DLL Shared Data Section Does Not Exist Error

I try to declare a shared data segment in a DLL. I declare the area with:

#pragma data_seg(".shared")
int varx=0; 
#pragma data_seg()
__declspec(allocate(".s开发者_开发百科hared")) 
// I found this declspec suggestion in another forum
#pragma comment (linker,"/section:.shared,RWS")

Also I add

SECTIONS
            .shared READ WRITE SHARED 

into the def file. However I always get:

LINK : warning LNK4039: section '.shared' specified with /SECTION option does not exist

error. If I do only one (.def or pragma comment) get only one, if do both get two errors.

Anything I miss?

Ive only seen that declspec used in this way:

 __declspec(allocate(".shared")) int varx=0;

I would try writting only this:

#pragma comment (linker,"/section:.shared,RWS")

 __declspec(allocate(".shared")) int varx=0;

avoiding declaring an empty section or a multiply defined one

To make it clear:

data_seg changes default section name in obj file where initialized to non-zero variables will go. So if you set varx = 1 this variable appeared in .shared section and will be shared across processes. I your case it didn't appeared there because of varx = 0.

Use #pragma section instead and specify the section to use when declaring your variable: __declspec(allocate(".shared")) int varx = 0.

Don't use data_seg keyword for your pupose. This will allow you NOT to share any other variables that initialized to non-zero :)