I/O object hierarchy implemented

src/Makefile.am

@@ -55,6 +55,7 @@ libzmq_la_SOURCES = \
     blob.hpp \
     command.hpp \
     config.hpp \
+    connect_session.hpp \
     ctx.hpp \
     decoder.hpp \
     devpoll.hpp \
@@ -70,15 +71,17 @@ libzmq_la_SOURCES = \
     ip.hpp \
     i_engine.hpp \
     i_poll_events.hpp \
+    i_terminate_events.hpp \
     kqueue.hpp \
     lb.hpp \
     likely.hpp \
     msg_content.hpp \
     msg_store.hpp \
     mutex.hpp \
+    named_session.hpp \
     object.hpp \
     options.hpp \
-    owned.hpp \
+    own.hpp \
     pgm_receiver.hpp \
     pgm_sender.hpp \
     pgm_socket.hpp \
@@ -106,6 +109,7 @@ libzmq_la_SOURCES = \
     tcp_listener.hpp \
     tcp_socket.hpp \
     thread.hpp \
+    transient_session.hpp \
     uuid.hpp \
     windows.hpp \
     wire.hpp \
@@ -123,6 +127,7 @@ libzmq_la_SOURCES = \
     zmq_listener.hpp \
     command.cpp \
     ctx.cpp \
+    connect_session.cpp \
     devpoll.cpp \
     epoll.cpp \
     err.cpp \
@@ -134,9 +139,10 @@ libzmq_la_SOURCES = \
     kqueue.cpp \
     lb.cpp \
     msg_store.cpp \
+    named_session.cpp \
     object.cpp \
     options.cpp \
-    owned.cpp \
+    own.cpp \
     pair.cpp \
     pgm_receiver.cpp \
     pgm_sender.cpp \
@@ -160,6 +166,7 @@ libzmq_la_SOURCES = \
     tcp_listener.cpp \
     tcp_socket.cpp \
     thread.cpp \
+    transient_session.cpp \
     uuid.cpp \
     xrep.cpp \
     xreq.cpp \

src/command.hpp

@@ -61,7 +61,7 @@ namespace zmq
 
             //  Sent to socket to let it know about the newly created object.
             struct {
-                class owned_t *object;
+                class own_t *object;
             } own;
 
             //  Attach the engine to the session.
@@ -104,7 +104,7 @@ namespace zmq
             //  Sent by I/O object ot the socket to request the shutdown of
             //  the I/O object.
             struct {
-                class owned_t *object;
+                class own_t *object;
             } term_req;
 
             //  Sent by socket to I/O object to start its shutdown.

src/connect_session.cpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "connect_session.hpp"
+#include "zmq_connecter.hpp"
+
+zmq::connect_session_t::connect_session_t (class io_thread_t *io_thread_,
+      class socket_base_t *socket_, const options_t &options_,
+      const char *protocol_, const char *address_) :
+    session_t (io_thread_, socket_, options_),
+    protocol (protocol_),
+    address (address_)
+{
+}
+
+zmq::connect_session_t::~connect_session_t ()
+{
+}
+
+void zmq::connect_session_t::process_plug ()
+{
+    //  Start connection process immediately.
+    start_connecting ();
+}
+
+void zmq::connect_session_t::start_connecting ()
+{
+    //  Create the connecter object.
+
+    //  Both TCP and IPC transports are using the same infrastructure.
+    if (protocol == "tcp" || protocol == "ipc") {        
+        zmq_connecter_t *connecter = new (std::nothrow) zmq_connecter_t (
+            choose_io_thread (options.affinity), this, options,
+            protocol.c_str (), address.c_str ());
+        zmq_assert (connecter);
+        launch_child (connecter);
+        return;
+    }
+
+#if defined ZMQ_HAVE_OPENPGM
+
+    //  Both PGM and EPGM transports are using the same infrastructure.
+    if (addr_type == "pgm" || addr_type == "epgm") {
+
+        //  For EPGM transport with UDP encapsulation of PGM is used.
+        bool udp_encapsulation = (addr_type == "epgm");
+
+        //  At this point we'll create message pipes to the session straight
+        //  away. There's no point in delaying it as no concept of 'connect'
+        //  exists with PGM anyway.
+        if (options.requires_out) {
+
+            //  PGM sender.
+            pgm_sender_t *pgm_sender =  new (std::nothrow) pgm_sender_t (
+                choose_io_thread (options.affinity), options);
+            zmq_assert (pgm_sender);
+
+            int rc = pgm_sender->init (udp_encapsulation, addr_args.c_str ());
+            if (rc != 0) {
+                delete pgm_sender;
+                return -1;
+            }
+
+            send_attach (this, pgm_sender, blob_t ());
+        }
+        else if (options.requires_in) {
+
+            //  PGM receiver.
+            pgm_receiver_t *pgm_receiver =  new (std::nothrow) pgm_receiver_t (
+                choose_io_thread (options.affinity), options);
+            zmq_assert (pgm_receiver);
+
+            int rc = pgm_receiver->init (udp_encapsulation, addr_args.c_str ());
+            if (rc != 0) {
+                delete pgm_receiver;
+                return -1;
+            }
+
+            send_attach (this, pgm_receiver, blob_t ());
+        }
+        else
+            zmq_assert (false);
+
+        return;
+    }
+#endif
+
+    zmq_assert (false);
+}
+
+void zmq::connect_session_t::detach ()
+{
+    //  Clean up the mess left over by the failed connection.
+    clean_pipes ();
+
+    //  Reconnect.
+    start_connecting ();
+}
+

src/connect_session.hpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_CONNECT_SESSION_HPP_INCLUDED__
+#define __ZMQ_CONNECT_SESSION_HPP_INCLUDED__
+
+#include <string>
+
+#include "session.hpp"
+
+namespace zmq
+{
+
+    //  Connect session contains an address to connect to. On disconnect it
+    //  attempts to reconnect.
+
+    class connect_session_t : public session_t
+    {
+    public:
+
+        connect_session_t (class io_thread_t *io_thread_,
+            class socket_base_t *socket_, const options_t &options_,
+            const char *protocol_, const char *address_);
+        ~connect_session_t ();
+
+        //  i_inout interface implementation.
+        void detach ();
+
+    private:
+
+        //  Start the connection process.
+        void start_connecting ();
+
+        //  Command handlers.
+        void process_plug ();
+
+        //  Address to connect to.
+        std::string protocol;
+        std::string address;
+    };
+
+}
+
+#endif

src/ctx.cpp

@@ -119,6 +119,7 @@ int zmq::ctx_t::term ()
     //  We don't even have to synchronise access to data.
     zmq_assert (sockets.empty ());
 
+//  TODO: We are accessing the list of zombies in unsynchronised manner here!
     //  Get rid of remaining zombie sockets.
     while (!zombies.empty ()) {
         dezombify ();
@@ -173,7 +174,7 @@ zmq::socket_base_t *zmq::ctx_t::create_socket (int type_)
     return s;
 }
 
-void zmq::ctx_t::zombify (socket_base_t *socket_)
+void zmq::ctx_t::zombify_socket (socket_base_t *socket_)
 {
     //  Zombification of socket basically means that its ownership is tranferred
     //  from the application that created it to the context.
@@ -284,7 +285,8 @@ zmq::socket_base_t *zmq::ctx_t::find_endpoint (const char *addr_)
 
 void zmq::ctx_t::dezombify ()
 {
-    //  Try to dezombify each zombie in the list.
+    //  Try to dezombify each zombie in the list. Note that caller is
+    //  responsible for calling this method in the slot_sync critical section.
     for (zombies_t::size_type i = 0; i != zombies.size ();)
         if (zombies [i]->dezombify ()) {
             empty_slots.push_back (zombies [i]->get_slot ());

src/ctx.hpp

@@ -58,7 +58,7 @@ namespace zmq
         class socket_base_t *create_socket (int type_);
 
         //  Make socket a zombie.
-        void zombify (socket_base_t *socket_);
+        void zombify_socket (socket_base_t *socket_);
 
         //  Send command to the destination slot.
         void send_command (uint32_t slot_, const command_t &command_);

src/fq.cpp

@@ -22,11 +22,14 @@
 #include "fq.hpp"
 #include "pipe.hpp"
 #include "err.hpp"
+#include "i_terminate_events.hpp"
 
-zmq::fq_t::fq_t () :
+zmq::fq_t::fq_t (i_terminate_events *sink_) :
     active (0),
     current (0),
-    more (false)
+    more (false),
+    sink (sink_),
+    terminating (false)
 {
 }
 
@@ -42,6 +45,10 @@ void zmq::fq_t::attach (reader_t *pipe_)
     pipes.push_back (pipe_);
     pipes.swap (active, pipes.size () - 1);
     active++;
+
+    //  If we are already terminating, ask the pipe to terminate straight away.
+    if (terminating)
+        pipe_->terminate ();
 }
 
 void zmq::fq_t::terminated (reader_t *pipe_)
@@ -59,15 +66,15 @@ void zmq::fq_t::terminated (reader_t *pipe_)
             current = 0;
     }
     pipes.erase (pipe_);
-}
 
-bool zmq::fq_t::has_pipes ()
-{
-    return !pipes.empty ();
+    if (terminating && pipes.empty ())
+        sink->terminated ();
 }
 
-void zmq::fq_t::term_pipes ()
+void zmq::fq_t::terminate ()
 {
+    terminating = true;
+
     for (pipes_t::size_type i = 0; i != pipes.size (); i++)
         pipes [i]->terminate ();
 }

src/fq.hpp

@@ -33,12 +33,11 @@ namespace zmq
     {
     public:
 
-        fq_t ();
+        fq_t (struct i_terminate_events *sink_);
         ~fq_t ();
 
         void attach (reader_t *pipe_);
-        bool has_pipes ();
-        void term_pipes ();
+        void terminate ();
 
         int recv (zmq_msg_t *msg_, int flags_);
         bool has_in ();
@@ -64,6 +63,12 @@ namespace zmq
         //  there are following parts still waiting in the current pipe.
         bool more;
 
+        //  Object to send events to.
+        i_terminate_events *sink;
+
+        //  If true, termination process is already underway.
+        bool terminating;
+
         fq_t (const fq_t&);
         void operator = (const fq_t&);
     };

src/i_engine.hpp

@@ -20,8 +20,6 @@
 #ifndef __ZMQ_I_ENGINE_HPP_INCLUDED__
 #define __ZMQ_I_ENGINE_HPP_INCLUDED__
 
-#include <stddef.h>
-
 namespace zmq
 {
 
@@ -30,18 +28,19 @@ namespace zmq
         virtual ~i_engine () {}
 
         //  Plug the engine to the session.
-        virtual void plug (struct i_inout *inout_) = 0;
+        virtual void plug (class io_thread_t *io_thread_,
+            struct i_inout *inout_) = 0;
 
         //  Unplug the engine from the session.
         virtual void unplug () = 0;
 
-        //  This method is called by the session to signalise that there
-        //  are messages to send available.
-        virtual void revive () = 0;
-
         //  This method is called by the session to signalise that more
         //  messages can be written to the pipe.
-        virtual void resume_input () = 0;
+        virtual void activate_in () = 0;
+
+        //  This method is called by the session to signalise that there
+        //  are messages to send available.
+        virtual void activate_out () = 0;
     };
 
 }

src/i_inout.hpp

@@ -31,28 +31,17 @@ namespace zmq
     {
         virtual ~i_inout () {}
 
-        //  Engine asks to get a message to send to the network.
+        //  Engine asks for a message to send to the network.
         virtual bool read (::zmq_msg_t *msg_) = 0;
 
