Problem: monitor events are unversioned

Solution: add monitor event socket option

CMakeLists.txt

@@ -639,6 +639,7 @@ set(cxx-sources
   devpoll.cpp
   dgram.cpp
   dist.cpp
+  endpoint.cpp
   epoll.cpp
   err.cpp
   fq.cpp
@@ -746,6 +747,7 @@ set(cxx-sources
   dish.hpp
   dist.hpp
   encoder.hpp
+  endpoint.hpp
   epoll.hpp
   err.hpp
   fd.hpp

Makefile.am

@@ -55,6 +55,8 @@ src_libzmq_la_SOURCES = \
 	src/dist.cpp \
 	src/dist.hpp \
 	src/encoder.hpp \
+	src/endpoint.hpp \
+	src/endpoint.cpp \
 	src/epoll.cpp \
 	src/epoll.hpp \
 	src/err.cpp \

include/zmq.h

@@ -723,6 +723,11 @@ ZMQ_EXPORT int zmq_socket_get_peer_state (void *socket,
                                           const void *routing_id,
                                           size_t routing_id_size);
 
+ZMQ_EXPORT int zmq_socket_monitor_versioned (void *s_,
+                                             const char *addr_,
+                                             uint64_t events_,
+                                             int event_version_);
+
 #endif // ZMQ_BUILD_DRAFT_API
 
 

src/endpoint.cpp

+/*
+    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "precompiled.hpp"
+#include "endpoint.hpp"
+
+zmq::endpoint_uri_pair_t
+zmq::make_unconnected_connect_endpoint_pair (const std::string &endpoint_)
+{
+    return endpoint_uri_pair_t (std::string (), endpoint_,
+                                endpoint_type_connect);
+}
+
+zmq::endpoint_uri_pair_t
+zmq::make_unconnected_bind_endpoint_pair (const std::string &endpoint_)
+{
+    return endpoint_uri_pair_t (endpoint_, std::string (), endpoint_type_bind);
+}

src/endpoint.hpp

+/*
+    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_ENDPOINT_HPP_INCLUDED__
+#define __ZMQ_ENDPOINT_HPP_INCLUDED__
+
+#include <string>
+
+namespace zmq
+{
+enum endpoint_type_t
+{
+    endpoint_type_none,   // a connection-less endpoint
+    endpoint_type_bind,   // a connection-oriented bind endpoint
+    endpoint_type_connect // a connection-oriented connect endpoint
+};
+
+struct endpoint_uri_pair_t
+{
+    endpoint_uri_pair_t () : local_type (endpoint_type_none) {}
+    endpoint_uri_pair_t (const std::string &local,
+                         const std::string &remote,
+                         endpoint_type_t local_type) :
+        local (local),
+        remote (remote),
+        local_type (local_type)
+    {
+    }
+
+    const std::string &identifier () const
+    {
+        return local_type == endpoint_type_bind ? local : remote;
+    }
+
+    std::string local, remote;
+    endpoint_type_t local_type;
+};
+
+endpoint_uri_pair_t
+make_unconnected_connect_endpoint_pair (const std::string &endpoint_);
+
+endpoint_uri_pair_t
+make_unconnected_bind_endpoint_pair (const std::string &endpoint_);
+}
+
+#endif

src/i_engine.hpp

@@ -30,6 +30,8 @@
 #ifndef __ZMQ_I_ENGINE_HPP_INCLUDED__
 #define __ZMQ_I_ENGINE_HPP_INCLUDED__
 
+#include "endpoint.hpp"
+
 namespace zmq
 {
 class io_thread_t;
@@ -61,7 +63,7 @@ struct i_engine
 
     virtual void zap_msg_available () = 0;
 
-    virtual const char *get_endpoint () const = 0;
+    virtual const endpoint_uri_pair_t &get_endpoint () const = 0;
 };
 }
 

src/ipc_connecter.cpp

@@ -92,7 +92,8 @@ void zmq::ipc_connecter_t::start_connecting ()
     else if (rc == -1 && errno == EINPROGRESS) {
         _handle = add_fd (_s);
         set_pollout (_handle);
-        _socket->event_connect_delayed (_endpoint, zmq_errno ());
+        _socket->event_connect_delayed (
+          make_unconnected_connect_endpoint_pair (_endpoint), zmq_errno ());
 
         // TODO, tcp_connecter_t adds a connect timer in this case; maybe this
         // should be done here as well (and then this could be pulled up to

src/ipc_listener.cpp

@@ -142,7 +142,8 @@ void zmq::ipc_listener_t::in_event ()
     //  If connection was reset by the peer in the meantime, just ignore it.
     //  TODO: Handle specific errors like ENFILE/EMFILE etc.
     if (fd == retired_fd) {
-        _socket->event_accept_failed (_endpoint, zmq_errno ());
+        _socket->event_accept_failed (
+          make_unconnected_bind_endpoint_pair (_endpoint), zmq_errno ());
         return;
     }
 
@@ -224,7 +225,8 @@ int zmq::ipc_listener_t::set_address (const char *addr_)
     _filename = ZMQ_MOVE (addr);
     _has_file = true;
 
-    _socket->event_listening (_endpoint, _s);
+    _socket->event_listening (make_unconnected_bind_endpoint_pair (_endpoint),
+                              _s);
     return 0;
 
 error:
@@ -252,12 +254,14 @@ int zmq::ipc_listener_t::close ()
         }
 
         if (rc != 0) {
-            _socket->event_close_failed (_endpoint, zmq_errno ());
+            _socket->event_close_failed (
+              make_unconnected_bind_endpoint_pair (_endpoint), zmq_errno ());
             return -1;
         }
     }
 
-    _socket->event_closed (_endpoint, fd_for_event);
+    _socket->event_closed (make_unconnected_bind_endpoint_pair (_endpoint),
+                           fd_for_event);
     return 0;
 }
 

src/norm_engine.cpp

@@ -709,9 +709,9 @@ zmq::norm_engine_t::NormRxStreamState::List::Iterator::GetNextItem ()
     return nextItem;
 } // end zmq::norm_engine_t::NormRxStreamState::List::Iterator::GetNextItem()
 
-const char *zmq::norm_engine_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::norm_engine_t::get_endpoint () const
 {
-    return "";
+    return _empty_endpoint;
 }
 
