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Why do I get an object reference error when i try to call my method?

For this peice of code I get an error when i try to call Square.EffectOnPlayer(player);
The error says an object reference is required, Why wont it accept player?
public void Move(int numberOfSquares, Player player) {
int current_pos;
int new_pos;
current_pos = Square.GetSquarenumber(location);
new_pos = numberOfSquares + current_pos;
location = Board.GetGameBoardSquare(new_pos);
Square.EffectOnPlayer(player);
}
will be refreshing on page to give more information if needed.
EDIT
this is the square class library which the method refers to (variables left out):
public class Win_Square : Square
{
public Win_Square(string n,int nu)
{
Name = n;
number = nu;
}
public override void EffectOnPlayer(Player who)
{
who.Add(add);
}
}
public class Lose_Square : Square
{
public Lose_Square(string n,int nu)
{
Name = n;
number = nu;
}
public override void EffectOnPlayer(Player who)
{
who.Deduct(deduct);
}
}
public class Chance_Square : Square
{
public Chance_Square(string n,int nu)
{
Name = n;
number = nu;
}
public override void EffectOnPlayer(Player who)
{
Random rand = new Random();
if (rand.Next(0, 2) == 0)
who.Deduct(one_hundred);
else
who.Add(one_hundred);
}
}
public static int GetSquarenumber(Square square)
{
int n = 0;
string name;
name = square.Name;
if (name == "Finish")
{
n = 55;
}
if (name == "Start")
{
n = 0;
}
else
{
n = Int32.Parse(name);
}
return n;
}
public virtual void EffectOnPlayer(Player who) { }
}

public override void EffectOnPlayer(Player who)
{
Random rand = new Random();
if (rand.Next(0, 2) == 0)
who.Deduct(one_hundred);
else
who.Add(one_hundred);
}
This function is not Static while the others are so calling EffectOnPlayer without a reference to an instance of Square class will result in an error. So you either need a reference to the Square instance or make it static.
If you just give the Move function a refences to a square instance everything should be ok.
public void Move(int numberOfSquares, Player player, Square square)
{
square.EffectOnPlayer(player);
...
}

Beep in C# .NET application on server side

To debug a firewall delay issue I need an application that will produce a beep on server side when it detects an HTTP GET request.
This code (test.ashx):
<%# WebHandler Language="C#" Class="TestHandler" %>
using System;
using System.Web;
public class TestHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
HttpResponse Response = context.Response;
try
{
Response.Write("Before beep");
Console.Beep();
Response.Write("After beep");
}
catch (Exception ex)
{
Response.Write(ex.Message + "<br />\n" + ex.InnerException.Message);
}
}
public bool IsReusable { get { return false; } }
}
produces sound only when debugging in IIS Express. After moving the web app to IIS, the sound disappears.

The three easy ways of producing a sound are System.Console.Beep(), System.Media.SoundPlayer, and System.Media.SystemSounds.Beep().
Unfortunately, these methods only work in desktop applications, and won't work in service applications. When ASP.Net apps are run under IIS Express (a desktop app), these sound methods work. However, when ASP.Net apps are run under the IIS service, the sound methods don't work.
System.Console.Beep() ultimately calls the kernel32.dll Beep() function. It's restricted to desktop apps only (scroll down to the Requirements section).
Same for System.Media.SoundPlayer and System.Media.SystemSounds.Beep(). They call the kernel32.dll MessageBeep() and the winmm.dll PlaySound() functions, respectively. They, too, are restricted to desktop apps.
One way to get sounds to play in a service is use NAudio. It's easy to install via NuGet.
This chunk of code is the only way I could get the sound to play. It has to be played on a separate worker thread, and the execution of the worker thread needs to be paused to let the .wav file finish playing.
using System;
using System.Diagnostics;
using System.Threading;
using NAudio.Dsp;
using NAudio.Wave;
...
protected void Button1_Click(object sender, EventArgs e)
{
var waveFilename = #"c:\Windows\Media\tada.wav";
/* Trying to play the .wav file on the main thread
doesn't seem to work. */
ThreadPool.QueueUserWorkItem(
(state) =>
{
using (var audioPlayback = new AudioPlayback())
{
audioPlayback.Load(waveFilename);
audioPlayback.Play(); // Asynchronous.
/* Need to sleep for the approximate length of .wav file,
otherwise no sound is produced because of the
asynchronous Play() call. */
Thread.Sleep(2000);
}
});
}
Here's the supporting code taken from code in NAudio's NAudioWPFDemo project:
public class MaxSampleEventArgs : EventArgs
{
[DebuggerStepThrough]
public MaxSampleEventArgs(float minValue, float maxValue)
{
this.MaxSample = maxValue;
this.MinSample = minValue;
}
public float MaxSample { get; private set; }
public float MinSample { get; private set; }
}
public class FftEventArgs : EventArgs
{
[DebuggerStepThrough]
public FftEventArgs(Complex[] result)
{
this.Result = result;
}
public Complex[] Result { get; private set; }
}
public class SampleAggregator : ISampleProvider
{
// volume
public event EventHandler<MaxSampleEventArgs> MaximumCalculated;
private float maxValue;
private float minValue;
public int NotificationCount { get; set; }
int count;
// FFT
public event EventHandler<FftEventArgs> FftCalculated;
public bool PerformFFT { get; set; }
private readonly Complex[] fftBuffer;
private readonly FftEventArgs fftArgs;
private int fftPos;
private readonly int fftLength;
private int m;
private readonly ISampleProvider source;
private readonly int channels;
public SampleAggregator(ISampleProvider source, int fftLength = 1024)
{
channels = source.WaveFormat.Channels;
if (!IsPowerOfTwo(fftLength))
throw new ArgumentException("FFT Length must be a power of two");
this.m = (int) Math.Log(fftLength, 2.0);
this.fftLength = fftLength;
this.fftBuffer = new Complex[fftLength];
this.fftArgs = new FftEventArgs(fftBuffer);
this.source = source;
}
private bool IsPowerOfTwo(int x)
{
return (x & (x - 1)) == 0;
}
public void Reset()
{
count = 0;
maxValue = minValue = 0;
}
private void Add(float value)
{
if (PerformFFT && FftCalculated != null)
{
fftBuffer[fftPos].X = (float) (value * FastFourierTransform.HammingWindow(fftPos, fftLength));
fftBuffer[fftPos].Y = 0;
fftPos++;
if (fftPos >= fftBuffer.Length)
{
fftPos = 0;
// 1024 = 2^10
FastFourierTransform.FFT(true, m, fftBuffer);
FftCalculated(this, fftArgs);
}
}
maxValue = Math.Max(maxValue, value);
minValue = Math.Min(minValue, value);
count++;
if (count >= NotificationCount && NotificationCount > 0)
{
if (MaximumCalculated != null)
MaximumCalculated(this, new MaxSampleEventArgs(minValue, maxValue));
Reset();
}
}
public WaveFormat WaveFormat { get { return source.WaveFormat; } }
public int Read(float[] buffer, int offset, int count)
{
var samplesRead = source.Read(buffer, offset, count);
for (int n = 0; n < samplesRead; n += channels)
Add(buffer[n + offset]);
return samplesRead;
}
}
public class AudioPlayback : IDisposable
{
private IWavePlayer _playbackDevice;
private WaveStream _fileStream;
public void Load(string fileName)
{
Stop();
CloseFile();
EnsureDeviceCreated();
OpenFile(fileName);
}
private void CloseFile()
{
if (_fileStream != null)
{
_fileStream.Dispose();
_fileStream = null;
}
}
private void OpenFile(string fileName)
{
try
{
var inputStream = new AudioFileReader(fileName);
_fileStream = inputStream;
var aggregator = new SampleAggregator(inputStream);
aggregator.NotificationCount = inputStream.WaveFormat.SampleRate / 100;
aggregator.PerformFFT = true;
_playbackDevice.Init(aggregator);
}
catch
{
CloseFile();
throw;
}
}
private void EnsureDeviceCreated()
{
if (_playbackDevice == null)
CreateDevice();
}
private void CreateDevice()
{
_playbackDevice = new WaveOut { DesiredLatency = 200 };
}
public void Play()
{
if (_playbackDevice != null && _fileStream != null && _playbackDevice.PlaybackState != PlaybackState.Playing)
_playbackDevice.Play();
}
public void Pause()
{
if (_playbackDevice != null)
_playbackDevice.Pause();
}
public void Stop()
{
if (_playbackDevice != null)
_playbackDevice.Stop();
if (_fileStream != null)
_fileStream.Position = 0;
}
public void Dispose()
{
Stop();
CloseFile();
if (_playbackDevice != null)
_playbackDevice.Dispose();
}
}