-        //  Engine sends the incoming message further on downstream.
+        //  Engine received message from the network and sends it further on.
         virtual bool write (::zmq_msg_t *msg_) = 0;
 
-        //  Flush all the previously written messages downstream.
+        //  Flush all the previously written messages.
         virtual void flush () = 0;
 
-        //  Drop all the references to the engine. The parameter is the object
-        //  to use to reconnect. If reconnection is not required, the argument
-        //  is set to NULL.
-        virtual void detach (class owned_t *reconnecter_) = 0;
-
-        //  Returns least loaded I/O thread.
-        virtual class io_thread_t *get_io_thread () = 0;
-
-        //  Return pointer to the owning socket.
-        virtual class socket_base_t *get_owner () = 0;
-
-        //  Return ordinal number of the session.
-        virtual uint64_t get_ordinal () = 0;
+        //  Engine is dead. Drop all the references to it.
+        virtual void detach () = 0;
     };
 
 }

src/i_terminate_events.hpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_I_TERMINATE_EVENTS_HPP_INCLUDED__
+#define __ZMQ_I_TERMINATE_EVENTS_HPP_INCLUDED__
+
+namespace zmq
+{
+
+    //  Algorithms such as fair queueing (fq_t) and load balancing (lb_t)
+    //  use this interface to communicate termination event to the socket.
+
+    struct i_terminate_events
+    {
+        virtual ~i_terminate_events () {}
+
+        virtual void terminated () = 0;
+    };
+
+}
+
+#endif

src/io_object.cpp

@@ -21,21 +21,35 @@
 #include "io_thread.hpp"
 #include "err.hpp"
 
-zmq::io_object_t::io_object_t (io_thread_t *io_thread_)
+zmq::io_object_t::io_object_t (io_thread_t *io_thread_) :
+    poller (NULL)
 {
-    //  Retrieve the poller from the thread we are running in.
-    poller = io_thread_->get_poller ();
+    if (io_thread_)
+        plug (io_thread_);
 }
 
 zmq::io_object_t::~io_object_t ()
 {
 }
 
-void zmq::io_object_t::set_io_thread (io_thread_t *io_thread_)
+void zmq::io_object_t::plug (io_thread_t *io_thread_)
 {
+    zmq_assert (io_thread_);
+    zmq_assert (!poller);
+
+    //  Retrieve the poller from the thread we are running in.
     poller = io_thread_->get_poller ();
 }
 
+void zmq::io_object_t::unplug ()
+{
+    zmq_assert (poller);
+
+    //  Forget about old poller in preparation to be migrated
+    //  to a different I/O thread.
+    poller = NULL;
+}
+
 zmq::io_object_t::handle_t zmq::io_object_t::add_fd (fd_t fd_)
 {
     return poller->add_fd (fd_, this);

src/io_object.hpp

@@ -40,15 +40,15 @@ namespace zmq
         io_object_t (class io_thread_t *io_thread_ = NULL);
         ~io_object_t ();
 
+        //  When migrating an object from one I/O thread to another, first
+        //  unplug it, then migrate it, then plug it to the new thread.
+        void plug (class io_thread_t *io_thread_);
+        void unplug ();
+
     protected:
 
         typedef poller_t::handle_t handle_t;
 
-        //  Derived class can init/swap the underlying I/O thread.
-        //  Caution: Remove all the file descriptors from the old I/O thread
-        //  before swapping to the new one!
-        void set_io_thread (class io_thread_t *io_thread_);
-
         //  Methods to access underlying poller object.
         handle_t add_fd (fd_t fd_);
         void rm_fd (handle_t handle_);

src/lb.cpp

@@ -22,11 +22,14 @@
 #include "lb.hpp"
 #include "pipe.hpp"
 #include "err.hpp"
+#include "i_terminate_events.hpp"
 
-zmq::lb_t::lb_t () :
+zmq::lb_t::lb_t (i_terminate_events *sink_) :
     active (0),
     current (0),
-    more (false)
+    more (false),
+    sink (sink_),
+    terminating (false)
 {
 }
 
@@ -42,17 +45,22 @@ void zmq::lb_t::attach (writer_t *pipe_)
     pipes.push_back (pipe_);
     pipes.swap (active, pipes.size () - 1);
     active++;
+
+    if (terminating)
+        pipe_->terminate ();
 }
 
-void zmq::lb_t::term_pipes ()
+void zmq::lb_t::terminate ()
 {
+    terminating = true;
+
     for (pipes_t::size_type i = 0; i != pipes.size (); i++)
         pipes [i]->terminate ();
 }
 
 void zmq::lb_t::terminated (writer_t *pipe_)
 {
-    // ???
+    // TODO: ???
     zmq_assert (!more || pipes [current] != pipe_);
 
     //  Remove the pipe from the list; adjust number of active pipes
@@ -63,11 +71,9 @@ void zmq::lb_t::terminated (writer_t *pipe_)
             current = 0;
     }
     pipes.erase (pipe_);
-}
 
-bool zmq::lb_t::has_pipes ()
-{
-    return !pipes.empty ();
+    if (terminating && pipes.empty ())
+        sink->terminated ();
 }
 
 void zmq::lb_t::activated (writer_t *pipe_)

src/lb.hpp

@@ -32,12 +32,11 @@ namespace zmq
     {
     public:
 
-        lb_t ();
+        lb_t (struct i_terminate_events *sink_);
         ~lb_t ();
 
         void attach (writer_t *pipe_);
-        void term_pipes ();
-        bool has_pipes ();
+        void terminate ();
         int send (zmq_msg_t *msg_, int flags_);
         bool has_out ();
 
@@ -61,6 +60,12 @@ namespace zmq
         //  True if last we are in the middle of a multipart message.
         bool more;
 
+        //  Object to send events to.
+        struct i_terminate_events *sink;
+
+        //  If true, termination process is already underway.
+        bool terminating;
+
         lb_t (const lb_t&);
         void operator = (const lb_t&);
     };

src/named_session.cpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "named_session.hpp"
+#include "socket_base.hpp"
+
+/*
+zmq::named_session_t::named_session_t (class io_thread_t *io_thread_,
+      socket_base_t *socket_, const options_t &options_,
+      const blob_t &name_) :
+    session_t (io_thread_, socket_, options_),
+    name (name_)
+{
+    //  Make double sure that the session has valid name.
+    zmq_assert (!name.empty ());
+    zmq_assert (name [0] != 0);
+
+    if (!socket_->register_session (name, this)) {
+
+        //  TODO: There's already a session with the specified
+        //  identity. We should log the error and drop the
+        //  session.
+        zmq_assert (false);
+    }
+}
+
+zmq::named_session_t::~named_session_t ()
+{
+}
+
+void zmq::named_session_t::detach ()
+{
+    //  TODO:
+    zmq_assert (false);
+}
+
+void zmq::named_session_t::attached (const blob_t &peer_identity_)
+{
+    if (!peer_identity.empty ()) {
+
+        //  If both IDs are temporary, no checking is needed.
+        //  TODO: Old ID should be reused in this case...
+        if (peer_identity.empty () || peer_identity [0] != 0 ||
+            peer_identity_.empty () || peer_identity_ [0] != 0) {
+
+            //  If we already know the peer name do nothing, just check whether
+            //  it haven't changed.
+            zmq_assert (peer_identity == peer_identity_);
+        }
+    }
+    else if (!peer_identity_.empty ()) {
+
+        //  Store the peer identity.
+        peer_identity = peer_identity_;
+
+        //  Register the session using the peer name.
+        if (!register_session (peer_identity, this)) {
+
+            //  TODO: There's already a session with the specified
+            //  identity. We should presumably syslog it and drop the
+            //  session.
+            zmq_assert (false);
+        }
+    }
+}
+
+void zmq::named_session_t::detached ()
+{
+    socket->unregister_session (peer_identity);
+}
+*/

src/named_session.hpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_NAMED_SESSION_HPP_INCLUDED__
+#define __ZMQ_NAMED_SESSION_HPP_INCLUDED__
+
+#include "session.hpp"
+#include "blob.hpp"
+
+namespace zmq
+{
+
+    //  Named session is created by listener object when the peer identifies
+    //  itself by a strong name. Named session survives reconnections.
+
+    class named_session_t : public session_t
+    {
+    public:
+
+        named_session_t (class io_thread_t *io_thread_,
+            class socket_base_t *socket_, const options_t &options_, 
+            const blob_t &name_);
+        ~named_session_t ();
+
+        //  i_inout interface implementation.
+        void detach ();
+
+        //  Handle events from session_t base class.
+        void attached (const blob_t &peer_identity_);
+        void detached ();
+
+    private:
+
+        //  Name of the session. Corresponds to the peer's strong identity.
+        blob_t name;
+    };
+
+}
+
+#endif

src/object.cpp

@@ -24,7 +24,6 @@
 #include "err.hpp"
 #include "pipe.hpp"
 #include "io_thread.hpp"
-#include "owned.hpp"
 #include "session.hpp"
 #include "socket_base.hpp"
 
@@ -143,9 +142,9 @@ zmq::io_thread_t *zmq::object_t::choose_io_thread (uint64_t taskset_)
     return ctx->choose_io_thread (taskset_);
 }
 
-void zmq::object_t::zombify (socket_base_t *socket_)
+void zmq::object_t::zombify_socket (socket_base_t *socket_)
 {
-    ctx->zombify (socket_);
+    ctx->zombify_socket (socket_);
 }
 
 void zmq::object_t::send_stop ()
@@ -158,7 +157,7 @@ void zmq::object_t::send_stop ()
     ctx->send_command (slot, cmd);
 }
 
-void zmq::object_t::send_plug (owned_t *destination_, bool inc_seqnum_)
+void zmq::object_t::send_plug (own_t *destination_, bool inc_seqnum_)
 {
     if (inc_seqnum_)
         destination_->inc_seqnum ();
@@ -169,7 +168,7 @@ void zmq::object_t::send_plug (owned_t *destination_, bool inc_seqnum_)
     send_command (cmd);
 }
 
-void zmq::object_t::send_own (socket_base_t *destination_, owned_t *object_)
+void zmq::object_t::send_own (own_t *destination_, own_t *object_)
 {
     destination_->inc_seqnum ();
     command_t cmd;
@@ -206,9 +205,8 @@ void zmq::object_t::send_attach (session_t *destination_, i_engine *engine_,
     send_command (cmd);
 }
 
-void zmq::object_t::send_bind (socket_base_t *destination_,
-    reader_t *in_pipe_, writer_t *out_pipe_, const blob_t &peer_identity_,
-    bool inc_seqnum_)
+void zmq::object_t::send_bind (own_t *destination_, reader_t *in_pipe_,
+    writer_t *out_pipe_, const blob_t &peer_identity_, bool inc_seqnum_)
 {
     if (inc_seqnum_)
         destination_->inc_seqnum ();
@@ -269,8 +267,8 @@ void zmq::object_t::send_pipe_term_ack (reader_t *destination_)
     send_command (cmd);
 }
 
-void zmq::object_t::send_term_req (socket_base_t *destination_,
-    owned_t *object_)
+void zmq::object_t::send_term_req (own_t *destination_,
+    own_t *object_)
 {
     command_t cmd;
     cmd.destination = destination_;
@@ -279,7 +277,7 @@ void zmq::object_t::send_term_req (socket_base_t *destination_,
     send_command (cmd);
 }
 
-void zmq::object_t::send_term (owned_t *destination_)
+void zmq::object_t::send_term (own_t *destination_)
 {
     command_t cmd;
     cmd.destination = destination_;
@@ -287,7 +285,7 @@ void zmq::object_t::send_term (owned_t *destination_)
     send_command (cmd);
 }
 