 #endif // ZMQ_HAVE_NORM

src/norm_engine.hpp

@@ -47,7 +47,7 @@ class norm_engine_t : public io_object_t, public i_engine
 
     virtual void zap_msg_available (){};
 
-    virtual const char *get_endpoint () const;
+    virtual const endpoint_uri_pair_t &get_endpoint () const;
 
     // i_poll_events interface implementation.
     // (we only need in_event() for NormEvent notification)
@@ -150,6 +150,8 @@ class norm_engine_t : public io_object_t, public i_engine
 
     }; // end class zmq::norm_engine_t::NormRxStreamState
 
+    const endpoint_uri_pair_t _empty_endpoint;
+
     session_base_t *zmq_session;
     options_t options;
     NormInstanceHandle norm_instance;

src/options.cpp

@@ -244,7 +244,8 @@ zmq::options_t::options_t () :
     loopback_fastpath (false),
     multicast_loop (true),
     zero_copy (true),
-    router_notify (0)
+    router_notify (0),
+    monitor_event_version (1)
 {
     memset (curve_public_key, 0, CURVE_KEYSIZE);
     memset (curve_secret_key, 0, CURVE_KEYSIZE);

src/options.hpp

@@ -266,6 +266,9 @@ struct options_t
 
     // Application metadata
     std::map<std::string, std::string> app_metadata;
+
+    // Version of monitor events to emit
+    int monitor_event_version;
 };
 
 inline bool get_effective_conflate_option (const options_t &options)

src/pgm_receiver.cpp

@@ -156,9 +156,9 @@ bool zmq::pgm_receiver_t::restart_input ()
     return true;
 }
 
-const char *zmq::pgm_receiver_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::pgm_receiver_t::get_endpoint () const
 {
-    return "";
+    return _empty_endpoint;
 }
 
 void zmq::pgm_receiver_t::in_event ()

src/pgm_receiver.hpp

@@ -60,7 +60,7 @@ class pgm_receiver_t : public io_object_t, public i_engine
     bool restart_input ();
     void restart_output ();
     void zap_msg_available () {}
-    const char *get_endpoint () const;
+    const endpoint_uri_pair_t &get_endpoint () const;
 
     //  i_poll_events interface implementation.
     void in_event ();
@@ -84,6 +84,8 @@ class pgm_receiver_t : public io_object_t, public i_engine
         rx_timer_id = 0xa1
     };
 
+    const endpoint_uri_pair_t _empty_endpoint;
+
     //  RX timer is running.
     bool has_rx_timer;
 

src/pgm_sender.cpp

@@ -143,9 +143,9 @@ bool zmq::pgm_sender_t::restart_input ()
     return true;
 }
 
-const char *zmq::pgm_sender_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::pgm_sender_t::get_endpoint () const
 {
-    return "";
+    return _empty_endpoint;
 }
 
 zmq::pgm_sender_t::~pgm_sender_t ()

src/pgm_sender.hpp

@@ -59,7 +59,7 @@ class pgm_sender_t : public io_object_t, public i_engine
     bool restart_input ();
     void restart_output ();
     void zap_msg_available () {}
-    const char *get_endpoint () const;
+    const endpoint_uri_pair_t &get_endpoint () const;
 
     //  i_poll_events interface implementation.
     void in_event ();
@@ -77,6 +77,8 @@ class pgm_sender_t : public io_object_t, public i_engine
         rx_timer_id = 0xa1
     };
 
+    const endpoint_uri_pair_t _empty_endpoint;
+
     //  Timers are running.
     bool has_tx_timer;
     bool has_rx_timer;

src/pipe.cpp

@@ -554,12 +554,12 @@ void zmq::pipe_t::send_hwms_to_peer (int inhwm_, int outhwm_)
     send_pipe_hwm (_peer, inhwm_, outhwm_);
 }
 
-void zmq::pipe_t::set_endpoint_uri (const char *name_)
+void zmq::pipe_t::set_endpoint_pair (zmq::endpoint_uri_pair_t endpoint_pair_)
 {
-    _endpoint_uri = name_;
+    _endpoint_pair = endpoint_pair_;
 }
 
-std::string &zmq::pipe_t::get_endpoint_uri ()
+const zmq::endpoint_uri_pair_t &zmq::pipe_t::get_endpoint_pair () const
 {
-    return _endpoint_uri;
+    return _endpoint_pair;
 }

src/pipe.hpp

@@ -37,6 +37,7 @@
 #include "array.hpp"
 #include "blob.hpp"
 #include "options.hpp"
+#include "endpoint.hpp"
 
 namespace zmq
 {
@@ -141,8 +142,8 @@ class pipe_t : public object_t,
     //  Returns true if HWM is not reached
     bool check_hwm () const;
 
-    void set_endpoint_uri (const char *name_);
-    std::string &get_endpoint_uri ();
+    void set_endpoint_pair (endpoint_uri_pair_t endpoint_pair_);
+    const endpoint_uri_pair_t &get_endpoint_pair () const;
 
   private:
     //  Type of the underlying lock-free pipe.
@@ -247,9 +248,8 @@ class pipe_t : public object_t,
 
     const bool _conflate;
 
-    // If the pipe belongs to socket's endpoint the endpoint's name is stored here.
-    // Otherwise this is empty.
-    std::string _endpoint_uri;
+    // The endpoints of this pipe.
+    endpoint_uri_pair_t _endpoint_pair;
 
     //  Disable copying.
     pipe_t (const pipe_t &);

src/session_base.cpp

@@ -117,7 +117,7 @@ zmq::session_base_t::session_base_t (class io_thread_t *io_thread_,
 {
 }
 
-const char *zmq::session_base_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::session_base_t::get_endpoint () const
 {
     return _engine->get_endpoint ();
 }

src/session_base.hpp

@@ -92,7 +92,7 @@ class session_base_t : public own_t, public io_object_t, public i_pipe_events
     int write_zap_msg (msg_t *msg_);
 
     socket_base_t *get_socket ();
-    const char *get_endpoint () const;
+    const endpoint_uri_pair_t &get_endpoint () const;
 
   protected:
     session_base_t (zmq::io_thread_t *io_thread_,

src/socket_base.cpp

@@ -31,6 +31,7 @@
 #include <new>
 #include <string>
 #include <algorithm>
+#include <limits>
 
 #include "macros.hpp"
 
