From ca05b93cddfa2cc495451410222af3753bfe1b4e Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Mon, 24 Jun 2019 02:52:22 +0000
Subject: ds: get rid of event_watch field

We don't need to keep track of that field since we always
know what events we're interested in when using one-shot
wakeups.
---
 lib/PublicInbox/DS.pm | 64 ++++++++++++++++++---------------------------------
 1 file changed, 23 insertions(+), 41 deletions(-)

(limited to 'lib/PublicInbox/DS.pm')

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 9c801214..f5986e55 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -29,8 +29,6 @@ use PublicInbox::Syscall qw(:epoll);
 use fields ('sock',              # underlying socket
             'wbuf',              # arrayref of coderefs or GLOB refs
             'wbuf_off',  # offset into first element of wbuf to start writing at
-            'event_watch',       # bitmask of events the client is interested in
-                                 # (EPOLLIN,OUT,etc.)
             );
 
 use Errno  qw(EAGAIN EINVAL);
@@ -318,6 +316,17 @@ sub PostEventLoop {
     return $keep_running;
 }
 
+# map EPOLL* bits to kqueue EV_* flags for EV_SET
+sub kq_flag ($$) {
+    my ($bit, $ev) = @_;
+    if ($ev & $bit) {
+        my $fl = EV_ADD() | EV_ENABLE();
+        ($ev & EPOLLONESHOT) ? ($fl|EV_ONESHOT()) : $fl;
+    } else {
+        EV_DISABLE();
+    }
+}
+
 #####################################################################
 ### PublicInbox::DS-the-object code
 #####################################################################
@@ -344,25 +353,21 @@ sub new {
     Carp::cluck("undef sock and/or fd in PublicInbox::DS->new.  sock=" . ($sock || "") . ", fd=" . ($fd || ""))
         unless $sock && $fd;
 
-    $self->{event_watch} = $ev;
-
     _InitPoller();
 
     if ($HaveEpoll) {
 retry:
         if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $ev)) {
             if ($! == EINVAL && ($ev & EPOLLEXCLUSIVE)) {
-                $self->{event_watch} = ($ev &= ~EPOLLEXCLUSIVE);
+                $ev &= ~EPOLLEXCLUSIVE;
                 goto retry;
             }
             die "couldn't add epoll watch for $fd: $!\n";
         }
     }
     elsif ($HaveKQueue) {
-        my $f = $ev & EPOLLIN ? EV_ENABLE() : EV_DISABLE();
-        $KQueue->EV_SET($fd, EVFILT_READ(), EV_ADD() | $f);
-        $f = $ev & EPOLLOUT ? EV_ENABLE() : EV_DISABLE();
-        $KQueue->EV_SET($fd, EVFILT_WRITE(), EV_ADD() | $f);
+        $KQueue->EV_SET($fd, EVFILT_READ(), EV_ADD() | kq_flag(EPOLLIN, $ev));
+        $KQueue->EV_SET($fd, EVFILT_WRITE(), EV_ADD() | kq_flag(EPOLLOUT, $ev));
     }
 
     Carp::cluck("PublicInbox::DS::new blowing away existing descriptor map for fd=$fd ($DescriptorMap{$fd})")
@@ -454,7 +459,7 @@ next_buf:
                     }
                 } elsif ($! == EAGAIN) {
                     $self->{wbuf_off} = $off;
-                    watch_write($self, 1);
+                    watch($self, EPOLLOUT|EPOLLONESHOT);
                     return 0;
                 } else {
                     return $self->close;
@@ -467,7 +472,6 @@ next_buf:
     } # while @$wbuf
 
     delete $self->{wbuf};
-    $self->watch_write(0);
     1; # all done
 }
 
@@ -544,7 +548,7 @@ sub write {
             return $self->close;
         }
         $self->{wbuf} = [ tmpbuf($bref, $written) ];
-        watch_write($self, 1);
+        watch($self, EPOLLOUT|EPOLLONESHOT);
         return 0;
     }
 }
@@ -563,49 +567,27 @@ sub msg_more ($$) {
 
             # queue up the unwritten substring:
             $self->{wbuf} = [ tmpbuf(\($_[1]), $n) ];
-            watch_write($self, 1);
+            watch($self, EPOLLOUT|EPOLLONESHOT);
             return 0;
         }
     }
     $self->write(\($_[1]));
 }
 
-sub watch_chg ($$$) {
-    my ($self, $bits, $set) = @_;
+sub watch ($$) {
+    my ($self, $ev) = @_;
     my $sock = $self->{sock} or return;
-    my $cur = $self->{event_watch};
-    my $changes = $cur;
-    if ($set) {
-        $changes |= $bits;
-    } else {
-        $changes &= ~$bits;
-    }
-    return if $changes == $cur;
     my $fd = fileno($sock);
     if ($HaveEpoll) {
-        epoll_ctl($Epoll, EPOLL_CTL_MOD, $fd, $changes) and
+        epoll_ctl($Epoll, EPOLL_CTL_MOD, $fd, $ev) and
             confess("EPOLL_CTL_MOD $!");
     } elsif ($HaveKQueue) {
-        my $flag = $set ? EV_ENABLE() : EV_DISABLE();
-        $KQueue->EV_SET($fd, EVFILT_READ(), $flag) if $bits & EPOLLIN;
-        $KQueue->EV_SET($fd, EVFILT_WRITE(), $flag) if $bits & EPOLLOUT;
+        $KQueue->EV_SET($fd, EVFILT_READ(), kq_flag(EPOLLIN, $ev));
+        $KQueue->EV_SET($fd, EVFILT_WRITE(), kq_flag(EPOLLOUT, $ev));
     }
-    $self->{event_watch} = $changes;
 }
 
-=head2 C<< $obj->watch_read( $boolean ) >>
-
-Turn 'readable' event notification on or off.
-
-=cut
-sub watch_read ($$) { watch_chg($_[0], EPOLLIN, $_[1]) };
-
-=head2 C<< $obj->watch_write( $boolean ) >>
-
-Turn 'writable' event notification on or off.
-
-=cut
-sub watch_write ($$) { watch_chg($_[0], EPOLLOUT, $_[1]) };
+sub watch_in1 ($) { watch($_[0], EPOLLIN | EPOLLONESHOT) }
 
 package PublicInbox::DS::Timer;
 # [$abs_float_firetime, $coderef];
-- 
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