-void zmq::object_t::send_term_ack (socket_base_t *destination_)
+void zmq::object_t::send_term_ack (own_t *destination_)
 {
     command_t cmd;
     cmd.destination = destination_;
@@ -305,7 +303,7 @@ void zmq::object_t::process_plug ()
     zmq_assert (false);
 }
 
-void zmq::object_t::process_own (owned_t *object_)
+void zmq::object_t::process_own (own_t *object_)
 {
     zmq_assert (false);
 }
@@ -342,7 +340,7 @@ void zmq::object_t::process_pipe_term_ack ()
     zmq_assert (false);
 }
 
-void zmq::object_t::process_term_req (owned_t *object_)
+void zmq::object_t::process_term_req (own_t *object_)
 {
     zmq_assert (false);
 }

src/object.hpp

@@ -53,18 +53,19 @@ namespace zmq
 
         //  Zombify particular socket. In other words, pass the ownership to
         //  the context.
-        void zombify (class socket_base_t *socket_);
+        void zombify_socket (class socket_base_t *socket_);
 
         //  Derived object can use these functions to send commands
         //  to other objects.
         void send_stop ();
-        void send_plug (class owned_t *destination_, bool inc_seqnum_ = true);
-        void send_own (class socket_base_t *destination_,
-            class owned_t *object_);
+        void send_plug (class own_t *destination_,
+            bool inc_seqnum_ = true);
+        void send_own (class own_t *destination_,
+            class own_t *object_);
         void send_attach (class session_t *destination_,
              struct i_engine *engine_, const blob_t &peer_identity_,
              bool inc_seqnum_ = true);
-        void send_bind (class socket_base_t *destination_,
+        void send_bind (class own_t *destination_,
              class reader_t *in_pipe_, class writer_t *out_pipe_,
              const blob_t &peer_identity_, bool inc_seqnum_ = true);
         void send_revive (class object_t *destination_);
@@ -72,16 +73,16 @@ namespace zmq
              uint64_t msgs_read_);
         void send_pipe_term (class writer_t *destination_);
         void send_pipe_term_ack (class reader_t *destination_);
-        void send_term_req (class socket_base_t *destination_,
-            class owned_t *object_);
-        void send_term (class owned_t *destination_);
-        void send_term_ack (class socket_base_t *destination_);
+        void send_term_req (class own_t *destination_,
+            class own_t *object_);
+        void send_term (class own_t *destination_);
+        void send_term_ack (class own_t *destination_);
 
         //  These handlers can be overloaded by the derived objects. They are
         //  called when command arrives from another thread.
         virtual void process_stop ();
         virtual void process_plug ();
-        virtual void process_own (class owned_t *object_);
+        virtual void process_own (class own_t *object_);
         virtual void process_attach (struct i_engine *engine_,
             const blob_t &peer_identity_);
         virtual void process_bind (class reader_t *in_pipe_,
@@ -90,7 +91,7 @@ namespace zmq
         virtual void process_reader_info (uint64_t msgs_read_);
         virtual void process_pipe_term ();
         virtual void process_pipe_term_ack ();
-        virtual void process_term_req (class owned_t *object_);
+        virtual void process_term_req (class own_t *object_);
         virtual void process_term ();
         virtual void process_term_ack ();
 

src/own.cpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "own.hpp"
+#include "err.hpp"
+#include "io_thread.hpp"
+
+zmq::own_t::own_t (class ctx_t *parent_, uint32_t slot_) :
+    object_t (parent_, slot_),
+    terminating (false),
+    sent_seqnum (0),
+    processed_seqnum (0),
+    owner (NULL),
+    term_acks (0)
+{
+}
+
+zmq::own_t::own_t (io_thread_t *io_thread_) :
+    object_t (io_thread_),
+    terminating (false),
+    sent_seqnum (0),
+    processed_seqnum (0),
+    owner (NULL),
+    term_acks (0)
+{
+}
+
+zmq::own_t::~own_t ()
+{
+}
+
+void zmq::own_t::set_owner (own_t *owner_)
+{
+    zmq_assert (!owner);
+    owner = owner_;
+}
+
+void zmq::own_t::inc_seqnum ()
+{
+    //  This function may be called from a different thread!
+    sent_seqnum.add (1);
+}
+
+void zmq::own_t::process_seqnum ()
+{
+    //  Catch up with counter of processed commands.
+    processed_seqnum++;
+
+    //  We may have catched up and still have pending terms acks.
+    check_term_acks ();
+}
+
+void zmq::own_t::launch_child (own_t *object_)
+{
+    //  Specify the owner of the object.
+    object_->set_owner (this);
+
+    //  Plug the object into the I/O thread.
+    send_plug (object_);
+
+    //  Take ownership of the object.
+    send_own (this, object_);
+}
+
+void zmq::own_t::launch_sibling (own_t *object_)
+{
+    //  Specify the owner of the object.
+    object_->set_owner (owner);
+
+    //  Plug the object into its I/O thread.
+    send_plug (object_);
+
+    //  Take ownership of the object.
+    send_own (owner, object_);
+}
+
+void zmq::own_t::process_term_req (own_t *object_)
+{
+    //  When shutting down we can ignore termination requests from owned
+    //  objects. The termination request was already sent to the object.
+    if (terminating)
+        return;
+
+    //  If I/O object is well and alive let's ask it to terminate.
+    owned_t::iterator it = std::find (owned.begin (), owned.end (), object_);
+
+    //  If not found, we assume that termination request was already sent to
+    //  the object so we can safely ignore the request.
+    if (it == owned.end ())
+        return;
+
+    owned.erase (it);
+    register_term_acks (1);
+    send_term (object_);
+}
+
+void zmq::own_t::process_own (own_t *object_)
+{
+    //  If the object is already being shut down, new owned objects are
+    //  immediately asked to terminate.
+    if (terminating) {
+        register_term_acks (1);
+        send_term (object_);
+        return;
+    }
+
+    //  Store the reference to the owned object.
+    owned.insert (object_);
+}
+
+void zmq::own_t::terminate ()
+{
+    //  If termination is already underway, there's no point
+    //  in starting it anew.
+    if (terminating)
+        return;
+
+    //  As for the root of the ownership tree, there's noone to terminate it,
+    //  so it has to terminate itself.
+    if (!owner) {
+        process_term ();
+        return;
+    }
+
+    //  If I am an owned object, I'll ask my owner to terminate me.
+    send_term_req (owner, this);
+}
+
+void zmq::own_t::process_term ()
+{
+    //  Double termination should never happen.
+    zmq_assert (!terminating);
+
+    //  Send termination request to all owned objects. 
+    for (owned_t::iterator it = owned.begin (); it != owned.end (); it++)
+        send_term (*it);
+    register_term_acks (owned.size ());
+    owned.clear ();
+
+    //  Start termination process and check whether by chance we cannot
+    //  terminate immediately.
+    terminating = true;
+    check_term_acks ();
+}
+
+void zmq::own_t::register_term_acks (int count_)
+{
+    term_acks += count_;
+}
+
+void zmq::own_t::unregister_term_ack ()
+{
+    zmq_assert (term_acks > 0);
+    term_acks--;
+
+    //  This may be a last ack we are waiting for before termination...
+    check_term_acks (); 
+}
+
+void zmq::own_t::process_term_ack ()
+{
+    unregister_term_ack ();
+}
+
+void zmq::own_t::check_term_acks ()
+{
+    if (terminating && processed_seqnum == sent_seqnum.get () &&
+          term_acks == 0) {
+
+        //  Sanity check. There should be no active children at this point.
+        zmq_assert (owned.empty ());
+
+        //  The root object has nobody to confirm the termination to.
+        //  Other nodes will confirm the termination to the owner.
+        if (owner)
+            send_term_ack (owner);
+
+        //  Deallocate the resources.
+        delete this;
+    }
+}
+

src/owned.hpp → src/own.hpp

@@ -17,26 +17,35 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef __ZMQ_OWNED_HPP_INCLUDED__
-#define __ZMQ_OWNED_HPP_INCLUDED__
+#ifndef __ZMQ_OWN_HPP_INCLUDED__
+#define __ZMQ_OWN_HPP_INCLUDED__
 
-#include "socket_base.hpp"
+#include <set>
+#include <algorithm>
+
+#include "object.hpp"
 #include "atomic_counter.hpp"
 #include "stdint.hpp"
 
 namespace zmq
 {
 
-    //  Base class for objects owned by individual sockets. Handles
-    //  initialisation and destruction of such objects.
+    //  Base class for objects forming a part of ownership hierarchy.
+    //  It handles initialisation and destruction of such objects.
 
-    class owned_t : public object_t
+    class own_t : public object_t
     {
     public:
 
-        //  The object will live in parent's thread, however, its lifetime
-        //  will be managed by its owner socket.
-        owned_t (object_t *parent_, socket_base_t *owner_);
+        //  Note that the owner is unspecified in the constructor.
+        //  It'll be supplied later on when the object is plugged in.
+
+        //  The object is not living within an I/O thread. It has it's own
+        //  thread outside of 0MQ infrastructure.
+        own_t (class ctx_t *parent_, uint32_t slot_);
+
+        //  The object is living within I/O thread.
+        own_t (class io_thread_t *io_thread_);
 
         //  When another owned object wants to send command to this object
         //  it calls this function to let it know it should not shut down
@@ -45,48 +54,77 @@ namespace zmq
 
     protected:
 
-        //  A mechanism allowing derived owned objects to postpone the
-        //  termination process. Default implementation defines no such delay.
-        //  Note that the derived object has to call finalise method when the
-        //  delay is over.
-        virtual bool is_terminable ();
-        void finalise ();
+        //  Launch the supplied object and become its owner.
+        void launch_child (own_t *object_);
 
-        //  Ask owner socket to terminate this object.
-        void term ();
+        //  Launch the supplied object and make it your sibling (make your
+        //  owner become its owner as well).
+        void launch_sibling (own_t *object_);
 
-        //  Derived object destroys owned_t. No point in allowing others to
-        //  invoke the destructor. At the same time, it has to be virtual so
-        //  that generic owned_t deallocation mechanism destroys specific type
-        //  of the owned object correctly.
-        virtual ~owned_t ();
+        //  Ask owner object to terminate this object. It may take a while
+        //  while actual termination is started. This function should not be
+        //  called more than once.
+        void terminate ();
 
-        //  io_object_t defines a new handler used to disconnect the object
-        //  from the poller object. Implement the handlen in the derived
-        //  classes to ensure sane cleanup.
-        virtual void process_unplug () = 0;
+        //  Derived object destroys own_t. There's no point in allowing
+        //  others to invoke the destructor. At the same time, it has to be
+        //  virtual so that generic own_t deallocation mechanism destroys
+        //  specific type of the owned object correctly.
+        virtual ~own_t ();
 
-        //  Socket owning this object. When the socket is being closed it's
-        //  responsible for shutting down this object.
-        socket_base_t *owner;
+        //  Term handler is protocted rather than private so that it can
+        //  be intercepted by the derived class. This is useful to add custom
+        //  steps to the beginning of the termination process.
+        void process_term ();
+
+        //  Use following two functions to wait for arbitrary events before
+        //  terminating. Just add number of events to wait for using
+        //  register_tem_acks functions. When event occurs, call
+        //  remove_term_ack. When number of pending acks reaches zero
+        //  object will be deallocated.
+        void register_term_acks (int count_);
+        void unregister_term_ack ();
 
     private:
 
