_cancel (controller->th);
-  /* Clear the message queue */
-  while (NULL != (mq_entry = controller->mq_head))
-  {
-    GNUNET_CONTAINER_DLL_remove (controller->mq_head, controller->mq_tail,
-                                 mq_entry);
-    GNUNET_free (mq_entry->msg);
-    GNUNET_free (mq_entry);
-  }
-  if (NULL != controller->client)
-    GNUNET_CLIENT_disconnect (controller->client);
-  GNUNET_CONFIGURATION_destroy (controller->cfg);
-  if (GNUNET_YES == controller->aux_host)
-    GNUNET_TESTBED_host_destroy (controller->host);
-  GNUNET_TESTBED_operation_queue_destroy_ (controller->opq_parallel_operations);
+  if (NULL != c->mq)
+  {
+    GNUNET_MQ_destroy (c->mq);
+    c->mq = NULL;
+  }
+  if (NULL != c->host)
+    GNUNET_TESTBED_deregister_host_at_ (c->host, c);
+  GNUNET_CONFIGURATION_destroy (c->cfg);
+  GNUNET_TESTBED_operation_queue_destroy_ (c->opq_parallel_operations);
   GNUNET_TESTBED_operation_queue_destroy_
-      (controller->opq_parallel_service_connections);
+      (c->opq_parallel_service_connections);
   GNUNET_TESTBED_operation_queue_destroy_
-      (controller->opq_parallel_topology_config_operations);
-  GNUNET_free (controller);
-}
-
-
-/**
- * Same as the GNUNET_TESTBED_controller_link_2, but with ids for delegated host
- * and slave host
- *
- * @param op_cls the operation closure for the event which is generated to
- *          signal success or failure of this operation
- * @param master handle to the master controller who creates the association
- * @param delegated_host_id id of the host to which requests should be delegated
- * @param slave_host_id id of the host which is used to run the slave controller
- * @param sxcfg serialized and compressed configuration
- * @param sxcfg_size the size sxcfg
- * @param scfg_size the size of uncompressed serialized configuration
- * @param is_subordinate GNUNET_YES if the controller at delegated_host should
- *          be started by the slave controller; GNUNET_NO if the slave
- *          controller has to connect to the already started delegated
- *          controller via TCP/IP
- * @return the operation handle
- */
-struct GNUNET_TESTBED_Operation *
-GNUNET_TESTBED_controller_link_2_ (void *op_cls,
-                                   struct GNUNET_TESTBED_Controller *master,
-                                   uint32_t delegated_host_id,
-                                   uint32_t slave_host_id, const char *sxcfg,
-                                   size_t sxcfg_size, size_t scfg_size,
-                                   int is_subordinate)
-{
-  struct OperationContext *opc;
-  struct GNUNET_TESTBED_ControllerLinkRequest *msg;
-  struct ControllerLinkData *data;
-  uint16_t msg_size;
-
-  msg_size = sxcfg_size + sizeof (struct GNUNET_TESTBED_ControllerLinkRequest);
-  msg = GNUNET_malloc (msg_size);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS);
-  msg->header.size = htons (msg_size);
-  msg->delegated_host_id = htonl (delegated_host_id);
-  msg->slave_host_id = htonl (slave_host_id);
-  msg->config_size = htons ((uint16_t) scfg_size);
-  msg->is_subordinate = (GNUNET_YES == is_subordinate) ? 1 : 0;
-  memcpy (&msg[1], sxcfg, sxcfg_size);
-  data = GNUNET_malloc (sizeof (struct ControllerLinkData));
-  data->msg = msg;
-  data->host_id = delegated_host_id;
-  opc = GNUNET_malloc (sizeof (struct OperationContext));
-  opc->c = master;
-  opc->data = data;
-  opc->type = OP_LINK_CONTROLLERS;
-  opc->id = GNUNET_TESTBED_get_next_op_id (opc->c);
-  opc->state = OPC_STATE_INIT;
-  opc->op_cls = op_cls;
-  msg->operation_id = GNUNET_htonll (opc->id);
-  opc->op =
-      GNUNET_TESTBED_operation_create_ (opc, &opstart_link_controllers,
-                                        &oprelease_link_controllers);
-  GNUNET_TESTBED_operation_queue_insert_ (master->opq_parallel_operations,
-                                          opc->op);
-  GNUNET_TESTBED_operation_begin_wait_ (opc->op);
-  return opc->op;
-}
-
-
-/**
- * Same as the GNUNET_TESTBED_controller_link, however expects configuration in
- * serialized and compressed
- *
- * @param op_cls the operation closure for the event which is generated to
- *          signal success or failure of this operation
- * @param master handle to the master controller who creates the association
- * @param delegated_host requests to which host should be delegated; cannot be NULL
- * @param slave_host which host is used to run the slave controller; use NULL to
- *          make the master controller connect to the delegated host
- * @param sxcfg serialized and compressed configuration