Try this System.Media.SystemSounds.Beep.Play();

Visual studio 2010- Application as a service in release mode

I have an desktop console application created in visual studio 2010.How do i convert it to windows service?. basically in debug mode i want it as normal app , but in release mode i want a service build output

You can do it this way:
namespace Program
{
static class Program
{
public static bool Stopped = false;
[STAThread]
static void Main(string[] args)
{
Interactive.Initialize();
Interactive.OnStopped += new Interactive.StopedDelegate(OnStopped);
Interactive.Title = Path.GetFileNameWithoutExtension(
Assembly.GetExecutingAssembly().Location);
if (args.Length == 0) Interactive.Run(RunProc);
else if (args[0] == "-svc") ServiceBase.Run(new Service());
}
public static void RunProc() { yourConsoleMain(); }
public static void OnStopped() { Stopped = true; exitFromMain(); }
}
public class Service : ServiceBase
{
public static string Name = Path.GetFileNameWithoutExtension(
Assembly.GetExecutingAssembly().Location);
public static string CmdLineSwitch = "-svc";
public static ServiceStartMode StartMode = ServiceStartMode.Automatic;
public static bool DesktopInteract = true;
public bool Stopped = false;
public Service() { ServiceName = Name; }
public void Start() { OnStart(null); }
protected override void OnStart(string[] args)
{
System.Diagnostics.EventLog.WriteEntry(
ServiceName, ServiceName + " service started.");
Thread thread = new Thread(MainThread);
thread.Start();
}
protected override void OnStop()
{
System.Diagnostics.EventLog.WriteEntry(
ServiceName, ServiceName + " service stopped.");
Stopped = true;
Application.Exit();
}
private void MainThread()
{
Interactive.Run(Program.RunProc);
if (!Stopped) Stop();
}
}
}
Let me explain this... Basically, in Main you define that your program starts as a service if it is started with argument '-svc'.
Put in RunProc() what you normally do in main(), and in OnStopped() event handler some code that will cause main() to exit.
Then, override ServiceBase and perform some basic start/stop service.
In Windows 7 and later you must explicitly define that your service can interact with desktop if you want to see some output. But there is another problem, console window cannot be shown. So I created this console simulator which can write and also read input.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Runtime.InteropServices;
namespace ProgramIO.Control
{
public delegate void WriteDelegate(string value, int x, int y);
public delegate void ReadDelegate(out string value, bool readLine);
public delegate void EnableInputDelegate(bool enable);
public partial class InteractiveForm : Form
{
private delegate void ClearInputBufferDelegate();
public enum EIOOperation { None = 0, Write, Read }
private EventWaitHandle eventInvoke =
new EventWaitHandle(false, EventResetMode.AutoReset);
private EventWaitHandle eventInput =
new EventWaitHandle(false, EventResetMode.AutoReset);
private bool readLine = false;
private string inputBuffer = "";
private int inputPosition = 0;
private int inputBufferPosition = 0;
private EIOOperation IOOperation;
private int bufferSize = 0x10000;
private bool CaretShown = false;
private delegate object DoInvokeDelegate(Delegate method, params object[] args);
private delegate void SetTitleDelegate(string value);
private delegate void SetForegroundcolorDelegate(Color value);
public string Title {
get { return Text; }
set {
if (InvokeRequired) InvokeEx(
(SetTitleDelegate)delegate(string title) { Text = title; },
1000, new object[] { value });
else Text = value; }}
public Color ForegroundColor {
get { return ForeColor; }
set {
if (InvokeRequired) InvokeEx(
(SetForegroundcolorDelegate)delegate(Color color) { ForeColor = color; },
1000, new object[] { value });
else ForeColor = value; }}
public InteractiveForm()
{
InitializeComponent();
DoubleBuffered = true;
}
#region Asynchronous Methods
private bool InvokeEx(Delegate method, int timeout, params object[] args)
{
BeginInvoke((DoInvokeDelegate)DoInvoke, new object[] { method, args });
if (eventInvoke.WaitOne(timeout)) return true;
else return false;
}
private void EnableInput(bool enable)
{
if (InvokeRequired)
InvokeEx((EnableInputDelegate)DoEnableInput, 1000, new object[] { enable });
else DoEnableInput(enable);
}
private void ClearInputBuffer()
{
if (InvokeRequired)
InvokeEx((ClearInputBufferDelegate)DoClearInputBuffer, 1000, new object[0]);
else DoClearInputBuffer();
}
public void Write(string value, int x = -1, int y = -1)
{
lock (this) {
IOOperation = EIOOperation.Write;
if (InvokeRequired)
InvokeEx((WriteDelegate)DoWrite, 1000, new object[] { value, x, y });
else DoWrite(value, x, y);
IOOperation = EIOOperation.None; }
}
public string Read(bool readLine)
{
lock (this) {
EnableInput(true);
IOOperation = EIOOperation.Read; this.readLine = readLine; string value = "";
ClearInputBuffer(); eventInput.WaitOne();
object[] args = new object[] { value, readLine };
if (InvokeRequired) {
InvokeEx((ReadDelegate)DoRead, 1000, args); value = (string) args[0]; }
else DoRead(out value, readLine);
//inputPosition = textBox.Text.Length; inputBuffer = "";
ClearInputBuffer();
IOOperation = EIOOperation.None;
EnableInput(false);
return value;
}
}
#endregion //Asynchronous Methods
#region Synchronous Methods
protected override void OnShown(EventArgs e) { base.OnShown(e); textBox.Focus(); }
public object DoInvoke(Delegate method, params object[] args)
{
object obj = method.DynamicInvoke(args);
eventInvoke.Set();
return obj;
}
private void CorrectSelection()
{
if (textBox.SelectionStart < inputPosition) {
if (textBox.SelectionLength > (inputPosition - textBox.SelectionStart))
textBox.SelectionLength -= inputPosition - textBox.SelectionStart;
else textBox.SelectionLength = 0;
