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From: Eric Wong <e@80x24.org>
To: spew@80x24.org
Subject: [PATCH] ds: use object-oriented API for epoll
Date: Mon, 11 Sep 2023 03:40:20 +0000	[thread overview]
Message-ID: <20230911034020.1289538-1-e@80x24.org> (raw)

This allows us to cut down on imports and reduce code.
This also makes it easier (in the next commit) to provide an option
to disable epoll/kqueue when saving an FD is valued over scalability.
---
 MANIFEST                   |  1 +
 lib/PublicInbox/DS.pm      | 40 ++++++++++++---------------------
 lib/PublicInbox/DSKQXS.pm  | 46 +++++++++++++++++---------------------
 lib/PublicInbox/DSPoll.pm  | 31 +++++++++----------------
 lib/PublicInbox/Epoll.pm   | 23 +++++++++++++++++++
 lib/PublicInbox/Syscall.pm |  6 -----
 t/ds-kqxs.t                |  4 ++--
 t/ds-poll.t                | 29 +++++++++++-------------
 t/epoll.t                  | 23 +++++++++----------
 9 files changed, 95 insertions(+), 108 deletions(-)
 create mode 100644 lib/PublicInbox/Epoll.pm

diff --git a/MANIFEST b/MANIFEST
index 1fe1c7f7..d7a670b8 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -184,6 +184,7 @@ lib/PublicInbox/EOFpipe.pm
 lib/PublicInbox/Emergency.pm
 lib/PublicInbox/Eml.pm
 lib/PublicInbox/EmlContentFoo.pm
+lib/PublicInbox/Epoll.pm
 lib/PublicInbox/ExtMsg.pm
 lib/PublicInbox/ExtSearch.pm
 lib/PublicInbox/ExtSearchIdx.pm
diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index d6e3d10e..9300ac77 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -28,7 +28,8 @@ use POSIX qw(WNOHANG sigprocmask SIG_SETMASK SIG_UNBLOCK);
 use Fcntl qw(SEEK_SET :DEFAULT O_APPEND);
 use Time::HiRes qw(clock_gettime CLOCK_MONOTONIC);
 use Scalar::Util qw(blessed);
-use PublicInbox::Syscall qw(:epoll %SIGNUM);
+use PublicInbox::Syscall qw(%SIGNUM
+	EPOLLIN EPOLLOUT EPOLLONESHOT EPOLLEXCLUSIVE);
 use PublicInbox::Tmpfile;
 use Errno qw(EAGAIN EINVAL ECHILD EINTR);
 use Carp qw(carp croak);
@@ -41,8 +42,7 @@ my $reap_armed;
 my $ToClose; # sockets to close when event loop is done
 our (
      %DescriptorMap,             # fd (num) -> PublicInbox::DS object
-     $Epoll,                     # Global epoll fd (or DSKQXS ref)
-     $ep_io,                     # IO::Handle for Epoll
+     $Epoll,  # global Epoll, DSPoll, or DSKQXS ref
 
      @post_loop_do,              # subref + args to call at the end of each loop
 
@@ -75,7 +75,6 @@ sub Reset {
 		my @q = delete @Stack{keys %Stack};
 		for my $q (@q) { @$q = () }
 		$AWAIT_PIDS = $nextq = $ToClose = undef;
-		$ep_io = undef; # closes real $Epoll FD
 		$Epoll = undef; # may call DSKQXS::DESTROY
 	} while (@Timers || keys(%Stack) || $nextq || $AWAIT_PIDS ||
 		$ToClose || keys(%DescriptorMap) ||
@@ -126,21 +125,13 @@ sub add_uniq_timer { # ($name, $secs, $coderef, @args) = @_;
 
 # caller sets return value to $Epoll
 sub _InitPoller () {
-	if (defined $PublicInbox::Syscall::SYS_epoll_create)  {
-		my $fd = epoll_create();
-		die "epoll_create: $!" if $fd < 0;
-		open($ep_io, '+<&=', $fd) or return;
-		fcntl($ep_io, F_SETFD, FD_CLOEXEC);
-		$fd;
-	} else {
-		my $cls;
-		for (qw(DSKQXS DSPoll)) {
-			$cls = "PublicInbox::$_";
-			last if eval "require $cls";
-		}
-		$cls->import(qw(epoll_ctl epoll_wait));
-		$cls->new;
+	my @try = ($^O eq 'linux' ? 'Epoll' : 'DSKQXS');
+	my $cls;
+	for (@try, 'DSPoll') {
+		$cls = "PublicInbox::$_";
+		last if eval "require $cls";
 	}
+	$cls->new;
 }
 
 sub now () { clock_gettime(CLOCK_MONOTONIC) }
@@ -307,7 +298,7 @@ sub event_loop (;$$) {
 		my $timeout = RunTimers();
 
