Hi all gurus,
forgive me if I'm bothering you. My .NET CF app is designoed to be executed
once in target PDAs. However, in customers' hands (actually, refereees) it
seems they are able to spawn app more than once, as I receive errors on
table locking and replying "OK" the app opens the table, while the design is
to loop in opening retries, and a certain numbers of little (?)
malfunctioning routines like this one. Even if this (most time) does not
lock the execution, there error messages are annoying and, the most
important thing, confusing. I guess that in the time the app performs some
inizialization, users are apple to launch it a couple of times, tapping on
HW button associated. How can I avoid this (kkep in mind that for a couple
of seconds nothing appear on PDA's screen. Can some1 point me to the right
direction? TIA!

You need to grab a named mutex at app startup. If it already exists, the
app is already running so exit. Search the archives for CreateMutex and/or
single instance.

-Chris


"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi all gurus,
> forgive me if I'm bothering you. My .NET CF app is designoed to be
> executed once in target PDAs. However, in customers' hands (actually,
> refereees) it seems they are able to spawn app more than once, as I
> receive errors on table locking and replying "OK" the app opens the table,
> while the design is to loop in opening retries, and a certain numbers of
> little (?) malfunctioning routines like this one. Even if this (most time)
> does not lock the execution, there error messages are annoying and, the
> most important thing, confusing. I guess that in the time the app performs
> some inizialization, users are apple to launch it a couple of times,
> tapping on HW button associated. How can I avoid this (kkep in mind that
> for a couple of seconds nothing appear on PDA's screen. Can some1 point me
> to the right direction? TIA!
>

Hi Chris,
thank you 4 your reply. What about CreateSemaphore function? Easier,
tricker, harder? TIA

"<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
news:(E-Mail Removed)...
> You need to grab a named mutex at app startup. If it already exists, the
> app is already running so exit. Search the archives for CreateMutex
> and/or single instance.
>
> -Chris
>
>
> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Hi all gurus,
>> forgive me if I'm bothering you. My .NET CF app is designoed to be
>> executed once in target PDAs. However, in customers' hands (actually,
>> refereees) it seems they are able to spawn app more than once, as I
>> receive errors on table locking and replying "OK" the app opens the
>> table, while the design is to loop in opening retries, and a certain
>> numbers of little (?) malfunctioning routines like this one. Even if this
>> (most time) does not lock the execution, there error messages are
>> annoying and, the most important thing, confusing. I guess that in the
>> time the app performs some inizialization, users are apple to launch it a
>> couple of times, tapping on HW button associated. How can I avoid this
>> (kkep in mind that for a couple of seconds nothing appear on PDA's
>> screen. Can some1 point me to the right direction? TIA!
>>
>
>

A semaphore is not something useful in this case. A mutex is, hence the
recommendation.

--
Chris Tacke
Co-founder
OpenNETCF.org
Has OpenNETCF helped you? Consider donating to support us!
http://www.opennetcf.org/donate


"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> Hi Chris,
> thank you 4 your reply. What about CreateSemaphore function? Easier,
> tricker, harder? TIA
>
> "<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
> news:(E-Mail Removed)...
>> You need to grab a named mutex at app startup. If it already exists, the
>> app is already running so exit. Search the archives for CreateMutex
>> and/or single instance.
>>
>> -Chris
>>
>>
>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> Hi all gurus,
>>> forgive me if I'm bothering you. My .NET CF app is designoed to be
>>> executed once in target PDAs. However, in customers' hands (actually,
>>> refereees) it seems they are able to spawn app more than once, as I
>>> receive errors on table locking and replying "OK" the app opens the
>>> table, while the design is to loop in opening retries, and a certain
>>> numbers of little (?) malfunctioning routines like this one. Even if
>>> this (most time) does not lock the execution, there error messages are
>>> annoying and, the most important thing, confusing. I guess that in the
>>> time the app performs some inizialization, users are apple to launch it
>>> a couple of times, tapping on HW button associated. How can I avoid this
>>> (kkep in mind that for a couple of seconds nothing appear on PDA's
>>> screen. Can some1 point me to the right direction? TIA!
>>>
>>
>>
>
>

