session_base: code cleanup

- add unlikely hints
- drop unnecessary assertion
- style fixes

There is no need to require the 'more' flag in the provided message
structure be 0 when pulling message from the session.

src/session_base.cpp

@@ -157,8 +157,7 @@ void zmq::session_base_t::attach_pipe (pipe_t *pipe_)
 int zmq::session_base_t::pull_msg (msg_t *msg_)
 {
     //  First message to send is identity
-    if (!identity_sent) {
-        zmq_assert (!(msg_->flags () & msg_t::more));
+    if (unlikely (!identity_sent)) {
         int rc = msg_->init_size (options.identity_size);
         errno_assert (rc == 0);
         memcpy (msg_->data (), options.identity, options.identity_size);
@@ -179,7 +178,7 @@ int zmq::session_base_t::pull_msg (msg_t *msg_)
 int zmq::session_base_t::push_msg (msg_t *msg_)
 {
     //  First message to receive is identity
-    if (!identity_received) {
+    if (unlikely (!identity_received)) {
         msg_->set_flags (msg_t::identity);
         identity_received = true;
         if (!options.recv_identity) {
@@ -228,10 +227,8 @@ void zmq::session_base_t::clean_pipes ()
             msg_t msg;
             int rc = msg.init ();
             errno_assert (rc == 0);
-            if (pull_msg (&msg) != 0) {
-                zmq_assert (!incomplete_in);
-                break;
-            }
+            rc = pull_msg (&msg);
+            errno_assert (rc == 0);
             rc = msg.close ();
             errno_assert (rc == 0);
         }
@@ -258,11 +255,10 @@ void zmq::session_base_t::terminated (pipe_t *pipe_)
         terminate ();
     }
 
-
     // If we are waiting for pending messages to be sent, at this point
     // we are sure that there will be no more messages and we can proceed
     // with termination safely.
-    if (pending && !pipe && terminating_pipes.size () == 0)
+    if (pending && !pipe && terminating_pipes.empty ())
         proceed_with_term ();
 }
 
@@ -470,13 +466,16 @@ void zmq::session_base_t::start_connecting (bool wait_)
     }
 #endif
 
-#if defined ZMQ_HAVE_OPENPGM
+#ifdef ZMQ_HAVE_OPENPGM
 
     //  Both PGM and EPGM transports are using the same infrastructure.
     if (addr->protocol == "pgm" || addr->protocol == "epgm") {
 
+        zmq_assert (options.type == ZMQ_PUB || options.type == ZMQ_XPUB
+                 || options.type == ZMQ_SUB || options.type == ZMQ_XSUB);
+
         //  For EPGM transport with UDP encapsulation of PGM is used.
-        bool udp_encapsulation = (addr->protocol == "epgm");
+        bool const udp_encapsulation = addr->protocol == "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'
@@ -484,7 +483,7 @@ void zmq::session_base_t::start_connecting (bool wait_)
         if (options.type == ZMQ_PUB || options.type == ZMQ_XPUB) {
 
             //  PGM sender.
-            pgm_sender_t *pgm_sender =  new (std::nothrow) pgm_sender_t (
+            pgm_sender_t *pgm_sender = new (std::nothrow) pgm_sender_t (
                 io_thread, options);
             alloc_assert (pgm_sender);
 
@@ -493,11 +492,10 @@ void zmq::session_base_t::start_connecting (bool wait_)
 
             send_attach (this, pgm_sender);
         }
-        else
-        if (options.type == ZMQ_SUB || options.type == ZMQ_XSUB) {
+        else {
 
             //  PGM receiver.
-            pgm_receiver_t *pgm_receiver =  new (std::nothrow) pgm_receiver_t (
+            pgm_receiver_t *pgm_receiver = new (std::nothrow) pgm_receiver_t (
                 io_thread, options);
             alloc_assert (pgm_receiver);
 
@@ -506,8 +504,6 @@ void zmq::session_base_t::start_connecting (bool wait_)
 
             send_attach (this, pgm_receiver);
         }
-        else
-            zmq_assert (false);
 
         return;
     }