port.cs

win CE .net Serial port class lib

//==========================================================================================
//
//		OpenNETCF.IO.Serial.Port
//		Copyright (c) 2003, OpenNETCF.org
//
//		This library is free software; you can redistribute it and/or modify it under 
//		the terms of the OpenNETCF.org Shared Source 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 OpenNETCF.org Shared Source License 
//		for more details.
//
//		You should have received a copy of the OpenNETCF.org Shared Source License 
//		along with this library; if not, email [e-mail] to request a copy.
//
//		If you wish to contact the OpenNETCF Advisory Board to discuss licensing, please 
//		email [e-mail].
//
//		For general enquiries, email [e-mail] or visit our website at:
//		http://www.opennetcf.org
//
//==========================================================================================

using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Text;
using System.Collections;

namespace OpenNETCF.IO.Serial
{
	/// <summary>
	/// Exceptions throw by the OpenNETCF.IO.Serial class
	/// </summary>
	public class CommPortException : Exception
	{
		/// <summary>
		/// Default CommPortException
		/// </summary>
		/// <param name="desc"></param>
		public CommPortException(string desc) : base(desc) {}
	}

	/// <summary>
	/// A class wrapper for serial port communications
	/// </summary>
	public class Port : IDisposable
	{
		[DllImport("kernel32", EntryPoint="LocalAlloc", SetLastError=true)]
		internal static extern IntPtr LocalAlloc(int uFlags, int uBytes);

		[DllImport("kernel32", EntryPoint="LocalFree", SetLastError=true)]
		internal static extern IntPtr LocalFree(IntPtr hMem);

		#region delegates and events
		/// <summary>
		/// Raised on all enabled communication events
		/// </summary>
		public delegate void CommEvent();
		/// <summary>
		/// Raised when the communication state changes
		/// </summary>
		public delegate void CommChangeEvent(bool NewState);
		/// <summary>
		/// Raised during any communication error
		/// </summary>
		public delegate void CommErrorEvent(string Description);
		/// <summary>
		///  A communication error has occurred
		/// </summary>
		public event CommErrorEvent OnError;
		/// <summary>
		/// Serial data has been received
		/// </summary>
		public event CommEvent DataReceived;
//		/// <summary>
//		/// Overrun of the transmit buffer
//		/// </summary>
//		public event CommEvent RxOverrun;
		/// <summary>
		/// Transmit complete
		/// </summary>
		public event CommEvent TxDone;
		/// <summary>
		/// Set flag character was in the receive stream
		/// </summary>
		public event CommEvent FlagCharReceived;
		/// <summary>
		/// Power change event has occurred
		/// </summary>
		public event CommEvent PowerEvent;
		/// <summary>
		/// Serial buffer's high-water level has been exceeded
		/// </summary>
		public event CommEvent HighWater;
		/// <summary>
		/// DSR state has changed
		/// </summary>
		public event CommChangeEvent DSRChange;
		/// <summary>
		/// Ring signal has been detected
		/// </summary>
		public event CommChangeEvent RingChange;
		/// <summary>
		/// CTS state has changed
		/// </summary>
		public event CommChangeEvent CTSChange;
		/// <summary>
		/// RLSD state has changed
		/// </summary>
		public event CommChangeEvent RLSDChange;
		#endregion

		#region ##### variable declarations #####
		private string portName;
		private IntPtr hPort = (IntPtr)CommAPI.INVALID_HANDLE_VALUE;
		
		// default Rx buffer is 1024 bytes
		private int rxBufferSize = 1024;
		private Queue rxFIFO;
		private int rthreshold = 1;

		// default Tx buffer is 1024 bytes
		private int txBufferSize = 1024;
		private byte[] txBuffer;
		private int ptxBuffer	= 0;
		private int sthreshold = 1;

		private Mutex rxBufferBusy = new Mutex();
		private int inputLength;

		private DCB dcb = new DCB();
		private DetailedPortSettings portSettings;

		private Thread eventThread;
		private ManualResetEvent threadStarted = new ManualResetEvent(false);
		
		private IntPtr closeEvent;
		private string closeEventName = "CloseEvent";

		private int		rts			= 0;
		private bool	rtsavail	= false;
		private int		dtr			= 0;
		private bool	dtravail	= false;
		private int		brk			= 0;
		private int		setir		= 0;
		private bool	isOpen		= false;

		private IntPtr txOverlapped = IntPtr.Zero;
		private IntPtr rxOverlapped = IntPtr.Zero;

		private CommAPI m_CommAPI;
		/// <summary>
		/// stores port's capabilities - capabilities can only be retreived not set
		/// </summary>
		public readonly CommCapabilities Capabilities = new CommCapabilities();

