Abort of C-code in a asynchronous_select

[Vincent Smeets <VSmeets@meppen.sema.slb.com>]

Hallo,

I have a driver for reading and writing data written in C. The
C-routines are protected with a semaphores against being called by two
threads at the same time. The code can't be changed.

I want to call the blocking C-Driver.Read routine from Ada but must be
able to abort the call in case of an application state change. I was
thinking of the statements:

select
   State.Not_Active;
then abort
   C_Driver.Read (Data, Data_Last);
end select;

I am assuming that in case the Read-call is aborted, the semaphore in C
isn't freed because C doesn't know anything about the Ada-abort. Am I
correct and how can I do it better?

-- 
Vincent Smeets
SchlumbergerSema -
Competence Center Informatik GmbH 
Lohberg 10 - 49716 Meppen - Germany
tel:  +49 5931-805-461
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mail: VSmeets@slb.com
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