@@ -591,7 +592,10 @@ int zmq::socket_base_t::bind (const char *endpoint_uri_)
         //  Save last endpoint URI
         paddr->to_string (_last_endpoint);
 
-        add_endpoint (endpoint_uri_, static_cast<own_t *> (session), newpipe);
+        //  TODO shouldn't this use _last_endpoint instead of endpoint_uri_? as in the other cases
+        add_endpoint (endpoint_uri_pair_t (endpoint_uri_, std::string (),
+                                           endpoint_type_none),
+                      static_cast<own_t *> (session), newpipe);
 
         return 0;
     }
@@ -611,15 +615,16 @@ int zmq::socket_base_t::bind (const char *endpoint_uri_)
         rc = listener->set_address (address.c_str ());
         if (rc != 0) {
             LIBZMQ_DELETE (listener);
-            event_bind_failed (address, zmq_errno ());
+            event_bind_failed (make_unconnected_bind_endpoint_pair (address),
+                               zmq_errno ());
             return -1;
         }
 
         // Save last endpoint URI
         listener->get_address (_last_endpoint);
 
-        add_endpoint (_last_endpoint.c_str (), static_cast<own_t *> (listener),
-                      NULL);
+        add_endpoint (make_unconnected_bind_endpoint_pair (_last_endpoint),
+                      static_cast<own_t *> (listener), NULL);
         options.connected = true;
         return 0;
     }
@@ -633,15 +638,16 @@ int zmq::socket_base_t::bind (const char *endpoint_uri_)
         int rc = listener->set_address (address.c_str ());
         if (rc != 0) {
             LIBZMQ_DELETE (listener);
-            event_bind_failed (address, zmq_errno ());
+            event_bind_failed (make_unconnected_bind_endpoint_pair (address),
+                               zmq_errno ());
             return -1;
         }
 
         // Save last endpoint URI
         listener->get_address (_last_endpoint);
 
-        add_endpoint (_last_endpoint.c_str (), static_cast<own_t *> (listener),
-                      NULL);
+        add_endpoint (make_unconnected_bind_endpoint_pair (_last_endpoint),
+                      static_cast<own_t *> (listener), NULL);
         options.connected = true;
         return 0;
     }
@@ -654,14 +660,17 @@ int zmq::socket_base_t::bind (const char *endpoint_uri_)
         int rc = listener->set_address (address.c_str ());
         if (rc != 0) {
             LIBZMQ_DELETE (listener);
-            event_bind_failed (address, zmq_errno ());
+            event_bind_failed (make_unconnected_bind_endpoint_pair (address),
+                               zmq_errno ());
             return -1;
         }
 
         // Save last endpoint URI
         listener->get_address (_last_endpoint);
 
-        add_endpoint (endpoint_uri_, static_cast<own_t *> (listener), NULL);
+        // TODO shouldn't this use _last_endpoint as in the other cases?
+        add_endpoint (make_unconnected_bind_endpoint_pair (endpoint_uri_),
+                      static_cast<own_t *> (listener), NULL);
         options.connected = true;
         return 0;
     }
@@ -970,48 +979,49 @@ int zmq::socket_base_t::connect (const char *endpoint_uri_)
     //  Save last endpoint URI
     paddr->to_string (_last_endpoint);
 
-    add_endpoint (endpoint_uri_, static_cast<own_t *> (session), newpipe);
+    add_endpoint (make_unconnected_connect_endpoint_pair (_last_endpoint),
+                  static_cast<own_t *> (session), newpipe);
     return 0;
 }
 
-std::string zmq::socket_base_t::resolve_tcp_addr (std::string endpoint_uri_,
-                                                  const char *tcp_address_)
+std::string
+zmq::socket_base_t::resolve_tcp_addr (std::string endpoint_uri_pair_,
+                                      const char *tcp_address_)
 {
     // The resolved last_endpoint is used as a key in the endpoints map.
     // The address passed by the user might not match in the TCP case due to
     // IPv4-in-IPv6 mapping (EG: tcp://[::ffff:127.0.0.1]:9999), so try to
     // resolve before giving up. Given at this stage we don't know whether a
     // socket is connected or bound, try with both.
-    if (_endpoints.find (endpoint_uri_) == _endpoints.end ()) {
+    if (_endpoints.find (endpoint_uri_pair_) == _endpoints.end ()) {
         tcp_address_t *tcp_addr = new (std::nothrow) tcp_address_t ();
         alloc_assert (tcp_addr);
         int rc = tcp_addr->resolve (tcp_address_, false, options.ipv6);
 
         if (rc == 0) {
-            tcp_addr->to_string (endpoint_uri_);
-            if (_endpoints.find (endpoint_uri_) == _endpoints.end ()) {
+            tcp_addr->to_string (endpoint_uri_pair_);
+            if (_endpoints.find (endpoint_uri_pair_) == _endpoints.end ()) {
                 rc = tcp_addr->resolve (tcp_address_, true, options.ipv6);
                 if (rc == 0) {
-                    tcp_addr->to_string (endpoint_uri_);
+                    tcp_addr->to_string (endpoint_uri_pair_);
                 }
             }
         }
         LIBZMQ_DELETE (tcp_addr);
     }
-    return endpoint_uri_;
+    return endpoint_uri_pair_;
 }
 
-void zmq::socket_base_t::add_endpoint (const char *endpoint_uri_,
-                                       own_t *endpoint_,
-                                       pipe_t *pipe_)
+void zmq::socket_base_t::add_endpoint (
+  const endpoint_uri_pair_t &endpoint_pair_, own_t *endpoint_, pipe_t *pipe_)
 {
     //  Activate the session. Make it a child of this socket.
     launch_child (endpoint_);
-    _endpoints.ZMQ_MAP_INSERT_OR_EMPLACE (std::string (endpoint_uri_),
+    _endpoints.ZMQ_MAP_INSERT_OR_EMPLACE (endpoint_pair_.identifier (),
                                           endpoint_pipe_t (endpoint_, pipe_));
 
     if (pipe_ != NULL)
-        pipe_->set_endpoint_uri (endpoint_uri_);
+        pipe_->set_endpoint_pair (endpoint_pair_);
 }
 
 int zmq::socket_base_t::term_endpoint (const char *endpoint_uri_)
@@ -1059,7 +1069,7 @@ int zmq::socket_base_t::term_endpoint (const char *endpoint_uri_)
         ? resolve_tcp_addr (endpoint_uri_str, uri_path.c_str ())
         : endpoint_uri_str;
 
