multi-part messages work with REQ/REP sockets

src/rep.cpp

@@ -27,7 +27,8 @@ zmq::rep_t::rep_t (class app_thread_t *parent_) :
     socket_base_t (parent_),
     active (0),
     current (0),
-    waiting_for_reply (false),
+    sending_reply (false),
+    tbc (false),
     reply_pipe (NULL)
 {
     options.requires_in = true;
@@ -58,6 +59,8 @@ void zmq::rep_t::xattach_pipes (class reader_t *inpipe_,
 
 void zmq::rep_t::xdetach_inpipe (class reader_t *pipe_)
 {
+    zmq_assert (sending_reply || !tbc || in_pipes [current] != pipe_);
+
     zmq_assert (pipe_);
     zmq_assert (in_pipes.size () == out_pipes.size ());
 
@@ -90,6 +93,8 @@ void zmq::rep_t::xdetach_inpipe (class reader_t *pipe_)
 
 void zmq::rep_t::xdetach_outpipe (class writer_t *pipe_)
 {
+    zmq_assert (!sending_reply || !tbc || reply_pipe != pipe_);
+
     zmq_assert (pipe_);
     zmq_assert (in_pipes.size () == out_pipes.size ());
 
@@ -98,7 +103,7 @@ void zmq::rep_t::xdetach_outpipe (class writer_t *pipe_)
     //  If the connection we've got the request from disconnects,
     //  there's nowhere to send the reply. Forget about the reply pipe.
     //  Once the reply is sent it will be dropped.
-    if (waiting_for_reply && pipe_ == reply_pipe)
+    if (sending_reply && pipe_ == reply_pipe)
         reply_pipe = NULL;
 
     //  If corresponding inpipe is still in place simply nullify the pointer
@@ -157,29 +162,36 @@ int zmq::rep_t::xsetsockopt (int option_, const void *optval_,
 
 int zmq::rep_t::xsend (zmq_msg_t *msg_, int flags_)
 {
-    if (!waiting_for_reply) {
+    if (!sending_reply) {
         errno = EFSM;
         return -1;
     }
 
-    //  Push message to the selected pipe. If requester have disconnected
-    //  in the meantime, drop the reply.
+    //  Check whether it's last part of the reply.
+    tbc = msg_->flags & ZMQ_MSG_TBC;
+
     if (reply_pipe) {
+
+        //  Push message to the reply pipe.
         bool written = reply_pipe->write (msg_);
-        if (written)
-            reply_pipe->flush ();
-        else
-            //  The pipe is full; just drop the reference to
-            //  the message content.
-            //  TODO: Tear down the underlying connection.
-            zmq_msg_close (msg_);
+        zmq_assert (!tbc || written);
+
+        //  The pipe is full...
+        //  TODO: Tear down the underlying connection (?)
+        zmq_assert (written);     
     }
     else {
+
+        //  If the requester have disconnected in the meantime, drop the reply.
         zmq_msg_close (msg_);
     }
 
-    waiting_for_reply = false;
-    reply_pipe = NULL;
+    //  Flush the reply to the requester.
+    if (!tbc) {
+        reply_pipe->flush ();
+        sending_reply = false;
+        reply_pipe = NULL;
+    }
 
     //  Detach the message from the data buffer.
     int rc = zmq_msg_init (msg_);
@@ -193,7 +205,7 @@ int zmq::rep_t::xrecv (zmq_msg_t *msg_, int flags_)
     //  Deallocate old content of the message.
     zmq_msg_close (msg_);
 
