What is wrong with this mutex code

[Academia]

I build the solution.

In the bin folder I run the .exe

Twice

It runs each time.

Why doesn't the below code abort the second run?



Thanks

Shared Function Main(ByVal cmdArgs() As String) As Integer

Dim mutexWasCreated As Boolean

Using mutx As New Mutex(True, "TestJunk", mutexWasCreated )



If Not mutexWasCreated Then Return 1

End Using

Try

Application.Ena bleVisualStyles ()

Application.Run (New FormStudioMdi)

Catch ex As Exception

[Stephany Young]

Re: What is wrong with this mutex code

Becaue you are releasing of the mutex way too early.

If you're going to have your Application.Run (...) in a Try/Catch/End Try
block then extend it to include a Finally section and release it there.


"Academia" <academiaNOSPAM @a-znet.comwrote in message
news:uGrpz3OTIH A.5360@TK2MSFTN GP03.phx.gbl...

>I build the solution.
>
In the bin folder I run the .exe
>
Twice
>
It runs each time.
>
Why doesn't the below code abort the second run?
>
>
>
Thanks
>
Shared Function Main(ByVal cmdArgs() As String) As Integer
>
Dim mutexWasCreated As Boolean
>
Using mutx As New Mutex(True, "TestJunk", mutexWasCreated )
>
>
>
If Not mutexWasCreated Then Return 1
>
End Using
>
Try
>
Application.Ena bleVisualStyles ()
>
Application.Run (New FormStudioMdi)
>
Catch ex As Exception
>
>

[kimiraikkonen]

Re: What is wrong with this mutex code

On Jan 2, 5:17 am, "Academia" <academiaNOS... @a-znet.comwrote:

I build the solution.
>
In the bin folder I run the .exe
>
Twice
>
It runs each time.
>
Why doesn't the below code abort the second run?
>
Thanks
>
Shared Function Main(ByVal cmdArgs() As String) As Integer
>
Dim mutexWasCreated As Boolean
>
Using mutx As New Mutex(True, "TestJunk", mutexWasCreated )
>
If Not mutexWasCreated Then Return 1
>
End Using
>
Try
>
Application.Ena bleVisualStyles ()
>
Application.Run (New FormStudioMdi)
>
Catch ex As Exception

"Finally" (optional) and "end try" (required) parts are missing. Also
you've defined "Catch" with no exception display method, you may
throw the exception.

[Herfried K. Wagner [MVP]]

Re: What is wrong with this mutex code

"Academia" <academiaNOSPAM @a-znet.comschrieb :

In the bin folder I run the .exe
>
Twice
>
It runs each time.
>
Why doesn't the below code abort the second run?

<URL:http://www.yoda.arachs ys.com/csharp/faq/#one.applicatio n.instance>

In VB 2005 and VB 2008 you can make your application single-instance by
enabling the application framework and checking a checkbox in the
application framework properties (available in "My Project").

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Academia]

Re: What is wrong with this mutex code

I've never used a mutex so I'm going to finish the way I started and then
look at your suggestion.

The site you referenced says I need not release the mutex and also suggest
using a static variable.

Is that what you would do?


Thanks


"Herfried K. Wagner [MVP]" <hirf-spam-me-here@gmx.atwrot e in message
news:uGSzwbTTIH A.3516@TK2MSFTN GP02.phx.gbl...

"Academia" <academiaNOSPAM @a-znet.comschrieb :

>In the bin folder I run the .exe
>>
>Twice
>>
>It runs each time.
>>
>Why doesn't the below code abort the second run?

>
<URL:http://www.yoda.arachs ys.com/csharp/faq/#one.applicatio n.instance>
>
In VB 2005 and VB 2008 you can make your application single-instance by
enabling the application framework and checking a checkbox in the
application framework properties (available in "My Project").
>
--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Academia]

Re: What is wrong with this mutex code


"Stephany Young" <noone@localhos twrote in message
news:e4wpWQPTIH A.6060@TK2MSFTN GP05.phx.gbl...

Becaue you are releasing of the mutex way too early.
>
If you're going to have your Application.Run (...) in a Try/Catch/End Try
block then extend it to include a Finally section and release it there.
>

I moved the End Using. Is that a good way?

Also, does it make sense to have the two message boxes.

I don't know a lot about the difference between two exceptions.

The revised code is below.



Thanks for the help

Shared Function Main(ByVal cmdArgs() As String) As Integer

Dim mutexWasCreated As Boolean

Using mutx As New Mutex(True, "TestJunk", mutexWasCreated )



If Not mutexWasCreated Then Return 1

Try

Application.Ena bleVisualStyles ()

Application.Run (New FormStudioMdi)

Catch ex As Exception

Utility.WriteSt ackTrace(ex)

If ex.InnerExcepti on IsNot Nothing Then
MessageBox.Show (ex.InnerExcept ion.Message, " Experienced An Unhandled Inner
Error And Must Exit", MessageBoxButto ns.OK)

If ex.GetBaseExcep tion IsNot Nothing Then
MessageBox.Show (ex.GetBaseExce ption.Message, " Experienced A BaseException
And Must Exit", MessageBoxButto ns.OK)

Return 1

End Try

Return 0

End Using

End Function

[Academia]

Re: What is wrong with this mutex code


I should have sent
Catch ex As Exception ..snip...
There is code I didn't show.
Maybe you could comment on my reply to Stephany Young which shows all the
code.

Thanks

>
"Finally" (optional) and "end try" (required) parts are missing. Also
you've defined "Catch" with no exception display method, you may
throw the exception.

[Herfried K. Wagner [MVP]]

Re: What is wrong with this mutex code

"Academia" <academiaNOSPAM @a-znet.comschrieb :

The site you referenced says I need not release the mutex and also suggest
using a static variable.
>
Is that what you would do?

Yes.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Academia]

Re: What is wrong with this mutex code

thanks


"Herfried K. Wagner [MVP]" <hirf-spam-me-here@gmx.atwrot e in message
news:uwLLqwUTIH A.5516@TK2MSFTN GP02.phx.gbl...

"Academia" <academiaNOSPAM @a-znet.comschrieb :

>The site you referenced says I need not release the mutex and also
>suggest using a static variable.
>>
>Is that what you would do?

>
Yes.
>
--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>