Shared Data Between EXE and DLL

[sweep123]

I am trying to have an MFC application that shares data with a DLL.
The DLL is loaded via a batch file in a C-Scripting environment.

I have included the following lines of code in both the EXE and DLL

#pragma data_seg(".CSL_DATA")

int volatile abortFlag = 0; /* The flag to abort the test */
int volatile contiuneFlag = 1; /* The flag to schedule the test to continue */
int volatile enterFlag = 0; /* The flag to schedule data entry the test */

#pragma data_seg()
#pragma comment(linker, "/SECTION:.CSL_DATA,RWS")

On the C-Scripting side of things the batch file loads the DLL as follows:-

#loadlibrary 'WHLLIB'

However any changes in the data (abortFlag say) is not reflected in the other side.

Basically all I want is the 3 variables to be visible by the libray and the application.

Am I doing it wrong?!?

 

[Cagliostro]

maybe you should declare like this:
#pragma...
__declspec(dllexport) int volatile abortFlag = 0;
...


Ion Filipski

 

[sweep123]

Tried it, it only works for instances of the same application. Not for two differently named applications.

Do I need to use Mailslots or memory mapped files just to share this small amount of data.

 

[Cagliostro]

In this case you should create this section in the exe

Ion Filipski

 

[sweep123]

Dont think thats a solution.

The DLL needs to be the server and use CreateMailslot to create the Mailslot. But how do you start this running (i.e. to check the Mailslot for messages). Dont have an Entrypoint for the DLL.

To recap all I want is the ability to share 3 integer value between the DLL and a application.

 

[Cagliostro]

In this case use sockets

Ion Filipski

 

[sweep123]

Got it sorted with the following code sample:-

http://www.codeproject.com/threads/csharedstruct.asp

Using Memory mapped shared data structures.

WIll always use this for applications on a single PC.