CODEWITHSUNDEEP
c#multithreadingservicemutex
John
John

Reputation: 1477

Open a mutex shared with a service

I have a service that creates a thread with a loop that should run until the mutex is signalled by another process. I have the following in my service code

        private readonly Mutex _applicationRunning = new Mutex(false, @"Global\HsteMaintenanceRunning");

        protected override void OnStart(string[] args)
        {
            new Thread(x => StartRunningThread()).Start();
        }

        internal void StartRunningThread()
        {
            while (_applicationRunning.WaitOne(1000))
            {
                FileTidyUp.DeleteExpiredFile();    
                _applicationRunning.ReleaseMutex();
                Thread.Sleep(1000);
            }

        }

Now I have a console application that should claim the mutex and force the while loop to be exited

        var applicationRunning = Mutex.OpenExisting(@"Global\HsteMaintenanceRunning");
        if (applicationRunning.WaitOne(15000))
        {
            Console.Write("Stopping");
            applicationRunning.ReleaseMutex();
            Thread.Sleep(10000);
        }

When the console application tries to open the mutex I get the error "The wait completed due to an abandoned mutex." Whats wrong here?

Upvotes: 1

Views: 749

Answers (1)

RogerN
RogerN

Reputation: 3821

I recommend that you use the Service's built-in stop signal rather than a mutex. The mutex class is more appropriate for managing exclusive access to a shared resource, which is not what's going on here. You could also use a system event but since services already have a built-in mechanism for signaling when they're stopping, why not use it?

Your service's code would look like this:

bool _stopping = false;
Thread _backgroundThread;
protected override void OnStart(string[] args)
{
    _backgroundThread = new Thread(x => StartRunningThread());
    _backgroundThread.Start();
}
protected override void OnStop()
{
    _stopping = true;
    _backgroundThread.Join(); // wait for background thread to exit
}
internal void StartRunningThread()
{
    while (!stopping)
    {
        FileTidyUp.DeleteExpiredFile();
        Thread.Sleep(1000);
    }
}

Then, your console application would need to use the framework's ServiceController class to send the shut down message to your service:

using System.ServiceProcess;
...
using (var controller = new ServiceController("myservicename")) {
    controller.Stop();
    controller.WaitForStatus(ServiceControllerStatus.Stopped, TimeSpan.FromSeconds(15.0));
}

Upvotes: 1

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