* Christian Brauner: > Unless I'm missing something the question here is PID (as in TGID aka > thread-group leader id gotten via getpid()) vs TID (thread specific id > gotten via gettid()). You want the thread-specific id as you want to > interact with the futex state of a specific thread not the thread-group > leader. > > Aside from that TIDs are subject to the same race conditions that PIDs > are. They are allocated from the same pool (see alloc_pid()). For most mutex types (but not robust mutexes), it is undefined in userspace if a thread exits while it has locked a mutex. Such a usage condition would ensure that the race doesn't happen, I believe. >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. Thanks, Florian
