When called with -e, epoll is used instead of poll. The poller does
very little in this code (just checks for any event without waiting) but
that's sufficient to see return values.
Now the connect() step becomes an action. It's still implicit before
any -c/-s but it allows the listener to close() before connect()
happens, showing the polling status for this condition:
$ dev/poll/poll -v -l clo -c pol
#### BEGIN ####
cmd #1 stp #1: do_clo(3): ret=0
cmd #2 stp #0: do_con(4): ret=-1 (Connection refused)
cmd #2 stp #1: do_pol(4): ret=1 ev=0x14 (OUT HUP)
#### END ####
which differs from a case where the server closes the just accepted
connection:
$ dev/poll/poll -v -s clo -c pol
#### BEGIN ####
cmd #1 stp #0: do_con(4): ret=0
cmd #1 stp #0: do_acc(3): ret=5
cmd #1 stp #1: do_clo(5): ret=0
cmd #2 stp #1: do_pol(4): ret=1 ev=0x2005 (IN OUT RDHUP)
#### END ####
It's interesting to see OUT+HUP since HUP indicates that both directions
were closed, hence nothing may be written now, thus OUT just wants the
write handler to be notified.
The $(Q), $(V), $(cmd_xx) handling needs to be reused in sub-project
makefiles and it's a pain to maintain inside the main makefile. Let's
just move that into a new subdir include/make/ with a dedicated file
"verbose.mk". It slightly cleans up the makefile in addition.
The "poll" and "tcploop" sub-projects have their own makefiles. But
since the cmd_* commands were migrated from "echo" to $(info) with
make 3.81, the command is confusingly displayed in the top-level
makefile before entering the directory, even making one think that
the build occurred.
Let's instead propagate the verbosity level through the sub-projects
and let them adapt their own cmd_CC. For now this peans a little bit
of duplication for poll and tcploop.
The following directories were moved from contrib/ to dev/ to make their
use case a bit clearer. In short, only developers are expected to ever
go there. The makefile was updated to build and clean from these ones.
base64/ flags/ hpack/ plug_qdisc/ poll/ tcploop/ trace/
Willy Tarreau