textBox.SelectionStart = inputPosition; }
}
protected void DoClearInputBuffer()
{
inputPosition = textBox.Text.Length; inputBuffer = "";
}
protected void DoEnableInput(bool enable)
{
if (enable) { textBox.ReadOnly = false; textBox.SetCaret(true); }
else { textBox.ReadOnly = true; textBox.SetCaret(false); }
}
protected void DoWrite(string value, int x, int y)
{
string[] lines = textBox.Text.Split(new string[] { "\r\n" }, StringSplitOptions.None);
string[] addLines = new string[0];
if (y == -1) y = lines.Length - 1;
if (lines.Length - 1 < y) addLines = new string[y - lines.Length - 1];
if (y < lines.Length) {
if (x == -1) x = lines[y].Length;
if (lines[y].Length < x)
lines[y] += new String(' ', x - lines[y].Length) + value;
else
lines[y] = lines[y].Substring(0, x) + value +
((x + value.Length) < lines[y].Length ?
lines[y].Substring(x + value.Length) : ""); }
else {
y -= lines.Length;
if (x == -1) x = addLines[y].Length;
addLines[y] += new String(' ', x - addLines[y].Length) + value; }
textBox.Text = (string.Join("\r\n", lines) +
(addLines.Length > 0 ? "\r\n" : "") + string.Join("\r\n", addLines));
textBox.Select(textBox.Text.Length, 0); textBox.ScrollToCaret();
inputBuffer = "";
}
protected void DoRead(out string value, bool readLine)
{
value = "";
if (readLine) {
int count = inputBuffer.IndexOf("\r\n");
if (count > 0) { value = inputBuffer.Substring(0, count); }}
else if (inputBuffer.Length > 0) {
value = inputBuffer.Substring(0, 1); }
inputBuffer = "";
}
private void textBox_TextChanged(object sender, EventArgs e)
{
if (IOOperation == EIOOperation.Read) {
inputBuffer = textBox.Text.Substring(inputPosition);
if (!readLine || inputBuffer.Contains("\r\n")) eventInput.Set(); }
if (textBox.Text.Length > bufferSize) { textBox.Text =
textBox.Text.Substring(textBox.Text.Length - bufferSize, bufferSize);
textBox.Select(textBox.Text.Length, 0); textBox.ScrollToCaret(); }
}
private void textBox_KeyDown(object sender, KeyEventArgs e)
{
if (IOOperation != EIOOperation.Read ||
(e.KeyCode == Keys.Back && inputBuffer.Length == 0))
e.SuppressKeyPress = true;
}
private void textBox_MouseUp(object sender, MouseEventArgs e)
{
CorrectSelection();
}
private void textBox_KeyUp(object sender, KeyEventArgs e)
{
if (!(IOOperation == EIOOperation.Read) ||
((e.KeyCode == Keys.Left || e.KeyCode == Keys.Up) &&
textBox.SelectionStart < inputPosition))
CorrectSelection();
}
private void InteractiveForm_FormClosing(object sender, FormClosingEventArgs e)
{
eventInput.Set();
lock (this) { }
}
#endregion //Synchronous Methods
}
public class InteractiveWindow : TextBox
{
[DllImport("user32.dll")]
static extern bool HideCaret(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool ShowCaret(IntPtr hWnd);
private delegate void SetCaretDelegate(bool visible);
private const int WM_SETFOCUS = 0x0007;
private bool CaretVisible = true;
public void SetCaret(bool visible)
{
if (InvokeRequired) Invoke((SetCaretDelegate)DoSetCaret, new object[] { visible });
else DoSetCaret(visible);
}
private void DoSetCaret(bool visible)
{
if (CaretVisible != visible)
{
CaretVisible = visible;
if (CaretVisible) ShowCaret(Handle);
else HideCaret(Handle);
}
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_SETFOCUS)
{
if (CaretVisible) { ShowCaret(Handle); }
else HideCaret(Handle);
}
}
}
}
namespace ProgramIO
{
using ProgramIO.Control;
public static class Interactive
{
public delegate void StopedDelegate();
public delegate void RunDelegate();
public static bool Initialized = false;
private static InteractiveForm frmIO = null;
private static Thread IOThread = null;
private static EventWaitHandle EventStarted =
new EventWaitHandle(false, EventResetMode.AutoReset);
public static string Title {
get { return frmIO.Title; }
set { frmIO.Title = value; } }
public static Color ForegroundColor {
get {return frmIO.ForeColor; }
set { frmIO.ForeColor = value; } }
public static event StopedDelegate OnStopped = null;
private static void form_Show(object sender, EventArgs e)
{
frmIO = sender as InteractiveForm;
EventStarted.Set();
}
private static void form_FormClosed(object sender, FormClosedEventArgs e)
{
lock (frmIO) {
frmIO = null;
Application.Exit(); }
}
public static void Initialize()
{
IOThread = new Thread(IOThreadProc);
IOThread.Name = "Interactive Thread"; IOThread.Start();
EventStarted.WaitOne();
Initialized = true;
}
public static void Run(RunDelegate runProc = null)
{
if (!Initialized) Initialize();
if (runProc != null) runProc();
Application.Run();
if (OnStopped != null) OnStopped();
}
public static void IOThreadProc()
{
InteractiveForm form = new InteractiveForm();
form.Shown += new EventHandler(form_Show);
form.FormClosed += new FormClosedEventHandler(form_FormClosed);
Application.Run(form);
}
public static void Write(string value, int x = -1, int y = -1)
{
if (frmIO != null) lock (frmIO) { frmIO.Write(value, x, y); }
}
public static void WriteLine(string value)
{
if (frmIO != null) lock (frmIO) {
Interactive.Write(value); Interactive.Write("\r\n"); }
}
public static int Read()
{
if (frmIO != null) lock (frmIO) {
string input = frmIO.Read(false);
if (input.Length > 0) return input[0]; }
return 0;
}
public static string ReadLine()
{
if (frmIO != null) lock (frmIO) { return frmIO.Read(true); }
else return "";
}
}
}
This last class, Interactive, actually serve as invoker for asynchronous methods, and it is used in Main() at the beginning.
You can skip this whole second section of code if you don't want to see console window when program is run as a windows service.
I have also created an Installer class for this, but it would be just to much code on this page.
EDIT: This InteractiveForm is actually a form with designer class, but very simple, consisting only of Form and EditBox inside filling its area.