+        //  Set owner of the object
+        void set_owner (own_t *owner_);
+
         //  Handlers for incoming commands.
-        void process_term ();
+        void process_own (own_t *object_);
+        void process_term_req (own_t *object_);
+        void process_term_ack ();
+
         void process_seqnum ();
 
+        //  Check whether all the peding term acks were delivered.
+        //  If so, deallocate this object.
+        void check_term_acks ();
+
+        //  True if termination was already initiated. If so, we can destroy
+        //  the object if there are no more child objects or pending term acks.
+        bool terminating;
+
         //  Sequence number of the last command sent to this object.
         atomic_counter_t sent_seqnum;
 
         //  Sequence number of the last command processed by this object.
         uint64_t processed_seqnum;
 
-        //  If true, the object is already shutting down.
-        bool shutting_down;
+        //  Socket owning this object. It's responsible for shutting down
+        //  this object.
+        own_t *owner;
+
+        //  List of all objects owned by this socket. We are responsible
+        //  for deallocating them before we quit.
+        typedef std::set <own_t*> owned_t;
+        owned_t owned;
+
+        //  Number of events we have to get before we can destroy the object.
+        int term_acks;
 
-        owned_t (const owned_t&);
-        void operator = (const owned_t&);
+        own_t (const own_t&);
+        void operator = (const own_t&);
     };
 
 }

src/pair.cpp

@@ -28,7 +28,8 @@ zmq::pair_t::pair_t (class ctx_t *parent_, uint32_t slot_) :
     inpipe (NULL),
     outpipe (NULL),
     inpipe_alive (false),
-    outpipe_alive (false)
+    outpipe_alive (false),
+    terminating (false)
 {
     options.requires_in = true;
     options.requires_out = true;
@@ -43,6 +44,7 @@ zmq::pair_t::~pair_t ()
 void zmq::pair_t::xattach_pipes (class reader_t *inpipe_,
     class writer_t *outpipe_, const blob_t &peer_identity_)
 {
+    zmq_assert (!terminating);
     zmq_assert (!inpipe && !outpipe);
 
     inpipe = inpipe_;
@@ -59,6 +61,9 @@ void zmq::pair_t::terminated (class reader_t *pipe_)
     zmq_assert (pipe_ == inpipe);
     inpipe = NULL;
     inpipe_alive = false;
+
+    if (terminating)
+        unregister_term_ack ();
 }
 
 void zmq::pair_t::terminated (class writer_t *pipe_)
@@ -66,19 +71,22 @@ void zmq::pair_t::terminated (class writer_t *pipe_)
     zmq_assert (pipe_ == outpipe);
     outpipe = NULL;
     outpipe_alive = false;
+
+    if (terminating)
+        unregister_term_ack ();
 }
 
-void zmq::pair_t::xterm_pipes ()
+void zmq::pair_t::process_term ()
 {
-    if (inpipe)
+    zmq_assert (inpipe && outpipe);
+
+    terminating = true;
+
+    register_term_acks (2);
     inpipe->terminate ();
-    if (outpipe)
     outpipe->terminate ();
-}
 
-bool zmq::pair_t::xhas_pipes ()
-{
-    return inpipe != NULL || outpipe != NULL;
+    socket_base_t::process_term ();
 }
 
 void zmq::pair_t::activated (class reader_t *pipe_)

src/pair.hpp

@@ -39,8 +39,6 @@ namespace zmq
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsend (zmq_msg_t *msg_, int flags_);
         int xrecv (zmq_msg_t *msg_, int flags_);
         bool xhas_in ();
@@ -56,12 +54,17 @@ namespace zmq
 
     private:
 
+        //  Hook into termination process.
+        void process_term ();
+
         class reader_t *inpipe;
         class writer_t *outpipe;
 
         bool inpipe_alive;
         bool outpipe_alive;
 
+        bool terminating;
+
         pair_t (const pair_t&);
         void operator = (const pair_t&);
     };

src/pub.cpp

@@ -26,7 +26,8 @@
 
 zmq::pub_t::pub_t (class ctx_t *parent_, uint32_t slot_) :
     socket_base_t (parent_, slot_),
-    active (0)
+    active (0),
+    terminating (false)
 {
     options.requires_in = false;
     options.requires_out = true;
@@ -40,6 +41,7 @@ zmq::pub_t::~pub_t ()
 void zmq::pub_t::xattach_pipes (class reader_t *inpipe_,
     class writer_t *outpipe_, const blob_t &peer_identity_)
 {
+    zmq_assert (!terminating);
     zmq_assert (!inpipe_);
 
     outpipe_->set_event_sink (this);
@@ -47,18 +49,26 @@ void zmq::pub_t::xattach_pipes (class reader_t *inpipe_,
     pipes.push_back (outpipe_);
     pipes.swap (active, pipes.size () - 1);
     active++;
+
+    if (terminating) {
+        register_term_acks (1);
+        outpipe_->terminate ();
+    }
 }
 
-void zmq::pub_t::xterm_pipes ()
+void zmq::pub_t::process_term ()
 {
+    terminating = true;
+
     //  Start shutdown process for all the pipes.
     for (pipes_t::size_type i = 0; i != pipes.size (); i++)
         pipes [i]->terminate ();
-}
 
-bool zmq::pub_t::xhas_pipes ()
-{
-    return !pipes.empty ();
+    //  Wait for pipes to terminate before terminating yourself.
+    register_term_acks (pipes.size ());
+
+    //  Continue with the termination immediately.
+    socket_base_t::process_term ();
 }
 
 void zmq::pub_t::activated (writer_t *pipe_)
@@ -75,6 +85,10 @@ void zmq::pub_t::terminated (writer_t *pipe_)
     if (pipes.index (pipe_) < active)
         active--;
     pipes.erase (pipe_);
+
+    //  If we are already terminating, wait for one term ack less.
+    if (terminating)
+        unregister_term_ack ();
 }
 
 int zmq::pub_t::xsend (zmq_msg_t *msg_, int flags_)

src/pub.hpp

@@ -37,8 +37,6 @@ namespace zmq
         //  Implementations of virtual functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsend (zmq_msg_t *msg_, int flags_);
         bool xhas_out ();
 
@@ -48,6 +46,9 @@ namespace zmq
 
     private:
 
+        //  Hook into the termination process.
+        void process_term ();
+
         //  Write the message to the pipe. Make the pipe inactive if writing
         //  fails. In such a case false is returned.
         bool write (class writer_t *pipe_, zmq_msg_t *msg_);
@@ -60,6 +61,9 @@ namespace zmq
         //  beginning of the pipes array.
         pipes_t::size_type active;
 
+        //  True if termination process is already underway.
+        bool terminating;
+
         pub_t (const pub_t&);
         void operator = (const pub_t&);
     };

src/pull.cpp

@@ -23,7 +23,8 @@
 #include "err.hpp"
 
 zmq::pull_t::pull_t (class ctx_t *parent_, uint32_t slot_) :
-    socket_base_t (parent_, slot_)
+    socket_base_t (parent_, slot_),
+    fq (this)
 {
     options.requires_in = true;
     options.requires_out = false;
@@ -40,14 +41,17 @@ void zmq::pull_t::xattach_pipes (class reader_t *inpipe_,
     fq.attach (inpipe_);
 }
 
-void zmq::pull_t::xterm_pipes ()
+void zmq::pull_t::process_term ()
 {
-    fq.term_pipes ();
+    register_term_acks (1);
+    fq.terminate ();
+
+    socket_base_t::process_term ();
 }
 
-bool zmq::pull_t::xhas_pipes ()
+void zmq::pull_t::terminated ()
 {
-    return fq.has_pipes ();
+    unregister_term_ack ();
 }
 
 int zmq::pull_t::xrecv (zmq_msg_t *msg_, int flags_)

src/pull.hpp

@@ -17,32 +17,39 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef __ZMQ_UPSTREAM_HPP_INCLUDED__
-#define __ZMQ_UPSTREAM_HPP_INCLUDED__
+#ifndef __ZMQ_PULL_HPP_INCLUDED__
+#define __ZMQ_PULL_HPP_INCLUDED__
 
+#include "i_terminate_events.hpp"
 #include "socket_base.hpp"
 #include "fq.hpp"
 
 namespace zmq
 {
 
-    class pull_t : public socket_base_t
+    class pull_t : public socket_base_t, public i_terminate_events
     {
     public:
 
         pull_t (class ctx_t *parent_, uint32_t slot_);
         ~pull_t ();
 
+    protected:
+
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xrecv (zmq_msg_t *msg_, int flags_);
         bool xhas_in ();
 
     private:
 
+        //  i_terminate_events interface implementation.
+        void terminated ();
+
+        //  Hook into the termination process.
+        void process_term ();
+
         //  Fair queueing object for inbound pipes.
         fq_t fq;
 

src/push.cpp

@@ -24,7 +24,8 @@
 #include "pipe.hpp"
 
 zmq::push_t::push_t (class ctx_t *parent_, uint32_t slot_) :
-    socket_base_t (parent_, slot_)
+    socket_base_t (parent_, slot_),
+    lb (this)
 {
     options.requires_in = false;
     options.requires_out = true;
@@ -41,14 +42,17 @@ void zmq::push_t::xattach_pipes (class reader_t *inpipe_,
     lb.attach (outpipe_);
 }
 
-void zmq::push_t::xterm_pipes ()
+void zmq::push_t::process_term ()
 {
-    lb.term_pipes ();
+    register_term_acks (1);
+    lb.terminate ();
+
+    socket_base_t::process_term ();
 }
 
-bool zmq::push_t::xhas_pipes ()
+void zmq::push_t::terminated ()
 {
-    return lb.has_pipes ();
+    unregister_term_ack ();
 }
 
 int zmq::push_t::xsend (zmq_msg_t *msg_, int flags_)

src/push.hpp

@@ -17,32 +17,39 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef __ZMQ_DOWNSTREAM_HPP_INCLUDED__
-#define __ZMQ_DOWNSTREAM_HPP_INCLUDED__
+#ifndef __ZMQ_PUSH_HPP_INCLUDED__
+#define __ZMQ_PUSH_HPP_INCLUDED__
 
+#include "i_terminate_events.hpp"
 #include "socket_base.hpp"
 #include "lb.hpp"
 
 namespace zmq
 {
 
-    class push_t : public socket_base_t
+    class push_t : public socket_base_t, public i_terminate_events
     {
     public:
 
         push_t (class ctx_t *parent_, uint32_t slot_);
         ~push_t ();
 
+    protected:
+
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsend (zmq_msg_t *msg_, int flags_);
         bool xhas_out ();
 
     private:
 
+        //  i_terminate_events interface implementation.
+        void terminated ();
+
+        //  Hook into the termination process.
+        void process_term ();
+
         //  Load balancer managing the outbound pipes.
         lb_t lb;
 

src/session.cpp

@@ -20,47 +20,25 @@
 #include <new>
 
 #include "session.hpp"
+#include "socket_base.hpp"
 #include "i_engine.hpp"
 #include "err.hpp"
 #include "pipe.hpp"
 