-    //  Find the endpoints range (if any) corresponding to the endpoint_uri_ string.
+    //  Find the endpoints range (if any) corresponding to the endpoint_uri_pair_ string.
     const std::pair<endpoints_t::iterator, endpoints_t::iterator> range =
       _endpoints.equal_range (resolved_endpoint_uri);
     if (range.first == range.second) {
@@ -1560,9 +1570,10 @@ void zmq::socket_base_t::pipe_terminated (pipe_t *pipe_)
     _pipes.erase (pipe_);
 
     // Remove the pipe from _endpoints (set it to NULL).
-    if (!pipe_->get_endpoint_uri ().empty ()) {
+    const std::string &identifier = pipe_->get_endpoint_pair ().identifier ();
+    if (!identifier.empty ()) {
         std::pair<endpoints_t::iterator, endpoints_t::iterator> range;
-        range = _endpoints.equal_range (pipe_->get_endpoint_uri ());
+        range = _endpoints.equal_range (identifier);
 
         for (endpoints_t::iterator it = range.first; it != range.second; ++it) {
             if (it->second.second == pipe_) {
@@ -1586,7 +1597,9 @@ void zmq::socket_base_t::extract_flags (msg_t *msg_)
     _rcvmore = (msg_->flags () & msg_t::more) != 0;
 }
 
-int zmq::socket_base_t::monitor (const char *endpoint_, int events_)
+int zmq::socket_base_t::monitor (const char *endpoint_,
+                                 uint64_t events_,
+                                 int event_version_)
 {
     scoped_lock_t lock (_monitor_sync);
 
@@ -1595,6 +1608,12 @@ int zmq::socket_base_t::monitor (const char *endpoint_, int events_)
         return -1;
     }
 
+    //  Event version 1 supports only first 16 events.
+    if (unlikely (event_version_ == 1 && events_ >> 16 != 0)) {
+        errno = EINVAL;
+        return -1;
+    }
+
     //  Support deregistering monitoring endpoints as well
     if (endpoint_ == NULL) {
         stop_monitor ();
@@ -1617,6 +1636,7 @@ int zmq::socket_base_t::monitor (const char *endpoint_, int events_)
     }
     //  Register events to monitor
     _monitor_events = events_;
+    options.monitor_event_version = event_version_;
     _monitor_socket = zmq_socket (get_ctx (), ZMQ_PAIR);
     if (_monitor_socket == NULL)
         return -1;
@@ -1635,137 +1655,174 @@ int zmq::socket_base_t::monitor (const char *endpoint_, int events_)
     return rc;
 }
 
-void zmq::socket_base_t::event_connected (const std::string &endpoint_uri_,
-                                          zmq::fd_t fd_)
+void zmq::socket_base_t::event_connected (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, zmq::fd_t fd_)
 {
-    event (endpoint_uri_, fd_, ZMQ_EVENT_CONNECTED);
+    event (endpoint_uri_pair_, fd_, ZMQ_EVENT_CONNECTED);
 }
 
 void zmq::socket_base_t::event_connect_delayed (
-  const std::string &endpoint_uri_, int err_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_CONNECT_DELAYED);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_CONNECT_DELAYED);
 }
 
 void zmq::socket_base_t::event_connect_retried (
-  const std::string &endpoint_uri_, int interval_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int interval_)
 {
-    event (endpoint_uri_, interval_, ZMQ_EVENT_CONNECT_RETRIED);
+    event (endpoint_uri_pair_, interval_, ZMQ_EVENT_CONNECT_RETRIED);
 }
 
-void zmq::socket_base_t::event_listening (const std::string &endpoint_uri_,
-                                          zmq::fd_t fd_)
+void zmq::socket_base_t::event_listening (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, zmq::fd_t fd_)
 {
-    event (endpoint_uri_, fd_, ZMQ_EVENT_LISTENING);
+    event (endpoint_uri_pair_, fd_, ZMQ_EVENT_LISTENING);
 }
 
-void zmq::socket_base_t::event_bind_failed (const std::string &endpoint_uri_,
-                                            int err_)
+void zmq::socket_base_t::event_bind_failed (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_BIND_FAILED);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_BIND_FAILED);
 }
 
-void zmq::socket_base_t::event_accepted (const std::string &endpoint_uri_,
-                                         zmq::fd_t fd_)
+void zmq::socket_base_t::event_accepted (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, zmq::fd_t fd_)
 {
-    event (endpoint_uri_, fd_, ZMQ_EVENT_ACCEPTED);
+    event (endpoint_uri_pair_, fd_, ZMQ_EVENT_ACCEPTED);
 }
 
-void zmq::socket_base_t::event_accept_failed (const std::string &endpoint_uri_,
-                                              int err_)
+void zmq::socket_base_t::event_accept_failed (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_ACCEPT_FAILED);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_ACCEPT_FAILED);
 }
 
-void zmq::socket_base_t::event_closed (const std::string &endpoint_uri_,
-                                       zmq::fd_t fd_)
+void zmq::socket_base_t::event_closed (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, zmq::fd_t fd_)
 {
-    event (endpoint_uri_, fd_, ZMQ_EVENT_CLOSED);
+    event (endpoint_uri_pair_, fd_, ZMQ_EVENT_CLOSED);
 }
 
-void zmq::socket_base_t::event_close_failed (const std::string &endpoint_uri_,
-                                             int err_)
+void zmq::socket_base_t::event_close_failed (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_CLOSE_FAILED);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_CLOSE_FAILED);
 }
 
-void zmq::socket_base_t::event_disconnected (const std::string &endpoint_uri_,
-                                             zmq::fd_t fd_)
+void zmq::socket_base_t::event_disconnected (
+  const endpoint_uri_pair_t &endpoint_uri_pair_, zmq::fd_t fd_)
 {
-    event (endpoint_uri_, fd_, ZMQ_EVENT_DISCONNECTED);
+    event (endpoint_uri_pair_, fd_, ZMQ_EVENT_DISCONNECTED);
 }
 
 void zmq::socket_base_t::event_handshake_failed_no_detail (
-  const std::string &endpoint_uri_, int err_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_NO_DETAIL);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_NO_DETAIL);
 }
 
 void zmq::socket_base_t::event_handshake_failed_protocol (
-  const std::string &endpoint_uri_, int err_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_PROTOCOL);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_PROTOCOL);
 }
 
 void zmq::socket_base_t::event_handshake_failed_auth (
-  const std::string &endpoint_uri_, int err_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_AUTH);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_HANDSHAKE_FAILED_AUTH);
 }
 
 void zmq::socket_base_t::event_handshake_succeeded (
-  const std::string &endpoint_uri_, int err_)
+  const endpoint_uri_pair_t &endpoint_uri_pair_, int err_)
 {
-    event (endpoint_uri_, err_, ZMQ_EVENT_HANDSHAKE_SUCCEEDED);
+    event (endpoint_uri_pair_, err_, ZMQ_EVENT_HANDSHAKE_SUCCEEDED);
 }
 
