Detection of pipe close with POLLHUP poll(3) event
On Linux, the POLLHUP poll(3) event is used to signal that the other end
of a pipe has been disconnected. Due to poor wording in the Single UNIX
Specification, differents UNIX implementation signal the EOF with
conflicting poll events .
The current implementation of pipe close detection in lttng-tools uses
the POLLHUP event. This could lead to infinite looping in threads on
platforms such as OpenBSD/Cygwin.
Possible workaround in 060a32b279132ceeeef14b96a611077195a2ca46.
Creating this issue so we don't forget this limitation if we want eventually
want to support those platforms.