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| | # Copyright (C) 2019 all contributors <meta@public-inbox.org>
# Licensed the same as Danga::Socket (and Perl5)
# License: GPL-1.0+ or Artistic-1.0-Perl
# <https://www.gnu.org/licenses/gpl-1.0.txt>
# <https://dev.perl.org/licenses/artistic.html>
#
# kqueue support via IO::KQueue XS module. This makes kqueue look
# like epoll to simplify the code in DS.pm. This is NOT meant to be
# an all encompassing emulation of epoll via IO::KQueue, but just to
# support cases public-inbox-nntpd/httpd care about.
# A pure-Perl version using syscall() is planned, and it should be
# faster due to the lack of syscall overhead.
package PublicInbox::DSKQXS;
use strict;
use warnings;
use parent qw(IO::KQueue);
use parent qw(Exporter);
use IO::KQueue;
use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLLET
EPOLL_CTL_ADD EPOLL_CTL_MOD EPOLL_CTL_DEL);
our @EXPORT_OK = qw(epoll_ctl epoll_wait);
my $owner_pid = -1; # kqueue is close-on-fork (yes, fork, not exec)
# map EPOLL* bits to kqueue EV_* flags for EV_SET
sub kq_flag ($$) {
my ($bit, $ev) = @_;
if ($ev & $bit) {
my $fl = EV_ENABLE;
$fl |= EV_CLEAR if $fl & EPOLLET;
# EV_DISPATCH matches EPOLLONESHOT semantics more closely
# than EV_ONESHOT, in that EV_ADD is not required to
# re-enable a disabled watch.
($ev & EPOLLONESHOT) ? ($fl | EV_DISPATCH) : $fl;
} else {
EV_DISABLE;
}
}
sub new {
my ($class) = @_;
die 'non-singleton use not supported' if $owner_pid == $$;
$owner_pid = $$;
$class->SUPER::new;
}
sub epoll_ctl {
my ($self, $op, $fd, $ev) = @_;
if ($op == EPOLL_CTL_MOD) {
$self->EV_SET($fd, EVFILT_READ, kq_flag(EPOLLIN, $ev));
$self->EV_SET($fd, EVFILT_WRITE, kq_flag(EPOLLOUT, $ev));
} elsif ($op == EPOLL_CTL_DEL) {
$self->EV_SET($fd, EVFILT_READ, EV_DISABLE);
$self->EV_SET($fd, EVFILT_WRITE, EV_DISABLE);
} else {
$self->EV_SET($fd, EVFILT_READ, EV_ADD|kq_flag(EPOLLIN, $ev));
$self->EV_SET($fd, EVFILT_WRITE, EV_ADD|kq_flag(EPOLLOUT, $ev));
}
0;
}
sub epoll_wait {
my ($self, $maxevents, $timeout_msec, $events) = @_;
@$events = eval { $self->kevent($timeout_msec) };
if (my $err = $@) {
# workaround https://rt.cpan.org/Ticket/Display.html?id=116615
if ($err =~ /Interrupted system call/) {
@$events = ();
} else {
die $err;
}
}
# caller only cares for $events[$i]->[0]
scalar(@$events);
}
sub DESTROY {
my ($self) = @_;
if ($owner_pid == $$) {
POSIX::close($$self);
$owner_pid = -1;
}
}
1;
|