lockfree interaction patter for 3 theads implemented

1 files changed, 149 insertions, 0 deletions

diff --git a/src/dispatcher.cpp b/src/dispatcher.cpp
new file mode 100644
index 0000000..0b68880
--- /dev/null
+++ b/src/dispatcher.cpp
@@ -0,0 +1,149 @@
+/*
+    Copyright (c) 2007-2009 FastMQ Inc.
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "../include/zmq.h"
+
+#include "dispatcher.hpp"
+#include "i_api.hpp"
+#include "app_thread.hpp"
+#include "io_thread.hpp"
+#include "platform.hpp"
+#include "err.hpp"
+#include "pipe.hpp"
+
+#if defined ZMQ_HAVE_WINDOWS
+#include "windows.h"
+#endif
+
+zmq::dispatcher_t::dispatcher_t (int app_threads_, int io_threads_)
+{
+#ifdef ZMQ_HAVE_WINDOWS
+    //  Intialise Windows sockets. Note that WSAStartup can be called multiple
+    //  times given that WSACleanup will be called for each WSAStartup.
+    WORD version_requested = MAKEWORD (2, 2);
+    WSADATA wsa_data;
+    int rc = WSAStartup (version_requested, &wsa_data);
+    zmq_assert (rc == 0);
+    zmq_assert (LOBYTE (wsa_data.wVersion) == 2 &&
+        HIBYTE (wsa_data.wVersion) == 2);
+#endif
+
+    //  Create application thread proxies.
+    for (int i = 0; i != app_threads_; i++) {
+        app_thread_t *app_thread = new app_thread_t (this, i);
+        zmq_assert (app_thread);
+        app_threads.push_back (app_thread);
+        signalers.push_back (app_thread->get_signaler ());
+    }
+
+    //  Create I/O thread objects.
+    for (int i = 0; i != io_threads_; i++) {
+        io_thread_t *io_thread = new io_thread_t (this, i + app_threads_);
+        zmq_assert (io_thread);
+        io_threads.push_back (io_thread);
+        signalers.push_back (io_thread->get_signaler ());
+    }
+
+    //  Create command pipe matrix.
+    command_pipes = new command_pipe_t [signalers.size () * signalers.size ()];
+    zmq_assert (command_pipes);
+
+    //  Launch I/O threads.
+    for (int i = 0; i != io_threads_; i++)
+        io_threads [i]->start ();
+}
+
+zmq::dispatcher_t::~dispatcher_t ()
+{
+    //  Close all application theads, sockets, io_objects etc.
+    for (app_threads_t::size_type i = 0; i != app_threads.size (); i++)
+        delete app_threads [i];
+
+    //  Ask I/O threads to terminate. If stop signal wasn't sent to I/O
+    //  thread subsequent invocation of destructor would hang-up.
+    for (io_threads_t::size_type i = 0; i != io_threads.size (); i++)
+        io_threads [i]->stop ();
+
+    //  Wait till I/O threads actually terminate.
+    for (io_threads_t::size_type i = 0; i != io_threads.size (); i++)
+        delete io_threads [i];
+
+    delete [] command_pipes;
+
+#ifdef ZMQ_HAVE_WINDOWS
+    //  On Windows, uninitialise socket layer.
+    int rc = WSACleanup ();
+    wsa_assert (rc != SOCKET_ERROR);
+#endif
+}
+
+int zmq::dispatcher_t::thread_slot_count ()
+{
+    return signalers.size ();
+}
+
+zmq::i_api *zmq::dispatcher_t::create_socket (int type_)
+{
+    threads_sync.lock ();
+    app_thread_t *thread = choose_app_thread ();
+    if (!thread) {
+        threads_sync.unlock ();
+        return NULL;
+    }
+    threads_sync.unlock ();
+
+    return thread->create_socket (type_);
+}
+
+zmq::app_thread_t *zmq::dispatcher_t::choose_app_thread ()
+{
+    //  Check whether thread ID is already assigned. If so, return it.
+    for (app_threads_t::size_type i = 0; i != app_threads.size (); i++)
+        if (app_threads [i]->is_current ())
+            return app_threads [i];
+
+    //  Check whether there's an unused thread slot in the cotext.
+    for (app_threads_t::size_type i = 0; i != app_threads.size (); i++)
+        if (app_threads [i]->make_current ())
+            return app_threads [i];
+
+    //  Thread limit was exceeded.
+    errno = EMFILE;
+    return NULL;
+}
+
+zmq::io_thread_t *zmq::dispatcher_t::choose_io_thread (uint64_t taskset_)
+{
+    zmq_assert (io_threads.size () > 0);
+
+    //  Find the I/O thread with minimum load.
+    int min_load = io_threads [0]->get_load ();
+    io_threads_t::size_type result = 0;
+    for (io_threads_t::size_type i = 1; i != io_threads.size (); i++) {
+        if (!taskset_ || (taskset_ & (uint64_t (1) << i))) {
+            int load = io_threads [i]->get_load ();
+            if (load < min_load) {
+                min_load = load;
+                result = i;
+            }
+        }
+    }
+
+    return io_threads [result];
+}