listener: use edge-triggered notifications

We don't need extra wakeups from the kernel when we know a
listener is already active.

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/PublicInbox/DSKQXS.pm b/lib/PublicInbox/DSKQXS.pm
index 364df3d6..278d3f88 100644
--- a/lib/PublicInbox/DSKQXS.pm
+++ b/lib/PublicInbox/DSKQXS.pm
@@ -16,7 +16,8 @@ use warnings;
 use parent qw(IO::KQueue);
 use parent qw(Exporter);
 use IO::KQueue;
-use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLL_CTL_DEL);
+use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLLET
+        EPOLL_CTL_DEL);
 our @EXPORT_OK = qw(epoll_ctl epoll_wait);
 my $owner_pid = -1; # kqueue is close-on-fork (yes, fork, not exec)
 
@@ -25,6 +26,7 @@ sub kq_flag ($$) {
         my ($bit, $ev) = @_;
         if ($ev & $bit) {
                 my $fl = EV_ADD | EV_ENABLE;
+                $fl |= EV_CLEAR if $fl & EPOLLET;
                 ($ev & EPOLLONESHOT) ? ($fl | EV_ONESHOT) : $fl;
         } else {
                 EV_ADD | EV_DISABLE;