using System; using System.Net.Sockets; using MediaBrowser.Model.Logging; using MediaBrowser.Model.Net; namespace Emby.Common.Implementations.Net { public class SocketAcceptor { private readonly ILogger _logger; private readonly Socket _originalSocket; private readonly Func _isClosed; private readonly Action _onAccept; public SocketAcceptor(ILogger logger, Socket originalSocket, Action onAccept, Func isClosed) { _logger = logger; _originalSocket = originalSocket; _isClosed = isClosed; _onAccept = onAccept; } public void StartAccept() { Socket dummy = null; StartAccept(null, ref dummy); } public void StartAccept(SocketAsyncEventArgs acceptEventArg, ref Socket accepted) { if (acceptEventArg == null) { acceptEventArg = new SocketAsyncEventArgs(); acceptEventArg.Completed += new EventHandler(AcceptEventArg_Completed); } else { // socket must be cleared since the context object is being reused acceptEventArg.AcceptSocket = null; } try { bool willRaiseEvent = _originalSocket.AcceptAsync(acceptEventArg); if (!willRaiseEvent) { ProcessAccept(acceptEventArg); } } catch (Exception ex) { if (accepted != null) { try { #if NET46 accepted.Close(); #else accepted.Dispose(); #endif } catch { } accepted = null; } } } // This method is the callback method associated with Socket.AcceptAsync // operations and is invoked when an accept operation is complete // void AcceptEventArg_Completed(object sender, SocketAsyncEventArgs e) { ProcessAccept(e); } private void ProcessAccept(SocketAsyncEventArgs e) { if (_isClosed()) { return; } // http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.acceptasync%28v=vs.110%29.aspx // Under certain conditions ConnectionReset can occur // Need to attept to re-accept if (e.SocketError == SocketError.ConnectionReset) { _logger.Error("SocketError.ConnectionReset reported. Attempting to re-accept."); Socket dummy = null; StartAccept(e, ref dummy); return; } var acceptSocket = e.AcceptSocket; if (acceptSocket != null) { //ProcessAccept(acceptSocket); _onAccept(new NetSocket(acceptSocket, _logger)); } if (_originalSocket != null) { // Accept the next connection request StartAccept(e, ref acceptSocket); } } } }