System.Timers.Timer stops firing event

[Pedro Sousa@discussions.microsoft.com Rui Pedro Sousa]

I have a Windows Service with a Timer object with an interval of 500 ms, in
each event the windows service starts a new thread, up to a limited number of
threads, and does some work.

It works fine as to the users requirements, but sometimes freezes. The
Service is running, its process is visible on Task Manager as usually, no
events on the Event Log are related to the service, but the work is not done.

After some tests I foun out that the the code associated with the OnTimer
Event stops being executed with no apparent reason.

I'm clueless.... :(

Some code:

public class QueueHandler : System.ServiceProcess.ServiceBase
{
private System.ComponentModel.Container components = null;
private System.Timers.Timer timer = new System.Timers.Timer();
private Thread[] serviceThreads;

protected override void OnStart(string[] args)
{
serviceThreads = new Thread[25];
int interval = 500;
string autoThreads = "no";

timer.Elapsed += new ElapsedEventHandler(OnTimer);
timer.Interval = interval;
timer.Enabled = true;
}

protected void OnTimer(Object Source,ElapsedEventArgs e)
{
int x = GetNextFreeThread();

if (x >= 0)
serviceThreads[x].Start();
}

private int GetNextFreeThread()
{
int threadID = -1;

MessageProcessor mProcessor = new MessageProcessor();
ThreadStart tStart = new ThreadStart(mProcessor.ProcessMessage);

for (int y = 0;y<serviceThreads.Length;y++)
{
//if thread slot is free instaciate new thread
if(serviceThreads[y] == null || serviceThreads[y].ThreadState ==
System.Threading.ThreadState.Stopped)
{
threadID = y;
serviceThreads[threadID] = new Thread(tStart);
serviceThreads[threadID].Name = "QueueThread_" + y.ToString();
serviceThreads[threadID].IsBackground = true;
serviceThreads[threadID].Priority = ThreadPriority.Lowest;
break;
}
}

return threadID;
}

[Bryan Phillips]

What classes are you using in the ProcessMessage method? I had problems
with hanging a windows service while I tried using the PrintDocument
class.

Bryan Phillips
MCSD, MCDBA, MCSE
Blog: http://bphillips76.spaces.live.com

"Rui Pedro Sousa" <Rui Pedro So...@discussions.microsoft.com> wrote in
message news:FBE45079-5582-4DD1...@microsoft.com:

[sloan]

I prefer to "code up" my timers.

I only have the vb.net version at the moment:

Private m_doTheWorkTimer As Timer

private sub RegisterTimer()

Dim dueTime As Long

Dim period As Long

' DUE TIME looks like it is the DELAY time .. from the time the service
starts,

' Until this specfic TIMER kicks in. So a Delay Time of 20000

' Will DELAY this timer shooting off until 20 seconds (20000 ms) after the
service starts

dueTime = 20000

period = 5000

' the magic bullet, notice the part after "AddressOf", which is the method

Dim timerHandler = New TimerCallback(AddressOf BeepClass.GoBeep)

m_doTheWorkTimer = New Timer(timerHandler , Me, dueTime, period)

end sub

Public Class BeepClass

Public Shared Sub GoBeep(ByVal state As Object)'' this uses a built in
delegate, with "state as Object" as the generic argument list

Beep()

End Sub

End Class

Outside of the wire up event handler, the C# conversion is easy.

HEre is C# code also:

http://msdn2.microsoft.com/en-us/library/system.threading.timercallback.aspx

"Rui Pedro Sousa" <Rui Pedro So...@discussions.microsoft.com> wrote in

message news:FBE45079-5582-4DD1...@microsoft.com...

[Morten Wennevik]

Hi,

There are some articles on the net describing that you should never use
System.Timers.Timer in a windows service, although I have yet to find out
why. I have, however, personal experiences with System.Timers.Timer not
working in a windows service.

The solution for this is to use System.Threading.Timer

--
Happy Coding!
Morten Wennevik [C# MVP]

[Rui Pedro Sousa]

Hi Bryan,

Thanks for your reply.

The MessageProcessor Class reads a MSMQ Queue, which can be a great part of
the problem because there is some unmanaged code behind System.Messaging.

It also writes stuff to SQL using the Data Application Block.

I'll post some code.

[Rui Pedro Sousa]

Hi Morten,

That was it. :)

When developing my service I followed some articles like this one
(http://www.codeguru.com/columns/dotnet/article.php/c6919/) that uses
System.Timers.Timer inside a Windows Service.

But with a more directed search I finnally found an KB article that explains
everything. (http://support.microsoft.com/kb/842793)

Thanks.

[Rui Pedro Sousa]

Hi sloan,

Your code is using the System.Threading.Timer class instead of the
System.Timers.Timer class I was using.

That was problem with my code, I was using the wrong class, as it is
explained in this article: http://support.microsoft.com/kb/842793

Thanks. ;)

[sloan]

Yeah,

I didn't like those "Drag and Drop" timers way back in VB4,VB5 or VB6.

Something told me to avoid them ..... when I was writing a Windows Service.

But thanks for the concrete reason at the KB.

You ought to email this shoney:
http://www.codeguru.com/columns/dotnet/article.php/c6919/
and let him know.

"Rui Pedro Sousa" <RuiPed...@discussions.microsoft.com> wrote in message
news:DC9DE035-70EE-4DFB...@microsoft.com...