CASA/c_micasad/communication/win/PipeManager.cs

/***********************************************************************
 * 
 *  Copyright (C) 2005-2006 Novell, Inc. All Rights Reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; version 2.1
 *  of the License.
 *
 *  This library 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 GNU
 *  Library Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, Novell, Inc.
 * 
 *  To contact Novell about this file by physical or electronic mail, 
 *  you may find current contact information at www.novell.com.
 * 
 ***********************************************************************/

using System;
using System.Collections;
using System.Threading;
using System.Web;
using System.IO;
using System.Configuration;
using System.Diagnostics;

using AppModule.InterProcessComm;
using AppModule.NamedPipes;

namespace sscs.communication.win {

	public class PipeManager : IChannelManager {

		public Hashtable Pipes;

		private uint NumberPipes = 16;
		private uint OutBuffer = 65536; //512;
		private uint InBuffer = 65536; //512;
		private const int MAX_READ_BYTES = 5000;
		private bool _listen = true;
		public bool Listen {
			get {
				return _listen;
			}
			set {
				_listen=value;
			}
		}
		private int numChannels = 0;
		private Hashtable _pipes = new Hashtable();

		//private Thread MainThread;		
		private string CASA_RPC_PIPE = "\\\\.\\PIPE\\SS_RPC_PIPE";
		private ManualResetEvent Mre;
		private const int PIPE_MAX_STUFFED_TIME = 5000;
		
		public object SyncRoot = new object();

		public void Initialize() {
			Pipes = Hashtable.Synchronized(_pipes);
			Mre = new ManualResetEvent(false);
			/*
			MainThread = new Thread(new ThreadStart(Start));
			MainThread.IsBackground = true;
			MainThread.Name = "Main Pipe Thread";
			MainThread.Start();
			*/
			Thread.Sleep(1000);
		}
		public string HandleRequest(string request) {
			string returnVal;

			//Form1.ActivityRef.AppendText(request + Environment.NewLine);
			returnVal = "Response to: " + request;

			return returnVal;
		}

		public void Start() {
			try {
				while (_listen) {
					int[] keys = new int[Pipes.Keys.Count];
					Pipes.Keys.CopyTo(keys,0);
					foreach (int key in keys) {
						ServerNamedPipe serverPipe = (ServerNamedPipe)Pipes[key];
						if (serverPipe != null && DateTime.Now.Subtract(serverPipe.LastAction).Milliseconds > PIPE_MAX_STUFFED_TIME && serverPipe.PipeConnection.GetState() != InterProcessConnectionState.WaitingForClient) {
							serverPipe.Listen = false;
							serverPipe.PipeThread.Abort();
							RemoveServerChannel(serverPipe.PipeConnection.NativeHandle);
						}
					}
					if (numChannels <= NumberPipes) {
						ServerNamedPipe pipe = new ServerNamedPipe(CASA_RPC_PIPE, OutBuffer, InBuffer, MAX_READ_BYTES);
						try {
							pipe.Connect();
							pipe.LastAction = DateTime.Now;
							System.Threading.Interlocked.Increment(ref numChannels);
							pipe.Start();
							Pipes.Add(pipe.PipeConnection.NativeHandle, pipe);
						}
						catch (InterProcessIOException) {
							RemoveServerChannel(pipe.PipeConnection.NativeHandle);
							pipe.Dispose();
						}
					}
					else {
						Mre.Reset();
						Mre.WaitOne(1000, false);
					}
				}
			}
			catch (Exception e)
			{
				Console.WriteLine("Exception starting server: "+e.ToString());
				// Log exception
			}
		}
		public void Stop() {
			_listen = false;
			Mre.Set();
			try {
				int[] keys = new int[Pipes.Keys.Count];
				Pipes.Keys.CopyTo(keys,0);
				foreach (int key in keys) {
					((ServerNamedPipe)Pipes[key]).Listen = false;
				}
				int i = numChannels * 3;
				for (int j = 0; j < i; j++) {
					StopServerPipe();
				}
				Pipes.Clear();
				Mre.Close();
				Mre = null;
			} 
			catch {	
				// Log exception
			}
		}

		public void WakeUp() {
			if (Mre != null) {
				Mre.Set();
			}
		}
		private void StopServerPipe() {
			try {
				ClientPipeConnection pipe = new ClientPipeConnection(CASA_RPC_PIPE);
				if (pipe.TryConnect()) {
					pipe.Close();
				}
			} catch {	
				// Log exception
			}
		}

		public void RemoveServerChannel(object param) {
			int handle = (int)param;
			System.Threading.Interlocked.Decrement(ref numChannels);
			Pipes.Remove(handle);
			this.WakeUp();
		}
	}
}