-void zmq::socket_base_t::event (const std::string &endpoint_uri_,
-                                intptr_t value_,
-                                int type_)
+void zmq::socket_base_t::event (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                                uint64_t value_,
+                                uint64_t type_)
 {
     scoped_lock_t lock (_monitor_sync);
     if (_monitor_events & type_) {
-        monitor_event (type_, value_, endpoint_uri_);
+        monitor_event (type_, value_, endpoint_uri_pair_);
     }
 }
 
 //  Send a monitor event
-void zmq::socket_base_t::monitor_event (int event_,
-                                        intptr_t value_,
-                                        const std::string &endpoint_uri_) const
+void zmq::socket_base_t::monitor_event (
+  uint64_t event_,
+  uint64_t value_,
+  const endpoint_uri_pair_t &endpoint_uri_pair_) const
 {
     // this is a private method which is only called from
-    // contexts where the mutex has been locked before
+    // contexts where the _monitor_sync mutex has been locked before
 
     if (_monitor_socket) {
-        //  Send event in first frame
-        const uint16_t event = static_cast<uint16_t> (event_);
-        const uint32_t value = static_cast<uint32_t> (value_);
         zmq_msg_t msg;
-        zmq_msg_init_size (&msg, sizeof (event) + sizeof (value));
-        uint8_t *data = static_cast<uint8_t *> (zmq_msg_data (&msg));
-        //  Avoid dereferencing uint32_t on unaligned address
-        memcpy (data + 0, &event, sizeof (event));
-        memcpy (data + sizeof (event), &value, sizeof (value));
-        zmq_sendmsg (_monitor_socket, &msg, ZMQ_SNDMORE);
 
-        //  Send address in second frame
-        zmq_msg_init_size (&msg, endpoint_uri_.size ());
-        memcpy (zmq_msg_data (&msg), endpoint_uri_.c_str (),
-                endpoint_uri_.size ());
-        zmq_sendmsg (_monitor_socket, &msg, 0);
+        switch (options.monitor_event_version) {
+            case 1: {
+                //  The API should not allow to activate unsupported events
+                zmq_assert (event_ <= std::numeric_limits<uint16_t>::max ());
+                zmq_assert (value_ <= std::numeric_limits<uint32_t>::max ());
+
+                //  Send event and value in first frame
+                const uint16_t event = static_cast<uint16_t> (event_);
+                const uint32_t value = static_cast<uint32_t> (value_);
+                zmq_msg_init_size (&msg, sizeof (event) + sizeof (value));
+                uint8_t *data = static_cast<uint8_t *> (zmq_msg_data (&msg));
+                //  Avoid dereferencing uint32_t on unaligned address
+                memcpy (data + 0, &event, sizeof (event));
+                memcpy (data + sizeof (event), &value, sizeof (value));
+                zmq_msg_send (&msg, _monitor_socket, ZMQ_SNDMORE);
+
+                const std::string &endpoint_uri =
+                  endpoint_uri_pair_.identifier ();
+
+                //  Send address in second frame
+                zmq_msg_init_size (&msg, endpoint_uri.size ());
+                memcpy (zmq_msg_data (&msg), endpoint_uri.c_str (),
+                        endpoint_uri.size ());
+                zmq_msg_send (&msg, _monitor_socket, 0);
+            } break;
+            case 2: {
+                //  Send event in first frame (64bit unsigned)
+                zmq_msg_init_size (&msg, sizeof event_);
+                memcpy (zmq_msg_data (&msg), &event_, sizeof event_);
+                zmq_msg_send (&msg, _monitor_socket, ZMQ_SNDMORE);
+
+                //  Send value in second frame (64bit unsigned)
+                zmq_msg_init_size (&msg, sizeof value_);
+                memcpy (zmq_msg_data (&msg), &value_, sizeof value_);
+                zmq_msg_send (&msg, _monitor_socket, ZMQ_SNDMORE);
+
+                //  Send local endpoint URI in third frame (string)
+                zmq_msg_init_size (&msg, endpoint_uri_pair_.local.size ());
+                memcpy (zmq_msg_data (&msg), endpoint_uri_pair_.local.c_str (),
+                        endpoint_uri_pair_.local.size ());
+                zmq_msg_send (&msg, _monitor_socket, ZMQ_SNDMORE);
+
+                //  Send remote endpoint URI in fourth frame (string)
+                zmq_msg_init_size (&msg, endpoint_uri_pair_.remote.size ());
+                memcpy (zmq_msg_data (&msg), endpoint_uri_pair_.remote.c_str (),
+                        endpoint_uri_pair_.remote.size ());
+                zmq_msg_send (&msg, _monitor_socket, 0);
+            } break;
+        }
     }
 }
 
 void zmq::socket_base_t::stop_monitor (bool send_monitor_stopped_event_)
 {
     // this is a private method which is only called from
-    // contexts where the mutex has been locked before
+    // contexts where the _monitor_sync mutex has been locked before
 
     if (_monitor_socket) {
         if ((_monitor_events & ZMQ_EVENT_MONITOR_STOPPED)
             && send_monitor_stopped_event_)
-            monitor_event (ZMQ_EVENT_MONITOR_STOPPED, 0, "");
+            monitor_event (ZMQ_EVENT_MONITOR_STOPPED, 0,
+                           endpoint_uri_pair_t ());
         zmq_close (_monitor_socket);
         _monitor_socket = NULL;
         _monitor_events = 0;

src/socket_base.hpp

@@ -43,6 +43,7 @@
 #include "i_mailbox.hpp"
 #include "clock.hpp"
 #include "pipe.hpp"
+#include "endpoint.hpp"
 
 extern "C" {
 void zmq_free_event (void *data_, void *hint_);
@@ -118,26 +119,38 @@ class socket_base_t : public own_t,
     void lock ();
     void unlock ();
 