-zmq::session_t::session_t (object_t *parent_, socket_base_t *owner_,
-      const options_t &options_) :
-    owned_t (parent_, owner_),
+zmq::session_t::session_t (class io_thread_t *io_thread_,
+      class socket_base_t *socket_, const options_t &options_) :
+    own_t (io_thread_),
+    options (options_),
     in_pipe (NULL),
     incomplete_in (false),
     active (true),
     out_pipe (NULL),
     engine (NULL),
-    options (options_)
+    socket (socket_),
+    io_thread (io_thread_),
+    attach_processed (false),
+    term_processed (false)
 {    
-    //  It's possible to register the session at this point as it will be
-    //  searched for only on reconnect, i.e. no race condition (session found
-    //  before it is plugged into it's I/O thread) is possible.
-    ordinal = owner->register_session (this);
-}
-
-zmq::session_t::session_t (object_t *parent_, socket_base_t *owner_,
-      const options_t &options_, const blob_t &peer_identity_) :
-    owned_t (parent_, owner_),
-    in_pipe (NULL),
-    incomplete_in (false),
-    active (true),
-    out_pipe (NULL),
-    engine (NULL),
-    ordinal (0),
-    peer_identity (peer_identity_),
-    options (options_)
-{
-    if (!peer_identity.empty () && peer_identity [0] != 0) {
-        if (!owner->register_session (peer_identity, this)) {
-
-            //  TODO: There's already a session with the specified
-            //  identity. We should presumably syslog it and drop the
-            //  session.
-            zmq_assert (false);
-        }
-    }
 }
 
 zmq::session_t::~session_t ()
@@ -69,10 +47,10 @@ zmq::session_t::~session_t ()
     zmq_assert (!out_pipe);
 }
 
-bool zmq::session_t::is_terminable ()
+void zmq::session_t::terminate ()
 {
-    //  The session won't send term_ack until both in & out pipe are closed.
-    return !in_pipe && !out_pipe;
+    //  TODO:
+    zmq_assert (false);
 }
 
 bool zmq::session_t::read (::zmq_msg_t *msg_)
@@ -105,17 +83,8 @@ void zmq::session_t::flush ()
         out_pipe->flush ();
 }
 
-void zmq::session_t::detach (owned_t *reconnecter_)
+void zmq::session_t::clean_pipes ()
 {
-    //  Plug in the reconnecter object if any.
-    if (reconnecter_) {
-        send_plug (reconnecter_);
-        send_own (owner, reconnecter_);
-    }
-
-    //  Engine is terminating itself. No need to deallocate it from here.
-    engine = NULL;
-
     //  Get rid of half-processed messages in the out pipe. Flush any
     //  unflushed messages upstream.
     if (out_pipe) {
@@ -135,26 +104,6 @@ void zmq::session_t::detach (owned_t *reconnecter_)
             zmq_msg_close (&msg);
         }
     }
-    
-    //  Terminate transient session.
-    if (!ordinal && (peer_identity.empty () || peer_identity [0] == 0))
-        term ();
-}
-
-zmq::io_thread_t *zmq::session_t::get_io_thread ()
-{
-    return choose_io_thread (options.affinity);
-}
-
-class zmq::socket_base_t *zmq::session_t::get_owner ()
-{
-    return owner;
-}
-
-uint64_t zmq::session_t::get_ordinal ()
-{
-    zmq_assert (ordinal);
-    return ordinal;
 }
 
 void zmq::session_t::attach_pipes (class reader_t *inpipe_,
@@ -172,6 +121,9 @@ void zmq::session_t::attach_pipes (class reader_t *inpipe_,
         out_pipe = outpipe_;
         out_pipe->set_event_sink (this);
     }
+
+    attach_processed = true;
+    finalise ();
 }
 
 void zmq::session_t::terminated (reader_t *pipe_)
@@ -192,14 +144,14 @@ void zmq::session_t::activated (reader_t *pipe_)
     zmq_assert (in_pipe == pipe_);
     active = true;
     if (engine)
-        engine->revive ();
+        engine->activate_out ();
 }
 
 void zmq::session_t::activated (writer_t *pipe_)
 {
     zmq_assert (out_pipe == pipe_);
     if (engine)
-        engine->resume_input ();
+        engine->activate_in ();
 }
 
 void zmq::session_t::process_plug ()
@@ -214,10 +166,9 @@ void zmq::session_t::process_unplug ()
     //  there may be some commands being sent to the session right now.
 
     //  Unregister the session from the socket.
-    if (ordinal)
-        owner->unregister_session (ordinal);
-    else if (!peer_identity.empty () && peer_identity [0] != 0)
-        owner->unregister_session (peer_identity);
+//    if (!peer_identity.empty () && peer_identity [0] != 0)
+//        unregister_session (peer_identity);
+//  TODO: Should be done in named session.
 
     //  Ask associated pipes to terminate.
     if (in_pipe)
@@ -232,63 +183,65 @@ void zmq::session_t::process_unplug ()
     }
 }
 
+void zmq::session_t::finalise ()
+{
+    //  If all conditions are met, proceed with termination:
+    //  1. Owner object already asked us to terminate.
+    //  2. The pipes were already attached to the session.
+    //  3. Both pipes have already terminated. Note that inbound pipe
+    //     is terminated after delimiter is read, i.e. all messages
+    //     were already sent to the wire.
+    if (term_processed && attach_processed && !in_pipe && !out_pipe)
+        own_t::process_term ();
+}
+
 void zmq::session_t::process_attach (i_engine *engine_,
     const blob_t &peer_identity_)
 {
-    if (!peer_identity.empty ()) {
-
-        //  If both IDs are temporary, no checking is needed.
-        //  TODO: Old ID should be reused in this case...
-        if (peer_identity.empty () || peer_identity [0] != 0 ||
-            peer_identity_.empty () || peer_identity_ [0] != 0) {
-
-            //  If we already know the peer name do nothing, just check whether
-            //  it haven't changed.
-            zmq_assert (peer_identity == peer_identity_);
-        }
-    }
-    else if (!peer_identity_.empty ()) {
-
-        //  Store the peer identity.
-        peer_identity = peer_identity_;
-
-        //  If the session is not registered with the ordinal, let's register
-        //  it using the peer name.
-        if (!ordinal) {
-            if (!owner->register_session (peer_identity, this)) {
-
-                //  TODO: There's already a session with the specified
-                //  identity. We should presumably syslog it and drop the
-                //  session.
-                zmq_assert (false);
-            }
-        }
-    }
-
     //  Check whether the required pipes already exist. If not so, we'll
     //  create them and bind them to the socket object.
     reader_t *socket_reader = NULL;
     writer_t *socket_writer = NULL;
 
     if (options.requires_in && !out_pipe) {
-        create_pipe (owner, this, options.hwm, options.swap, &socket_reader,
+        create_pipe (socket, this, options.hwm, options.swap, &socket_reader,
             &out_pipe);
         out_pipe->set_event_sink (this);
     }
 
     if (options.requires_out && !in_pipe) {
-        create_pipe (this, owner, options.hwm, options.swap, &in_pipe,
+        create_pipe (this, socket, options.hwm, options.swap, &in_pipe,
             &socket_writer);
         in_pipe->set_event_sink (this);
     }
 
     if (socket_reader || socket_writer)
-        send_bind (owner, socket_reader, socket_writer, peer_identity);
+        send_bind (socket, socket_reader, socket_writer, peer_identity);
 
     //  Plug in the engine.
     zmq_assert (!engine);
     zmq_assert (engine_);
     engine = engine_;
-    engine->plug (this);
+    engine->plug (io_thread, this);
+
+    //  Trigger the notfication about the attachment.
+    attached (peer_identity_);
+}
+
+void zmq::session_t::process_term ()
+{
+    //  Here we are pugging into the own_t's termination mechanism.
+    //  The goal is to postpone the termination till all the pending messages
+    //  are sent to the peer.
+    term_processed = true;
+    finalise ();
+}
+
+void zmq::session_t::attached (const blob_t &peer_identity_)
+{
+}
+
+void zmq::session_t::detached ()
+{
 }
 

src/session.hpp

@@ -20,8 +20,8 @@
 #ifndef __ZMQ_SESSION_HPP_INCLUDED__
 #define __ZMQ_SESSION_HPP_INCLUDED__
 
+#include "own.hpp"
 #include "i_inout.hpp"
-#include "owned.hpp"
 #include "options.hpp"
 #include "blob.hpp"
 #include "pipe.hpp"
@@ -30,29 +30,22 @@ namespace zmq
 {
 
     class session_t :
-        public owned_t,
+        public own_t,
         public i_inout,
         public i_reader_events,
         public i_writer_events
     {
     public:
 
-        //  Creates unnamed session.
-        session_t (object_t *parent_, socket_base_t *owner_,
-            const options_t &options_);
+        session_t (class io_thread_t *io_thread_,
+            class socket_base_t *socket_, const options_t &options_);
 
-        //  Creates named session.
-        session_t (object_t *parent_, socket_base_t *owner_,
-            const options_t &options_, const blob_t &peer_identity_);
-
-        //  i_inout interface implementation.
+        //  i_inout interface implementation. Note that detach method is not
+        //  implemented by generic session. Different session types may handle
+        //  engine disconnection in different ways.
         bool read (::zmq_msg_t *msg_);
         bool write (::zmq_msg_t *msg_);
         void flush ();
-        void detach (owned_t *reconnecter_);
-        class io_thread_t *get_io_thread ();
-        class socket_base_t *get_owner ();
-        uint64_t get_ordinal ();
 
         void attach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
@@ -65,19 +58,40 @@ namespace zmq
         void activated (class writer_t *pipe_);
         void terminated (class writer_t *pipe_);
 
-    private:
+    protected:
+
+        //  Forcefully close this session (without sending
+        //  outbound messages to the wire).
+        void terminate ();
+
+        //  Two events for the derived session type. Attached is triggered
+        //  when session is attached to a peer, detached is triggered at the
+        //  beginning of the termination process when session is about to
+        //  be detached from the peer.
+        virtual void attached (const blob_t &peer_identity_);
+        virtual void detached ();
 
         ~session_t ();
 
-        //  Define the delayed termination. (I.e. termination is postponed
-        //  till all the data is flushed to the kernel.)
-        bool is_terminable ();
+        //  Remove any half processed messages. Flush unflushed messages.
+        //  Call this function when engine disconnect to get rid of leftovers.
+        void clean_pipes ();
+
+        //  Inherited socket options. These are visible to all session classes.
+        options_t options;
+
+    private:
 
         //  Handlers for incoming commands.
         void process_plug ();
         void process_unplug ();
         void process_attach (struct i_engine *engine_,
             const blob_t &peer_identity_);
+        void process_term ();
+
+        //  Check whether object is ready for termination. If so proceed
+        //  with closing child objects.
+        void finalise ();
 
         //  Inbound pipe, i.e. one the session is getting messages from.
         class reader_t *in_pipe;
@@ -92,18 +106,25 @@ namespace zmq
         //  Outbound pipe, i.e. one the socket is sending messages to.
         class writer_t *out_pipe;
 
+        //  The protocol I/O engine connected to the session.
         struct i_engine *engine;
 
-        //  Session is identified by ordinal in the case when it was created
-        //  before connection to the peer was established and thus we are
-        //  unaware of peer's identity.
-        uint64_t ordinal;
-
-        //  Identity of the peer.
+        //  Identity of the peer (say the component on the other side
+        //  of TCP connection).
         blob_t peer_identity;
 
-        //  Inherited socket options.
-        options_t options;
+        //  The socket the session belongs to.
+        class socket_base_t *socket;
+
+        //  I/O thread the session is living in. It will be used to plug in
+        //  the engines into the same thread.
+        class io_thread_t *io_thread;
+
+        //  True if pipes were already attached.
+        bool attach_processed;
+
+        //  True if term command was already processed.
+        bool term_processed;
 
         session_t (const session_t&);
         void operator = (const session_t&);

src/socket_base.hpp

@@ -20,13 +20,12 @@
 #ifndef __ZMQ_SOCKET_BASE_HPP_INCLUDED__
 #define __ZMQ_SOCKET_BASE_HPP_INCLUDED__
 
