From: Stefan Seefeld (seefeld_at_[hidden])
Date: 2004-02-08 19:55:13
Jeff Garland wrote:
>>It can always be added on a higher level that wraps the 'join()' call.
>
>
> This might be true, but I would think the exception abstractions and framework
> would need to be part of the library. If you look at the RW docs you there
> are some examples that show they build it in at this level. It looks
> something like:
>
> ThreadFunction someThread = ...;
> try {
> someThread.start(); // Start the thread
> someThread.join();
> someThread.raise(); // Rethrow any exception that was caught!
> }
> catch(rethrowable_exception& msg) {
> cout << "Exception! " << msg.why() << endl;
> }
for this to work you'd need a way to marshall exceptions from one thread
to another, which imposes some constraints on the exception types to be thrown.
A similar problem arises when C++ code is used to wrap a C 'middleware' library,
where you want to pass through exceptions from C++ callbacks to the C++ application.
I'v seen examples where the C++ wrapper code defines its own exception types
that provide 'clone()' methods so they could be stored and rethrown in a different
context. I'm curious to learn whether the boost experts have better techniques
to deal with these situations.
Regards,
Stefan