on Mon Mar 26 2007, Roland Schwarz <roland.schwarz-AT-chello.at> wrote:
What I really meant by "do we need cancellation" is the inherent meaning of cancellation: once started you can't stop it.
That's not inherent. You're stepping into a minefield here...
Your example seems to imply this, but I don't think this necessarily is the case.
"Everybody" in the C++ community wants cancellation to be an ordinary, stoppable, C++ exception, thrown only synchronously, at well-defined cancellation points. Anything else makes writing cancellation-safe code basically untenable. In fact, the only person I know of in *any* community who insists that cancellation must be unstoppable is Ullrich Drepper.
Another point (not a strict technical one though): Developing a mechanism that could be used for cancellation but strictly speaking _is_ _not_ cancellation could end the stalling discussions about cancellation, which are lasting almost forever now.
I suggest that trying to use meanings of "cancellation" other than the one(s) used in the pthread standard at this point can only confuse things, which hardly seems like a way to un-stall the process. -- Dave Abrahams Boost Consulting www.boost-consulting.com