-#include <set>
 #include <map>
 #include <vector>
 
 #include "../include/zmq.h"
 
-#include "object.hpp"
+#include "own.hpp"
 #include "yarray_item.hpp"
 #include "mutex.hpp"
 #include "options.hpp"
@@ -35,12 +34,13 @@
 #include "signaler.hpp"
 #include "stdint.hpp"
 #include "blob.hpp"
+#include "own.hpp"
 
 namespace zmq
 {
 
     class socket_base_t :
-        public object_t,
+        public own_t,
         public yarray_item_t
     {
     public:
@@ -65,30 +65,16 @@ namespace zmq
         int recv (zmq_msg_t *msg_, int flags_);
         int close ();
 
-        //  When another owned object wants to send command to this object
-        //  it calls this function to let it know it should not shut down
-        //  before the command is delivered.
-        void inc_seqnum ();
-
         //  These functions are used by the polling mechanism to determine
         //  which events are to be reported from this socket.
         bool has_in ();
         bool has_out ();
 
-        //  The list of sessions cannot be accessed via inter-thread
-        //  commands as it is unacceptable to wait for the completion of the
-        //  action till user application yields control of the application
-        //  thread to 0MQ. Locking is used instead.
-        //  There are two distinct types of sessions: those identified by name
-        //  and those identified by ordinal number. Thus two sets of session
-        //  management functions.
+        //  Registry of named sessions.
         bool register_session (const blob_t &peer_identity_,
             class session_t *session_);
         void unregister_session (const blob_t &peer_identity_);
         class session_t *find_session (const blob_t &peer_identity_);
-        uint64_t register_session (class session_t *session_);
-        void unregister_session (uint64_t ordinal_);
-        class session_t *find_session (uint64_t ordinal_);
 
         //  i_reader_events interface implementation.
         void activated (class reader_t *pipe_);
@@ -99,7 +85,7 @@ namespace zmq
         void terminated (class writer_t *pipe_);
 
         //  This function should be called only on zombie sockets. It tries
-        //  to deallocate the zombie and returns true is successful.
+        //  to deallocate the zombie. Returns true if zombie is finally dead.
         bool dezombify ();
 
     protected:
@@ -109,11 +95,8 @@ namespace zmq
 
         //  Concrete algorithms for the x- methods are to be defined by
         //  individual socket types.
-
         virtual void xattach_pipes (class reader_t *inpipe_,
             class writer_t *outpipe_, const blob_t &peer_identity_) = 0;
-        virtual void xterm_pipes () = 0;
-        virtual bool xhas_pipes () = 0;
 
         //  The default implementation assumes there are no specific socket
         //  options for the particular socket type. If not so, overload this
@@ -132,12 +115,22 @@ namespace zmq
         //  Socket options.
         options_t options;
 
+        //  We are declaring termination handler as protected so that
+        //  individual socket types can hook into the termination process
+        //  by overloading it.
+        void process_term ();
+
+    private:
+
+//  TODO: Check whether we still need this flag...
         //  If true, socket was already closed but not yet deallocated
         //  because either shutdown is in process or there are still pipes
         //  attached to the socket.
         bool zombie;
 
-    private:
+        //  Check whether transport protocol, as specified in connect or
+        //  bind, is available and compatible with the socket type.
+        int check_protocol (const std::string &protocol_);
 
         //  If no identity set generate one and call xattach_pipes ().
         void attach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
@@ -151,12 +144,9 @@ namespace zmq
 
         //  Handlers for incoming commands.
         void process_stop ();
-        void process_own (class owned_t *object_);
         void process_bind (class reader_t *in_pipe_, class writer_t *out_pipe_,
             const blob_t &peer_identity_);
-        void process_term_req (class owned_t *object_);
-        void process_term_ack ();
-        void process_seqnum ();
+        void process_unplug ();
 
         //  App thread's signaler object.
         signaler_t signaler;
@@ -164,36 +154,18 @@ namespace zmq
         //  Timestamp of when commands were processed the last time.
         uint64_t last_processing_time;
 
-        //  List of all I/O objects owned by this socket. The socket is
-        //  responsible for deallocating them before it quits.
-        typedef std::set <class owned_t*> io_objects_t;
-        io_objects_t io_objects;
-
-        //  Number of I/O objects that were already asked to terminate
-        //  but haven't acknowledged it yet.
-        int pending_term_acks;
-
         //  Number of messages received since last command processing.
         int ticks;
 
         //  If true there's a half-read message in the socket.
         bool rcvmore;
 
-        //  Sequence number of the last command sent to this object.
-        atomic_counter_t sent_seqnum;
-
-        //  Sequence number of the last command processed by this object.
-        uint64_t processed_seqnum;
-
         //  Lists of existing sessions. This lists are never referenced from
-        //  within the socket, instead they are used by I/O objects owned by
+        //  within the socket, instead they are used by objects owned by
         //  the socket. As those objects can live in different threads,
         //  the access is synchronised by mutex.
-        typedef std::map <blob_t, session_t*> named_sessions_t;
-        named_sessions_t named_sessions;
-        typedef std::map <uint64_t, session_t*> unnamed_sessions_t;
-        unnamed_sessions_t unnamed_sessions;
-        uint64_t next_ordinal;
+        typedef std::map <blob_t, session_t*> sessions_t;
+        sessions_t sessions;
         mutex_t sessions_sync;
 
         socket_base_t (const socket_base_t&);

src/sub.cpp

@@ -26,6 +26,7 @@
 
 zmq::sub_t::sub_t (class ctx_t *parent_, uint32_t slot_) :
     socket_base_t (parent_, slot_),
+    fq (this),
     has_message (false),
     more (false)
 {
@@ -46,14 +47,17 @@ void zmq::sub_t::xattach_pipes (class reader_t *inpipe_,
     fq.attach (inpipe_);
 }
 
-void zmq::sub_t::xterm_pipes ()
+void zmq::sub_t::process_term ()
 {
-    fq.term_pipes ();
+    register_term_acks (1);
+    fq.terminate ();
+
+    socket_base_t::process_term ();
 }
 
-bool zmq::sub_t::xhas_pipes ()
+void zmq::sub_t::terminated ()
 {
-    return fq.has_pipes ();
+    unregister_term_ack ();
 }
 
 int zmq::sub_t::xsetsockopt (int option_, const void *optval_,

src/sub.hpp

@@ -24,12 +24,13 @@
 
 #include "prefix_tree.hpp"
 #include "socket_base.hpp"
+#include "i_terminate_events.hpp"
 #include "fq.hpp"
 
 namespace zmq
 {
 
-    class sub_t : public socket_base_t
+    class sub_t : public socket_base_t, public i_terminate_events
     {
     public:
 
@@ -41,14 +42,18 @@ namespace zmq
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsetsockopt (int option_, const void *optval_, size_t optvallen_);
         int xrecv (zmq_msg_t *msg_, int flags_);
         bool xhas_in ();
 
     private:
 
+        //  i_terminate_events interface implementation.
+        void terminated ();
+
+        //  Hook into the termination process.
+        void process_term ();
+
         //  Check whether the message matches at least one subscription.
         bool match (zmq_msg_t *msg_);
 

src/owned.cpp → src/transient_session.cpp

@@ -17,61 +17,20 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "owned.hpp"
-#include "err.hpp"
+#include "transient_session.hpp"
 
-zmq::owned_t::owned_t (object_t *parent_, socket_base_t *owner_) :
-    object_t (parent_),
-    owner (owner_),
-    sent_seqnum (0),
-    processed_seqnum (0),
-    shutting_down (false)
+zmq::transient_session_t::transient_session_t (class io_thread_t *io_thread_,
+      class socket_base_t *socket_, const options_t &options_) :
+    session_t (io_thread_, socket_, options_)
 {
 }
 
-zmq::owned_t::~owned_t ()
+zmq::transient_session_t::~transient_session_t ()
 {
 }
 
-void zmq::owned_t::inc_seqnum ()
+void zmq::transient_session_t::detach ()
 {
-    //  This function may be called from a different thread!
-    sent_seqnum.add (1);
+    //  There's no way to reestablish a transient session. Tear it down.
+    terminate ();
 }
-
-void zmq::owned_t::term ()
-{
-    send_term_req (owner, this);
-}
-
-void zmq::owned_t::process_term ()
-{
-    zmq_assert (!shutting_down);
-    shutting_down = true;
-    finalise ();
-}
-
-void zmq::owned_t::process_seqnum ()
-{
-    //  Catch up with counter of processed commands.
-    processed_seqnum++;
-    finalise ();
-}
-
-void zmq::owned_t::finalise ()
-{
-    //  If termination request was already received and there are no more
-    //  commands to wait for, terminate the object.
-    if (shutting_down && processed_seqnum == sent_seqnum.get ()
-          && is_terminable ()) {
-        process_unplug ();
-        send_term_ack (owner);
-        delete this;
-    }
-}
-
-bool zmq::owned_t::is_terminable ()
-{
-    return true;
-}
-

src/transient_session.hpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_TRANSIENT_SESSION_HPP_INCLUDED__
+#define __ZMQ_TRANSIENT_SESSION_HPP_INCLUDED__
+
+#include "session.hpp"
+
+namespace zmq
+{
+
+    //  Transient session is created by the listener when the connected peer
+    //  stays anonymous. Transient session is destroyed on disconnect.
+
+    class transient_session_t : public session_t
+    {
+    public:
+
+        transient_session_t (class io_thread_t *io_thread_,
+            class socket_base_t *socket_, const options_t &options_);
+        ~transient_session_t ();
+
+        //  i_inout interface implementation.
+        void detach ();
+
+    };
+
+}
+
+#endif

src/xrep.cpp

@@ -29,7 +29,8 @@ zmq::xrep_t::xrep_t (class ctx_t *parent_, uint32_t slot_) :
     prefetched (false),
     more_in (false),
     current_out (NULL),
-    more_out (false)
+    more_out (false),
+    terminating (false)
 {
     options.requires_in = true;
     options.requires_out = true;
@@ -62,16 +63,27 @@ void zmq::xrep_t::xattach_pipes (reader_t *inpipe_, writer_t *outpipe_,
 
     inpipe_t inpipe = {inpipe_, peer_identity_, true};
     inpipes.push_back (inpipe);
+
+    if (terminating) {
+        register_term_acks (1);
+        inpipe_->terminate ();
+    }
 }
 
-void zmq::xrep_t::xterm_pipes ()
+void zmq::xrep_t::process_term ()
 {
+    terminating = true;
+
+    register_term_acks (inpipes.size () + outpipes.size ());
+
     for (inpipes_t::iterator it = inpipes.begin (); it != inpipes.end ();
           it++)
         it->reader->terminate ();
     for (outpipes_t::iterator it = outpipes.begin (); it != outpipes.end ();
           it++)
         it->second.writer->terminate ();
+
+    socket_base_t::process_term ();
 }
 
 void zmq::xrep_t::terminated (reader_t *pipe_)
@@ -80,6 +92,8 @@ void zmq::xrep_t::terminated (reader_t *pipe_)
           it++) {
         if (it->reader == pipe_) {
             inpipes.erase (it);
+            if (terminating)
+                unregister_term_ack ();
             return;
         }
     }
@@ -94,17 +108,14 @@ void zmq::xrep_t::terminated (writer_t *pipe_)
             outpipes.erase (it);
             if (pipe_ == current_out)
                 current_out = NULL;
+            if (terminating)
+                unregister_term_ack ();
             return;
         }
     }
     zmq_assert (false);
 }
 