Thank you, Chris, for your reply.
Useless to say, I'm moving my first steps into inter-program and inter-task
syncronization, so pls forgive me if I'm bothering you.
However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2), as
there's only an "Already owned" parameter in New function. Should I create a
Win32-wrapper? Where can I find C# or VB declaration for PPC2002/2003
targets? TIA

"Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel messaggio
news:(E-Mail Removed)...
>A semaphore is not something useful in this case. A mutex is, hence the
>recommendation.
>
> --
> Chris Tacke
> Co-founder
> OpenNETCF.org
> Has OpenNETCF helped you? Consider donating to support us!
> http://www.opennetcf.org/donate
>
>
> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>> Hi Chris,
>> thank you 4 your reply. What about CreateSemaphore function? Easier,
>> tricker, harder? TIA
>>
>> "<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>> news:(E-Mail Removed)...
>>> You need to grab a named mutex at app startup. If it already exists,
>>> the app is already running so exit. Search the archives for CreateMutex
>>> and/or single instance.
>>>
>>> -Chris
>>>
>>>
>>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)...
>>>> Hi all gurus,
>>>> forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>> executed once in target PDAs. However, in customers' hands (actually,
>>>> refereees) it seems they are able to spawn app more than once, as I
>>>> receive errors on table locking and replying "OK" the app opens the
>>>> table, while the design is to loop in opening retries, and a certain
>>>> numbers of little (?) malfunctioning routines like this one. Even if
>>>> this (most time) does not lock the execution, there error messages are
>>>> annoying and, the most important thing, confusing. I guess that in the
>>>> time the app performs some inizialization, users are apple to launch it
>>>> a couple of times, tapping on HW button associated. How can I avoid
>>>> this (kkep in mind that for a couple of seconds nothing appear on PDA's
>>>> screen. Can some1 point me to the right direction? TIA!
>>>>
>>>
>>>
>>
>>
>
>

http://www.mvps.org/vcfaq/mfc/2.htm

Thanks,

Matt
"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Thank you, Chris, for your reply.
> Useless to say, I'm moving my first steps into inter-program and
> inter-task syncronization, so pls forgive me if I'm bothering you.
> However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2),
> as there's only an "Already owned" parameter in New function. Should I
> create a Win32-wrapper? Where can I find C# or VB declaration for
> PPC2002/2003 targets? TIA
>
> "Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel
> messaggio news:(E-Mail Removed)...
>>A semaphore is not something useful in this case. A mutex is, hence the
>>recommendation.
>>
>> --
>> Chris Tacke
>> Co-founder
>> OpenNETCF.org
>> Has OpenNETCF helped you? Consider donating to support us!
>> http://www.opennetcf.org/donate
>>
>>
>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>> news:%(E-Mail Removed)...
>>> Hi Chris,
>>> thank you 4 your reply. What about CreateSemaphore function? Easier,
>>> tricker, harder? TIA
>>>
>>> "<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>>> news:(E-Mail Removed)...
>>>> You need to grab a named mutex at app startup. If it already exists,
>>>> the app is already running so exit. Search the archives for
>>>> CreateMutex and/or single instance.
>>>>
>>>> -Chris
>>>>
>>>>
>>>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>> news:(E-Mail Removed)...
>>>>> Hi all gurus,
>>>>> forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>>> executed once in target PDAs. However, in customers' hands (actually,
>>>>> refereees) it seems they are able to spawn app more than once, as I
>>>>> receive errors on table locking and replying "OK" the app opens the
>>>>> table, while the design is to loop in opening retries, and a certain
>>>>> numbers of little (?) malfunctioning routines like this one. Even if
>>>>> this (most time) does not lock the execution, there error messages are
>>>>> annoying and, the most important thing, confusing. I guess that in the
>>>>> time the app performs some inizialization, users are apple to launch
>>>>> it a couple of times, tapping on HW button associated. How can I avoid
>>>>> this (kkep in mind that for a couple of seconds nothing appear on
>>>>> PDA's screen. Can some1 point me to the right direction? TIA!
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>

Here is an example how to create a named event to accomplish the single
instance behaviour for your application in SmartPhone. This code snippet
should work for PPC either:
http://www.sergeybogdanov.com/Sample...leInstance.zip


