When -e is passed, epoll is used instead of poll. The FD is added
then removed around the call to epoll_wait() so that we don't need
to track it. The only purpose is to compare events reported by each
syscall.
There are multiple call places for poll(), let's first centralize them
to make it easier to enhance it. All callers now use the wait_for_fd()
function which was extended to take a timeout and which can return the
indication that an error was seen.
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 Listen command automatically relies on it (without passing its
argument), and both Listen and Connect now support working with the
existing socket, so that it's possible to Bind an ip:port on an
existing socket or to create a new one for the purpose of listening
or connecting. It now becomes possible to do:
tcploop 0 L1234 C8888
to connect from port 1234 to port 8888.
Sometimes it's more convenient to be able to specify where to connect on
the connect() statement, let's make it possible to pass it in argument to
the C command.
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/
