race condition in inproc transport shutdown fixed

src/command.hpp

@@ -69,9 +69,12 @@ namespace zmq
             } attach;
 
             //  Sent from session to socket to establish pipe(s) between them.
+            //  If adjust_seqnum is true, caller have used inc_seqnum beforehand
+            //  and thus the callee should take care of catching up.
             struct {
                 class reader_t *in_pipe;
                 class writer_t *out_pipe;
+                bool adjust_seqnum;
             } bind;
 
             //  Sent by pipe writer to inform dormant pipe reader that there

src/object.cpp

@@ -83,7 +83,8 @@ void zmq::object_t::process_command (command_t &cmd_)
         return;
 
     case command_t::bind:
-        process_bind (cmd_.args.bind.in_pipe, cmd_.args.bind.out_pipe);
+        process_bind (cmd_.args.bind.in_pipe, cmd_.args.bind.out_pipe,
+            cmd_.args.bind.adjust_seqnum);
         return;
 
     case command_t::pipe_term:
@@ -183,13 +184,14 @@ void zmq::object_t::send_attach (session_t *destination_, i_engine *engine_)
 }
 
 void zmq::object_t::send_bind (object_t *destination_,
-    reader_t *in_pipe_, writer_t *out_pipe_)
+    reader_t *in_pipe_, writer_t *out_pipe_, bool adjust_seqnum_)
 {
     command_t cmd;
     cmd.destination = destination_;
     cmd.type = command_t::bind;
     cmd.args.bind.in_pipe = in_pipe_;
     cmd.args.bind.out_pipe = out_pipe_;
+    cmd.args.bind.adjust_seqnum = adjust_seqnum_;
     send_command (cmd);
 }
 
@@ -263,7 +265,8 @@ void zmq::object_t::process_attach (i_engine *engine_)
     zmq_assert (false);
 }
 
-void zmq::object_t::process_bind (reader_t *in_pipe_, writer_t *out_pipe_)
+void zmq::object_t::process_bind (reader_t *in_pipe_, writer_t *out_pipe_,
+    bool adjust_seqnum_)
 {
     zmq_assert (false);
 }

src/object.hpp

@@ -68,8 +68,8 @@ namespace zmq
             class owned_t *object_);
         void send_attach (class session_t *destination_,
             struct i_engine *engine_);
-        void send_bind (object_t *destination_,
-            class reader_t *in_pipe_, class writer_t *out_pipe_);
+        void send_bind (object_t *destination_, class reader_t *in_pipe_,
+             class writer_t *out_pipe_, bool adjust_seqnum_);
         void send_revive (class object_t *destination_);
         void send_pipe_term (class writer_t *destination_);
         void send_pipe_term_ack (class reader_t *destination_);
@@ -85,7 +85,7 @@ namespace zmq
         virtual void process_own (class owned_t *object_);
         virtual void process_attach (struct i_engine *engine_);
         virtual void process_bind (class reader_t *in_pipe_,
-            class writer_t *out_pipe_);
+            class writer_t *out_pipe_, bool adjust_seqnum_);
         virtual void process_revive ();
         virtual void process_pipe_term ();
         virtual void process_pipe_term_ack ();

src/session.cpp

@@ -155,8 +155,10 @@ void zmq::session_t::process_plug ()
             out_pipe->set_endpoint (this);
         }
 
+        //  Note that initial call to inc_seqnum was optimised out. Last
+        //  parameter conveys the fact to the callee.
         send_bind (owner, outbound ? &outbound->reader : NULL,
-            inbound ? &inbound->writer : NULL);
+            inbound ? &inbound->writer : NULL, false);
     }
 
     owned_t::process_plug ();

src/socket_base.cpp

@@ -158,10 +158,10 @@ int zmq::socket_base_t::connect (const char *addr_)
             out_pipe ? &out_pipe->writer : NULL);
 
         //  Attach the pipes to the peer socket. Note that peer's seqnum
-        //  was incremented in find_endpoint function. When this command
-        //  is delivered, peer will consider the seqnum to be processed.
+        //  was incremented in find_endpoint function. The callee is notified
+        //  about the fact via the last parameter.
         send_bind (peer, out_pipe ? &out_pipe->reader : NULL,
-            in_pipe ? &in_pipe->writer : NULL);
+            in_pipe ? &in_pipe->writer : NULL, true);
 
         return 0;
     }
@@ -509,8 +509,16 @@ void zmq::socket_base_t::process_own (owned_t *object_)
     io_objects.insert (object_);
 }
 
-void zmq::socket_base_t::process_bind (reader_t *in_pipe_, writer_t *out_pipe_)
+void zmq::socket_base_t::process_bind (reader_t *in_pipe_, writer_t *out_pipe_,
+     bool adjust_seqnum_)
 {
+    //  In case of inproc transport, the seqnum should catch up here.
+    //  For other transports the seqnum modification can be optimised out
+    //  because final handshaking between the socket and the session ensures
+    //  that no 'bind' command will be left unprocessed.
+    if (adjust_seqnum_)
+        processed_seqnum++;
+
     attach_pipes (in_pipe_, out_pipe_);
 }
 

src/socket_base.hpp

@@ -114,7 +114,8 @@ namespace zmq
 
         //  Handlers for incoming commands.
         void process_own (class owned_t *object_);
-        void process_bind (class reader_t *in_pipe_, class writer_t *out_pipe_);
+        void process_bind (class reader_t *in_pipe_, class writer_t *out_pipe_,
+            bool adjust_seqnum_);
         void process_term_req (class owned_t *object_);
         void process_term_ack ();