-bool zmq::xrep_t::xhas_pipes ()
-{
-    return !inpipes.empty () || !outpipes.empty ();
-}
-
 void zmq::xrep_t::activated (reader_t *pipe_)
 {
     for (inpipes_t::iterator it = inpipes.begin (); it != inpipes.end ();

src/xrep.hpp

@@ -44,13 +44,16 @@ namespace zmq
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (reader_t *inpipe_, writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsend (zmq_msg_t *msg_, int flags_);
         int xrecv (zmq_msg_t *msg_, int flags_);
         bool xhas_in ();
         bool xhas_out ();
 
+    private:
+
+        //  Hook into the termination process.
+        void process_term ();
+
         //  i_reader_events interface implementation.
         void activated (reader_t *pipe_);
         void terminated (reader_t *pipe_);
@@ -59,8 +62,6 @@ namespace zmq
         void activated (writer_t *pipe_);
         void terminated (writer_t *pipe_);
 
-    private:
-
         struct inpipe_t
         {
             class reader_t *reader;
@@ -100,6 +101,9 @@ namespace zmq
         //  If true, more outgoing message parts are expected.
         bool more_out;
 
+        //  If true, termination process is already underway.
+        bool terminating;
+
         xrep_t (const xrep_t&);
         void operator = (const xrep_t&);
     };

src/xreq.cpp

@@ -23,7 +23,9 @@
 #include "err.hpp"
 
 zmq::xreq_t::xreq_t (class ctx_t *parent_, uint32_t slot_) :
-    socket_base_t (parent_, slot_)
+    socket_base_t (parent_, slot_),
+    fq (this),
+    lb (this)
 {
     options.requires_in = true;
     options.requires_out = true;
@@ -41,15 +43,18 @@ void zmq::xreq_t::xattach_pipes (class reader_t *inpipe_,
     lb.attach (outpipe_);
 }
 
-void zmq::xreq_t::xterm_pipes ()
+void zmq::xreq_t::process_term ()
 {
-    fq.term_pipes ();
-    lb.term_pipes ();
+    register_term_acks (2);
+    fq.terminate ();
+    lb.terminate ();
+
+    socket_base_t::process_term ();
 }
 
-bool zmq::xreq_t::xhas_pipes ()
+void zmq::xreq_t::terminated ()
 {
-    return fq.has_pipes () || lb.has_pipes ();
+    unregister_term_ack ();
 }
 
 int zmq::xreq_t::xsend (zmq_msg_t *msg_, int flags_)

src/xreq.hpp

@@ -21,24 +21,25 @@
 #define __ZMQ_XREQ_HPP_INCLUDED__
 
 #include "socket_base.hpp"
+#include "i_terminate_events.hpp"
 #include "fq.hpp"
 #include "lb.hpp"
 
 namespace zmq
 {
 
-    class xreq_t : public socket_base_t
+    class xreq_t : public socket_base_t, public i_terminate_events
     {
     public:
 
         xreq_t (class ctx_t *parent_, uint32_t slot_);
         ~xreq_t ();
 
+    protected:
+
         //  Overloads of functions from socket_base_t.
         void xattach_pipes (class reader_t *inpipe_, class writer_t *outpipe_,
             const blob_t &peer_identity_);
-        void xterm_pipes ();
-        bool xhas_pipes ();
         int xsend (zmq_msg_t *msg_, int flags_);
         int xrecv (zmq_msg_t *msg_, int flags_);
         bool xhas_in ();
@@ -46,6 +47,12 @@ namespace zmq
 
     private:
 
+        //  i_terminate_events interface implementation.
+        void terminated ();
+
+        //  Hook into the termination process.
+        void process_term ();
+
         //  Messages are fair-queued from inbound pipes. And load-balanced to
         //  the outbound pipes.
         fq_t fq;

src/zmq_connecter.cpp

@@ -25,33 +25,24 @@
 #include "io_thread.hpp"
 #include "err.hpp"
 
-zmq::zmq_connecter_t::zmq_connecter_t (io_thread_t *parent_,
-      socket_base_t *owner_, const options_t &options_,
-      uint64_t session_ordinal_, bool wait_) :
-    owned_t (parent_, owner_),
-    io_object_t (parent_),
+zmq::zmq_connecter_t::zmq_connecter_t (class io_thread_t *io_thread_,
+      class session_t *session_, const options_t &options_,
+      const char *protocol_, const char *address_) :
+    own_t (io_thread_),
+    io_object_t (io_thread_),
     handle_valid (false),
-    wait (wait_),
-    session_ordinal (session_ordinal_),
+    wait (false),
+    session (session_),
     options (options_)
 {
+     int rc = tcp_connecter.set_address (protocol_, address_);
+     zmq_assert (rc == 0);
 }
 
 zmq::zmq_connecter_t::~zmq_connecter_t ()
 {
 }
 
-int zmq::zmq_connecter_t::set_address (const char *protocol_,
-    const char *address_)
-{
-     int rc = tcp_connecter.set_address (protocol_, address_);
-     if (rc != 0)
-         return rc;
-     protocol = protocol_;
-     address = address_;
-     return 0;
-}
-
 void zmq::zmq_connecter_t::process_plug ()
 {
     if (wait)
@@ -92,15 +83,12 @@ void zmq::zmq_connecter_t::out_event ()
 
     //  Create an init object. 
     zmq_init_t *init = new (std::nothrow) zmq_init_t (
-        choose_io_thread (options.affinity), owner,
-        fd, options, true, protocol.c_str (), address.c_str (),
-        session_ordinal);
+        choose_io_thread (options.affinity), NULL, session, fd, options);
     zmq_assert (init);
-    send_plug (init);
-    send_own (owner, init);
+    launch_sibling (init);
 
-    //  Ask owner socket to shut the connecter down.
-    term ();
+    //  Shut the connecter down.
+    terminate ();
 }
 
 void zmq::zmq_connecter_t::timer_event ()

src/zmq_connecter.hpp

@@ -20,9 +20,7 @@
 #ifndef __ZMQ_ZMQ_CONNECTER_HPP_INCLUDED__
 #define __ZMQ_ZMQ_CONNECTER_HPP_INCLUDED__
 
-#include <string>
-
-#include "owned.hpp"
+#include "own.hpp"
 #include "io_object.hpp"
 #include "tcp_connecter.hpp"
 #include "options.hpp"
@@ -31,17 +29,17 @@
 namespace zmq
 {
 
-    class zmq_connecter_t : public owned_t, public io_object_t
+    class zmq_connecter_t : public own_t, public io_object_t
     {
     public:
 
-        zmq_connecter_t (class io_thread_t *parent_, socket_base_t *owner_,
-            const options_t &options_, uint64_t session_ordinal_, bool wait_);
+        //  If 'wait' is true connecter first waits for a while, then starts
+        //  connection process.
+        zmq_connecter_t (class io_thread_t *io_thread_,
+            class session_t *session_, const options_t &options_,
+            const char *protocol_, const char *address_);
         ~zmq_connecter_t ();
 
-        //  Set address to connect to.
-        int set_address (const char *protocol_, const char *address_);
-
     private:
 
         //  Handlers for incoming commands.
@@ -69,16 +67,12 @@ namespace zmq
         //  If true, connecter is waiting a while before trying to connect.
         bool wait;
 
-        //  Ordinal of the session to attach to.
-        uint64_t session_ordinal;
+        //  Reference to the session we belong to.
+        class session_t *session;
 
         //  Associated socket options.
         options_t options;
 
-        //  Protocol and address to connect to.
-        std::string protocol;
-        std::string address;
-
         zmq_connecter_t (const zmq_connecter_t&);
         void operator = (const zmq_connecter_t&);
     };

src/zmq_engine.cpp

@@ -32,10 +32,7 @@
 #include "config.hpp"
 #include "err.hpp"
 
-zmq::zmq_engine_t::zmq_engine_t (io_thread_t *parent_, fd_t fd_,
-      const options_t &options_, bool reconnect_, 
-      const char *protocol_, const char *address_) :
-    io_object_t (parent_),
+zmq::zmq_engine_t::zmq_engine_t (fd_t fd_, const options_t &options_) :
     inpos (NULL),
     insize (0),
     decoder (in_batch_size),
@@ -43,14 +40,8 @@ zmq::zmq_engine_t::zmq_engine_t (io_thread_t *parent_, fd_t fd_,
     outsize (0),
     encoder (out_batch_size),
     inout (NULL),
-    options (options_),
-    reconnect (reconnect_)
+    options (options_)
 {
-    if (reconnect) {
-        protocol = protocol_;
-        address = address_;
-    }
-
     //  Initialise the underlying socket.
     int rc = tcp_socket.open (fd_, options.sndbuf, options.rcvbuf);
     zmq_assert (rc == 0);
@@ -60,26 +51,37 @@ zmq::zmq_engine_t::~zmq_engine_t ()
 {
 }
 
-void zmq::zmq_engine_t::plug (i_inout *inout_)
+void zmq::zmq_engine_t::plug (io_thread_t *io_thread_, i_inout *inout_)
 {
+    //  Conncet to session/init object.
     zmq_assert (!inout);
-
+    zmq_assert (inout_);
     encoder.set_inout (inout_);
     decoder.set_inout (inout_);
+    inout = inout_;
+
+    //  Connect to I/O threads poller object.
+    io_object_t::plug (io_thread_);
 
     handle = add_fd (tcp_socket.get_fd ());
     set_pollin (handle);
     set_pollout (handle);
 
-    inout = inout_;
-
     //  Flush all the data that may have been already received downstream.
     in_event ();
+
+   //  TODO: Re-plug to the new I/O thread & poller!
 }
 
 void zmq::zmq_engine_t::unplug ()
 {
+    //  Cancel all fd subscriptions.
     rm_fd (handle);
+
+    //  Disconnect from I/O threads poller object.
+    io_object_t::unplug ();
+
+    //  Disconnect from init/session object.
     encoder.set_inout (NULL);
     decoder.set_inout (NULL);
     inout = NULL;
@@ -155,7 +157,7 @@ void zmq::zmq_engine_t::out_event ()
     outsize -= nbytes;
 }
 
-void zmq::zmq_engine_t::revive ()
+void zmq::zmq_engine_t::activate_out ()
 {
     set_pollout (handle);
 
@@ -166,30 +168,18 @@ void zmq::zmq_engine_t::revive ()
     out_event ();
 }
 
-void zmq::zmq_engine_t::resume_input ()
+void zmq::zmq_engine_t::activate_in ()
 {
     set_pollin (handle);
 
+    //  Speculative read.
     in_event ();
 }
 
 void zmq::zmq_engine_t::error ()
 {
     zmq_assert (inout);
-
-    zmq_connecter_t *reconnecter = NULL;
-    if (reconnect) {
-
-        //  Create a connecter object to attempt reconnect.
-        //  Ask it to wait for a while before reconnecting.
-        reconnecter = new (std::nothrow) zmq_connecter_t (
-            inout->get_io_thread (), inout->get_owner (),
-            options, inout->get_ordinal (), true);
-        zmq_assert (reconnecter);
-        reconnecter->set_address (protocol.c_str(), address.c_str ());
-    }
-
-    inout->detach (reconnecter);
+    inout->detach ();
     unplug ();
     delete this;
 }

src/zmq_engine.hpp

@@ -38,16 +38,14 @@ namespace zmq
     {
     public:
 
-        zmq_engine_t (class io_thread_t *parent_, fd_t fd_,
-            const options_t &options_, bool reconnect_, 
-            const char *protocol_, const char *address_);
+        zmq_engine_t (fd_t fd_, const options_t &options_);
         ~zmq_engine_t ();
 
