lockfree interaction patter for 3 theads implemented

1 files changed, 122 insertions, 0 deletions

diff --git a/src/dispatcher.hpp b/src/dispatcher.hpp
new file mode 100644
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--- /dev/null
+++ b/src/dispatcher.hpp
@@ -0,0 +1,122 @@
+/*
+    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/>.
+*/
+
+#ifndef __ZMQ_DISPATCHER_HPP_INCLUDED__
+#define __ZMQ_DISPATCHER_HPP_INCLUDED__
+
+#include <vector>
+#include <map>
+#include <string>
+
+#include "i_signaler.hpp"
+#include "ypipe.hpp"
+#include "command.hpp"
+#include "config.hpp"
+#include "mutex.hpp"
+#include "stdint.hpp"
+
+namespace zmq
+{
+
+    //  Dispatcher implements bidirectional thread-safe passing of commands
+    //  between N threads. It consists of a ypipes to pass commands and
+    //  signalers to wake up the receiver thread when new commands are
+    //  available. Note that dispatcher is inefficient for passing messages
+    //  within a thread (sender thread = receiver thread). The optimisation is
+    //  not part of the class and should be implemented by individual threads
+    //  (presumably by calling the command handling function directly).
+    
+    class dispatcher_t
+    {
+    public:
+
+        //  Create the dispatcher object. Matrix of pipes to communicate between
+        //  each socket and each I/O thread is created along with appropriate
+        //  signalers.
+        dispatcher_t (int app_threads_, int io_threads_);
+
+        //  To be called to terminate the whole infrastructure (zmq_term).
+        ~dispatcher_t ();
+
+        //  Create a socket.
+        struct i_api *create_socket (int type_);
+
+        //  Returns number of thread slots in the dispatcher. To be used by
+        //  individual threads to find out how many distinct signals can be
+        //  received.
+        int thread_slot_count ();
+
+        //  Send command from the source to the destination.
+        inline void write (int source_, int destination_,
+            const command_t &command_)
+        {
+            command_pipe_t &pipe =
+                command_pipes [source_ * signalers.size () + destination_];
+            pipe.write (command_);
+            if (!pipe.flush ())
+                signalers [destination_]->signal (source_);
+        }
+
+        //  Receive command from the source. Returns false if there is no
+        //  command available.
+        inline bool read (int source_,  int destination_, command_t *command_)
+        {
+            return command_pipes [source_ * signalers.size () +
+                destination_].read (command_);
+        }
+
+        //  Returns the I/O thread that is the least busy at the moment.
+        //  Taskset specifies which I/O threads are eligible (0 = all).
+        class io_thread_t *choose_io_thread (uint64_t taskset_);
+
+    private:
+
+        //  Returns the app thread associated with the current thread.
+        //  NULL if we are out of app thread slots.
+        class app_thread_t *choose_app_thread ();
+
+        //  Application threads.
+        typedef std::vector <class app_thread_t*> app_threads_t;
+        app_threads_t app_threads;
+
+        //  I/O threads.
+        typedef std::vector <class io_thread_t*> io_threads_t;
+        io_threads_t io_threads;
+
+        //  Signalers for both application and I/O threads.
+        std::vector <i_signaler*> signalers;
+
+        //  Pipe to hold the commands.
+        typedef ypipe_t <command_t, true,
+            command_pipe_granularity> command_pipe_t;
+
+        //  NxN matrix of command pipes.
+        command_pipe_t *command_pipes;
+
+        //  Synchronisation of accesses to shared thread data.
+        mutex_t threads_sync;
+
+        dispatcher_t (const dispatcher_t&);
+        void operator = (const dispatcher_t&);
+    };
+    
+}
+
+#endif
+