* Christian Brauner: >> From a glibc perspective, we typically cannot use long-term file >> descriptors (that are kept open across function calls) because some >> applications do not expect them, or even close them behind our back. > > Yeah, good point. Note, I suggested it as an extension not as a > replacement for the TID. I still think it would be a useful extension in > general. Applications will need a way to determine when it is safe to close the pidfd, though. If we automate this in glibc (in the same way we handle thread stack deallocation for example), I think we are essentially back to square one, except that pidfd collisions are much more likely than TID collisions, especially on systems that have adjusted kernel.pid_max. (File descriptor allocation is designed to maximize collisions, after all.) Thanks, Florian