         //  i_engine interface implementation.
-        void plug (struct i_inout *inout_);
+        void plug (class io_thread_t *io_thread_, struct i_inout *inout_);
         void unplug ();
-        void revive ();
-        void resume_input ();
+        void activate_in ();
+        void activate_out ();
 
         //  i_poll_events interface implementation.
         void in_event ();
@@ -73,10 +71,6 @@ namespace zmq
 
         options_t options;
 
-        bool reconnect;
-        std::string protocol;
-        std::string address;
-
         zmq_engine_t (const zmq_engine_t&);
         void operator = (const zmq_engine_t&);
     };

src/zmq_init.cpp

@@ -20,24 +20,29 @@
 #include <string.h>
 
 #include "zmq_init.hpp"
+#include "transient_session.hpp"
+#include "named_session.hpp"
+#include "socket_base.hpp"
 #include "zmq_engine.hpp"
 #include "io_thread.hpp"
 #include "session.hpp"
 #include "uuid.hpp"
+#include "blob.hpp"
 #include "err.hpp"
 
-zmq::zmq_init_t::zmq_init_t (io_thread_t *parent_, socket_base_t *owner_,
-      fd_t fd_, const options_t &options_, bool reconnect_,
-      const char *protocol_, const char *address_, uint64_t session_ordinal_) :
-    owned_t (parent_, owner_),
+zmq::zmq_init_t::zmq_init_t (io_thread_t *io_thread_,
+      socket_base_t *socket_, session_t *session_, fd_t fd_,
+      const options_t &options_) :
+    own_t (io_thread_),
     sent (false),
     received (false),
-    session_ordinal (session_ordinal_),
-    options (options_)
+    socket (socket_),
+    session (session_),
+    options (options_),
+    io_thread (io_thread_)
 {
     //  Create the engine object for this connection.
-    engine = new (std::nothrow) zmq_engine_t (parent_, fd_, options,
-        reconnect_, protocol_, address_);
+    engine = new (std::nothrow) zmq_engine_t (fd_, options);
     zmq_assert (engine);
 }
 
@@ -62,7 +67,7 @@ bool zmq::zmq_init_t::read (::zmq_msg_t *msg_)
 
     //  If initialisation is done, pass the engine to the session and
     //  destroy the init object.
-    finalise ();
+    finalise_initialisation ();
 
     return true;
 }
@@ -99,44 +104,28 @@ void zmq::zmq_init_t::flush ()
 
     //  If initialisation is done, pass the engine to the session and
     //  destroy the init object.
-    finalise ();
+    finalise_initialisation ();
 }
 
-void zmq::zmq_init_t::detach (owned_t *reconnecter_)
+void zmq::zmq_init_t::detach ()
 {
     //  This function is called by engine when disconnection occurs.
 
-    //  If required, launch the reconnecter.
-    if (reconnecter_) {
-        send_plug (reconnecter_);
-        send_own (owner, reconnecter_);
-    }
+    //  If there is an associated session, send it a null engine to let it know
+    //  that connection process was unsuccesful.
+    if (session)
+        send_attach (session, NULL, blob_t (), true);
 
     //  The engine will destroy itself, so let's just drop the pointer here and
     //  start termination of the init object.
     engine = NULL;
-    term ();
-}
-
-zmq::io_thread_t *zmq::zmq_init_t::get_io_thread ()
-{
-    return choose_io_thread (options.affinity);
-}
-
-class zmq::socket_base_t *zmq::zmq_init_t::get_owner ()
-{
-    return owner;
-}
-
-uint64_t zmq::zmq_init_t::get_ordinal ()
-{
-    return session_ordinal;
+    terminate ();
 }
 
 void zmq::zmq_init_t::process_plug ()
 {
     zmq_assert (engine);
-    engine->plug (this);
+    engine->plug (io_thread, this);
 }
 
 void zmq::zmq_init_t::process_unplug ()
@@ -145,51 +134,62 @@ void zmq::zmq_init_t::process_unplug ()
         engine->unplug ();
 }
 
-void zmq::zmq_init_t::finalise ()
+void zmq::zmq_init_t::finalise_initialisation ()
 {
     if (sent && received) {
 
-        //  Disconnect the engine from the init object.
+        //  If we know what session we belong to, it's easy, just send the
+        //  engine to that session and destroy the init object.
+        if (session) {
             engine->unplug ();
-
-        session_t *session = NULL;
-        
-        //  If we have the session ordinal, let's use it to find the session.
-        //  If it is not found, it means socket is already being shut down
-        //  and the session have been deallocated.
-        //  TODO: We should check whether the name of the peer haven't changed
-        //  upon reconnection.
-        if (session_ordinal) {
-            session = owner->find_session (session_ordinal);
-            if (!session) {
-                term ();
+            send_attach (session, engine, peer_identity, true);
+            engine = NULL;
+            terminate ();
             return;
         }
-        }
-        else {
 
-            //  If the peer has a unique name, find the associated session.
-            //  If it does not exist, create it.
-            zmq_assert (!peer_identity.empty ());
-            session = owner->find_session (peer_identity);
-            if (!session) {
-                session = new (std::nothrow) session_t (
-                    choose_io_thread (options.affinity), owner, options,
-                    peer_identity);
-                zmq_assert (session);
-                send_plug (session);
-                send_own (owner, session);
+        //  All the cases below are listener-based. Therefore we need the socket
+        //  reference so that new sessions can bind to that socket.
+        zmq_assert (socket);
 
-                //  Reserve a sequence number for following 'attach' command.
-                session->inc_seqnum ();
-            }
+        //  We have no associated session. If the peer has no identity we'll
+        //  create a transient session for the connection.
+        if (peer_identity [0] == 0) {
+            session = new (std::nothrow) transient_session_t (io_thread,
+                socket, options);
+            zmq_assert (session);
+            launch_sibling (session);
+            engine->unplug ();
+            send_attach (session, engine, peer_identity, true);
+            engine = NULL;
+            terminate ();
+            return;
         }
         
-        //  No need to increment seqnum as it was already incremented above.
+        //  Try to find the session corresponding to the peer's identity.
+        //  If found, send the engine to that session and destroy this object.
+        //  Note that session's seqnum is incremented by find_session rather
+        //  than by send_attach.
+        session = socket->find_session (peer_identity);
+        if (session) {
+            engine->unplug ();
             send_attach (session, engine, peer_identity, false);
+            engine = NULL;
+            terminate ();
+            return;
+        }
 
-        //  Destroy the init object.
+        //  There's no such named session. We have to create one.
+//  TODO:
+zmq_assert (false);
+//        session = new (std::nothrow) named_session_t (io_thread, socket,
+//            options, peer_identity);
+        zmq_assert (session);
+        launch_sibling (session);
+        engine->unplug ();
+        send_attach (session, engine, peer_identity, true);
         engine = NULL;
-        term ();
+        terminate ();
+        return;
     }
 }

src/zmq_init.hpp

@@ -22,7 +22,7 @@
 
 #include "i_inout.hpp"
 #include "i_engine.hpp"
-#include "owned.hpp"
+#include "own.hpp"
 #include "fd.hpp"
 #include "stdint.hpp"
 #include "options.hpp"
@@ -34,28 +34,23 @@ namespace zmq
 
     //  The class handles initialisation phase of 0MQ wire-level protocol.
 
-    class zmq_init_t : public owned_t, public i_inout
+    class zmq_init_t : public own_t, public i_inout
     {
     public:
 
-        zmq_init_t (class io_thread_t *parent_, socket_base_t *owner_,
-            fd_t fd_, const options_t &options_, bool reconnect_,
-            const char *protocol_, const char *address_,
-            uint64_t session_ordinal_);
+        zmq_init_t (class io_thread_t *io_thread_, class socket_base_t *socket_,
+            class session_t *session_, fd_t fd_, const options_t &options_);
         ~zmq_init_t ();
 
     private:
 
-        void finalise ();
+        void finalise_initialisation ();
 
         //  i_inout interface implementation.
         bool read (::zmq_msg_t *msg_);
         bool write (::zmq_msg_t *msg_);
         void flush ();
-        void detach (owned_t *reconnecter_);
-        class io_thread_t *get_io_thread ();
-        class socket_base_t *get_owner ();
-        uint64_t get_ordinal ();
+        void detach ();
 
         //  Handlers for incoming commands.
         void process_plug ();
@@ -70,16 +65,24 @@ namespace zmq
         //  True if peer's identity was already received.
         bool received;
 
+        //  Socket the object belongs to.
+        class socket_base_t *socket;
+
+        //  Reference to the session the init object belongs to.
+        //  If the associated session is unknown and should be found
+        //  depending on peer identity this value is NULL.
+        class session_t *session;
+
         //  Identity of the peer socket.
         blob_t peer_identity;
 
-        //  TCP connecter creates session before the name of the peer is known.
-        //  Thus we know only its ordinal number.
-        uint64_t session_ordinal;
-
         //  Associated socket options.
         options_t options;
 
+        //  I/O thread the object is living in. It will be used to plug
+        //  the engine into the same I/O thread.
+        class io_thread_t *io_thread;
+
         zmq_init_t (const zmq_init_t&);
         void operator = (const zmq_init_t&);
     };

src/zmq_listener.cpp

@@ -24,11 +24,12 @@
 #include "io_thread.hpp"
 #include "err.hpp"
 
-zmq::zmq_listener_t::zmq_listener_t (io_thread_t *parent_,
-      socket_base_t *owner_, const options_t &options_) :
-    owned_t (parent_, owner_),
-    io_object_t (parent_),
-    options (options_)
+zmq::zmq_listener_t::zmq_listener_t (io_thread_t *io_thread_,
+      socket_base_t *socket_, const options_t &options_) :
+    own_t (io_thread_),
+    io_object_t (io_thread_),
+    options (options_),
+    socket (socket_)
 {
 }
 
@@ -62,13 +63,11 @@ void zmq::zmq_listener_t::in_event ()
     if (fd == retired_fd)
         return;
 
-    //  Create an init object. 
-    io_thread_t *io_thread = choose_io_thread (options.affinity);
+    //  Create and launch an init object. 
     zmq_init_t *init = new (std::nothrow) zmq_init_t (
-        io_thread, owner, fd, options, false, NULL, NULL, 0);
+        choose_io_thread (options.affinity), socket, NULL, fd, options);
     zmq_assert (init);
-    send_plug (init);
-    send_own (owner, init);
+    launch_sibling (init);
 }
 
 

src/zmq_listener.hpp

@@ -20,7 +20,7 @@
 #ifndef __ZMQ_ZMQ_LISTENER_HPP_INCLUDED__
 #define __ZMQ_ZMQ_LISTENER_HPP_INCLUDED__
 
-#include "owned.hpp"
+#include "own.hpp"
 #include "io_object.hpp"
 #include "tcp_listener.hpp"
 #include "options.hpp"
@@ -29,12 +29,12 @@
 namespace zmq
 {
 
-    class zmq_listener_t : public owned_t, public io_object_t
+    class zmq_listener_t : public own_t, public io_object_t
     {
     public:
 
-        zmq_listener_t (class io_thread_t *parent_, socket_base_t *owner_,
-            const options_t &options_);
+        zmq_listener_t (class io_thread_t *io_thread_,
+            class socket_base_t *socket_, const options_t &options_);
         ~zmq_listener_t ();
 
         //  Set address to listen on.
@@ -58,6 +58,9 @@ namespace zmq
         //  Associated socket options.
         options_t options;
 
+        //  Socket the listerner belongs to.
+        class socket_base_t *socket;
+
         zmq_listener_t (const zmq_listener_t&);
         void operator = (const zmq_listener_t&);
     };