- * @param sxcfg_size the size sxcfg
- * @param scfg_size the size of uncompressed serialized configuration
- * @param is_subordinate GNUNET_YES if the controller at delegated_host should
- *          be started by the slave controller; GNUNET_NO if the slave
- *          controller has to connect to the already started delegated
- *          controller via TCP/IP
- * @return the operation handle
- */
-struct GNUNET_TESTBED_Operation *
-GNUNET_TESTBED_controller_link_2 (void *op_cls,
-                                  struct GNUNET_TESTBED_Controller *master,
-                                  struct GNUNET_TESTBED_Host *delegated_host,
-                                  struct GNUNET_TESTBED_Host *slave_host,
-                                  const char *sxcfg, size_t sxcfg_size,
-                                  size_t scfg_size, int is_subordinate)
-{
-  uint32_t delegated_host_id;
-  uint32_t slave_host_id;
-
-  GNUNET_assert (GNUNET_YES ==
-                 GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
-  delegated_host_id = GNUNET_TESTBED_host_get_id_ (delegated_host);
-  slave_host_id =
-      GNUNET_TESTBED_host_get_id_ ((NULL !=
-                                    slave_host) ? slave_host : master->host);
-  if ((NULL != slave_host) && (0 != GNUNET_TESTBED_host_get_id_ (slave_host)))
-    GNUNET_assert (GNUNET_YES ==
-                   GNUNET_TESTBED_is_host_registered_ (slave_host, master));
-
-  return GNUNET_TESTBED_controller_link_2_ (op_cls, master, delegated_host_id,
-                                            slave_host_id, sxcfg, sxcfg_size,
-                                            scfg_size, is_subordinate);
+      (c->opq_parallel_topology_config_operations);
+  if (NULL != c->opc_map)
+  {
+    GNUNET_assert (GNUNET_SYSERR !=
+                   GNUNET_CONTAINER_multihashmap32_iterate (c->opc_map,
+                                                            &opc_free_iterator,
+                                                            c->opc_map));
+    GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap32_size (c->opc_map));
+    GNUNET_CONTAINER_multihashmap32_destroy (c->opc_map);
+  }
+  GNUNET_free (c);
 }
 
 
@@ -1633,7 +1756,8 @@ GNUNET_TESTBED_controller_link_2 (void *op_cls,
  * @return the size of the xconfig
  */
 size_t
-GNUNET_TESTBED_compress_config_ (const char *config, size_t size,
+GNUNET_TESTBED_compress_config_ (const char *config,
+                                 size_t size,
                                  char **xconfig)
 {
   size_t xsize;
@@ -1665,61 +1789,13 @@ GNUNET_TESTBED_compress_cfg_ (const struct GNUNET_CONFIGURATION_Handle *cfg,
   char *xconfig;
   size_t size_;
   size_t xsize_;
-  
+
   config = GNUNET_CONFIGURATION_serialize (cfg, &size_);
   xsize_ = GNUNET_TESTBED_compress_config_ (config, size_, &xconfig);
   GNUNET_free (config);
   *size = size_;
   *xsize = xsize_;
   return xconfig;
-}                             
-
-
-/**
- * Same as the GNUNET_TESTBED_controller_link, but with ids for delegated host
- * and slave host
- *
- * @param op_cls the operation closure for the event which is generated to
- *          signal success or failure of this operation
- * @param master handle to the master controller who creates the association
- * @param delegated_host_id id of the host to which requests should be
- *          delegated; cannot be NULL
- * @param slave_host_id id of the host which should connect to controller
- *          running on delegated host ; use NULL to make the master controller
- *          connect to the delegated host
- * @param slave_cfg configuration to use for the slave controller
- * @param is_subordinate GNUNET_YES if the controller at delegated_host should
- *          be started by the slave controller; GNUNET_NO if the slave
- *          controller has to connect to the already started delegated
- *          controller via TCP/IP
- * @return the operation handle
- */
-struct GNUNET_TESTBED_Operation *
-GNUNET_TESTBED_controller_link_ (void *op_cls,
-                                 struct GNUNET_TESTBED_Controller *master,
-                                 uint32_t delegated_host_id,
-                                 uint32_t slave_host_id,
-                                 const struct GNUNET_CONFIGURATION_Handle
-                                 *slave_cfg, int is_subordinate)
-{
-  struct GNUNET_TESTBED_Operation *op;
-  char *config;
-  char *cconfig;
-  size_t cc_size;
-  size_t config_size;
-
