inproc transport - initial commit

src/dispatcher.cpp

@@ -20,6 +20,7 @@
 #include "../bindings/c/zmq.h"
 
 #include "dispatcher.hpp"
+#include "socket_base.hpp"
 #include "app_thread.hpp"
 #include "io_thread.hpp"
 #include "platform.hpp"
@@ -202,3 +203,58 @@ void zmq::dispatcher_t::unregister_pipe (class pipe_t *pipe_)
     zmq_assert (erased == 1);
     pipes_sync.unlock ();
 }
+
+int zmq::dispatcher_t::register_endpoint (const char *addr_,
+    socket_base_t *socket_)
+{
+    endpoints_sync.lock ();
+
+    bool inserted = endpoints.insert (std::make_pair (addr_, socket_)).second;
+    if (!inserted) {
+        errno = EADDRINUSE;
+        endpoints_sync.unlock ();
+        return -1;
+    }
+
+    endpoints_sync.unlock ();
+    return 0;
+}
+
+void zmq::dispatcher_t::unregister_endpoints (socket_base_t *socket_)
+{
+    endpoints_sync.lock ();
+
+    endpoints_t::iterator it = endpoints.begin ();
+    while (it != endpoints.end ()) {
+        if (it->second == socket_) {
+            endpoints_t::iterator to_erase = it;
+            it++;
+            endpoints.erase (to_erase);
+            continue;
+        }
+        it++;
+    }
+        
+    endpoints_sync.unlock ();
+}
+
+zmq::socket_base_t *zmq::dispatcher_t::find_endpoint (const char *addr_)
+{
+     endpoints_sync.lock ();
+
+     endpoints_t::iterator it = endpoints.find (addr_);
+     if (it == endpoints.end ()) {
+         endpoints_sync.unlock ();
+         errno = ECONNREFUSED;
+         return NULL;
+     }
+     socket_base_t *endpoint = it->second;
+
+     //  Increment the command sequence number of the peer so that it won't
+     //  get deallocated until "bind" command is issued by the caller.
+     endpoint->inc_seqnum ();
+
+     endpoints_sync.unlock ();
+     return endpoint;
+}
+

src/dispatcher.hpp

@@ -97,6 +97,11 @@ namespace zmq
         void register_pipe (class pipe_t *pipe_);
         void unregister_pipe (class pipe_t *pipe_);
 
+        //  Management of inproc endpoints.
+        int register_endpoint (const char *addr_, class socket_base_t *socket_);
+        void unregister_endpoints (class socket_base_t *socket_);
+        class socket_base_t *find_endpoint (const char *addr_);
+
     private:
 
         ~dispatcher_t ();
@@ -149,6 +154,13 @@ namespace zmq
         //  and 'terminated' flag).
         mutex_t term_sync;
 
+        //  List of inproc endpoints within this context.
+        typedef std::map <std::string, class socket_base_t*> endpoints_t;
+        endpoints_t endpoints;
+
+        //  Synchronisation of access to the list of inproc endpoints.
+        mutex_t endpoints_sync;
+
         dispatcher_t (const dispatcher_t&);
         void operator = (const dispatcher_t&);
     };

src/object.cpp

@@ -122,6 +122,21 @@ void zmq::object_t::unregister_pipe (class pipe_t *pipe_)
     dispatcher->unregister_pipe (pipe_);
 }
 
+int zmq::object_t::register_endpoint (const char *addr_, socket_base_t *socket_)
+{
+    return dispatcher->register_endpoint (addr_, socket_);
+}
+
+void zmq::object_t::unregister_endpoints (socket_base_t *socket_)
+{
+    return dispatcher->unregister_endpoints (socket_);
+}
+
+zmq::socket_base_t *zmq::object_t::find_endpoint (const char *addr_)
+{
+    return dispatcher->find_endpoint (addr_);
+}
+
 zmq::io_thread_t *zmq::object_t::choose_io_thread (uint64_t taskset_)
 {
     return dispatcher->choose_io_thread (taskset_);

src/object.hpp

@@ -49,6 +49,12 @@ namespace zmq
 
     protected:
 
+        //  Using following function, socket is able to access global
+        //  repository of inproc endpoints.
+        int register_endpoint (const char *addr_, class socket_base_t *socket_);
+        void unregister_endpoints (class socket_base_t *socket_);
+        class socket_base_t *find_endpoint (const char *addr_);
+
         //  Derived object can use following functions to interact with
         //  global repositories. See dispatcher.hpp for function details.
         int thread_slot_count ();

src/socket_base.cpp

@@ -43,7 +43,9 @@ zmq::socket_base_t::socket_base_t (app_thread_t *parent_) :
     pending_term_acks (0),
     ticks (0),
     app_thread (parent_),
-    shutting_down (false)
+    shutting_down (false),
+    sent_seqnum (0),
+    processed_seqnum (0)
 {
 }
 
