Diagnostic Explorer

#region Copyright

// Diagnostic Explorer, a .Net diagnostic toolset
// Copyright (C) 2010 Cameron Elliot
// 
// This file is part of Diagnostic Explorer.
// 
// Diagnostic Explorer 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, either version 3 of the License, or
// (at your option) any later version.
// 
// Diagnostic Explorer 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 Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with Diagnostic Explorer.  If not, see <http://www.gnu.org/licenses/>.
// 
// http://diagexplorer.sourceforge.net/

#endregion

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.Remoting;
using System.ServiceModel;
using System.ServiceProcess;
using System.Text;
using System.Threading;
using log4net;
using log4net.Config;
using System.Diagnostics;
using DiagnosticExplorer.WinService;


namespace DiagnosticExplorer.WindowsService
{

	[DiagnosticClass(AttributedPropertiesOnly = true)]
	public class DiagnosticWinService : ServiceBase
	{
		private ILog _log = LogManager.GetLogger(typeof (DiagnosticWinService));
		private ServiceHost _svcHost;
		private bool _isStarted;

		public DiagnosticWinService()
		{
			DiagnosticManager.Register(this, "Diagnostic WinService", "System");
		}

		protected override void OnStart(string[] args)
		{
			_log.Info("Starting Service");

			try
			{
				_isStarted = true;
				string configDir = AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
				string configPath = Path.Combine(configDir, "log4net.config");
				XmlConfigurator.ConfigureAndWatch(new FileInfo(configPath));
				DiagnosticHostingService.Start();

				OpenServiceHost(0);
			}
			catch (Exception ex)
			{
				File.WriteAllText(@"d:\Error.txt", ex.ToString());
				Trace.WriteLine(ex);
				_log.Error("An exception was thrown during service startup", ex);
				throw;
			}
		}

		private void OpenServiceHost(int sleepMillis)
		{
			if (sleepMillis > 0)
				Thread.Sleep(sleepMillis);

			if (_isStarted)
			{
				_svcHost = new ServiceHost(typeof(DiagnosticLogger));
				_svcHost.Faulted += HandleHostFaulted;
				_svcHost.BeginOpen(OpenFinished, null);
			}
		}

		public string ServiceHostStatus
		{
			get { return _svcHost == null ? "NULL" : _svcHost.State.ToString(); }
		}

		private void OpenFinished(IAsyncResult result)
		{
			
		}

		private void HandleHostFaulted(object sender, EventArgs e)
		{
			_log.Info("Host faulted");
			Action action = () => OpenServiceHost(2000);
			action.BeginInvoke(null, null);
		}

		protected override void OnStop()
		{
			_log.Info("DBDiagService Stopping");
			try
			{
				_isStarted = false;
				DiagnosticHostingService.Stop();

				if (_svcHost != null && _svcHost.State == CommunicationState.Opened)
				{
					_svcHost.Close();
					_svcHost = null;
				}
			}
			catch (Exception ex)
			{
				_log.Error("An exception was thrown during service shutdown", ex);
				// don't rethrow - an unhandled exception during service shutdown might leave it running 
			}
		}
	}
}