--
Sergey Bogdanov
http://www.sergeybogdanov.com


Saverio Tedeschi wrote:
> Thank you, Chris, for your reply.
> Useless to say, I'm moving my first steps into inter-program and inter-task
> syncronization, so pls forgive me if I'm bothering you.
> However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2), as
> there's only an "Already owned" parameter in New function. Should I create a
> Win32-wrapper? Where can I find C# or VB declaration for PPC2002/2003
> targets? TIA
>
> "Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel messaggio
> news:(E-Mail Removed)...
>
>>A semaphore is not something useful in this case. A mutex is, hence the
>>recommendation.
>>
>>--
>>Chris Tacke
>>Co-founder
>>OpenNETCF.org
>>Has OpenNETCF helped you? Consider donating to support us!
>>http://www.opennetcf.org/donate
>>
>>
>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>news:%(E-Mail Removed)...
>>
>>>Hi Chris,
>>>thank you 4 your reply. What about CreateSemaphore function? Easier,
>>>tricker, harder? TIA
>>>
>>>"<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>>>news:(E-Mail Removed)...
>>>
>>>>You need to grab a named mutex at app startup. If it already exists,
>>>>the app is already running so exit. Search the archives for CreateMutex
>>>>and/or single instance.
>>>>
>>>>-Chris
>>>>
>>>>
>>>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>>news:(E-Mail Removed)...
>>>>
>>>>>Hi all gurus,
>>>>>forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>>>executed once in target PDAs. However, in customers' hands (actually,
>>>>>refereees) it seems they are able to spawn app more than once, as I
>>>>>receive errors on table locking and replying "OK" the app opens the
>>>>>table, while the design is to loop in opening retries, and a certain
>>>>>numbers of little (?) malfunctioning routines like this one. Even if
>>>>>this (most time) does not lock the execution, there error messages are
>>>>>annoying and, the most important thing, confusing. I guess that in the
>>>>>time the app performs some inizialization, users are apple to launch it
>>>>>a couple of times, tapping on HW button associated. How can I avoid
>>>>>this (kkep in mind that for a couple of seconds nothing appear on PDA's
>>>>>screen. Can some1 point me to the right direction? TIA!
>>>>>
>>>>
>>>>
>>>
>>
>
>

Thank you Matt, 4 your suggestion.
My problem is, I'm not able to call CreateMutex from inside my code, as .NET
1.1 only allows 1 parameter (Hold) and I don't know parameters requested by
Win32 function not in what dll it is, to build a wrapper. If you could me
help me in this... LOT anyway.

"ME" <(E-Mail Removed)> ha scritto nel messaggio
news:kKKdnTxyqJfUNzjfRVn-(E-Mail Removed)...
> http://www.mvps.org/vcfaq/mfc/2.htm
>
> Thanks,
>
> Matt
> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Thank you, Chris, for your reply.
>> Useless to say, I'm moving my first steps into inter-program and
>> inter-task syncronization, so pls forgive me if I'm bothering you.
>> However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2),
>> as there's only an "Already owned" parameter in New function. Should I
>> create a Win32-wrapper? Where can I find C# or VB declaration for
>> PPC2002/2003 targets? TIA
>>
>> "Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel
>> messaggio news:(E-Mail Removed)...
>>>A semaphore is not something useful in this case. A mutex is, hence the
>>>recommendation.
>>>
>>> --
>>> Chris Tacke
>>> Co-founder
>>> OpenNETCF.org
>>> Has OpenNETCF helped you? Consider donating to support us!
>>> http://www.opennetcf.org/donate
>>>
>>>
>>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>> news:%(E-Mail Removed)...
>>>> Hi Chris,
>>>> thank you 4 your reply. What about CreateSemaphore function? Easier,
>>>> tricker, harder? TIA
>>>>
>>>> "<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>>>> news:(E-Mail Removed)...
>>>>> You need to grab a named mutex at app startup. If it already exists,
>>>>> the app is already running so exit. Search the archives for
>>>>> CreateMutex and/or single instance.
>>>>>
>>>>> -Chris
>>>>>
>>>>>
>>>>> "Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>>> news:(E-Mail Removed)...
>>>>>> Hi all gurus,
>>>>>> forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>>>> executed once in target PDAs. However, in customers' hands (actually,
>>>>>> refereees) it seems they are able to spawn app more than once, as I
>>>>>> receive errors on table locking and replying "OK" the app opens the
>>>>>> table, while the design is to loop in opening retries, and a certain
>>>>>> numbers of little (?) malfunctioning routines like this one. Even if
>>>>>> this (most time) does not lock the execution, there error messages
>>>>>> are annoying and, the most important thing, confusing. I guess that
>>>>>> in the time the app performs some inizialization, users are apple to
>>>>>> launch it a couple of times, tapping on HW button associated. How can
>>>>>> I avoid this (kkep in mind that for a couple of seconds nothing
>>>>>> appear on PDA's screen. Can some1 point me to the right direction?
>>>>>> TIA!
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>