Basicallly you need 3 projects in your solution:
Application itself
WinService for production
Console Application for test purposes
So your application must have some kind of Start() method with e.g. infinite loop that does all work and maybe Stop() method to stop processing.
Winservice project must contain class derived from ServiceBase, it'l have OnStartmethod that calls your application's Start and OnStop that calls application's Stop method.
Next, in console application you do pretty much same - calling Start method in console's entry point.
So far for debug you run your console app, and for release you publish your winservice project
Winservice class might look like:
upd
Winservice codez:
public class MyWinService : ServiceBase
{
IMyApplicationService _myApplicationService;
//constructor - resolve dependencies here
public MyWinService()
{
_myApplicationService = new MyApplicationService();
}
protected override void OnStart(string[] args)
{
base.OnStart(args);
try
{
_myApplicationService.Start();
}
catch (Exception exception)
{
//log exception
}
}
protected override void OnStop()
{
base.OnStop();
try
{
_myApplicationService.Stop();
}
catch (Exception exception)
{
//log exception
}
}
}
Application service:
public class MyApplicationService : IMyApplicationService
{
public MyApplicationService()
{
//some initializations
}
public Start()
{
//do work here
}
public Stop()
{
//...
}
}

Why the number of threads is continuously increasing with SerialPort.CatchReceivedEvents()

