daemon: reduce timer-related allocations

We can reduce the allocation and overhead needed for
Danga::Socket timers for immediately-executed responses by
combining identical timers and reducing anonymous sub creation.

1 files changed, 22 insertions, 8 deletions

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index e143d15c..a4cf25e2 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -41,6 +41,23 @@ our $EXPTIME = 180; # 3 minutes
 my $WEAKEN = {}; # string(nntpd) -> nntpd
 my $WEAKTIMER;
 
+my $next_tick;
+my $nextq = [];
+sub next_tick () {
+        $next_tick = undef;
+        my $q = $nextq;
+        $nextq = [];
+        foreach my $nntp (@$q) {
+                # for request && response protocols, always finish writing
+                # before finishing reading:
+                if (my $long_cb = $nntp->{long_res}) {
+                        $nntp->write($long_cb);
+                } elsif (&Danga::Socket::POLLIN & $nntp->{event_watch}) {
+                        event_read($nntp);
+                }
+        }
+}
+
 sub update_idle_time ($) {
         my ($self) = @_;
         my $tmp = $self->{sock} or return;
@@ -591,9 +608,9 @@ sub long_response ($$$$) {
                         # no recursion, schedule another call ASAP
                         # but only after all pending writes are done
                         update_idle_time($self);
-                        Danga::Socket->AddTimer(0, sub {
-                                $self->write($self->{long_res});
-                        });
+
+                        push @$nextq, $self;
+                        $next_tick ||= Danga::Socket->AddTimer(0, *next_tick);
                 } else { # all done!
                         $self->{long_res} = undef;
                         $self->watch_read(1);
@@ -952,11 +969,8 @@ sub watch_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.
-                Danga::Socket->AddTimer(0, sub {
-                        if (&Danga::Socket::POLLIN & $self->{event_watch}) {
-                                event_read($self);
-                        }
-                });
+                push @$nextq, $self;
+                $next_tick ||= Danga::Socket->AddTimer(0, *next_tick);
         }
         $rv;
 }