Thank you Sergey, for your reply.
The problem is, referees try to call program twice (or three times, or four)
before it can display a form, for it needs to do some housekeeping. I
immediately spawn a secondary task to display splash screen, but it has not
the name of the main form, and more, it closes by itself after 10 seconds
(housekeeping takes abot 12 secs on a 200MHz XScale processor, or on a 400
forced to 200 for battery-lasting purposes). I appreciate your clue anyway.

"Sergey Bogdanov" <(E-Mail Removed)> ha scritto nel messaggio
news:(E-Mail Removed)...
> Here is an example how to create a named event to accomplish the single
> instance behaviour for your application in SmartPhone. This code snippet
> should work for PPC either:
> http://www.sergeybogdanov.com/Sample...leInstance.zip
>
>
> --
> Sergey Bogdanov
> http://www.sergeybogdanov.com
>
>
> Saverio Tedeschi wrote:
>> Thank you, Chris, for your reply.
>> Useless to say, I'm moving my first steps into inter-program and
>> inter-task syncronization, so pls forgive me if I'm bothering you.
>> However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2),
>> as there's only an "Already owned" parameter in New function. Should I
>> create a Win32-wrapper? Where can I find C# or VB declaration for
>> PPC2002/2003 targets? TIA
>>
>> "Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel
>> messaggio news:(E-Mail Removed)...
>>
>>>A semaphore is not something useful in this case. A mutex is, hence the
>>>recommendation.
>>>
>>>--
>>>Chris Tacke
>>>Co-founder
>>>OpenNETCF.org
>>>Has OpenNETCF helped you? Consider donating to support us!
>>>http://www.opennetcf.org/donate
>>>
>>>
>>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>news:%(E-Mail Removed)...
>>>
>>>>Hi Chris,
>>>>thank you 4 your reply. What about CreateSemaphore function? Easier,
>>>>tricker, harder? TIA
>>>>
>>>>"<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>>>>news:(E-Mail Removed)...
>>>>
>>>>>You need to grab a named mutex at app startup. If it already exists,
>>>>>the app is already running so exit. Search the archives for
>>>>>CreateMutex and/or single instance.
>>>>>
>>>>>-Chris
>>>>>
>>>>>
>>>>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>>>news:(E-Mail Removed)...
>>>>>
>>>>>>Hi all gurus,
>>>>>>forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>>>>executed once in target PDAs. However, in customers' hands (actually,
>>>>>>refereees) it seems they are able to spawn app more than once, as I
>>>>>>receive errors on table locking and replying "OK" the app opens the
>>>>>>table, while the design is to loop in opening retries, and a certain
>>>>>>numbers of little (?) malfunctioning routines like this one. Even if
>>>>>>this (most time) does not lock the execution, there error messages are
>>>>>>annoying and, the most important thing, confusing. I guess that in the
>>>>>>time the app performs some inizialization, users are apple to launch
>>>>>>it a couple of times, tapping on HW button associated. How can I avoid
>>>>>>this (kkep in mind that for a couple of seconds nothing appear on
>>>>>>PDA's screen. Can some1 point me to the right direction? TIA!
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>

The example demonstrates how to use named event and does not depend from
the main form:

IntPtr evnt = CreateEvent(IntPtr.Zero, false, false, AppNamedEvent);
if (Marshal.GetLastWin32Error() != 0)
{
// one instance of application is run, activate it
IntPtr hwnd = FindWindow(null, "Form1");
if (hwnd != IntPtr.Zero)
{
SetForegroundWindow(hwnd);
}

return;
}

As you can see it will activate the main form if it exists and exit all
the same.

