c#: help me pinpoint my unsafe thread object!

[matthewaveryusa]

okay so I have an app that updates it's status every second to run tests and grab information from various files/places on a system. My app works great but I get a funny error from time to time: System.InvalidO perationExcepti on "object is being used" (or something similar).

every second a timer sets off an event. this event creates a thread to run the tests as to not freeze the GUI. However before the test is run, it fetches a static boolean that says whether a thread like this is already running or not. if the bool returns true then the thread is not initialized.


here is the code for the timer event:

        private void scheduler_event(object source, System.Timers.ElapsedEventArgs e)
        {
            DateTime static_time_now = DateTime.Now;
            bool pre_busy = constants.busy;
            constants.busy = true;

            if (constants.firstrun == true)
            {
                constants.firstrun = false;
                constants.busystatus = new bool[] { false, false, false };
                constants.updatestatus = new bool[] { true, true, true };
                Thread firstrunthread = new Thread(firstrun);
                firstrunthread.Start();
            }

                if (pre_busy == false)//when program is fired up, prebusy is set to false
            {
                constants.updatestatus[0] = ((constants.next_sysinfo <= static_time_now) && (constants.busystatus[0] == false));
                constants.updatestatus[1] = ((constants.next_drive <= static_time_now) && (constants.busystatus[1] == false));
                constants.updatestatus[2] = ((constants.next_eventlog <= static_time_now) && (constants.busystatus[2] == false));
           
                Thread runthread = new Thread(run);
                runthread.Start();
            }

        }

constants is an abstract class with static methods I use as global values.

now in my run code, once the test has finished, I set

constants.busy = false

can this be the problem? If yes, how do I get rid of it?

[danrabydotcom]

I am also new to the C# world, but I am writing a similar app.

What I've done is created a thread with a loop in it. This way you do not have to worry about multiples threads colliding.

public void threadMethod()
{
          //Init Code - Things to happen only on the first run.
          Thread.Sleep(1000);
          //Now the loop
          while (condition)
          {
                    // Get Stats
                    Thread.Sleep(1000);

          }
}

[matthewaveryusa]

yes but this will freeze my Gui, especially when I call Perl scripts in my testing that take 10 minutes to complete.

I found the answer to my question:

I lock my whole constants class (this is the class with my static methods/variables) whenever I change busy.
so instead of:

constants.busy = false;

I have:

lock(constants){
{
constants.busy = false;
}
}

app running for 48 hours and no problems... looking good!

[danrabydotcom]

Great!

I see what you mean now. I wasn't sure how long it would take to process your requests.