Mutex in a implicit linked DLL always returns that it exists

Hello

I attached a C++ solution based sample where a executable just loads a implicit linked DLL, just to show my problem.
The sample does export some small objects but just to get the DLL loaded when starting up the application, no snese behind.
I let it run on a Netdcu8 as platform.

The Problem:
If I create a new Mutex in the DLL it always returns that it is already existing(see error code in DLL)
If I create a new Mutex in the Executable, it works as expected, it is created new. You can try in the code, just remove the remarkes in the exe.
Do you see the same results?
It doesn´t matter if I change the mutex name in the DLL or cold reboot the device, it is always doing the same behaviour, telling me that the mutex is already there or created.
Does anybody have an idea how to come behind the that?
Is it forbidden to create mutex in DLL? I thought always it should be same as in executable, may be it is not?

bye[attachment=0]<!-- ia0 -->TestMutexDllExe.zip<!-- ia0 -->[/attachment]

Hi again

As attach there is a Word document where the difference between W32 and a device application is showed.
As W32 on the PC it is working as expected but not as device Apllication.

Main difference is that the adress of the testdll.dll is in a strange area, a mouse tootip says that it is not the standard area.
Don´t know if this matters, but red sign is never good. Also the adress of the Handle, returned by CreateMutex is in very different area.
Could be that PC locates the stuff in other areas as device?

I do not know further please have a look. May be there is a solution for me.

bye

Hello

Thanks a lot for the hint with the retailmessage, indeed, this message comes twice!!
How to prevent dll loading twice? Could you give me a another big help please.

bye

Hello
I set a breakpoint right int the DLL_PROCESS_ATTACH switch case at the retail message.
the output when program starts is follwing:

DLL_PROCESS_ATTACH
MUTEX CREATION OK
DLL_PROCESS_DETACH
DLL_PROCESS_ATTACH
ERROR_ALREADY_EXISTS
DLL_PROCESS_DETACH

after the breakpoint (program runs) this:
DLL_PROCESS_ATTACH
ERROR_ALREADY_EXISTS

When closing the program:
DLL_PROCESS_DETACH

Thanks for any help

Hi

It is the conmanclient2.exe (0x83b94b76) that is calling this DLL. I use conmanclient2 to connect the Visual Studio to the target device.
Now I understand the behaviour of another DLL that I use, in debugging environment...

Here the output of the serial line:

DLL_PROCESS_ATTACH, ProcessID: 0x83b94b76
ERROR_ALREADY_EXISTS, ProcessID: 0x83b94b76
DLL_PROCESS_DETACH, ProcessID: 0x83b94b76
<LF>
DLL_PROCESS_ATTACH, ProcessID: 0x63ac1276
ERROR_ALREADY_EXISTS, ProcessID: 0x63ac1276
<LF>
DLL_PROCESS_DETACH, ProcessID: 0x63ac1276

Is this possible to prevent or do I need to live with it?
When I start the exe on the device, without conmanclient2 started, it is ok.

bye

Hello

after trying to workaround the problem, I found, that even when I just deploy the exe/dll to the device, the serial output shows me that(after power on the device, nothing was loaded before):

DLL_PROCESS_ATTACH, ProcessID: 0x63c2423a
Call from path \ffsdisk\conn\conmanclient2.exe
Call from ConManClient2, do nothing
DLL_PROCESS_DETACH, ProcessID: 0x63c2423a

Then I start the application, having a breakpoint in the DLL_PROCESS_ATTACH swtich:
DLL_PROCESS_ATTACH, ProcessID: 0x63c2423a
Call from path \ffsdisk\conn\conmanclient2.exe
Call from ConManClient2, do nothing
DLL_PROCESS_DETACH, ProcessID: 0x63c2423a

Then after the breakpoint this:
DLL_PROCESS_ATTACH, ProcessID: 0x 3b626ae
Call from path \ffsdisk\testEXE\testEXE.exe
Call from EXE
MUTEX CREATION OK, ProcessID: 0x 3b626ae

The code in the attach section:

Hello

For me it is better this way. So I can live with my workaround, but anyway would be interested why this work this way...Did you know this?

thanks for helping,bye

Hello

now a more heavy problem arised concerning this issue(seems one of Murphys laws has been proved again).

I cannot debug anymore, from one moment to the other. Deployment still works, but when I start any NETDCU 8 application from VS2008
then there appears a VS 2008 messsage box, that Debug is no more possible. I saw at the serial debug output the following:

Data Abort: Thread=83ba2400 Proc=80eff0d0 'conmanclient2.exe'
AKY=ffffffff PC=8015c300(NK.EXE+0x00023300) RA=8015c2a0(NK.EXE+0x000232a0) BVA=1800003c FSR=00000007

So it depends to the conection manager conmanclient2. Can you give me any instructions what to do?

bye

I did this of course, but didn´t help.
What helped was...wait an hour or two, then magically it was working again. strange...

The problem occured again:

After start of the debugger from VS2008 there is the following ouput at the serial debug interface of the NETCDU8:
Data Abort: Thread=83b13a78 Proc=80eff0d0 'conmanclient2.exe'
AKY=ffffffff PC=8015c300(NK.EXE+0x00023300) RA=8015c2a0(NK.EXE+0x000232a0) BVA=1800003c FSR=00000007

VS says that it cannot start application.

Workarround, if s.o. has this problem, too:
After you find such an error, when you start you application afterwards directly on the device(no VS debugger), then stop it, then you can debug again afterwards(don´t ask em why). At least here it was like this.

@F&S: Are there fir this case descriptions about AKY, PC, RA BVA, FSR to make further investigation? (mapping Files ??)

bye