-  config = GNUNET_CONFIGURATION_serialize (slave_cfg, &config_size);
-  cc_size = GNUNET_TESTBED_compress_config_ (config, config_size, &cconfig);
-  GNUNET_free (config);
-  /* Configuration doesn't fit in 1 message */
-  GNUNET_assert ((UINT16_MAX -
-                  sizeof (struct GNUNET_TESTBED_ControllerLinkRequest)) >=
-                 cc_size);
-  op = GNUNET_TESTBED_controller_link_2_ (op_cls, master, delegated_host_id,
-                                          slave_host_id, (const char *) cconfig,
-                                          cc_size, config_size, is_subordinate);
-  GNUNET_free (cconfig);
-  return op;
 }
 
 
@@ -1745,7 +1821,6 @@ GNUNET_TESTBED_controller_link_ (void *op_cls,
  * @param delegated_host requests to which host should be delegated; cannot be NULL
  * @param slave_host which host is used to run the slave controller; use NULL to
  *          make the master controller connect to the delegated host
- * @param slave_cfg configuration to use for the slave controller
  * @param is_subordinate GNUNET_YES if the controller at delegated_host should
  *          be started by the slave controller; GNUNET_NO if the slave
  *          controller has to connect to the already started delegated
@@ -1757,12 +1832,15 @@ GNUNET_TESTBED_controller_link (void *op_cls,
                                 struct GNUNET_TESTBED_Controller *master,
                                 struct GNUNET_TESTBED_Host *delegated_host,
                                 struct GNUNET_TESTBED_Host *slave_host,
-                                const struct GNUNET_CONFIGURATION_Handle
-                                *slave_cfg, int is_subordinate)
+                                int is_subordinate)
 {
+  struct OperationContext *opc;
+  struct GNUNET_TESTBED_ControllerLinkRequest *msg;
+  struct ControllerLinkData *data;
   uint32_t slave_host_id;
   uint32_t delegated_host_id;
-  
+  uint16_t msg_size;
+
   GNUNET_assert (GNUNET_YES ==
                  GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
   slave_host_id =
@@ -1772,11 +1850,31 @@ GNUNET_TESTBED_controller_link (void *op_cls,
   if ((NULL != slave_host) && (0 != slave_host_id))
     GNUNET_assert (GNUNET_YES ==
                    GNUNET_TESTBED_is_host_registered_ (slave_host, master));
-  return GNUNET_TESTBED_controller_link_ (op_cls, master, delegated_host_id,
-                                          slave_host_id,
-                                          GNUNET_TESTBED_host_get_cfg_ (delegated_host),
-                                          is_subordinate);
-
+  msg_size = sizeof (struct GNUNET_TESTBED_ControllerLinkRequest);
+  msg = GNUNET_malloc (msg_size);
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS);
+  msg->header.size = htons (msg_size);
+  msg->delegated_host_id = htonl (delegated_host_id);
+  msg->slave_host_id = htonl (slave_host_id);
+  msg->is_subordinate = (GNUNET_YES == is_subordinate) ? 1 : 0;
+  data = GNUNET_new (struct ControllerLinkData);
+  data->msg = msg;
+  data->host_id = delegated_host_id;
+  opc = GNUNET_new (struct OperationContext);
+  opc->c = master;
+  opc->data = data;
+  opc->type = OP_LINK_CONTROLLERS;
+  opc->id = GNUNET_TESTBED_get_next_op_id (opc->c);
+  opc->state = OPC_STATE_INIT;
+  opc->op_cls = op_cls;
+  msg->operation_id = GNUNET_htonll (opc->id);
+  opc->op =
+      GNUNET_TESTBED_operation_create_ (opc, &opstart_link_controllers,
+                                        &oprelease_link_controllers);
+  GNUNET_TESTBED_operation_queue_insert_ (master->opq_parallel_operations,
+                                          opc->op);
+  GNUNET_TESTBED_operation_begin_wait_ (opc->op);
+  return opc->op;
 }
 
 
@@ -1800,9 +1898,9 @@ GNUNET_TESTBED_get_slave_config_ (void *op_cls,
   struct OperationContext *opc;
   struct GetSlaveConfigData *data;
 
-  data = GNUNET_malloc (sizeof (struct GetSlaveConfigData));
+  data = GNUNET_new (struct GetSlaveConfigData);
   data->slave_id = slave_host_id;
-  opc = GNUNET_malloc (sizeof (struct OperationContext));
+  opc = GNUNET_new (struct OperationContext);
   opc->state = OPC_STATE_INIT;
   opc->c = master;
   opc->id = GNUNET_TESTBED_get_next_op_id (master);
@@ -1921,13 +2019,25 @@ GNUNET_TESTBED_create_helper_init_msg_ (const char *trusted_ip,
 
 
 /**
- * Signal that the information from an operation has been fully
- * processed.  This function MUST be called for each event
- * of type 'operation_finished' to fully remove the operation
- * from the operation queue.  After calling this function, the
- * 'op_result' becomes invalid (!).
