Remove unplug from i_engine interface

src/i_engine.hpp

@@ -37,9 +37,6 @@ namespace zmq
         virtual void plug (zmq::io_thread_t *io_thread_,
             class session_base_t *session_) = 0;
 
-        //  Unplug the engine from the session.
-        virtual void unplug () = 0;
-
         //  Terminate and deallocate the engine. Note that 'detached'
         //  events are not fired on termination.
         virtual void terminate () = 0;

src/pgm_receiver.hpp

@@ -59,7 +59,6 @@ namespace zmq
         //  i_engine interface implementation.
         void plug (zmq::io_thread_t *io_thread_,
             zmq::session_base_t *session_);
-        void unplug ();
         void terminate ();
         void activate_in ();
         void activate_out ();
@@ -70,6 +69,9 @@ namespace zmq
 
     private:
 
+        //  Unplug the engine from the session.
+        void unplug ();
+
         //  PGM is not able to move subscriptions upstream. Thus, drop all
         //  the pending subscriptions.
         void drop_subscriptions ();

src/pgm_sender.hpp

@@ -57,7 +57,6 @@ namespace zmq
         //  i_engine interface implementation.
         void plug (zmq::io_thread_t *io_thread_,
             zmq::session_base_t *session_);
-        void unplug ();
         void terminate ();
         void activate_in ();
         void activate_out ();
@@ -69,6 +68,9 @@ namespace zmq
 
     private:
 
+        //  Unplug the engine from the session.
+        void unplug ();
+
         //  TX and RX timeout timer ID's.
         enum {tx_timer_id = 0xa0, rx_timer_id = 0xa1};
 

src/stream_engine.hpp

@@ -51,7 +51,6 @@ namespace zmq
         //  i_engine interface implementation.
         void plug (zmq::io_thread_t *io_thread_,
            zmq::session_base_t *session_);
-        void unplug ();
         void terminate ();
         void activate_in ();
         void activate_out ();
@@ -62,6 +61,9 @@ namespace zmq
 
     private:
 
+        //  Unplug the engine from the session.
+        void unplug ();
+
         //  Function to handle network disconnections.
         void error ();