diff options
Diffstat (limited to 'lib/PublicInbox/Select.pm')
-rw-r--r-- | lib/PublicInbox/Select.pm | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/lib/PublicInbox/Select.pm b/lib/PublicInbox/Select.pm new file mode 100644 index 00000000..face8edc --- /dev/null +++ b/lib/PublicInbox/Select.pm @@ -0,0 +1,43 @@ +# Copyright (C) all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> +# +# This makes select(2) look like epoll to simplify the code in DS.pm. +# Unlike IO::Select, it does NOT hold references to IO handles. +# This is NOT meant to be an all encompassing emulation of epoll +# via select, but only to support cases we care about. +package PublicInbox::Select; +use v5.12; +use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT); +use Errno; + +sub new { bless {}, __PACKAGE__ } # fd => events + +sub ep_wait { + my ($self, $msec, $events) = @_; + my ($rvec, $wvec) = ('', ''); # we don't use EPOLLERR + while (my ($fd, $ev) = each %$self) { + vec($rvec, $fd, 1) = 1 if $ev & EPOLLIN; + vec($wvec, $fd, 1) = 1 if $ev & EPOLLOUT; + } + @$events = (); + my $to = $msec < 0 ? undef : ($msec/1000); + my $n = select $rvec, $wvec, undef, $to or return; # timeout expired + return if $n < 0 && $! == Errno::EINTR; # caller recalculates timeout + die "select: $!" if $n < 0; + while (my ($fd, $ev) = each %$self) { + if (vec($rvec, $fd, 1) || vec($wvec, $fd, 1)) { + delete($self->{$fd}) if $ev & EPOLLONESHOT; + push @$events, $fd; + } + } + $n == scalar(@$events) or + warn "BUG? select() returned $n, but got ".scalar(@$events); +} + +sub ep_del { delete($_[0]->{fileno($_[1])}); 0 } +sub ep_add { $_[0]->{fileno($_[1])} = $_[2]; 0 } + +no warnings 'once'; +*ep_mod = \&ep_add; + +1; |