 		# get up to 1000 events
-		epoll_wait($Epoll, 1000, $timeout, \@events);
+		$Epoll->ep_wait(1000, $timeout, \@events);
 		for my $fd (@events) {
 			# it's possible epoll_wait returned many events,
 			# including some at the end that ones in the front
@@ -345,7 +336,7 @@ sub new {
 
     $Epoll //= _InitPoller();
 retry:
-    if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $ev)) {
+    if ($Epoll->ep_add($sock, $ev)) {
         if ($! == EINVAL && ($ev & EPOLLEXCLUSIVE)) {
             $ev &= ~EPOLLEXCLUSIVE;
             goto retry;
@@ -399,9 +390,7 @@ sub close {
 
     # if we're using epoll, we have to remove this from our epoll fd so we stop getting
     # notifications about it
-    my $fd = fileno($sock);
-    epoll_ctl($Epoll, EPOLL_CTL_DEL, $fd, 0) and
-        croak("EPOLL_CTL_DEL($self/$sock): $!");
+    $Epoll->ep_del($sock) and croak("EPOLL_CTL_DEL($self/$sock): $!");
 
     # we explicitly don't delete from DescriptorMap here until we
     # actually close the socket, as we might be in the middle of
@@ -619,9 +608,8 @@ sub msg_more ($$) {
 }
 
 sub epwait ($$) {
-    my ($sock, $ev) = @_;
-    epoll_ctl($Epoll, EPOLL_CTL_MOD, fileno($sock), $ev) and
-        croak("EPOLL_CTL_MOD($sock): $!");
+	my ($io, $ev) = @_;
+	$Epoll->ep_mod($io, $ev) and croak("EPOLL_CTL_MOD($io): $!");
 }
 
 # return true if complete, false if incomplete (or failure)
diff --git a/lib/PublicInbox/DSKQXS.pm b/lib/PublicInbox/DSKQXS.pm
index b6e5c4e9..8ef8ffb6 100644
--- a/lib/PublicInbox/DSKQXS.pm
+++ b/lib/PublicInbox/DSKQXS.pm
@@ -12,13 +12,10 @@
 # It also implements signalfd(2) emulation via "tie".
 package PublicInbox::DSKQXS;
 use v5.12;
-use parent qw(Exporter);
 use Symbol qw(gensym);
 use IO::KQueue;
 use Errno qw(EAGAIN);
-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);
+use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLLET);
 
 sub EV_DISPATCH () { 0x0080 }
 
@@ -97,30 +94,29 @@ sub READ { # called by sysread() for signalfd compatibility
 # for fileno() calls in PublicInbox::DS
 sub FILENO { ${$_[0]->{kq}} }
 
-sub epoll_ctl {
-	my ($self, $op, $fd, $ev) = @_;
-	my $kq = $self->{kq};
-	if ($op == EPOLL_CTL_MOD) {
-		$kq->EV_SET($fd, EVFILT_READ, kq_flag(EPOLLIN, $ev));
-		eval { $kq->EV_SET($fd, EVFILT_WRITE, kq_flag(EPOLLOUT, $ev)) };
-	} elsif ($op == EPOLL_CTL_DEL) {
-		$kq // return; # called in cleanup
-		$kq->EV_SET($fd, EVFILT_READ, EV_DISABLE);
-		eval { $kq->EV_SET($fd, EVFILT_WRITE, EV_DISABLE) };
-	} else { # EPOLL_CTL_ADD
-		$kq->EV_SET($fd, EVFILT_READ, EV_ADD|kq_flag(EPOLLIN, $ev));
-
-		# we call this blindly for read-only FDs such as tied
-		# DSKQXS (signalfd emulation) and Listeners
-		eval {
-			$kq->EV_SET($fd, EVFILT_WRITE, EV_ADD |
-							kq_flag(EPOLLOUT, $ev));
-		};
-	}
+sub _ep_mod_add ($$$$) {
+	my ($kq, $fd, $ev, $add) = @_;
+	$kq->EV_SET($fd, EVFILT_READ, $add|kq_flag(EPOLLIN, $ev));
+
+	# we call this blindly for read-only FDs such as tied
+	# DSKQXS (signalfd emulation) and Listeners
+	eval { $kq->EV_SET($fd, EVFILT_WRITE, $add|kq_flag(EPOLLOUT, $ev)) };
+	0;
+}
+
+sub ep_add { _ep_mod_add($_[0]->{kq}, fileno($_[1]), $_[2], EV_ADD) };
+sub ep_mod { _ep_mod_add($_[0]->{kq}, fileno($_[1]), $_[2], 0) };
+
+sub ep_del {
+	my ($self, $io, $ev) = @_;
+	my $kq = $_[0]->{kq} // return; # called in cleanup
+	my $fd = fileno($io);
+	$kq->EV_SET($fd, EVFILT_READ, EV_DISABLE);
+	eval { $kq->EV_SET($fd, EVFILT_WRITE, EV_DISABLE) };
 	0;
 }
 