-    int monitor (const char *endpoint_, int events_);
+    int monitor (const char *endpoint_, uint64_t events_, int event_version_);
 
-    void event_connected (const std::string &endpoint_uri_, zmq::fd_t fd_);
-    void event_connect_delayed (const std::string &endpoint_uri_, int err_);
-    void event_connect_retried (const std::string &endpoint_uri_,
+    void event_connected (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                          zmq::fd_t fd_);
+    void event_connect_delayed (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                                int err_);
+    void event_connect_retried (const endpoint_uri_pair_t &endpoint_uri_pair_,
                                 int interval_);
-    void event_listening (const std::string &endpoint_uri_, zmq::fd_t fd_);
-    void event_bind_failed (const std::string &endpoint_uri_, int err_);
-    void event_accepted (const std::string &endpoint_uri_, zmq::fd_t fd_);
-    void event_accept_failed (const std::string &endpoint_uri_, int err_);
-    void event_closed (const std::string &endpoint_uri_, zmq::fd_t fd_);
-    void event_close_failed (const std::string &endpoint_uri_, int err_);
-    void event_disconnected (const std::string &endpoint_uri_, zmq::fd_t fd_);
-    void event_handshake_failed_no_detail (const std::string &endpoint_uri_,
-                                           int err_);
-    void event_handshake_failed_protocol (const std::string &endpoint_uri_,
-                                          int err_);
-    void event_handshake_failed_auth (const std::string &endpoint_uri_,
-                                      int err_);
-    void event_handshake_succeeded (const std::string &endpoint_uri_, int err_);
+    void event_listening (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                          zmq::fd_t fd_);
+    void event_bind_failed (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                            int err_);
+    void event_accepted (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                         zmq::fd_t fd_);
+    void event_accept_failed (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                              int err_);
+    void event_closed (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                       zmq::fd_t fd_);
+    void event_close_failed (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                             int err_);
+    void event_disconnected (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                             zmq::fd_t fd_);
+    void event_handshake_failed_no_detail (
+      const endpoint_uri_pair_t &endpoint_uri_pair_, int err_);
+    void event_handshake_failed_protocol (
+      const endpoint_uri_pair_t &endpoint_uri_pair_, int err_);
+    void
+    event_handshake_failed_auth (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                                 int err_);
+    void
+    event_handshake_succeeded (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                               int err_);
 
     //  Query the state of a specific peer. The default implementation
     //  always returns an ENOTSUP error.
@@ -186,19 +199,22 @@ class socket_base_t : public own_t,
 
   private:
     // test if event should be sent and then dispatch it
-    void event (const std::string &endpoint_uri_, intptr_t value_, int type_);
+    void event (const endpoint_uri_pair_t &endpoint_uri_pair_,
+                uint64_t value_,
+                uint64_t type_);
 
     // Socket event data dispatch
-    void monitor_event (int event_,
-                        intptr_t value_,
-                        const std::string &endpoint_uri_) const;
+    void monitor_event (uint64_t event_,
+                        uint64_t value_,
+                        const endpoint_uri_pair_t &endpoint_uri_pair_) const;
 
     // Monitor socket cleanup
     void stop_monitor (bool send_monitor_stopped_event_ = true);
 
     //  Creates new endpoint ID and adds the endpoint to the map.
-    void
-    add_endpoint (const char *endpoint_uri_, own_t *endpoint_, pipe_t *pipe_);
+    void add_endpoint (const endpoint_uri_pair_t &endpoint_pair_,
+                       own_t *endpoint_,
+                       pipe_t *pipe_);
 
     //  Map of open endpoints.
     typedef std::pair<own_t *, pipe_t *> endpoint_pipe_t;
@@ -295,7 +311,7 @@ class socket_base_t : public own_t,
     void *_monitor_socket;
 
     // Bitmask of events being monitored
-    int _monitor_events;
+    int64_t _monitor_events;
 
     // Last socket endpoint resolved URI
     std::string _last_endpoint;

src/socks_connecter.cpp

@@ -150,15 +150,19 @@ void zmq::socks_connecter_t::in_event ()
             if (rc == -1)
                 error ();
             else {
+                //  TODO query the remote endpoint and pass it here
+                endpoint_uri_pair_t endpoint_pair =
+                  make_unconnected_connect_endpoint_pair (_endpoint);
+
                 //  Create the engine object for this connection.
-                stream_engine_t *engine =
-                  new (std::nothrow) stream_engine_t (_s, options, _endpoint);
+                stream_engine_t *engine = new (std::nothrow)
+                  stream_engine_t (_s, options, endpoint_pair);
                 alloc_assert (engine);
 
                 //  Attach the engine to the corresponding session object.
                 send_attach (_session, engine);
 
-                _socket->event_connected (_endpoint, _s);
+                _socket->event_connected (endpoint_pair, _s);
 
                 rm_fd (_handle);
                 _s = -1;
@@ -225,7 +229,8 @@ void zmq::socks_connecter_t::initiate_connect ()
         _handle = add_fd (_s);
         set_pollout (_handle);
         _status = waiting_for_proxy_connection;
-        _socket->event_connect_delayed (_endpoint, zmq_errno ());
+        _socket->event_connect_delayed (
+          make_unconnected_connect_endpoint_pair (_endpoint), zmq_errno ());
     }
     //  Handle any other error condition by eventual reconnect.
     else {
@@ -272,7 +277,8 @@ void zmq::socks_connecter_t::start_timer ()
         const int interval = get_new_reconnect_ivl ();
         add_timer (interval, reconnect_timer_id);
         _status = waiting_for_reconnect_time;
-        _socket->event_connect_retried (_endpoint, interval);
+        _socket->event_connect_retried (
+          make_unconnected_connect_endpoint_pair (_endpoint), interval);
     }
 }
 