@@ -81,6 +83,9 @@ int zmq::socket_base_t::bind (const char *addr_)
     addr_type = addr.substr (0, pos);
     addr_args = addr.substr (pos + 3);
 
+    if (addr_type == "inproc")
+        return register_endpoint (addr_args.c_str (), this);
+
     if (addr_type == "tcp") {
         zmq_listener_t *listener = new zmq_listener_t (
             choose_io_thread (options.affinity), this, options);
@@ -126,6 +131,42 @@ int zmq::socket_base_t::connect (const char *addr_)
     addr_type = addr.substr (0, pos);
     addr_args = addr.substr (pos + 3);
 
+    if (addr_type == "inproc") {
+
+        //  Find the peer socket.
+        socket_base_t *peer = find_endpoint (addr_args.c_str ());
+        if (!peer)
+            return -1;
+
+        pipe_t *in_pipe = NULL;
+        pipe_t *out_pipe = NULL;
+
+        //  Create inbound pipe, if required.
+        if (options.requires_in) {
+            in_pipe = new pipe_t (this, peer, options.hwm, options.lwm);
+            zmq_assert (in_pipe);
+        }
+
+        //  Create outbound pipe, if required.
+        if (options.requires_out) {
+            out_pipe = new pipe_t (peer, this, options.hwm, options.lwm);
+            zmq_assert (out_pipe);
+        }
+
+        //  Attach the pipes to this socket object.
+        attach_pipes (in_pipe ? &in_pipe->reader : NULL,
+            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.
+        //  TODO: Seems that 'session' parameter is unused...
+        send_bind (peer, NULL, out_pipe ? &out_pipe->reader : NULL,
+            in_pipe ? &in_pipe->writer : NULL);
+
+        return 0;
+    }
+
     //  Create the session.
     io_thread_t *io_thread = choose_io_thread (options.affinity);
     session_t *session = new session_t (io_thread, this, session_name.c_str (),
@@ -319,13 +360,24 @@ int zmq::socket_base_t::recv (::zmq_msg_t *msg_, int flags_)
 
 int zmq::socket_base_t::close ()
 {
+    shutting_down = true;
+
+    //  Let the thread know that the socket is no longer available.
     app_thread->remove_socket (this);
 
     //  Pointer to the dispatcher must be retrieved before the socket is
     //  deallocated. Afterwards it is not available.
     dispatcher_t *dispatcher = get_dispatcher ();
 
-    shutting_down = true;
+    //  Unregister all inproc endpoints associated with this socket.
+    //  From this point we are sure that inc_seqnum won't be called again
+    //  on this object.
+    dispatcher->unregister_endpoints (this);
+
+    //  Wait till all undelivered commands are delivered. This should happen
+    //  very quickly. There's no way to wait here for extensive period of time.
+    while (processed_seqnum != sent_seqnum.get ())
+        app_thread->process_commands (true, false);
 
     while (true) {
 
@@ -364,6 +416,12 @@ int zmq::socket_base_t::close ()
     return 0;
 }
 
+void zmq::socket_base_t::inc_seqnum ()
+{
+    //  NB: This function may be called from a different thread!
+    sent_seqnum.add (1);
+}
+
 zmq::app_thread_t *zmq::socket_base_t::get_thread ()
 {
     return app_thread;

src/socket_base.hpp

@@ -33,6 +33,7 @@
 #include "mutex.hpp"
 #include "options.hpp"
 #include "stdint.hpp"
+#include "atomic_counter.hpp"
 
 namespace zmq
 {
@@ -54,6 +55,11 @@ 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 ();
+
         //  This function is used by the polling mechanism to determine
         //  whether the socket belongs to the application thread the poll
         //  is called from.
@@ -132,6 +138,12 @@ namespace zmq
         //  started.
         bool shutting_down;
 
+        //  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;
+
         //  List of existing sessions. This list is never referenced from within
         //  the socket, instead it is used by I/O objects owned by the session.
         //  As those objects can live in different threads, the access is

src/zmq.cpp

@@ -198,8 +198,10 @@ size_t zmq_msg_size (zmq_msg_t *msg_)
 
 void *zmq_init (int app_threads_, int io_threads_, int flags_)
 {
-    //  There should be at least a single thread managed by the dispatcher.
-    if (app_threads_ <= 0 || io_threads_ <= 0 ||
+    //  There should be at least a single application thread managed
+    //  by the dispatcher. There's no need for I/O threads if 0MQ is used
+    //  only for inproc messaging
+    if (app_threads_ < 1 || io_threads_ < 0 ||
           app_threads_ > 63 || io_threads_ > 63) {
         errno = EINVAL;
         return NULL;