-    if (waiting_for_reply) {
+    if (sending_reply) {
         errno = EFSM;
         return -1;
     }
@@ -201,15 +213,19 @@ int zmq::rep_t::xrecv (zmq_msg_t *msg_, int flags_)
     //  Round-robin over the pipes to get next message.
     for (int count = active; count != 0; count--) {
         bool fetched = in_pipes [current]->read (msg_);
+        zmq_assert (!(tbc && !fetched));
+        
         if (fetched) {
-            reply_pipe = out_pipes [current];
-            waiting_for_reply = true;
-        }
-        current++;
-        if (current >= active)
-            current = 0;
-        if (fetched)
+            tbc = msg_->flags & ZMQ_MSG_TBC;
+            if (!tbc) {
+                reply_pipe = out_pipes [current];
+                sending_reply = true;
+                current++;
+                if (current >= active)
+                    current = 0;
+            }
             return 0;
+        }
     }
 
     //  No message is available. Initialise the output parameter
@@ -221,9 +237,12 @@ int zmq::rep_t::xrecv (zmq_msg_t *msg_, int flags_)
 
 bool zmq::rep_t::xhas_in ()
 {
+    if (!sending_reply && tbc)
+        return true;
+
     for (int count = active; count != 0; count--) {
         if (in_pipes [current]->check_read ())
-            return !waiting_for_reply;
+            return !sending_reply;
         current++;
         if (current >= active)
             current = 0;
@@ -234,6 +253,10 @@ bool zmq::rep_t::xhas_in ()
 
 bool zmq::rep_t::xhas_out ()
 {
-    return waiting_for_reply;
+    if (sending_reply && tbc)
+        return true;
+
+    //  TODO: No check for write here...
+    return sending_reply;
 }
 

src/rep.hpp

@@ -64,8 +64,13 @@ namespace zmq
         //  Index of the next inbound pipe to read a request from.
         in_pipes_t::size_type current;
 
-        //  If true, request was already received and reply wasn't sent yet.
-        bool waiting_for_reply;
+        //  If true, request was already received and reply wasn't completely
+        //  sent yet.
+        bool sending_reply;
+
+        //  True, if message processed at the moment (either sent or received)
+        //  is processed only partially.
+        bool tbc;
 
         //  Pipe we are going to send reply to.
         class writer_t *reply_pipe;

src/req.cpp

@@ -27,8 +27,9 @@ zmq::req_t::req_t (class app_thread_t *parent_) :
     socket_base_t (parent_),
     active (0),
     current (0),
-    waiting_for_reply (false),
+    receiving_reply (false),
     reply_pipe_active (false),
+    tbc (false),
     reply_pipe (NULL)
 {
     options.requires_in = true;
@@ -56,12 +57,14 @@ void zmq::req_t::xattach_pipes (class reader_t *inpipe_,
 
 void zmq::req_t::xdetach_inpipe (class reader_t *pipe_)
 {
+    zmq_assert (!receiving_reply || !tbc || reply_pipe != pipe_);
+
     zmq_assert (pipe_);
     zmq_assert (in_pipes.size () == out_pipes.size ());
 
     //  TODO: The pipe we are awaiting the reply from is detached. What now?
     //  Return ECONNRESET from subsequent recv?
-    if (waiting_for_reply && pipe_ == reply_pipe) {
+    if (receiving_reply && pipe_ == reply_pipe) {
         zmq_assert (false);
     }
 
@@ -93,6 +96,8 @@ void zmq::req_t::xdetach_inpipe (class reader_t *pipe_)
 
 void zmq::req_t::xdetach_outpipe (class writer_t *pipe_)
 {
+    zmq_assert (receiving_reply || !tbc || out_pipes [current] != pipe_);
+
     zmq_assert (pipe_);
     zmq_assert (in_pipes.size () == out_pipes.size ());
 
@@ -124,7 +129,7 @@ void zmq::req_t::xdetach_outpipe (class writer_t *pipe_)
 
 void zmq::req_t::xkill (class reader_t *pipe_)
 {
-    zmq_assert (waiting_for_reply);
+    zmq_assert (receiving_reply);
     zmq_assert (pipe_ == reply_pipe);
 
     reply_pipe_active = false;
@@ -161,7 +166,7 @@ int zmq::req_t::xsend (zmq_msg_t *msg_, int flags_)
 {
     //  If we've sent a request and we still haven't got the reply,
     //  we can't send another request.
-    if (waiting_for_reply) {
+    if (receiving_reply) {
         errno = EFSM;
         return -1;
     }
@@ -170,6 +175,7 @@ int zmq::req_t::xsend (zmq_msg_t *msg_, int flags_)
         if (out_pipes [current]->check_write ())
             break;
 