--
Sergey Bogdanov
http://www.sergeybogdanov.com


Saverio Tedeschi wrote:
> Thank you Sergey, for your reply.
> The problem is, referees try to call program twice (or three times, or four)
> before it can display a form, for it needs to do some housekeeping. I
> immediately spawn a secondary task to display splash screen, but it has not
> the name of the main form, and more, it closes by itself after 10 seconds
> (housekeeping takes abot 12 secs on a 200MHz XScale processor, or on a 400
> forced to 200 for battery-lasting purposes). I appreciate your clue anyway.
>
> "Sergey Bogdanov" <(E-Mail Removed)> ha scritto nel messaggio
> news:(E-Mail Removed)...
>
>>Here is an example how to create a named event to accomplish the single
>>instance behaviour for your application in SmartPhone. This code snippet
>>should work for PPC either:
>>http://www.sergeybogdanov.com/Sample...leInstance.zip
>>
>>
>>--
>>Sergey Bogdanov
>>http://www.sergeybogdanov.com
>>
>>
>>Saverio Tedeschi wrote:
>>
>>>Thank you, Chris, for your reply.
>>>Useless to say, I'm moving my first steps into inter-program and
>>>inter-task syncronization, so pls forgive me if I'm bothering you.
>>>However, I can't find how2 create a named mutex in VS 2003 (CF 1.0 SP2),
>>>as there's only an "Already owned" parameter in New function. Should I
>>>create a Win32-wrapper? Where can I find C# or VB declaration for
>>>PPC2002/2003 targets? TIA
>>>
>>>"Chris Tacke, eMVP" <(E-Mail Removed)> ha scritto nel
>>>messaggio news:(E-Mail Removed)...
>>>
>>>
>>>>A semaphore is not something useful in this case. A mutex is, hence the
>>>>recommendation.
>>>>
>>>>--
>>>>Chris Tacke
>>>>Co-founder
>>>>OpenNETCF.org
>>>>Has OpenNETCF helped you? Consider donating to support us!
>>>>http://www.opennetcf.org/donate
>>>>
>>>>
>>>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>>news:%(E-Mail Removed)...
>>>>
>>>>
>>>>>Hi Chris,
>>>>>thank you 4 your reply. What about CreateSemaphore function? Easier,
>>>>>tricker, harder? TIA
>>>>>
>>>>>"<ctacke/>" <ctacke_AT_OpenNETCF_com> ha scritto nel messaggio
>>>>>news:(E-Mail Removed)...
>>>>>
>>>>>
>>>>>>You need to grab a named mutex at app startup. If it already exists,
>>>>>>the app is already running so exit. Search the archives for
>>>>>>CreateMutex and/or single instance.
>>>>>>
>>>>>>-Chris
>>>>>>
>>>>>>
>>>>>>"Saverio Tedeschi" <(E-Mail Removed)> wrote in message
>>>>>>news:(E-Mail Removed)...
>>>>>>
>>>>>>
>>>>>>>Hi all gurus,
>>>>>>>forgive me if I'm bothering you. My .NET CF app is designoed to be
>>>>>>>executed once in target PDAs. However, in customers' hands (actually,
>>>>>>>refereees) it seems they are able to spawn app more than once, as I
>>>>>>>receive errors on table locking and replying "OK" the app opens the
>>>>>>>table, while the design is to loop in opening retries, and a certain
>>>>>>>numbers of little (?) malfunctioning routines like this one. Even if
>>>>>>>this (most time) does not lock the execution, there error messages are
>>>>>>>annoying and, the most important thing, confusing. I guess that in the
>>>>>>>time the app performs some inizialization, users are apple to launch
>>>>>>>it a couple of times, tapping on HW button associated. How can I avoid
>>>>>>>this (kkep in mind that for a couple of seconds nothing appear on
>>>>>>>PDA's screen. Can some1 point me to the right direction? TIA!
>>>>>>>
>>>>>>
>>>>>>
>