I´m running a C# application with .NET Framework 2.0 to read data from SerialPort to get the weight from a scale.
The application works fine, does what it is supposed to do, but the number of threads keeps increasing and more memory is consumed until the application crashes, usually after around 4 hours.
When running with a serialport simulator the number of threads is stable around 30. But when I use an actual scale it goes greater than 500 threads.
I used Microsoft Managed Stack Explorer 1.0 to take a dump of the threads and almost all of them have exactly the following stack:
0. System.IO.Ports.SerialPort.CatchReceivedEvents (Source Unavailable)
1. System.IO.Ports.SerialStream.EventLoopRunner.CallReceiveEvents (Source Unavailable)
2. System.Threading._ThreadPoolWaitCallback.WaitCallback_Context (Source Unavailable)
3. System.Threading.ExecutionContext.Run (Source Unavailable)
4. System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal (Source Unavailable)
5. System.Threading._ThreadPoolWaitCallback.PerformWaitCallback (Source Unavailable)
I'm not able to identify the reason these threads are being created. Does anybody have any idea of what I'm missing here? Thanks!
This is my code:
Scale.cs -> creates a thread when method open() is called. The thread reads the value from getWeight().
Scales.cs -> treats events from serial port in method SerialPort_DataReceived(...). It's where m_SerialPort.ReadLine() is called and ends up providing the value to getWeight().
Scale.cs:
using System;
using System.Collections.Generic;
using System.Threading;
using ScalesGSS;
using StateMachine.Exceptions;
using StateMachine.Log;
using StateMachine.MessageOutput;
namespace StateMachine.DriverImplementation
{
class Scale : AScale
{
private const int Scale_version = 1;
private Thread thread = null;
private IScales gScale = null;
//
private string m_Type;
private string m_PortName;
private int m_BaudRate;
private char m_Parity;
private int m_DataBits;
private string m_StopBits;
private int m_CommandReturnLength;
private string m_CommandType;
private string m_CommandValue;
private int m_ReadTimeOutInMilliseconds;
private int m_WeightInitialPosition;
private int m_WeightFinalPosition;
private int m_TimeBetweenReadsInMilliseconds;
private int m_StableReadQuantity;
private int m_MinimumWeight;
private int m_ScaleID;
//
private double m_OldWeight = 0.0;
private double m_Offset = 0.0;
private double m_CurrentWeight = 0.0;
int m_WeightEqualCount = 0;
//
byte m_Status = 3; // "NO COMMUNICATION"
//
private bool m_Closed = false;
private static LogFactory m_Log = new LogFactory(LogCategory.Device, "");
ErrorDialog m_ErrorDialog = new ErrorDialog();
public Scale()
{
this.setClassName("Scale");
this.setDeviceType(DeviceType.Scale);
}
public void run()
{
try
{
if (this.m_Type.ToUpper().Equals("GENERICSCALES")) // GENERICSCALES or MOCKSCALES
this.gScale = new ScalesGSS.GenericScales();
else
this.gScale = new ScalesGSS.MockScales();
this.gScale.PortName = this.m_PortName;
this.gScale.BaudRate = this.m_BaudRate;
this.gScale.Parity = this.m_Parity.ToString();
this.gScale.DataBits = this.m_DataBits;
this.gScale.StopBits = this.m_StopBits;
this.gScale.CommandReturnLength = this.m_CommandReturnLength;
this.gScale.CommandType = this.m_CommandType;
this.gScale.CommandValue = this.m_CommandValue;
this.gScale.ReadTimeOut = this.m_ReadTimeOutInMilliseconds;
this.gScale.WeightInitialPosition = this.m_WeightInitialPosition;
this.gScale.WeightFinalPosition = this.m_WeightFinalPosition;
this.gScale.setParameters();
this.gScale.configurePort();
while (true)
{
if (this.m_Closed)
{
if (this.OpenedPort())
this.gScale.closePort();
break;
}
Thread.Sleep(this.m_TimeBetweenReadsInMilliseconds);
if (!this.OpenedPort())
{
if (!this.OpenPort())
{
m_Log.writeLogWarning("Error opening serialport.", " Port: " + this.m_PortName, true);
}
}
if (this.ErrorReadingWeight())
{
m_Log.writeLogWarning("Invalid weight.", " Port: " + this.m_PortName, true);
}
this.m_CurrentWeight = getWeight();
if (!ReadingTimeout())
{
if (this.m_WeightEqualCount > m_StableReadQuantity)
{
if (m_CurrentWeight > m_MinimumWeight)
m_Status = 2; // "WEIGHT STABLE"
else
{
m_Status = 0; // "SCALE FREE"
m_WeightEqualCount = 0;
}
}
else
{
if (m_CurrentWeight > m_MinimumWeight)
{
m_Status = 1; // "STABILIZING"
if ((this.m_CurrentWeight >= (this.m_OldWeight - this.m_Offset)) && (this.m_CurrentWeight <= (this.m_OldWeight + this.m_Offset)))
this.m_WeightEqualCount++;
else
this.m_WeightEqualCount = 0;
this.m_OldWeight = this.m_CurrentWeight;
}
else
{
m_Status = 0; // "SCALE FREE"
m_WeightEqualCount = 0;
}
}
}
else
{
m_WeightEqualCount = 0;
m_Status = 3; // "NO COMMUNICATION"
string v_Message = "No communication with scale. Port: " + m_PortName;
m_Log.writeLogWarning(v_Message, "", true);
AutoClosingMessageBox.Show(v_Message, "Scale", 10000);
}
}
}
catch (Exception v_Exception)
{
m_Log.writeLogError("run()", v_Exception);
}
}
private bool OpenedPort()
{
return this.gScale.OpenedPort;
}
private bool OpenPort()
{
bool v_OpenPort;
v_OpenPort = this.gScale.openPort();
if (!v_OpenPort)
{
m_ErrorDialog.getScaleErrorMessage(gScale);
}
return v_OpenPort;
}
private bool ErrorReadingWeight()
{
return this.gScale.ErrorReadingWeight;
}
private double getWeight()
{
return this.gScale.getWeight();
}
private DateTime LastGoodReading()
{
return gScale.LastGoodReading;
}
private void setLastGoodReading(DateTime p_Value)
{
gScale.LastGoodReading = p_Value;
}
private bool ReadingTimeout()
{
if (m_ReadTimeOutInMilliseconds > 0)
{
DateTime v_LastGoodReading = LastGoodReading() == DateTime.MinValue ? DateTime.Now : LastGoodReading();
setLastGoodReading(DateTime.Now);
return DateTime.Now > v_LastGoodReading.AddMilliseconds(m_ReadTimeOutInMilliseconds);
}
else
return false;
}
#region "IDriverService"
public override byte getStatus()
{
return m_Status;
}
public override byte[] read()
{
return System.Text.ASCIIEncoding.ASCII.GetBytes(m_CurrentWeight.ToString());
}
public override byte[] read(int p_InitialPosition, int p_Size)
{
return read();
}
public override byte[] write(byte[] p_Data)
{
string v_Temp = System.Text.ASCIIEncoding.ASCII.GetString(p_Data);
if (v_Temp.Equals("getScaleNumber"))
return System.Text.ASCIIEncoding.ASCII.GetBytes(m_ScaleID.ToString());
else
throw new EDriverAccess(1, "Not implemented");
}
public override bool open()
{
this.thread = new Thread(run);
this.thread.Name = "SCALE";
this.thread.IsBackground = true;
this.thread.Start();
return true;
}
public override bool close()
{
try
{
this.release();
return true;
}
catch
{
return false;
}
}
public override int getVersion()
{
return Scale_version;
}
public override void setProperties(Dictionary<string, string> p_props)
{
try
{
this.m_Type = p_props["type"];
this.m_PortName = p_props["portName"];
this.m_BaudRate = Int32.Parse(p_props["baudRate"]);
this.m_Parity = char.Parse(p_props["parity"]);
this.m_DataBits = Int32.Parse(p_props["dataBits"]);
this.m_StopBits = p_props["stopBits"];
this.m_CommandReturnLength = Int32.Parse(p_props["returnLength"]);
this.m_CommandType = p_props["commandType"];
this.m_CommandValue = p_props["commandValue"];
this.m_ReadTimeOutInMilliseconds = Int32.Parse(p_props["readTimeout"]);
this.m_WeightInitialPosition = Int32.Parse(p_props["weightInitPos"]);
this.m_WeightFinalPosition = Int32.Parse(p_props["weightFinPos"]);
this.m_TimeBetweenReadsInMilliseconds = Int32.Parse(p_props["delayLeitura"]);
this.m_StableReadQuantity = Int32.Parse(p_props["qtdeLeituraEstavel"]);
this.m_MinimumWeight = Int32.Parse(p_props["pesoMinimo"]);