-sub epoll_wait {
+sub ep_wait {
 	my ($self, $maxevents, $timeout_msec, $events) = @_;
 	@$events = eval { $self->{kq}->kevent($timeout_msec) };
 	if (my $err = $@) {
diff --git a/lib/PublicInbox/DSPoll.pm b/lib/PublicInbox/DSPoll.pm
index 56a400c2..fc282de0 100644
--- a/lib/PublicInbox/DSPoll.pm
+++ b/lib/PublicInbox/DSPoll.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2019-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) 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>
@@ -9,28 +9,13 @@
 # an all encompassing emulation of epoll via IO::Poll, but just to
 # support cases public-inbox-nntpd/httpd care about.
 package PublicInbox::DSPoll;
-use strict;
-use warnings;
-use parent qw(Exporter);
+use v5.12;
 use IO::Poll;
-use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLL_CTL_DEL);
-our @EXPORT_OK = qw(epoll_ctl epoll_wait);
+use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT);
 
-sub new { bless {}, $_[0] } # fd => events
+sub new { bless {}, __PACKAGE__ } # fd => events
 
-sub epoll_ctl {
-	my ($self, $op, $fd, $ev) = @_;
-
-	# not wasting time on error checking
-	if ($op != EPOLL_CTL_DEL) {
-		$self->{$fd} = $ev;
-	} else {
-		delete $self->{$fd};
-	}
-	0;
-}
-
-sub epoll_wait {
+sub ep_wait {
 	my ($self, $maxevents, $timeout_msec, $events) = @_;
 	my @pset;
 	while (my ($fd, $events) = each %$self) {
@@ -54,4 +39,10 @@ sub epoll_wait {
 	}
 }
 