+ * This function is used to signal that the event information (struct
+ * GNUNET_TESTBED_EventInformation) from an operation has been fully processed
+ * i.e. if the event callback is ever called for this operation. If the event
+ * callback for this operation has not yet been called, calling this function
+ * cancels the operation, frees its resources and ensures the no event is
+ * generated with respect to this operation. Note that however cancelling an
+ * operation does NOT guarantee that the operation will be fully undone (or that
+ * nothing ever happened).
+ *
+ * This function MUST be called for every operation to fully remove the
+ * operation from the operation queue.  After calling this function, if
+ * operation is completed and its event information is of type
+ * GNUNET_TESTBED_ET_OPERATION_FINISHED, the 'op_result' becomes invalid (!).
+
+ * If the operation is generated from GNUNET_TESTBED_service_connect() then
+ * calling this function on such as operation calls the disconnect adapter if
+ * the connect adapter was ever called.
  *
- * @param operation operation to signal completion for
+ * @param operation operation to signal completion or cancellation
  */
 void
 GNUNET_TESTBED_operation_done (struct GNUNET_TESTBED_Operation *operation)
@@ -1940,11 +2050,13 @@ GNUNET_TESTBED_operation_done (struct GNUNET_TESTBED_Operation *operation)
 /**
  * Generates configuration by uncompressing configuration in given message. The
  * given message should be of the following types:
- * GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONFIGURATION,
- * GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_CONFIGURATION,
- * GNUNET_MESSAGE_TYPE_TESTBED_ADD_HOST,
- * GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS,
- * GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT,
+ * #GNUNET_MESSAGE_TYPE_TESTBED_PEER_INFORMATION,
+ * #GNUNET_MESSAGE_TYPE_TESTBED_SLAVE_CONFIGURATION,
+ * #GNUNET_MESSAGE_TYPE_TESTBED_ADD_HOST,
+ * #GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS,
+ * #GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT,
+ *
+ * FIXME: This API is incredibly ugly.