		#endregion

		private void Init()
		{
			// create the API class based on the target
			if (System.Environment.OSVersion.Platform != PlatformID.WinCE)
				m_CommAPI=new IO.Serial.WinCommAPI();
			else
				m_CommAPI=new IO.Serial.CECommAPI();

			// create a system event for synchronizing Closing
			closeEvent = m_CommAPI.CreateEvent(true, false, closeEventName);

			rxFIFO = new Queue(rxBufferSize);
			txBuffer = new byte[txBufferSize];
			portSettings = new DetailedPortSettings();
		}

		#region constructors
		/// <summary>
		/// Create a serial port class.  The port will be created with defualt settings.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		public Port(string PortName)
		{
			this.PortName = PortName;
			Init();
		}

		/// <summary>
		/// Create a serial port class.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		/// <param name="InitialSettings">BasicPortSettings to apply to the new Port</param>
		public Port(string PortName, BasicPortSettings InitialSettings)
		{
			this.PortName = PortName;
			Init();

			//override default ettings
			portSettings.BasicSettings = InitialSettings;
		}

		/// <summary>
		/// Create a serial port class.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		/// <param name="InitialSettings">DetailedPortSettings to apply to the new Port</param>
		public Port(string PortName, DetailedPortSettings InitialSettings)
		{
			this.PortName = PortName;
			Init();

			//override default ettings
			portSettings = InitialSettings;
		}

		/// <summary>
		/// Create a serial port class.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		/// <param name="RxBufferSize">Receive buffer size, in bytes</param>
		/// <param name="TxBufferSize">Transmit buffer size, in bytes</param>
		public Port(string PortName, int RxBufferSize, int TxBufferSize)
		{
			rxBufferSize = RxBufferSize;
			txBufferSize = TxBufferSize;
			this.PortName = PortName;
			Init();
		}
		
		/// <summary>
		/// Create a serial port class.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		/// <param name="InitialSettings">BasicPortSettings to apply to the new Port</param>
		/// <param name="RxBufferSize">Receive buffer size, in bytes</param>
		/// <param name="TxBufferSize">Transmit buffer size, in bytes</param>
		public Port(string PortName, BasicPortSettings InitialSettings, int RxBufferSize, int TxBufferSize)
		{
			rxBufferSize = RxBufferSize;
			txBufferSize = TxBufferSize;
			this.PortName = PortName;
			Init();

			//override default ettings
			portSettings.BasicSettings = InitialSettings;
		}

		/// <summary>
		/// Create a serial port class.
		/// </summary>
		/// <param name="PortName">The port to open (i.e. "COM1:")</param>
		/// <param name="InitialSettings">DetailedPortSettings to apply to the new Port</param>
		/// <param name="RxBufferSize">Receive buffer size, in bytes</param>
		/// <param name="TxBufferSize">Transmit buffer size, in bytes</param>
		public Port(string PortName, DetailedPortSettings InitialSettings, int RxBufferSize, int TxBufferSize)
		{
			rxBufferSize = RxBufferSize;
			txBufferSize = TxBufferSize;
			this.PortName = PortName;
			Init();

			//override default ettings
			portSettings = InitialSettings;
		}
		#endregion

		// since the event thread blocks until the port handle is closed
		// implement both a Dispose and destrucor to make sure that we
		// clean up as soon as possible
		/// <summary>
		/// Dispose the object's resources
		/// </summary>
		public void Dispose()
		{
			if(isOpen)
				this.Close();
		}
		
		/// <summary>
		/// Class destructor
		/// </summary>
		~Port()
		{
			if(isOpen)
				this.Close();
		}

		/// <summary>
		/// The name of the Port (i.e. "COM1:")
		/// </summary>
		public string PortName
		{
			get
			{
				return portName;
			}
			set
			{
				if(! CommAPI.FullFramework)
				{
					// for CE, ensure the port name is colon terminated "COMx:"
					if(! value.EndsWith(":"))
					{
						portName = value + ":";
						return;
					}
				}

				portName = value;
			}
		}

		/// <summary>
		/// Returns whether or not the port is currently open
		/// </summary>
		public bool IsOpen
		{
			get
			{
				return isOpen;
			}
		}

