I want to do some periodic work on a worker thread which signals when the work is completed. When signaled, I want to wait for 5 seconds and re-do the work. I wrote the following code:
public class WinService : ServiceBase
{
private readonly ManualResetEvent stopPeriodicProcess = new ManualResetEvent(false);
protected override void OnStart(string[] args)
{
stopPeriodicProcess.Reset();
ThreadPool.RegisterWaitForSingleObject(stopPeriodicProcess, InitializeEngines, null,5000, true);
}
public void InitializeEngines(object state, bool timedOut)
{
engine.LoadSettings();
Task.Factory.StartNew(engine.DoSomeWork); //Fire and forget
}
private void WorkCompletedEventHandler(object sender, WorkCompletedEventArgs e)
{
ThreadPool.RegisterWaitForSingleObject(stopPeriodicProcess,
(state, timedOut) => DoPeriodicProcess(state, timedOut, e.EngineId), null,
5000, true);
}
public void DoPeriodicProcess(object state, bool timedOut, string engineId)
{
if (timedOut)
{
Task.Factory.StartNew(engine.DoSomeWork); //Fire and forget
}
}
}
public class Engine
{
public event EventHandler<WorkCompletedEventArgs> WorkCompleted;
public void DoSomeWork()
{
//Doing some work..
//Raise an event to signal that the work has been completed
var args = new WorkCompletedEventArgs {EngineId = Settings.EngineId};
RaiseWorkCompletedEvent(args);
}
protected virtual void RaiseWorkCompletedEvent(WorkCompletedEventArgs e)
{
EventHandler<WorkCompletedEventArgs> handler = WorkCompleted;
if (handler != null)
{
handler(this, e);
}
}
}
When I run the code, the CPU usage shows 100% after few seconds. Upon debugging in VS, I see too many alive worker threads waiting at RegisterWaitForSingleObject inside WorkCompletedEventHandler.
Why aren't the threads dying after calling RegisterWaitForSingleObject? Am I missing something?