  *
  * @param msg the message containing compressed configuration
  * @return handle to the parsed configuration; NULL upon error while parsing the message
@@ -1961,7 +2073,7 @@ GNUNET_TESTBED_extract_config_ (const struct GNUNET_MessageHeader *msg)
 
   switch (ntohs (msg->type))
   {
-  case GNUNET_MESSAGE_TYPE_TESTBED_PEER_CONFIGURATION:
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEER_INFORMATION:
   {
     const struct GNUNET_TESTBED_PeerConfigurationInformationMessage *imsg;
 
@@ -1990,11 +2102,11 @@ GNUNET_TESTBED_extract_config_ (const struct GNUNET_MessageHeader *msg)
     {
       const struct GNUNET_TESTBED_AddHostMessage *imsg;
       uint16_t osize;
-      
+
       imsg = (const struct GNUNET_TESTBED_AddHostMessage *) msg;
       data_len = (uLong) ntohs (imsg->config_size);
       osize = sizeof (struct GNUNET_TESTBED_AddHostMessage) +
-          ntohs (imsg->username_length) + ntohs (imsg->hostname_length); 
+          ntohs (imsg->username_length) + ntohs (imsg->hostname_length);
       xdata_len = ntohs (imsg->header.size) - osize;
       xdata = (const Bytef *) ((const void *) imsg + osize);
     }
@@ -2002,21 +2114,33 @@ GNUNET_TESTBED_extract_config_ (const struct GNUNET_MessageHeader *msg)
   case GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT:
     {
       const struct GNUNET_TESTBED_ControllerLinkResponse *imsg;
-      
+
       imsg = (const struct GNUNET_TESTBED_ControllerLinkResponse *) msg;
       data_len = ntohs (imsg->config_size);
-      xdata_len = ntohs (imsg->header.size) - 
+      xdata_len = ntohs (imsg->header.size) -
           sizeof (const struct GNUNET_TESTBED_ControllerLinkResponse);
       xdata = (const Bytef *) &imsg[1];
     }
     break;
-  case GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS:
+  case GNUNET_MESSAGE_TYPE_TESTBED_CREATE_PEER:
     {
-      const struct GNUNET_TESTBED_ControllerLinkRequest *imsg;
-      imsg = (const struct GNUNET_TESTBED_ControllerLinkRequest *) msg;
+      const struct GNUNET_TESTBED_PeerCreateMessage *imsg;
+
+      imsg = (const struct GNUNET_TESTBED_PeerCreateMessage *) msg;
       data_len = ntohs (imsg->config_size);
-      xdata_len = ntohs (imsg->header.size) - sizeof (const struct
-      GNUNET_TESTBED_ControllerLinkRequest);
+      xdata_len = ntohs (imsg->header.size) -
+          sizeof (struct GNUNET_TESTBED_PeerCreateMessage);
+      xdata = (const Bytef *) &imsg[1];
+    }
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_RECONFIGURE_PEER:
+    {
+      const struct GNUNET_TESTBED_PeerReconfigureMessage *imsg;
+
+      imsg = (const struct GNUNET_TESTBED_PeerReconfigureMessage *) msg;
+      data_len =  ntohs (imsg->config_size);
+      xdata_len = ntohs (imsg->header.size) -
+          sizeof (struct GNUNET_TESTBED_PeerReconfigureMessage);
       xdata = (const Bytef *) &imsg[1];
     }
     break;
@@ -2027,17 +2151,18 @@ GNUNET_TESTBED_extract_config_ (const struct GNUNET_MessageHeader *msg)
   if (Z_OK != (ret = uncompress (data, &data_len, xdata, xdata_len)))
   {
     GNUNET_free (data);
-    GNUNET_break_op (0);
+    GNUNET_break_op (0);        /* Un-compression failure */
     return NULL;
   }
   cfg = GNUNET_CONFIGURATION_create ();
   if (GNUNET_OK !=
-      GNUNET_CONFIGURATION_deserialize (cfg, (const char *) data,
+      GNUNET_CONFIGURATION_deserialize (cfg,
+                                       (const char *) data,
                                         (size_t) data_len,
-                                        GNUNET_NO))
+                                        NULL))
   {
     GNUNET_free (data);
-    GNUNET_break_op (0);
+    GNUNET_break_op (0);        /* De-serialization failure */
     return NULL;
   }
   GNUNET_free (data);
@@ -2102,16 +2227,17 @@ static void
 opstart_shutdown_peers (void *cls)
 {
   struct OperationContext *opc = cls;
+  struct GNUNET_MQ_Envelope *env;
   struct GNUNET_TESTBED_ShutdownPeersMessage *msg;
 
   opc->state = OPC_STATE_STARTED;
-  msg = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_ShutdownPeersMessage));
-  msg->header.size = 
-      htons (sizeof (struct GNUNET_TESTBED_ShutdownPeersMessage));
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_SHUTDOWN_PEERS);