this.m_ScaleID = Int32.Parse(p_props["numBalanca"]);
if (p_props.ContainsKey("precision"))
this.m_Offset = Int32.Parse(p_props["precision"]);
}
catch (Exception)
{
throw new Exception();
}
}
public override void release()
{
this.m_Closed = true;
m_Status = 3; // "NO COMMUNICATION"
}
#endregion
}
}
Scales.cs:
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Ports;
using System.Reflection;
using System.Timers;
using Scales.Util;
namespace Scales.DLL
{
public class Scales : Status
{
public event EventHandler StableWeightChanged;
protected virtual void OnCountdownCompleted(EventArgs e)
{
if (StableWeightChanged != null)
StableWeightChanged(this, e);
}
System.Timers.Timer timerTimeWithoutSample;
private int m_IntervalsWithoutSample = 0;
private string m_EndOfWeightChar = "";
private void _timer_Elapsed(object sender, ElapsedEventArgs e)
{
m_IntervalsWithoutSample++;
}
public int IntervalsWithoutSample { get { return m_IntervalsWithoutSample; } }
private SerialPort m_SerialPort;
public string PortName { get; set; }
public int BaudRate { get; set; }
public int DataBits { get; set; }
private Double m_Weight = 0;
public Double Weight
{
get
{
if (m_BufferWeights.Count > 0)
{
try
{
m_Weight = treatReceivedValue(m_BufferWeights[m_BufferWeights.Count - 1]);
}
catch
{
}
finally
{
ErrorReadingWeight = (m_Weight != -1 ? false : true);
}
}
else
{
m_Weight = 0;
}
return m_Weight;
}
}
public List<Double> getAndFlushPastWeights()
{
List<Double> v_FlushedValues = new List<double>();
Double v_WeightCursor;
while (m_BufferWeights.Count > 1 && v_FlushedValues.Count < 200)
{
v_WeightCursor = treatReceivedValue(m_BufferWeights[0]);
if (v_WeightCursor >= 0)
{
v_FlushedValues.Add(v_WeightCursor);
}
m_BufferWeights.RemoveAt(0);
}
return v_FlushedValues;
}
public void ResetWeights()
{
if (m_BufferWeights != null)
{
m_BufferWeights.Clear();
}
}
public string NewLineCommandType { get; set; }
public string NewLineCommand { get; set; }
public int ReturnLength { get; set; }
public int WeightInitialPosition { get; set; }
public int WeightFinalPosition { get; set; }
public int MotionBitPos { get; set; }
public int ReadTimeOut { get; set; }
public bool OpenedPort { get; private set; }
public bool ErrorReadingWeight { get; private set; }
public DateTime LastGoodReading { get; private set; }
public bool IsStable { get; private set; }
private Parity PortParity { get; set; }
public string SerialParity
{
get { return PortParity.ToString(); }
set
{
setParity(value);
}
}
public int WeightReadLength
{
get
{
if (WeightFinalPosition >= WeightInitialPosition)
{
return WeightFinalPosition - WeightInitialPosition + 1;
}
else
{
return 0;
}
}
}
private StopBits PortStopBits { get; set; }
public string SerialStopBits
{
get { return PortStopBits.ToString(); }
set
{
setStopBits(value);
}
}
private void setParity(string p_Parity)
{
if (p_Parity.Equals(Parity.Even.ToString()))
{
PortParity = Parity.Even;
}
else if (p_Parity.Equals(Parity.Mark.ToString()))
{
PortParity = Parity.Mark;
}
else if (p_Parity.Equals(Parity.Odd.ToString()))
{
PortParity = Parity.Odd;
}
else if (p_Parity.Equals(Parity.Space.ToString()))
{
PortParity = Parity.Space;
}
else
{
PortParity = Parity.None;
}
}
private void setStopBits(string p_StopBits)
{
if (p_StopBits.Equals(StopBits.One.ToString()))
{
PortStopBits = StopBits.One;
}
else if (p_StopBits.Equals(StopBits.OnePointFive.ToString()))
{
PortStopBits = StopBits.OnePointFive;
}
else if (p_StopBits.Equals(StopBits.Two.ToString()))
{
PortStopBits = StopBits.Two;
}
else if (p_StopBits.Equals("1"))
{
PortStopBits = StopBits.One;
}
else if (p_StopBits.Equals("1.5"))
{
PortStopBits = StopBits.OnePointFive;
}
else if (p_StopBits.Equals("2"))
{
PortStopBits = StopBits.Two;
}
else
{
PortStopBits = StopBits.None;
}
}
public Scales()
{
OpenedPort = false;
ErrorReadingWeight = false;
IsStable = false;
m_IntervalsWithoutSample = 999999;
timerTimeWithoutSample = new System.Timers.Timer(5);
timerTimeWithoutSample.Elapsed += new ElapsedEventHandler(_timer_Elapsed);
}
private int ignoreNextXValues;
public void resetScale()
{
ErrorReadingWeight = false;
IsStable = false;
m_IntervalsWithoutSample = 999999;
ignoreNextXValues = 2;
m_BufferWeights.Clear();
m_BufferTime.Clear();
if (m_SerialPort != null && m_SerialPort.IsOpen)
{
m_SerialPort.Close();
m_SerialPort.Open();
m_SerialPort.DiscardInBuffer();
}
}
List<String> m_BufferWeights = new List<String>();
List<String> m_BufferTime = new List<String>();
public bool openPort()
{
try
{
if (m_SerialPort.IsOpen)
{
m_SerialPort.Close();
}
m_SerialPort.Open();
resetScale();
OpenedPort = true;
return true;
}
catch (Exception ex)
{
MessageDetail = ex.Message;
Return = -100;
OpenedPort = false;
return false;
}
}
public bool closePort()
{
try
{
if (m_SerialPort != null)
{
if (m_SerialPort.IsOpen)
{
m_SerialPort.Close();
}
}
OpenedPort = false;
return true;
}
catch (Exception ex)
{
MessageDetail = ex.Message;
Return = -101;
return false;
}
}
public bool configurePort()
{
try
{
m_SerialPort = new SerialPort();
m_SerialPort.PortName = PortName;
m_SerialPort.BaudRate = BaudRate;
m_SerialPort.Parity = PortParity;
m_SerialPort.DataBits = DataBits;
m_SerialPort.StopBits = PortStopBits;
m_SerialPort.ReadTimeout = ReadTimeOut > 0 ? ReadTimeOut : SerialPort.InfiniteTimeout;
m_SerialPort.NewLine = getNewLineCommand();
m_SerialPort.DataReceived += new SerialDataReceivedEventHandler(SerialPort_DataReceived);
return true;
}
catch (Exception ex)
{
MessageDetail = ex.Message;
Return = -102;
return false;
}
}
private string getNewLineCommand()
{
string v_Command = string.Empty;
if (NewLineCommandType.ToUpper().Equals(CommandTypes.CHAR.ToUpper()))
{
byte v_Char = Convert.ToByte(NewLineCommand);
v_Command = Convert.ToChar(v_Char).ToString();
}
else if (NewLineCommandType.ToUpper().Equals(CommandTypes.STRING.ToUpper()))
{
v_Command = NewLineCommand;
}
else
{
char[] v_delimiters = { '|' };
String[] v_Strings = NewLineCommand.Split(v_delimiters);
if (v_Strings.Length == 2)
{
v_Command = v_Strings[0];
m_EndOfWeightChar = v_Strings[1];
}
else
{
v_Command = NewLineCommand;
}
}
return v_Command;
}
private void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
try
{
LastGoodReading = DateTime.Now;
string ReadLine = m_SerialPort.ReadLine();
m_BufferWeights.Add(ReadLine);
}
catch (Exception)
{
m_Weight = 0;
LastGoodReading = DateTime.MinValue;
}
}
private Double treatReceivedValue(string p_ReceivedValue)
{
try
{
if (ignoreNextXValues > 0) ignoreNextXValues--;
if (ignoreNextXValues > 0) return 0;
double v_Value = double.MinValue;
p_ReceivedValue = p_ReceivedValue.Replace("\r", "").Replace("\n", "");
m_IntervalsWithoutSample = 0;
if (p_ReceivedValue.Length < WeightInitialPosition + WeightReadLength)
{
return -1;
}
if (MotionBitPos != -1 && p_ReceivedValue.Length < MotionBitPos - 1)
{
return -1;
}
string strValor = "";
if (NewLineCommandType.ToUpper().Equals(CommandTypes.VARIABLE_LENGTH.ToUpper()))
{
int v_EndCharPos = p_ReceivedValue.IndexOf(m_EndOfWeightChar);
if (v_EndCharPos != -1)
{
strValor = p_ReceivedValue.Substring(0, v_EndCharPos).Trim();
}
}
else
{
strValor = p_ReceivedValue.Substring(WeightInitialPosition, WeightReadLength).Trim();
}
bool IsDouble = double.TryParse(strValor, out v_Value);
if (IsDouble)
{
if (MotionBitPos != -1)
{
string bit = p_ReceivedValue.Substring(MotionBitPos, 1).Trim();
if (bit == "1")
{
IsStable = true;
}
else IsStable = false;
}
else
{
IsStable = true;
}
return v_Value;
}
else
{
return -1;
}
}
catch (Exception ex)
{
Return = -200;
MessageDetail = ex.Message + " - Fonte:readScales";
ErrorReadingWeight = true;
}
return -1;
}
}
}

