[omniORB] Repost: Why this call failed in dll?

[Sai-Lai Lo]

I think the problem is that you have not qualified "extern ServiceClass
Service" with a __declspec(dllimport) when your application code is
compiled. In omniORB2 all global variables in the DLLs that have to be
accessed in the application code are prefixed with the macro
_OMNIORB_NTDLL_IMPORT which translate into __declspec(dllimport) when the
header files are included in the application code.

Don't just take my word for it. Please read up on the MSVC++ dllimport
crap..

Regards,

Sai-Lai




>>>>> Bing Zhang writes:

> I have a very simple class in file services.h:
> class ServiceClass {
>    unsigned long caminStartTime;
> public:
>   ServiceClass();
>  resetStartTime(unsigned long delta);
>  unsigned long currentTime();
> };
> extern ServiceClass Service;

> In file service.cc,

> ServiceClass::ServiceClass() {
>   caminStartTime = (unsigned long) timeGetTime();
> }
> ServiceClass::resetStartTime(unsigned long delta) {
>         caminStartTime = delta;
> }
> unsigned long ServiceClass::currentTime() {
>       return (unsinged long) timeGetTime();
> }
> ServiceClass Service;

> In my main(), I call

> Service.resetStartTime(0);

> This works fine if I compile my main, application codes and omniORB2
> source code (I modified some part of omniORB codes to suit our
> situation) together with service.cc.

> But when I put the service.cc along with omniORB source code in a dll
> and link my application code to this
> dll, every time this call is made, it throws out a "The instruction at
> xxxxxx reference memory at xxxxxxx. The memory can not be wrriten" error

> when  the statement

> caminStartTime = delta;

> is executed. But the call Service.currentTime() runs ok. So I think the
> system does not want me to modify the member variable of Service, which
> is
> now a global variable inside the dll.

> I am using vc++ 5.0 and omniORB 2.4. I built the dll by adding my source

> codes to the dir.mk of omniORB.

> What is wrong?


-- 
Dr. Sai-Lai Lo                          |       Research Scientist
                                        |
E-mail:         S.Lo@orl.co.uk          |       Olivetti & Oracle Research Lab
                                        |       24a Trumpington Street
Tel:            +44 223 343000          |       Cambridge CB2 1QA
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