Mutex results are varying in systems

Question

I have a console application in C# and I want to restrict my application to run only one instance at a time.It's work fine in one system.When i try to run the exe in another system it's not working.The problem is In one pc i can open only one exe. When i try to run on another pc i can open more than one exe.How can i resolve this issue? Below are the code i have written.

string mutexId = Application.ProductName;
using (var mutex = new Mutex(false, mutexId))
{
    if (!mutex.WaitOne(0, false))
    {
        MessageBox.Show("Instance Already Running!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Hand);
        return;
    }

        //Remaining Code here
}

What other system is it not working in can you be more specific JEMI — MethodMan, Jan 16 '13 at 09:51
"It's not working" is *never* enough detail. You should *always* explain what you expect to see and what you're *actually* seeing. — Jon Skeet, Jan 16 '13 at 09:52
Have you thought about refactoring the way that the Mutex and the check to see if an existing application is running..? please see this stackoverflow post it's very straight forward http://stackoverflow.com/questions/819773/run-single-instance-of-an-application-using-mutex — MethodMan, Jan 16 '13 at 09:54
In one pc i can open only one exe. When i try to run on another pc i can open more than one exe — Jameel Moideen, Jan 16 '13 at 09:56
It seems pretty clear to me: One one PC it detects the previous instance, and on a different PC it doesn't. — Matthew Watson, Jan 16 '13 at 10:04
I think you need to add `mutex.ReleaseMutex()`; before the closing brace of your using statement. The JIT may be deciding to Dispose/GC the Mutex — Mesh, Jan 16 '13 at 10:24

score 1 · Answer 1 · answered Jan 16 '13 at 10:03

I would use this approach instead anyway:

// Use a named EventWaitHandle to determine if the application is already running.

bool eventWasCreatedByThisInstance;

using (new EventWaitHandle(false, EventResetMode.ManualReset, Application.ProductName, out eventWasCreatedByThisInstance))
{
    if (eventWasCreatedByThisInstance)
    {
        runTheProgram();
        return;
    }
    else // This instance didn't create the event, therefore another instance must be running.
    {
        return; // Display warning message here if you need it.
    }
}

score 0 · Answer 2 · edited May 23 '17 at 11:56

My good old solution:

    private static bool IsAlreadyRunning()
    {
        string strLoc = Assembly.GetExecutingAssembly().Location;
        FileSystemInfo fileInfo = new FileInfo(strLoc);
        string sExeName = fileInfo.Name;
        bool bCreatedNew;

        Mutex mutex = new Mutex(true, "Global\\"+sExeName, out bCreatedNew);
        if (bCreatedNew)
            mutex.ReleaseMutex();

        return !bCreatedNew;
    }

Source

Mutex results are varying in systems

2 Answers2