		/// <summary>
		/// Open the current port
		/// </summary>
		/// <returns>true if successful, false if it fails</returns>
		public bool Open()
		{
			if(isOpen) return false;

			if(CommAPI.FullFramework)
			{
				// set up the overlapped tx IO
				//				AutoResetEvent are = new AutoResetEvent(false);
				OVERLAPPED o = new OVERLAPPED();
				txOverlapped = LocalAlloc(0x40, Marshal.SizeOf(o));
				o.Offset = 0; 
				o.OffsetHigh = 0;
				o.hEvent = IntPtr.Zero;
				Marshal.StructureToPtr(o, txOverlapped, true);
			}

			hPort = m_CommAPI.CreateFile(portName);

			if(hPort == (IntPtr)CommAPI.INVALID_HANDLE_VALUE)
			{
				int e = Marshal.GetLastWin32Error();

				if(e == (int)APIErrors.ERROR_ACCESS_DENIED)
				{
					// port is unavailable
					return false;
				}

				// ClearCommError failed!
				string error = String.Format("CreateFile Failed: {0}", e);
				throw new CommPortException(error);
			}

			
			isOpen = true;

			// set queue sizes
			m_CommAPI.SetupComm(hPort, rxBufferSize, txBufferSize);

			// transfer the port settings to a DCB structure
			dcb.BaudRate = (uint)portSettings.BasicSettings.BaudRate;
			dcb.ByteSize = portSettings.BasicSettings.ByteSize;
			dcb.EofChar = (sbyte)portSettings.EOFChar;
			dcb.ErrorChar = (sbyte)portSettings.ErrorChar;
			dcb.EvtChar = (sbyte)portSettings.EVTChar;
			dcb.fAbortOnError = portSettings.AbortOnError;
			dcb.fBinary = true;
			dcb.fDsrSensitivity = portSettings.DSRSensitive;
			dcb.fDtrControl = (DCB.DtrControlFlags)portSettings.DTRControl;
			dcb.fErrorChar = portSettings.ReplaceErrorChar;
			dcb.fInX = portSettings.InX;
			dcb.fNull = portSettings.DiscardNulls;
			dcb.fOutX = portSettings.OutX;
			dcb.fOutxCtsFlow = portSettings.OutCTS;
			dcb.fOutxDsrFlow = portSettings.OutDSR;
			dcb.fParity = (portSettings.BasicSettings.Parity == Parity.none) ? false : true;
			dcb.fRtsControl = (DCB.RtsControlFlags)portSettings.RTSControl;
			dcb.fTXContinueOnXoff = portSettings.TxContinueOnXOff;
			dcb.Parity = (byte)portSettings.BasicSettings.Parity;

			dcb.StopBits = (byte)portSettings.BasicSettings.StopBits;
			dcb.XoffChar = (sbyte)portSettings.XoffChar;
			dcb.XonChar = (sbyte)portSettings.XonChar;

			dcb.XonLim = dcb.XoffLim = (ushort)(rxBufferSize / 10);
			
			m_CommAPI.SetCommState(hPort, dcb);

			// store some state values
			brk = 0;
			dtr = dcb.fDtrControl == DCB.DtrControlFlags.Enable ? 1 : 0;
			rts = dcb.fRtsControl == DCB.RtsControlFlags.Enable ? 1 : 0;

			// set the Comm timeouts
			CommTimeouts ct = new CommTimeouts();

			// reading we'll return immediately
			// this doesn't seem to work as documented
			ct.ReadIntervalTimeout = uint.MaxValue; // this = 0xffffffff
			ct.ReadTotalTimeoutConstant = 0;
			ct.ReadTotalTimeoutMultiplier = 0;

			// writing we'll give 5 seconds
			ct.WriteTotalTimeoutConstant = 5000;
			ct.WriteTotalTimeoutMultiplier = 0;

			m_CommAPI.SetCommTimeouts(hPort, ct);

			// read the ports capabilities
			bool status=GetPortProperties();

			// start the receive thread
			eventThread = new Thread(new ThreadStart(CommEventThread));
			eventThread.Start();

