nntp: simplify re-arming/requeue logic

We can be smarter about requeuing clients to run and avoid
excessive epoll_ctl calls since we can trust event_step to do
the right thing depending on the state of the client.

1 files changed, 10 insertions, 23 deletions

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 42fbb255..468a22f5 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -58,6 +58,11 @@ sub next_tick () {
         }
 }
 
+sub requeue ($) {
+        push @$nextq, $_[0];
+        $nextt ||= PublicInbox::EvCleanup::asap(*next_tick);
+}
+
 sub update_idle_time ($) {
         my ($self) = @_;
         my $sock = $self->{sock} or return;
@@ -633,7 +638,7 @@ sub long_response ($$) {
                         }
                         if ($self->{sock}) {
                                 update_idle_time($self);
-                                check_read($self);
+                                requeue($self);
                         } else {
                                 out($self, " deferred[$fd] aborted - %0.6f",
                                            now() - $t0);
@@ -642,14 +647,12 @@ sub long_response ($$) {
                         # no recursion, schedule another call ASAP
                         # but only after all pending writes are done
                         update_idle_time($self);
-
-                        push @$nextq, $self;
-                        $nextt ||= PublicInbox::EvCleanup::asap(*next_tick);
+                        requeue($self);
                 } else { # all done!
                         delete $self->{long_res};
-                        check_read($self);
                         res($self, '.');
                         out($self, " deferred[$fd] done - %0.6f", now() - $t0);
+                        requeue($self);
                 }
         };
         $self->{long_res}->(); # kick off!
@@ -930,6 +933,7 @@ sub out ($$;@) {
         printf { $self->{nntpd}->{out} } $fmt."\n", @args;
 }
 
+# callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
 sub event_step {
         my ($self) = @_;
 
@@ -965,24 +969,7 @@ sub event_step {
 
         # maybe there's more pipelined data, or we'll have
         # to register it for socket-readiness notifications
-        check_read($self) unless ($self->{long_res} || $self->{wbuf});
-}
-
-sub check_read {
-        my ($self) = @_;
-        if (index($self->{rbuf}, "\n") >= 0) {
-                # Force another read if there is a pipelined request.
-                # We don't know if the socket has anything for us to read,
-                # and we must double-check again by the time the timer fires
-                # in case we really did dispatch a read event and started
-                # another long response.
-                push @$nextq, $self;
-                $nextt ||= PublicInbox::EvCleanup::asap(*next_tick);
-        } else {
-                # no pipelined requests available, let the kernel know
-                # to wake us up if there's more
-                $self->watch_in1; # PublicInbox::DS::watch_in1
-        }
+        requeue($self) unless ($self->{long_res} || $self->{wbuf});
 }
 
 sub not_idle_long ($$) {