On Sun, 08 Feb 2004 16:11:03 -0500, Stefan Seefeld wrote
So the question seems to me: what do you gain in a multi-threaded application to report thread execution failure as an exception to the main thread (the one calling 'join') ?
You don't have to revert to C style error handling and pass error return codes from threads.
While it seems entirely possible to declare some exception types that are throwable across threads (in the same way there are CORBA::Exceptions that can be exchanged across ORBs), I don't really see why a generic threading library should provide such a facility.
Rogue Wave seems to disagree and has built this directly into their threading package. It is a pure C++ example that I think you'all missed in the first email... http://www.roguewave.com/support/docs/leif/foundation/html/threadsug/9.html http://www.roguewave.com/support/docs/leif/foundation/html/threadsug/booktoc... Of course this doesn't prove it is useful, but it's mere existance in a cross-platform C++ library does show it can be done.
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; } I'm not trying to argue that this should be the focus of boost::threads, just that I wouldn't dismiss the potential need. There are lots of other things that boost.threads lacks when stacked up against more comprehensive solutions which are probably more important than cross-thread exceptions... Jeff