[c++-pthreads] Re: pthread_cancel and EH: let's try this again

[Peter Dimov]

Alexander Terekhov wrote:
> Peter Dimov wrote:
> [...]
>> D. to match POSIX semantics, cancellation points don't throw if
>> there is an unfinished exception.
>
> It actually breaks straight POSIX semantics.
>
>  int main() {
>    pthread_cancel(pthread_self());
>    try { throw 0; } catch(...) { pthread_testcancel(); }
>    printf("Never reach this point under straight POSIX.");
>  }

Yes, it does change the behavior of such programs. I'm hoping that it 
doesn't break them, though, because it only delays the cancellation 
exception a while, and there is usually a race between the pthread_cancel 
and the pthread_testcancel in real code.

> This probably won't please Tru64 and OpenVMS folk.

The only way to find out is to implement these semantics and see what 
happens.