Easy mutex problem...

[google]

Hi Guys,

I'm having a bizarre problem here with mutexes.

If I have the following code in a page (note that it never releases the
mutex!), then load the page twice, in 2 seperate browsers, I do not get
a mutex lock.

Any ideas? I'm trying to get a globally accessible mutex. Is using the
Application[] object wrong somehow?

In Global.asax:

void Application_Start(object sender, EventArgs e)
{
Application["AppMutex"] = new System.Threading.Mutex();
}

In my page:-

protected void Page_Load(object sender, EventArgs e)
{
if (!((System.Threading.Mutex)Application["AppMutex"]).WaitOne())
Label1.Text = "Cannot lock mutex";
else
Label1.Text = "Mutex locked ok";
}

 

[Alvin Bruney]

What are you doing with the mutex? Why do you need one that is global but is
being accessed on a per page basis?

--

________________________
Warm regards,
Alvin Bruney [MVP ASP.NET]

[Shameless Author plug]
Professional VSTO.NET - Wrox/Wiley
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[Vodzurk]

I was trying to control access to a resource at an application level,
not per-page-level or session-level.

 

[Alvin Bruney]

I figured that was what you were after. I mutex is really overkill for that
situation. Just lock the resource. As to the original issue, I'm not sure
why it is happening. Maybe if you could scratch up some code to reproduce
the issue, we could look at it.

lock(resource)
{
}

--

________________________
Warm regards,
Alvin Bruney [MVP ASP.NET]

[Shameless Author plug]
Professional VSTO.NET - Wrox/Wiley
The O.W.C. Black Book with .NET
www.lulu.com/owc, Amazon
Blog: http://www.msmvps.com/blogs/alvin

 

[Alvin Bruney]

You also need to explicitly release the mutex object by the way which is why
the mutex isn't being released. Since it is a kernel object, it isn't scoped
to the block of code it is running in.

--

________________________
Warm regards,
Alvin Bruney [MVP ASP.NET]

[Shameless Author plug]
Professional VSTO.NET - Wrox/Wiley
The O.W.C. Black Book with .NET
www.lulu.com/owc, Amazon
Blog: http://www.msmvps.com/blogs/alvin