+        zmq_assert (!tbc);
         active--;
         if (current < active) {
             in_pipes.swap (current, active);
@@ -187,23 +193,25 @@ int zmq::req_t::xsend (zmq_msg_t *msg_, int flags_)
     //  Push message to the selected pipe.
     bool written = out_pipes [current]->write (msg_);
     zmq_assert (written);
-    out_pipes [current]->flush ();
-
-    waiting_for_reply = true;
-    reply_pipe = in_pipes [current];
-
-    //  We can safely assume that the reply pipe is active as the last time
-    //  we've used it we've read the reply and haven't tried to read from it
-    //  anymore.
-    reply_pipe_active = true;
+    tbc = msg_->flags & ZMQ_MSG_TBC;
+    if (!tbc) {
+        out_pipes [current]->flush ();
+        receiving_reply = true;
+        reply_pipe = in_pipes [current];
+
+        //  We can safely assume that the reply pipe is active as the last time
+        //  we've used it we've read the reply and haven't tried to read from it
+        //  anymore.
+        reply_pipe_active = true;
+
+        //  Move to the next pipe (load-balancing).
+        current = (current + 1) % active;
+    }
 
     //  Detach the message from the data buffer.
     int rc = zmq_msg_init (msg_);
     zmq_assert (rc == 0);
 
-    //  Move to the next pipe (load-balancing).
-    current = (current + 1) % active;
-
     return 0;
 }
 
@@ -213,7 +221,7 @@ int zmq::req_t::xrecv (zmq_msg_t *msg_, int flags_)
     zmq_msg_close (msg_);
 
     //  If request wasn't send, we can't wait for reply.
-    if (!waiting_for_reply) {
+    if (!receiving_reply) {
         zmq_msg_init (msg_);
         errno = EFSM;
         return -1;
@@ -226,14 +234,22 @@ int zmq::req_t::xrecv (zmq_msg_t *msg_, int flags_)
         return -1;
     }
 
-    waiting_for_reply = false;
-    reply_pipe = NULL;
+    //  If this was last part of the reply, switch to request phase.
+    tbc = msg_->flags & ZMQ_MSG_TBC;
+    if (!tbc) {
+        receiving_reply = false;
+        reply_pipe = NULL;
+    }
+
     return 0;
 }
 
 bool zmq::req_t::xhas_in ()
 {
-    if (!waiting_for_reply || !reply_pipe_active)
+    if (receiving_reply && tbc)
+        return true;
+
+    if (!receiving_reply || !reply_pipe_active)
         return false;
 
     zmq_assert (reply_pipe);    
@@ -247,7 +263,10 @@ bool zmq::req_t::xhas_in ()
 
 bool zmq::req_t::xhas_out ()
 {
-    if (waiting_for_reply)
+    if (!receiving_reply && tbc)
+        return true;
+
+    if (receiving_reply)
         return false;
 
     while (active > 0) {

src/req.hpp

@@ -70,12 +70,17 @@ namespace zmq
         //  that's processing the request at the moment.
         out_pipes_t::size_type current;
 
-        //  If true, request was already sent and reply wasn't received yet.
-        bool waiting_for_reply;
+        //  If true, request was already sent and reply wasn't received yet or
+        //  was raceived partially.
+        bool receiving_reply;
 
         //  True, if read can be attempted from the reply pipe.
         bool reply_pipe_active;
 
+        //  True, if message processed at the moment (either sent or received)
+        //  is processed only partially.
+        bool tbc;
+
         //  Pipe we are awaiting the reply from.
         class reader_t *reply_pipe;