System.Net.Sockets.Socket.Dispose C# (CSharp) Method

        protected virtual void Dispose(bool disposing)
        {
            if (!disposing)
            {
                return;
            }

            if (NetEventSource.IsEnabled)
            {
                try
                {
                    NetEventSource.Info(this, $"disposing:true CleanedUp:{CleanedUp}");
                    NetEventSource.Enter(this);
                }
                catch (Exception exception) when (!ExceptionCheck.IsFatal(exception)) { }
            }

            // Make sure we're the first call to Dispose and no SetAsyncEventSelect is in progress.
            int last;
            SpinWait sw = new SpinWait();
            while ((last = Interlocked.CompareExchange(ref _intCleanedUp, 1, 0)) == 2)
            {
                sw.SpinOnce();
            }

            if (last == 1)
            {
                if (NetEventSource.IsEnabled) NetEventSource.Exit(this);
                return;
            }

            SetToDisconnected();

            // Close the handle in one of several ways depending on the timeout.
            // Ignore ObjectDisposedException just in case the handle somehow gets disposed elsewhere.
            try
            {
                int timeout = _closeTimeout;
                if (timeout == 0)
                {
                    // Abortive.
                    if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Calling _handle.Dispose()");
                    _handle.Dispose();
                }
                else
                {
                    SocketError errorCode;

                    // Go to blocking mode.  We know no WSAEventSelect is pending because of the lock and UnsetAsyncEventSelect() above.
                    if (!_willBlock || !_willBlockInternal)
                    {
                        bool willBlock;
                        errorCode = SocketPal.SetBlocking(_handle, false, out willBlock);
                        if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"handle:{_handle} ioctlsocket(FIONBIO):{errorCode}");
                    }

                    if (timeout < 0)
                    {
                        // Close with existing user-specified linger option.
                        if (NetEventSource.IsEnabled) NetEventSource.Info(this, "Calling _handle.CloseAsIs()");
                        _handle.CloseAsIs();
                    }
                    else
                    {
                        // Since our timeout is in ms and linger is in seconds, implement our own sortof linger here.
                        errorCode = SocketPal.Shutdown(_handle, _isConnected, _isDisconnected, SocketShutdown.Send);
                        if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"handle:{_handle} shutdown():{errorCode}");

                        // This should give us a timeout in milliseconds.
                        errorCode = SocketPal.SetSockOpt(
                            _handle,
                            SocketOptionLevel.Socket,
                            SocketOptionName.ReceiveTimeout,
                            timeout);
                        if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"handle:{_handle} setsockopt():{errorCode}");

                        if (errorCode != SocketError.Success)
                        {
                            _handle.Dispose();
                        }
                        else
                        {
                            int unused;
                            errorCode = SocketPal.Receive(_handle, null, 0, 0, SocketFlags.None, out unused);
                            if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"handle:{_handle} recv():{errorCode}");

                            if (errorCode != (SocketError)0)
                            {
                                // We got a timeout - abort.
                                _handle.Dispose();
                            }
                            else
                            {
                                // We got a FIN or data.  Use ioctlsocket to find out which.
                                int dataAvailable = 0;
                                errorCode = SocketPal.GetAvailable(_handle, out dataAvailable);
                                if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"handle:{_handle} ioctlsocket(FIONREAD):{errorCode}");

                                if (errorCode != SocketError.Success || dataAvailable != 0)
                                {
                                    // If we have data or don't know, safest thing is to reset.
                                    _handle.Dispose();
                                }
                                else
                                {
                                    // We got a FIN.  It'd be nice to block for the remainder of the timeout for the handshake to finish.
                                    // Since there's no real way to do that, close the socket with the user's preferences.  This lets
                                    // the user decide how best to handle this case via the linger options.
                                    _handle.CloseAsIs();
                                }
                            }
                        }
                    }
                }
            }
            catch (ObjectDisposedException)
            {
                NetEventSource.Fail(this, $"handle:{_handle}, Closing the handle threw ObjectDisposedException.");
            }
        }

        /// <summary>
        /// 停止服务
        /// </summary>
        public void Dispose()
        {
            if (socket != null)
            {
#if DotNetStandard
                AutoCSer.Net.TcpServer.CommandBase.CloseServer(socket);
#else
                socket.Dispose();
#endif
                socket = null;
            }
        }