			// wait for the thread to actually get spun up
			threadStarted.WaitOne();

			return true;
		}

		/// <summary>
		/// Query the current port's capabilities without accessing it. You can only call the Close()
		/// method after reading the capabilities. This method does neither initialize nor Open() the
		/// port.
		/// </summary>
		/// 
		/// <example>
		/// 
		/// </example>
		public bool Query()
		{
			if(isOpen) return false;

			hPort = m_CommAPI.QueryFile(portName);

			if(hPort == (IntPtr)CommAPI.INVALID_HANDLE_VALUE)
			{
				int e = Marshal.GetLastWin32Error();

				if(e == (int)APIErrors.ERROR_ACCESS_DENIED)
				{
					// port is unavailable
					return false;
				}

				// ClearCommError failed!
				string error = String.Format("CreateFile Failed: {0}", e);
				throw new CommPortException(error);
			}


			// read the port's capabilities
			bool status=GetPortProperties();

			return true;
		}

		// parameters without closing and reopening the port
		/// <summary>
		/// Updates communication settings of the port
		/// </summary>
		/// <returns>true if successful, false if it fails</returns>
		private bool UpdateSettings()
		{
			if(!isOpen) return false;

			// transfer the port settings to a DCB structure
			dcb.BaudRate = (uint)portSettings.BasicSettings.BaudRate;
			dcb.ByteSize = portSettings.BasicSettings.ByteSize;
			dcb.EofChar = (sbyte)portSettings.EOFChar;
			dcb.ErrorChar = (sbyte)portSettings.ErrorChar;
			dcb.EvtChar = (sbyte)portSettings.EVTChar;
			dcb.fAbortOnError = portSettings.AbortOnError;
			dcb.fBinary = true;
			dcb.fDsrSensitivity = portSettings.DSRSensitive;
			dcb.fDtrControl = (DCB.DtrControlFlags)portSettings.DTRControl;
			dcb.fErrorChar = portSettings.ReplaceErrorChar;
			dcb.fInX = portSettings.InX;
			dcb.fNull = portSettings.DiscardNulls;
			dcb.fOutX = portSettings.OutX;
			dcb.fOutxCtsFlow = portSettings.OutCTS;
			dcb.fOutxDsrFlow = portSettings.OutDSR;
			dcb.fParity = (portSettings.BasicSettings.Parity == Parity.none) ? false : true;
			dcb.fRtsControl = (DCB.RtsControlFlags)portSettings.RTSControl;
			dcb.fTXContinueOnXoff = portSettings.TxContinueOnXOff;
			dcb.Parity = (byte)portSettings.BasicSettings.Parity;
			dcb.StopBits = (byte)portSettings.BasicSettings.StopBits;
			dcb.XoffChar = (sbyte)portSettings.XoffChar;
			dcb.XonChar = (sbyte)portSettings.XonChar;

			dcb.XonLim = dcb.XoffLim = (ushort)(rxBufferSize / 10);
			
			return m_CommAPI.SetCommState(hPort, dcb);

		}

		/// <summary>
		/// Close the current serial port
		/// </summary>
		/// <returns>true indicates success, false indicated failure</returns>
		public bool Close()
		{

			if(txOverlapped != IntPtr.Zero)
			{
				LocalFree(txOverlapped);
				txOverlapped = IntPtr.Zero;
			}

			if(!isOpen) return false;

			isOpen = false; // to help catch intentional close

			if(m_CommAPI.CloseHandle(hPort))
			{
				m_CommAPI.SetEvent(closeEvent);

				isOpen = false;

				hPort = (IntPtr)CommAPI.INVALID_HANDLE_VALUE;
				
				m_CommAPI.SetEvent(closeEvent);

				return true;
			}

			return false;
		}

		/// <summary>
		/// The Port's output buffer.  Set this property to send data.
		/// </summary>
		public byte[] Output
		{
			set
			{
				if(!isOpen) 
					throw new CommPortException("Port not open");

				int written = 0;

				// more than threshold amount so send without buffering
				if(value.GetLength(0) > sthreshold)
				{
					// first send anything already in the buffer
					if(ptxBuffer > 0)
					{
						m_CommAPI.WriteFile(hPort, txBuffer, ptxBuffer, ref written, txOverlapped);
						ptxBuffer = 0;
					}

					m_CommAPI.WriteFile(hPort, value, (int)value.GetLength(0), ref written, txOverlapped);
				}
				else
				{
					// copy it to the tx buffer
					value.CopyTo(txBuffer, (int)ptxBuffer);
					ptxBuffer += (int)value.Length;

					// now if the buffer is above sthreshold, send it
					if(ptxBuffer >= sthreshold)