@@ -443,7 +449,8 @@ void zmq::socks_connecter_t::close ()
     const int rc = ::close (_s);
     errno_assert (rc == 0);
 #endif
-    _socket->event_closed (_endpoint, _s);
+    _socket->event_closed (make_unconnected_connect_endpoint_pair (_endpoint),
+                           _s);
     _s = retired_fd;
 }
 

src/stream_connecter_base.cpp

@@ -94,7 +94,8 @@ void zmq::stream_connecter_base_t::add_reconnect_timer ()
     if (options.reconnect_ivl != -1) {
         const int interval = get_new_reconnect_ivl ();
         add_timer (interval, reconnect_timer_id);
-        _socket->event_connect_retried (_endpoint, interval);
+        _socket->event_connect_retried (
+          make_unconnected_connect_endpoint_pair (_endpoint), interval);
         _reconnect_timer_started = true;
     }
 }
@@ -131,7 +132,8 @@ void zmq::stream_connecter_base_t::close ()
     const int rc = ::close (_s);
     errno_assert (rc == 0);
 #endif
-    _socket->event_closed (_endpoint, _s);
+    _socket->event_closed (make_unconnected_connect_endpoint_pair (_endpoint),
+                           _s);
     _s = retired_fd;
 }
 
@@ -145,9 +147,12 @@ void zmq::stream_connecter_base_t::in_event ()
 
 void zmq::stream_connecter_base_t::create_engine (fd_t fd)
 {
+    const endpoint_uri_pair_t endpoint_pair ("TODO query local endpoint",
+                                             _endpoint, endpoint_type_connect);
+
     //  Create the engine object for this connection.
     stream_engine_t *engine =
-      new (std::nothrow) stream_engine_t (fd, options, _endpoint);
+      new (std::nothrow) stream_engine_t (fd, options, endpoint_pair);
     alloc_assert (engine);
 
     //  Attach the engine to the corresponding session object.
@@ -156,7 +161,7 @@ void zmq::stream_connecter_base_t::create_engine (fd_t fd)
     //  Shut the connecter down.
     terminate ();
 
-    _socket->event_connected (_endpoint, fd);
+    _socket->event_connected (endpoint_pair, fd);
 }
 
 void zmq::stream_connecter_base_t::timer_event (int id_)

src/stream_engine.cpp

@@ -100,9 +100,10 @@ static std::string get_peer_address (zmq::fd_t s_)
 }
 
 
-zmq::stream_engine_t::stream_engine_t (fd_t fd_,
-                                       const options_t &options_,
-                                       const std::string &endpoint_) :
+zmq::stream_engine_t::stream_engine_t (
+  fd_t fd_,
+  const options_t &options_,
+  const endpoint_uri_pair_t &endpoint_uri_pair_) :
     _s (fd_),
     _handle (static_cast<handle_t> (NULL)),
     _inpos (NULL),
@@ -117,7 +118,7 @@ zmq::stream_engine_t::stream_engine_t (fd_t fd_,
     _greeting_bytes_read (0),
     _session (NULL),
     _options (options_),
-    _endpoint (endpoint_),
+    _endpoint_uri_pair (endpoint_uri_pair_),
     _plugged (false),
     _next_msg (&stream_engine_t::routing_id_msg),
     _process_msg (&stream_engine_t::process_routing_id_msg),
@@ -894,9 +895,9 @@ void zmq::stream_engine_t::zap_msg_available ()
         restart_output ();
 }
 
-const char *zmq::stream_engine_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::stream_engine_t::get_endpoint () const
 {
-    return _endpoint.c_str ();
+    return _endpoint_uri_pair;
 }
 
 void zmq::stream_engine_t::mechanism_ready ()
@@ -960,7 +961,7 @@ void zmq::stream_engine_t::mechanism_ready ()
         alloc_assert (_metadata);
     }
 
-    _socket->event_handshake_succeeded (_endpoint, 0);
+    _socket->event_handshake_succeeded (_endpoint_uri_pair, 0);
 }
 
 int zmq::stream_engine_t::pull_msg_from_session (msg_t *msg_)
@@ -1081,10 +1082,10 @@ void zmq::stream_engine_t::error (error_reason_t reason_)
         && (_mechanism == NULL
             || _mechanism->status () == mechanism_t::handshaking)) {
         int err = errno;
-        _socket->event_handshake_failed_no_detail (_endpoint, err);
+        _socket->event_handshake_failed_no_detail (_endpoint_uri_pair, err);
     }
 
-    _socket->event_disconnected (_endpoint, _s);
+    _socket->event_disconnected (_endpoint_uri_pair, _s);
     _session->flush ();
     _session->engine_error (reason_);
     unplug ();

src/stream_engine.hpp

@@ -70,7 +70,7 @@ class stream_engine_t : public io_object_t, public i_engine
 
     stream_engine_t (fd_t fd_,
                      const options_t &options_,
-                     const std::string &endpoint_);
+                     const endpoint_uri_pair_t &endpoint_uri_pair_);
     ~stream_engine_t ();
 
     //  i_engine interface implementation.
@@ -79,7 +79,7 @@ class stream_engine_t : public io_object_t, public i_engine
     bool restart_input ();
     void restart_output ();
     void zap_msg_available ();
-    const char *get_endpoint () const;
+    const endpoint_uri_pair_t &get_endpoint () const;
 
     //  i_poll_events interface implementation.
     void in_event ();
@@ -190,8 +190,8 @@ class stream_engine_t : public io_object_t, public i_engine
 
     const options_t _options;
 
-    // String representation of endpoint
-    const std::string _endpoint;
+    //  Representation of the connected endpoints.
+    const endpoint_uri_pair_t _endpoint_uri_pair;
 
     bool _plugged;
 

src/stream_listener_base.cpp

@@ -96,7 +96,7 @@ int zmq::stream_listener_base_t::close ()
     const int rc = ::close (_s);
     errno_assert (rc == 0);
 #endif
-    _socket->event_closed (_endpoint, _s);
+    _socket->event_closed (make_unconnected_bind_endpoint_pair (_endpoint), _s);
     _s = retired_fd;
 
     return 0;
@@ -104,8 +104,11 @@ int zmq::stream_listener_base_t::close ()
 
 void zmq::stream_listener_base_t::create_engine (fd_t fd)
 {
+    const endpoint_uri_pair_t endpoint_pair (_endpoint, get_socket_name (fd),
+                                             endpoint_type_bind);
+
     stream_engine_t *engine =
-      new (std::nothrow) stream_engine_t (fd, options, _endpoint);
+      new (std::nothrow) stream_engine_t (fd, options, endpoint_pair);
     alloc_assert (engine);
 
