I want to build a windows Service, which should execute different methods at different times. Its not about accuracy at all.
Im using a system.timers.timer, and regulate the different methods to be executed within the Eventhandler-method with counters. Thats working allright that far.

All of the methods are accessing a COM-port, making it neccessary to grant acceess-rights to only one method at a time. But since the methods can take some time to finish, the timer might tick again and want to execute another method while the COM-port is still being occupied. In this case, the event can and should just be dismissed.

Simplified down to one method, my elapsedEventHandler-method looks something like the following (try-catch and the different methods excluded here)

Note: While this is running perfectly on my Win7 x64, it struggles on a Win7 x86 machine with pretty much the very same software installed, whenever the method to be executed takes a long time. The timer wont tick any more, no Exception is thrown. Nothing! my question now is: Am I doing the part with access-control and the timer right, so that i can focus on other things? Im just not that familiar with timers and especially threading 

```
     private static int m_synchPoint=0;
     private System.Timers.Timer timerForData = null;

    public MyNewService()
    {

        timerForData = new System.Timers.Timer();
        timerForData.Interval = 3000;
        timerForData.Elapsed += new ElapsedEventHandler(Timer_tick);
    }
    //Initialize all the timers, and start them
    protected override void OnStart(string[] args)
    {

        timerForData.AutoReset = true;
        timerForData.Enabled = true;
        timerForData.Start();
    }

    //Event-handled method
    private void Timer_tick(object sender, System.Timers.ElapsedEventArgs e)
    {
            ////safe to perform event - no other thread is running the event?                      
            if (System.Threading.Interlocked.CompareExchange(ref m_synchPoint, 1, 0) == 0)

            {
             //via different else-ifs basically always this is happening here, except switching aMethod,bMethod...
             processedevent++; 
             Thread workerThread = new Thread(aMethod);
             workerThread.Start();
             workerThread.Join(); 
             m_synchPoint=0;
             }
             else
             {
              //Just dismiss the event
              skippedevent++;
             }
     }   

```

Thank you very much in advance!  

Any help is greatly appreciated!