I had a similar problem, using SerialPort.ReadExisting() insted of SerialPort.ReadLine() I was able to avoid the creation of infinite threads.

You should try to reduce your problematic code down to something more manageable, as it will make it easier for others to debug. There's a lot of application logic in there that's probably not relevant to the problem which can make it hard for people to see what's going on. You'll get a lot more answers if your example is shorter. You may even figure the problem out yourself in the process!
Having said that, I have a hunch about what's wrong but you'll need to do a little bit of the leg-work yourself to discover if I'm right or wrong:
The .NET serial port works by waiting for data to come in, and then firing the DataReceived event on a worker thread whenever it notices that there's new data. I believe you have 400 or 500 of these worker threads that never complete their work, so they never go away.
Your event handler for the SerialPort.DataReceived event looks like it's blocking waiting for a whole line to come in, but the event is going to be fired whenever there's some amount of new data on the serial port (not necessarily a whole line). If a long line of text comes in, the DataReceived event is going to fire many times, each on it's own worker thread. These worker threads are synchronized to each other, so they're all going to wait for the previous one to finish.
The first thread that gets queued up is going to wait for a while at m_SerialPort.ReadLine() until the whole line comes in.
A bunch of threads queue up behind the first thread as more characters come in. The rest of the threads will end up waiting for the first thread to finish running your event handler.
Finally, the whole line comes in. The first thread finishes, and one of the 5 or 6 that are queued up behind it gets to run and the process starts all over.
The running thread blocks on ReadLine, 5 or 6 more queue up behind it. (We're now back at 1)
Eventually you have so many threads queued up that you run into memory issues.
You probably have the read-timeout on m_SerialPort set to timeout.Infinite. If you set the timeout to something smaller, like 1 second (1000) and you get a lot of TimeoutExceptions in your SerialPort_DataReceived method, then I'm probably right
Side Note You should catch a more specific exception type in your DataReceived event handler. Catching exception can mask exactly this type of problem.
If I've correctly diagnosed the problem, you'll need to change the architecture of your program a little bit. The simplest thing to do is not subscribe to the DataReceived event and to have a single worker thread call m_SerialPort.ReadLine(); with an infinite timeout. When it reads a line, have that worker thread raise an event with the whole line of text received and subscribe to THAT event instead of the SerialPort.DataReceived(); event.
Alternatively, if you want to subscribe to the SerialPort.DataReceived(); event, then read individual characters out of the SerialPort until SerialPort.BytesToRead is zero and stick them in a buffer. Then, when you have a whole line raise some "LineReceived" event that you make yourself that returns the whole line at once as one of the EventArgs. This method is doesn't require you to spool up your own thread that persists for a really long time.

Implementation of processing items asynchronously

Is there any good implementation of processing queue items asynchronously?

If you're using .NET 4, a lot of this comes for free out of the box.
If you've already got all the items, you can use Parallel.ForEach. If you need a producer/consumer queue, you can use BlockingCollection<T> to wrap one of the concurrent collections (such as ConcurrentQueue<T> or ConcurrentStack<T>). How you use that is up to you; there's a blog post here going into a detailed example, and there are probably other similar posts around too. (You might want to look at the Parallel Team Blog for a lot more material.)

