Multiple Versions of an Application 1

[sweep123]

I have an application that transmits data to a unit, but in the final system they will be 4 applications (all identical).
Now each application will need to detect if another instance of the application is running and adjust one of its parameters.

i.e. the 1st instance will be know as 1, then 2nd needs to determine if 1 is already running and mark itself as 2 etc.

How do you do this? Dont want to use batch files or command line parameters.

Sweep

 

[Cagliostro]

specify in linker parameters:
/section:sweep123

in the .cpp code you will put a segment:
#pragma data_seg( "sweep123 &quot
static bool isRunningAlready = false;
static int versionRunning = -1;
.....
#pragma data_seg()

the values from segment sweep123 are shared between processes, so if you change value in one application, you will read changed values from any other applications what has this segment.

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[PerFnurt]

>specify in linker parameters:
>/section:sweep123

Which can easily be done with the pragma comment statement, ie

#pragma data_seg("sweep123")
bool volatile isRunningAlready = false;
int volatile versionRunning = -1;
#pragma data_seg()

#pragma comment(linker, "/section:sweep123,rws")

/Per
[sub]
if (typos) cout << &quot;My fingers are faster than my brain. Sorry for the typos.&quot;;
[/sub]

 

[sweep123]

OK thanks chaps.

Simple when you know how.

 

[sweep123]

On other question, can you lock any of the data during an update.

i.e. one instance of the application will be required to update some data. So need to block out the reader durng this activity.

How can this be done?

Sweep

 

[Cagliostro]

yes, for process synchronisation you should use mutex'es.

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com