     //  Choose I/O thread to run connecter in. Given that we are already
@@ -120,5 +123,6 @@ void zmq::stream_listener_base_t::create_engine (fd_t fd)
     session->inc_seqnum ();
     launch_child (session);
     send_attach (session, engine, false);
-    _socket->event_accepted (_endpoint, fd);
+
+    _socket->event_accepted (endpoint_pair, fd);
 }

src/tcp_connecter.cpp

@@ -140,7 +140,8 @@ void zmq::tcp_connecter_t::start_connecting ()
     else if (rc == -1 && errno == EINPROGRESS) {
         _handle = add_fd (_s);
         set_pollout (_handle);
-        _socket->event_connect_delayed (_endpoint, zmq_errno ());
+        _socket->event_connect_delayed (
+          make_unconnected_connect_endpoint_pair (_endpoint), zmq_errno ());
 
         //  add userspace connect timeout
         add_connect_timer ();

src/tcp_listener.cpp

@@ -72,7 +72,8 @@ void zmq::tcp_listener_t::in_event ()
     //  If connection was reset by the peer in the meantime, just ignore it.
     //  TODO: Handle specific errors like ENFILE/EMFILE etc.
     if (fd == retired_fd) {
-        _socket->event_accept_failed (_endpoint, zmq_errno ());
+        _socket->event_accept_failed (
+          make_unconnected_bind_endpoint_pair (_endpoint), zmq_errno ());
         return;
     }
 
@@ -83,7 +84,8 @@ void zmq::tcp_listener_t::in_event ()
              options.tcp_keepalive_idle, options.tcp_keepalive_intvl);
     rc = rc | tune_tcp_maxrt (fd, options.tcp_maxrt);
     if (rc != 0) {
-        _socket->event_accept_failed (_endpoint, zmq_errno ());
+        _socket->event_accept_failed (
+          make_unconnected_bind_endpoint_pair (_endpoint), zmq_errno ());
         return;
     }
 
@@ -107,7 +109,8 @@ int zmq::tcp_listener_t::set_address (const char *addr_)
 
     if (options.use_fd != -1) {
         _s = options.use_fd;
-        _socket->event_listening (_endpoint, _s);
+        _socket->event_listening (
+          make_unconnected_bind_endpoint_pair (_endpoint), _s);
         return 0;
     }
 
@@ -194,7 +197,8 @@ int zmq::tcp_listener_t::set_address (const char *addr_)
         goto error;
 #endif
 
-    _socket->event_listening (_endpoint, _s);
+    _socket->event_listening (make_unconnected_bind_endpoint_pair (_endpoint),
+                              _s);
     return 0;
 
 error:

src/tipc_connecter.cpp

@@ -94,7 +94,8 @@ void zmq::tipc_connecter_t::start_connecting ()
     else if (rc == -1 && errno == EINPROGRESS) {
         _handle = add_fd (_s);
         set_pollout (_handle);
-        _socket->event_connect_delayed (_endpoint, zmq_errno ());
+        _socket->event_connect_delayed (
+          make_unconnected_connect_endpoint_pair (_endpoint), zmq_errno ());
     }
 
     //  Handle any other error condition by eventual reconnect.

src/tipc_listener.cpp

@@ -68,7 +68,8 @@ void zmq::tipc_listener_t::in_event ()
     //  If connection was reset by the peer in the meantime, just ignore it.
     //  TODO: Handle specific errors like ENFILE/EMFILE etc.
     if (fd == retired_fd) {
-        _socket->event_accept_failed (_endpoint, zmq_errno ());
+        _socket->event_accept_failed (
+          make_unconnected_bind_endpoint_pair (_endpoint), zmq_errno ());
         return;
     }
 
@@ -129,7 +130,8 @@ int zmq::tipc_listener_t::set_address (const char *addr_)
     if (rc != 0)
         goto error;
 
-    _socket->event_listening (_endpoint, _s);
+    _socket->event_listening (make_unconnected_bind_endpoint_pair (_endpoint),
+                              _s);
     return 0;
 
 error:

src/udp_engine.cpp

@@ -444,9 +444,9 @@ void zmq::udp_engine_t::out_event ()
         reset_pollout (_handle);
 }
 
-const char *zmq::udp_engine_t::get_endpoint () const
+const zmq::endpoint_uri_pair_t &zmq::udp_engine_t::get_endpoint () const
 {
-    return "";
+    return _empty_endpoint;
 }
 
 void zmq::udp_engine_t::restart_output ()

src/udp_engine.hpp

@@ -43,12 +43,14 @@ class udp_engine_t : public io_object_t, public i_engine
     void in_event ();
     void out_event ();
 
-    const char *get_endpoint () const;
+    const endpoint_uri_pair_t &get_endpoint () const;
 
   private:
     int resolve_raw_address (char *addr_, size_t length_);
     void sockaddr_to_msg (zmq::msg_t *msg_, sockaddr_in *addr_);
 
+    const endpoint_uri_pair_t _empty_endpoint;
+
     bool _plugged;
 
     fd_t _fd;

src/zmq.cpp

@@ -267,12 +267,20 @@ int zmq_getsockopt (void *s_, int option_, void *optval_, size_t *optvallen_)
     return s->getsockopt (option_, optval_, optvallen_);
 }
 
-int zmq_socket_monitor (void *s_, const char *addr_, int events_)
+int zmq_socket_monitor_versioned (void *s_,
+                                  const char *addr_,
+                                  uint64_t events_,
+                                  int event_version_)
 {
     zmq::socket_base_t *s = as_socket_base_t (s_);
     if (!s)
         return -1;
-    return s->monitor (addr_, events_);
+    return s->monitor (addr_, events_, event_version_);
+}
+
+int zmq_socket_monitor (void *s_, const char *addr_, int events_)
+{
+    return zmq_socket_monitor_versioned (s_, addr_, events_, 1);
 }
 
 int zmq_join (void *s_, const char *group_)

src/zmq_draft.h

@@ -123,6 +123,11 @@ int zmq_socket_get_peer_state (void *socket_,
                                const void *routing_id_,
                                size_t routing_id_size_);
 
+int zmq_socket_monitor_versioned (void *s_,
+                                  const char *addr_,
+                                  uint64_t events_,
+                                  int event_version_);
+
 #endif // ZMQ_BUILD_DRAFT_API
 
 #endif //ifndef __ZMQ_DRAFT_H_INCLUDED__