FreeBSD's pollscan clears POLLOUT whenever POLLHUP is set, so a write end
whose read end is closed reports POLLHUP alone, with POLLIN and POLLRDNORM
when they were asked for; both host paths reported POLLOUT | POLLHUP.
POLLOUT on a read end now throws. FreeBSD opens both ends FREAD | FWRITE
and pipe_poll reports the read end writable, which a one-way host pipe
cannot back.
guest_poll drained 1 KiB from the full pipe before expecting POLLOUT, but
Linux reports it only once a whole 4 KiB page is free, so the test aborted
there. It now drains the pipe, which is writable on every host.
ProsperoTV (PPSA99003) stops after its menu opens because poll threw for
the read end of a pipe it polls next to its sockets. poll now reports pipe
readiness as FreeBSD's pipe_poll does: readable when data is buffered,
POLLHUP once the other end is closed, writable when PIPE_BUF bytes are
free. On Windows the pipe is checked with NtQueryInformationFile while the
sockets are waited on in 1 ms slices; on Linux the host poll waits on both.
A closed descriptor below the socket range reports POLLNVAL.
Translate the FreeBSD pollfd layout and flags to WSAPoll on Windows and
poll on Linux. Closed socket descriptors report POLLNVAL, a timeout below
-1 fails with EINVAL and a null array with EFAULT. Non-socket
descriptors, unknown event bits, POLLPRI on Windows and an infinite wait
without sockets throw; these are recorded in TechnicalDebt.
DOOM (PPSA99666) imports poll for its upload server.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Dean Galvin
DariusHQ
Scott Schuster