You could take a look at a Producer/Consumer pattern if you are unfortunate enough not to be using .net 4.
Here is my code I have disassembled, my apologies for the mess but you should be able to use this by adding to a project and recompiling, then creating your process using the resulting dll.
Enum for ChannelState:
public enum ChannelState
{
WaitingForSend,
WaitingForReceive,
Open
}
Interfaces:
public interface IChannel<TMessage>
{
// Methods
TMessage Receive();
void Send(TMessage message);
// Properties
bool CanReceive { get; }
bool CanSend { get; }
ChannelState State { get; }
}
using System;
public interface IReceiver<TMessage>
{
// Events
event EventHandler<MessageReceivedEventArgs<TMessage>> MessageReceived;
// Methods
void Activate();
void Deactivate();
// Properties
bool IsActive { get; }
}
Concrete classes:
using System.Collections.Generic;
using System.Threading;
using System;
public class BufferedChannel<TMessage> : IChannel<TMessage>
{
// Fields
private int _blockedReceivers;
private int _blockedSenders;
private Queue<TMessage> _buffer;
private int _capacity;
private EventWaitHandle _capacityAvailableEvent;
private EventWaitHandle _messagesAvailableEvent;
// Methods
public BufferedChannel()
{
this._buffer = new Queue<TMessage>();
this._messagesAvailableEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
this._capacityAvailableEvent = new EventWaitHandle(true, EventResetMode.AutoReset);
this._capacity = 50;
}
public BufferedChannel(int bufferSize)
{
this._buffer = new Queue<TMessage>();
this._messagesAvailableEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
this._capacityAvailableEvent = new EventWaitHandle(true, EventResetMode.AutoReset);
this._capacity = 50;
if (bufferSize <= 0)
{
throw new ArgumentOutOfRangeException("bufferSize", bufferSize, ExceptionMessages.ChannelsBufferSizeMustBeGreaterThanZero);
}
this._capacity = bufferSize;
}
public TMessage Receive()
{
Interlocked.Increment(ref this._blockedReceivers);
try
{
this._messagesAvailableEvent.WaitOne();
}
catch
{
lock (this._buffer)
{
Interlocked.Decrement(ref this._blockedReceivers);
}
throw;
}
lock (this._buffer)
{
Interlocked.Decrement(ref this._blockedReceivers);
this._capacityAvailableEvent.Set();
if ((this._buffer.Count - 1) > this._blockedReceivers)
{
this._messagesAvailableEvent.Set();
}
return this._buffer.Dequeue();
}
}
public void Send(TMessage message)
{
Interlocked.Increment(ref this._blockedSenders);
try
{
this._capacityAvailableEvent.WaitOne();
}
catch
{
lock (this._buffer)
{
Interlocked.Decrement(ref this._blockedSenders);
}
throw;
}
lock (this._buffer)
{
Interlocked.Decrement(ref this._blockedSenders);
this._buffer.Enqueue(message);
if (this._buffer.Count < this.BufferSize)
{
this._capacityAvailableEvent.Set();
}
this._messagesAvailableEvent.Set();
}
}
// Properties
public int BufferCount
{
get
{
lock (this._buffer)
{
return this._buffer.Count;
}
}
}
public int BufferSize
{
get
{
lock (this._buffer)
{
return this._capacity;
}
}
set
{
lock (this._buffer)
{
if (value <= 0)
{
throw new ArgumentOutOfRangeException("BufferSize", value, ExceptionMessages.ChannelsBufferSizeMustBeGreaterThanZero);
}
this._capacity = value;
if ((this._blockedSenders > 0) && (this._capacity > this._buffer.Count))
{
this._capacityAvailableEvent.Set();
}
}
}
}
public bool CanReceive
{
get
{
return true;
}
}
public bool CanSend
{
get
{
return true;
}
}
public ChannelState State
{
get
{
if (this._blockedSenders > 0)
{
return ChannelState.WaitingForReceive;
}
if (this._blockedReceivers > 0)
{
return ChannelState.WaitingForSend;
}
return ChannelState.Open;
}
}
}
using System;
using System.Collections.Generic;
using System.Threading;
using System.ComponentModel;
using System.Runtime.CompilerServices;
public sealed class Receiver<TMessage> : Component, IReceiver<TMessage>
{
// Fields
private volatile bool _continue;
private object _controlLock;
private volatile bool _disposed;
private Thread _receiverThread;
private bool _receiving;
private object _receivingLock;
private object _threadLock;
[CompilerGenerated]
private IChannel<TMessage> channel;
// Events
public event EventHandler<MessageReceivedEventArgs<TMessage>> MessageReceived;
// Methods
public Receiver(IChannel<TMessage> channel)
{
this._controlLock = new object();
this._threadLock = new object();
this._receivingLock = new object();
if (channel == null)
{
throw new ArgumentNullException("channel");
}
this.Channel = channel;
}
public void Activate()
{
this.CheckDisposed();
lock (this._controlLock)
{
if (this._receiverThread != null)
{
throw new InvalidOperationException();
}
this._continue = true;
this._receiverThread = new Thread(new ThreadStart(this.RunAsync));
this._receiverThread.IsBackground = true;
this._receiverThread.Start();
}
}
private void CheckDisposed()
{
if (this._disposed)
{
throw new ObjectDisposedException(base.GetType().Name);
}
}
public void Deactivate()
{
lock (this._controlLock)
{
if (this._continue)
{
this._continue = false;
lock (this._threadLock)
{
if (this._receiverThread != null)
{
this.SafeInterrupt();
this._receiverThread.Join();
this._receiverThread = null;
}
}
}
}
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (disposing)
{
this.Deactivate();
this._disposed = true;
}
}
private void OnMessageReceived(TMessage message)
{
EventHandler<MessageReceivedEventArgs<TMessage>> messageReceived = this.MessageReceived;
if (messageReceived != null)
{
messageReceived(this, new MessageReceivedEventArgs<TMessage>(message));
}
}
private void RunAsync()
{
while (this._continue)
{
TMessage message = default(TMessage);
bool flag = false;
try
{
lock (this._receivingLock)
{
this._receiving = true;
}
message = this.Channel.Receive();
flag = true;
lock (this._receivingLock)
{
this._receiving = false;
}
Thread.Sleep(0);
}
catch (ThreadInterruptedException)
{
}
if (!this._continue)
{
if (flag)
{
this.Channel.Send(message);
return;
}
break;
}
this.OnMessageReceived(message);
}
}
private void SafeInterrupt()
{
lock (this._receivingLock)
{
lock (this._threadLock)
{
if (this._receiving && (this._receiverThread != null))
{
this._receiverThread.Interrupt();
}
}
}
}
// Properties
protected override bool CanRaiseEvents
{
get
{
return true;
}
}
public IChannel<TMessage> Channel
{
[CompilerGenerated]
get
{
return this.channel;
}
[CompilerGenerated]
private set
{
this.channel = value;
}
}
public bool IsActive
{
get
{
lock (this._controlLock)
{
return (this._receiverThread != null);
}
}
}
}
using System;
using System.Runtime.CompilerServices;
public class MessageReceivedEventArgs<TMessage> : EventArgs
{
// Fields
[CompilerGenerated]
private TMessage message;
// Methods
public MessageReceivedEventArgs(TMessage message)
{
this.Message = message;
}
// Properties
public TMessage Message
{
[CompilerGenerated]
get
{
return this.message;
}
[CompilerGenerated]
private set
{
this.message = value;
}
}
}
using System.Threading;
public class BlockingChannel<TMessage> : IChannel<TMessage>
{
// Fields
private TMessage _message;
private EventWaitHandle _messageReceiveEvent;
private EventWaitHandle _messageReceiveyEvent;
private object _sendLock;
private ChannelState _state;
private object _stateLock;
// Methods
public BlockingChannel()
{
this._state = ChannelState.Open;
this._stateLock = new object();
this._messageReceiveyEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
this._messageReceiveEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
this._sendLock = new object();
}
public TMessage Receive()
{
this.State = ChannelState.WaitingForSend;
this._messageReceiveyEvent.WaitOne();
this._messageReceiveEvent.Set();
this.State = ChannelState.Open;
return this._message;
}
public void Send(TMessage message)
{
lock (this._sendLock)
{
this._message = message;
this.State = ChannelState.WaitingForReceive;
this._messageReceiveyEvent.Set();
this._messageReceiveEvent.WaitOne();
}
}
// Properties
public bool CanReceive
{
get
{
return true;
}
}
public bool CanSend
{
get
{
return true;
}
}
public ChannelState State
{
get
{
lock (this._stateLock)
{
return this._state;
}
}
private set
{
lock (this._stateLock)
{
this._state = value;
}
}
}
}

Pretty old but this is the good one that I know off http://www.codeproject.com/KB/cs/inprocessasynservicesincs.aspx

Use .NET 4 tasks.
var t = Task<int>.Factory.StartNew(() => ProcessItem());
Use the ConcurrencyOptions to set the maximum degree of parallelism on that processing.
If you want to roll it yourself, use BlockingCollection<T> which provides blocking and bounding capabilities for thread-safe collections and implement a separate thread (or threads) for the consumer.