akka-io: Stop select loop on idle

akkadotnet · Aug 12, 2015 · e545780 · e545780
1 parent ccf6680
commit e545780
Showing 1 changed file with 47 additions and 39 deletions.
diff --git a/src/core/Akka/IO/SelectionHandler.cs b/src/core/Akka/IO/SelectionHandler.cs
@@ -196,7 +196,6 @@ public ChannelRegistryImpl(ILoggingAdapter log)
             {
                 _log = log;
                 _executionContext = new SingleThreadExecutionContext();
-                Execute(Select);
             }
 
             private void Execute(Action action)
@@ -206,40 +205,39 @@ private void Execute(Action action)
 
             private void Select()
             {
-                if (_read.Count > 0 || _write.Count > 0)
+                if (_read.Count == 0 && _write.Count == 0) return;  // Stop select loop when no more interested sockets. It will be started again once a socket is registered
+
+                var readable = _read.Keys.ToList();
+                var writeable = _write.Keys.ToList();
+                try
                 {
-                    var readable = _read.Keys.ToList();
-                    var writeable = _write.Keys.ToList();
-                    try
+                    Socket.Select(readable, writeable, null, 1);
+                    foreach (var socket in readable)
                     {
-                        Socket.Select(readable, writeable, null, 1);
-                        foreach (var socket in readable)
-                        {
-                            var channel = _read[socket];
-                            if (channel.IsOpen())
-                                channel.Connection.Tell(ChannelReadable.Instance);
-                            else
-                                channel.Connection.Tell(ChannelAcceptable.Instance);
-                            _read.Remove(socket);
-                        }
-                        foreach (var socket in writeable)
-                        {
-                            var channel = _write[socket];
-                            if (channel.IsOpen())
-                                channel.Connection.Tell(ChannelWritable.Instance);
-                            else
-                                channel.Connection.Tell(ChannelConnectable.Instance);
-                            _write.Remove(socket);
-                        }
+                        var channel = _read[socket];
+                        if (channel.IsOpen())
+                            channel.Connection.Tell(ChannelReadable.Instance);
+                        else
+                            channel.Connection.Tell(ChannelAcceptable.Instance);
+                        _read.Remove(socket);
                     }
-                    catch (SocketException ex)
+                    foreach (var socket in writeable)
                     {
-                        if (ex.SocketErrorCode == SocketError.NotSocket)
-                        {
-                            // One of the sockets has been closed
-                            readable.Where(x => !x.Connected).ForEach(x =>_read.Remove(x));
-                            writeable.Where(x => !x.Connected).ForEach(x => _write.Remove(x));
-                        }
+                        var channel = _write[socket];
+                        if (channel.IsOpen())
+                            channel.Connection.Tell(ChannelWritable.Instance);
+                        else
+                            channel.Connection.Tell(ChannelConnectable.Instance);
+                        _write.Remove(socket);
+                    }
+                }
+                catch (SocketException ex)
+                {
+                    if (ex.SocketErrorCode == SocketError.NotSocket)
+                    {
+                        // One of the sockets has been closed
+                        readable.Where(x => !x.Connected).ForEach(x =>_read.Remove(x));
+                        writeable.Where(x => !x.Connected).ForEach(x => _write.Remove(x));
                     }
                 }
                 Execute(Select);
@@ -262,14 +260,24 @@ private void EnableInterest(SocketChannel channel, SocketAsyncOperation op)
             {
                 switch (op)
                 {
-                        case SocketAsyncOperation.Accept:
-                        case SocketAsyncOperation.Receive:
-                            Execute(() => _read.Add(channel.Socket, channel));                            
-                            break;
-                        case SocketAsyncOperation.Connect:
-                        case SocketAsyncOperation.Send:
-                            Execute(() => _write.Add(channel.Socket, channel));
-                            break;
+                    case SocketAsyncOperation.Accept:
+                    case SocketAsyncOperation.Receive:
+                        Execute(() =>
+                        {
+                            _read.Add(channel.Socket, channel);
+                            if (_read.Count == 1 && _write.Count == 0)  // Start the select loop on initial enable interest
+                                Select();                               // The select loop will stop itself if no more interested sockets
+                        });
+                        break;
+                    case SocketAsyncOperation.Connect:
+                    case SocketAsyncOperation.Send:
+                        Execute(() =>
+                        {
+                            _write.Add(channel.Socket, channel);        // Start the select loop on initial enable interest
+                            if (_read.Count == 0 && _write.Count == 1)  // The select loop will stop itself if no more interested sockets
+                                Select();
+                        });
+                        break;
                 }
             }
             private void DisableInterest(SocketChannel channel, SocketAsyncOperation op)