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_TESTBED_SHUTDOWN_PEERS);
   msg->operation_id = GNUNET_htonll (opc->id);
-  GNUNET_CONTAINER_DLL_insert_tail (opc->c->ocq_head, opc->c->ocq_tail, opc);
-  GNUNET_TESTBED_queue_message_ (opc->c, &msg->header);
+  GNUNET_TESTBED_insert_opc_ (opc->c,
+                              opc);
+  GNUNET_MQ_send (opc->c->mq,
+                  env);
 }
 
 
@@ -2128,7 +2254,7 @@ oprelease_shutdown_peers (void *cls)
   switch (opc->state)
   {
   case OPC_STATE_STARTED:
-    GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+    GNUNET_TESTBED_remove_opc_ (opc->c, opc);
     /* no break; continue */
   case OPC_STATE_INIT:
     GNUNET_free (opc->data);
@@ -2148,7 +2274,7 @@ oprelease_shutdown_peers (void *cls)
  * when there are no other pending operations.  If there are pending operations,
  * it will return NULL
  *
- * @param controller the controller to send this message to
+ * @param c the controller to send this message to
  * @param op_cls closure for the operation
  * @param cb the callback to call when all peers are stopped and destroyed
  * @param cb_cls the closure for the callback
@@ -2156,7 +2282,7 @@ oprelease_shutdown_peers (void *cls)
  *           present
  */
 struct GNUNET_TESTBED_Operation *
-GNUNET_TESTBED_shutdown_peers (struct GNUNET_TESTBED_Controller *controller,
+GNUNET_TESTBED_shutdown_peers (struct GNUNET_TESTBED_Controller *c,
                                void *op_cls,
                                GNUNET_TESTBED_OperationCompletionCallback cb,
                                void *cb_cls)
@@ -2164,18 +2290,18 @@ GNUNET_TESTBED_shutdown_peers (struct GNUNET_TESTBED_Controller *controller,
   struct OperationContext *opc;
   struct ShutdownPeersData *data;
 
-  if (NULL != controller->ocq_head)
+  if (0 != GNUNET_CONTAINER_multihashmap32_size (c->opc_map))
     return NULL;
-  data = GNUNET_malloc (sizeof (struct ShutdownPeersData));
+  data = GNUNET_new (struct ShutdownPeersData);
   data->cb = cb;
   data->cb_cls = cb_cls;
-  opc = GNUNET_malloc (sizeof (struct OperationContext));
-  opc->c = controller;
+  opc = GNUNET_new (struct OperationContext);
+  opc->c = c;
   opc->op_cls = op_cls;
   opc->data = data;
-  opc->id =  GNUNET_TESTBED_get_next_op_id (controller);
+  opc->id =  GNUNET_TESTBED_get_next_op_id (c);
   opc->type = OP_SHUTDOWN_PEERS;
-  opc->state = OPC_STATE_INIT;  
+  opc->state = OPC_STATE_INIT;
   opc->op = GNUNET_TESTBED_operation_create_ (opc, &opstart_shutdown_peers,
                                               &oprelease_shutdown_peers);
   GNUNET_TESTBED_operation_queue_insert_ (opc->c->opq_parallel_operations,
@@ -2185,4 +2311,165 @@ GNUNET_TESTBED_shutdown_peers (struct GNUNET_TESTBED_Controller *controller,
 }
 
 
+/**
+ * Return the index of the peer inside of the total peer array,
+ * aka. the peer's "unique ID".
+ *
+ * @param peer Peer handle.
+ *
+ * @return The peer's unique ID.
+ */
+uint32_t
+GNUNET_TESTBED_get_index (const struct GNUNET_TESTBED_Peer *peer)
+{
+  return peer->unique_id;
+}
+
+
+/**
+ * Remove a barrier and it was the last one in the barrier hash map, destroy the
+ * hash map
+ *
+ * @param barrier the barrier to remove
+ */
+void
+GNUNET_TESTBED_barrier_remove_ (struct GNUNET_TESTBED_Barrier *barrier)
+{
+  struct GNUNET_TESTBED_Controller *c = barrier->c;
+
+  GNUNET_assert (NULL != c->barrier_map); /* No barriers present */
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONTAINER_multihashmap_remove (c->barrier_map,
+                                                       &barrier->key,
+                                                       barrier));
+  GNUNET_free (barrier->name);
+  GNUNET_free (barrier);
+  if (0 == GNUNET_CONTAINER_multihashmap_size (c->barrier_map))
+  {
+    GNUNET_CONTAINER_multihashmap_destroy (c->barrier_map);
+    c->barrier_map = NULL;
+  }
+}
+
+
+/**
+ * Initialise a barrier and call the given callback when the required percentage
+ * of peers (quorum) reach the barrier OR upon error.
+ *
+ * @param controller the handle to the controller
+ * @param name identification name of the barrier
+ * @param quorum the percentage of peers that is required to reach the barrier.
