PlatSec - Process Isolation check under 9.1

[SimonJudge]

I have a client-server arrangement where the server is doing a RThread::RequestComplete to complete an asynchronous request.

I am getting the following in the debug messages...

"*PlatSec* WARNING - Process Isolation check would have failed - Thread xxxxServer.EXE::xxxxServer attempted an prohibited operation. Additional diagnostic message: Attempt to use RThread::RequestComplete on a thread in another process"

The server currently has capability All - TCB. The emulator currently has Platsec disabled.

What do I have to do pass the process isolation check?

Thanks

Simon Judge

[Paul.Todd]

This API function is deprecated in 9.x and should not be used, so I guess you will have to reengineer the code.

This check is independant of the capabilities.

AFAIK there is no alternative as I can see it, aside from using RMessage

[SimonJudge]

Paul

Thanks for the reply. I am using RThread::RequestComplete() to signal to the client that the server process has initialised. Until this happens, it's not safe to use SendReceive() (and hence RMessage).

What's the recommended way to detect a Server has initialised under 9.1? What mechanism do the built-in servers use under 9.1?

Thanks

Simon

[wizard_hu_]

I am using RThread::RequestComplete() to signal to the client that the server process has initialised. Until this happens, it's not safe to use SendReceive() (and hence RMessage).

It is better (and possible) to use Publish and Subscribe, for example "Speculative publishing".

[Paul.Todd]

The recommended way to do this (ok my personal opinion) is to use the Rendezvous functions in RThread and RProcess.

There are sample in the OS9 and OS7 devkits on it.

[symbianab]

Like this?
On the client side:
TRequestStatus status = KRequestPending;
RProcess server;
server.Create(.....); // Create the server process
server.Rendezvous(status); // Trigger rendezvous on the supplied TRequestStatus objekt

User::WaitForRequest(status); // Wait for the request to complete

and on the server side:
RProcess myProcess; // Get my current process
myProcess.Rendezvous(err); // Indicate to the calling process/thread that this process has completed startup

[Paul.Todd]

After the server.Create, you need a server.Resume() to kick off the process, but thats more or less it.

[david.caabeiro]

Yes, definitely RendezVous() is the way to go..

(symbianab, note also that it's not necessary to set status to KRequestPending manually..I'd even say it's not recommended at all..)

[lenclud]

Does RProcess::Rendezvous works the other way around?
So if a process is waiting for a RProcess::Rendezvous on itself and another process is completing the Rendezvous using the first process handle?

It looks to me like it won't work. I guess I'll have to use P&S and RProperty.

[Paul.Todd]

I can't see a use case for a process or thread to rendezvous on itself, it plain does not make sense

Can you explain further about what you are trying to do?

[lenclud]

Your typical use case is where one process is completing the Rendezvous using his own handle. So you are sending an integer value across the process boundary to anyone waiting for that process Rendezvous.

What I'm saying is the the complete Rendezvous function appears to work only if called by the process itself. So a process can't complete Rendezvous on an other process handle only on his own handle. Hope it makes sense.

All I wanted to do was send an integer from one process to another. I used RProperty and it works just fine.

[Paul.Todd]

I think I see the problem.

For RProcess, one of the Rendezvous functions (the static one) is used to signal the waiting process that it is ready. (This one is called on the server)

The other Rendezvous function actually sets up the rendezvous call. (This one goes on the client)

You might want to look at Hamish Willee's etal's excellent tutorial (http://developer.symbian.com/main/do...nOSv9_v1.3.pdf) on how to use rendezvous

[stenlik]

Hi,

I faced exactly the same problem - I passed client thread id and TRequestStatus wrapped as command line parameters to the server during stratup.
When server was initialized I opened thread handle using passed id and call RThread::RequestComplete(), so client code continued executing.

This approach unfortunately causes "process isolation error" on OS9. Happily it offers rendezvous mechanism, which is clean and much more easy-to-use solution. I'm also using it now

Regards,
STeN

[paipeng]

can somebody tell me, how to use the Rendezvous?


I have an not completed exammple, and need help.

Thanks

[ltomuta]

You might want to look at Hamish Willee's excellent tutorial (http://developer.symbian.com/main/do...nOSv9_v1.3.pdf) on how to use rendezvous

have you seen that one?