+ *   Peers signal reaching a barrier by calling
+ *   GNUNET_TESTBED_barrier_reached().
+ * @param cb the callback to call when the barrier is reached or upon error.
+ *   Cannot be NULL.
+ * @param cls closure for the above callback
+ * @param echo GNUNET_YES to echo the barrier crossed status message back to the
+ *   controller
+ * @return barrier handle; NULL upon error
+ */
+struct GNUNET_TESTBED_Barrier *
+GNUNET_TESTBED_barrier_init_ (struct GNUNET_TESTBED_Controller *controller,
+                              const char *name,
+                              unsigned int quorum,
+                              GNUNET_TESTBED_barrier_status_cb cb, void *cls,
+                              int echo)
+{
+  struct GNUNET_TESTBED_BarrierInit *msg;
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_TESTBED_Barrier *barrier;
+  struct GNUNET_HashCode key;
+  size_t name_len;
+
+  GNUNET_assert (quorum <= 100);
+  GNUNET_assert (NULL != cb);
+  name_len = strlen (name);
+  GNUNET_assert (0 < name_len);
+  GNUNET_CRYPTO_hash (name, name_len, &key);
+  if (NULL == controller->barrier_map)
+    controller->barrier_map = GNUNET_CONTAINER_multihashmap_create (3, GNUNET_YES);
+  if (GNUNET_YES ==
+      GNUNET_CONTAINER_multihashmap_contains (controller->barrier_map,
+                                              &key))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  LOG_DEBUG ("Initialising barrier `%s'\n", name);
+  barrier = GNUNET_new (struct GNUNET_TESTBED_Barrier);
+  barrier->c = controller;
+  barrier->name = GNUNET_strdup (name);
+  barrier->cb = cb;
+  barrier->cls = cls;
+  barrier->echo = echo;
+  GNUNET_memcpy (&barrier->key, &key, sizeof (struct GNUNET_HashCode));
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONTAINER_multihashmap_put (controller->barrier_map,
+                                                    &barrier->key,
+                                                    barrier,
+                                                    GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST));
+
+  env = GNUNET_MQ_msg_extra (msg,
+                             name_len,
+                             GNUNET_MESSAGE_TYPE_TESTBED_BARRIER_INIT);
+  msg->quorum = (uint8_t) quorum;
+  GNUNET_memcpy (msg->name,
+                 barrier->name,
+                 name_len);
+  GNUNET_MQ_send (barrier->c->mq,
+                  env);
+  return barrier;
+}
+
+
+/**
+ * Initialise a barrier and call the given callback when the required percentage
+ * of peers (quorum) reach the barrier OR upon error.
+ *
+ * @param controller the handle to the controller
+ * @param name identification name of the barrier
+ * @param quorum the percentage of peers that is required to reach the barrier.
+ *   Peers signal reaching a barrier by calling
+ *   GNUNET_TESTBED_barrier_reached().
+ * @param cb the callback to call when the barrier is reached or upon error.
+ *   Cannot be NULL.
+ * @param cls closure for the above callback
+ * @return barrier handle; NULL upon error
+ */
+struct GNUNET_TESTBED_Barrier *
+GNUNET_TESTBED_barrier_init (struct GNUNET_TESTBED_Controller *controller,
+                             const char *name,
+                             unsigned int quorum,
+                             GNUNET_TESTBED_barrier_status_cb cb, void *cls)
+{
+  return GNUNET_TESTBED_barrier_init_ (controller,
+                                       name, quorum, cb, cls, GNUNET_YES);
+}
+
+
+/**
+ * Cancel a barrier.
+ *
+ * @param barrier the barrier handle
+ */
+void
+GNUNET_TESTBED_barrier_cancel (struct GNUNET_TESTBED_Barrier *barrier)
+{
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_TESTBED_BarrierCancel *msg;
+  size_t slen;
+
+  slen = strlen (barrier->name);
+  env = GNUNET_MQ_msg_extra (msg,
+                             slen,
+                             GNUNET_MESSAGE_TYPE_TESTBED_BARRIER_CANCEL);
+  GNUNET_memcpy (msg->name,
+                 barrier->name,
+                 slen);
+  GNUNET_MQ_send (barrier->c->mq,
+                  env);
+  GNUNET_TESTBED_barrier_remove_ (barrier);
+}
+
+
 /* end of testbed_api.c */