+sub ep_del { delete($_[0]->{fileno($_[1])}); 0 }
+sub ep_add { $_[0]->{fileno($_[1])} = $_[2]; 0 }
+
+no warnings 'once';
+*ep_mod = \&ep_add;
+
 1;
diff --git a/lib/PublicInbox/Epoll.pm b/lib/PublicInbox/Epoll.pm
new file mode 100644
index 00000000..d55c8535
--- /dev/null
+++ b/lib/PublicInbox/Epoll.pm
@@ -0,0 +1,23 @@
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# OO API for epoll
+package PublicInbox::Epoll;
+use v5.12;
+use PublicInbox::Syscall qw(epoll_create epoll_ctl epoll_wait
+	EPOLL_CTL_ADD EPOLL_CTL_MOD EPOLL_CTL_DEL);
+use Fcntl qw(F_SETFD FD_CLOEXEC);
+use autodie qw(open fcntl);
+
+sub new {
+	open(my $fh, '+<&=', epoll_create());
+	fcntl($fh, F_SETFD, FD_CLOEXEC);
+	bless \$fh, __PACKAGE__;
+}
+
+sub ep_add { epoll_ctl(fileno(${$_[0]}), EPOLL_CTL_ADD, fileno($_[1]), $_[2]) }
+sub ep_mod { epoll_ctl(fileno(${$_[0]}), EPOLL_CTL_MOD, fileno($_[1]), $_[2]) }
+sub ep_del { epoll_ctl(fileno(${$_[0]}), EPOLL_CTL_DEL, fileno($_[1]), 0) }
+sub ep_wait { epoll_wait(fileno(${$_[0]}), @_[1, 2, 3]) }
+
+1;
diff --git a/lib/PublicInbox/Syscall.pm b/lib/PublicInbox/Syscall.pm
index 14cd1720..0a0912fb 100644
--- a/lib/PublicInbox/Syscall.pm
+++ b/lib/PublicInbox/Syscall.pm
@@ -29,12 +29,6 @@ our @EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait
                   EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
                   EPOLLONESHOT EPOLLEXCLUSIVE
                   signalfd rename_noreplace %SIGNUM);
-our %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait
-                             EPOLLIN EPOLLOUT
-                             EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
-                             EPOLLONESHOT EPOLLEXCLUSIVE)],
-                );
-
 use constant {
 	EPOLLIN => 1,
 	EPOLLOUT => 4,
diff --git a/t/ds-kqxs.t b/t/ds-kqxs.t
index 43c71fed..57acb53f 100644
--- a/t/ds-kqxs.t
+++ b/t/ds-kqxs.t
@@ -1,9 +1,9 @@
-# Copyright (C) 2019-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) 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>
-use strict;
+use v5.12;
 use Test::More;
 unless (eval { require IO::KQueue }) {
 	my $m = $^O !~ /bsd/ ? 'DSKQXS is only for *BSD systems'
diff --git a/t/ds-poll.t b/t/ds-poll.t
index d8861369..57fac3ef 100644
--- a/t/ds-poll.t
+++ b/t/ds-poll.t
@@ -1,12 +1,11 @@
-# Copyright (C) 2019-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) 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>
-use strict;
-use warnings;
+use v5.12;
 use Test::More;
-use PublicInbox::Syscall qw(:epoll);
+use PublicInbox::Syscall qw(EPOLLIN EPOLLOUT EPOLLONESHOT);
 my $cls = $ENV{TEST_IOPOLLER} // 'PublicInbox::DSPoll';
 use_ok $cls;
 my $p = $cls->new;
@@ -14,37 +13,35 @@ my $p = $cls->new;
 my ($r, $w, $x, $y);
 pipe($r, $w) or die;
 pipe($x, $y) or die;
-is($p->epoll_ctl(EPOLL_CTL_ADD, fileno($r), EPOLLIN), 0, 'add EPOLLIN');
+is($p->ep_add($r, EPOLLIN), 0, 'add EPOLLIN');
 my $events = [];
-$p->epoll_wait(9, 0, $events);
+$p->ep_wait(9, 0, $events);
 is_deeply($events, [], 'no events set');
-is($p->epoll_ctl(EPOLL_CTL_ADD, fileno($w), EPOLLOUT|EPOLLONESHOT), 0,
-	'add EPOLLOUT|EPOLLONESHOT');
-$p->epoll_wait(9, -1, $events);
+is($p->ep_add($w, EPOLLOUT|EPOLLONESHOT), 0, 'add EPOLLOUT|EPOLLONESHOT');
+$p->ep_wait(9, -1, $events);
 is(scalar(@$events), 1, 'got POLLOUT event');
 is($events->[0], fileno($w), '$w ready');
 
-$p->epoll_wait(9, 0, $events);
+$p->ep_wait(9, 0, $events);
 is(scalar(@$events), 0, 'nothing ready after oneshot');
 is_deeply($events, [], 'no events set after oneshot');
 
 syswrite($w, '1') == 1 or die;
 for my $t (0..1) {
-	$p->epoll_wait(9, $t, $events);
+	$p->ep_wait(9, $t, $events);
 	is($events->[0], fileno($r), "level-trigger POLLIN ready #$t");
 	is(scalar(@$events), 1, "only event ready #$t");
 }
 syswrite($y, '1') == 1 or die;
-is($p->epoll_ctl(EPOLL_CTL_ADD, fileno($x), EPOLLIN|EPOLLONESHOT), 0,
-	'EPOLLIN|EPOLLONESHOT add');
-$p->epoll_wait(9, -1, $events);
+is($p->ep_add($x, EPOLLIN|EPOLLONESHOT), 0, 'EPOLLIN|EPOLLONESHOT add');
+$p->ep_wait(9, -1, $events);
 is(scalar @$events, 2, 'epoll_wait has 2 ready');
 my @fds = sort @$events;
 my @exp = sort((fileno($r), fileno($x)));
 is_deeply(\@fds, \@exp, 'got both ready FDs');
 
-is($p->epoll_ctl(EPOLL_CTL_DEL, fileno($r), 0), 0, 'EPOLL_CTL_DEL OK');
-$p->epoll_wait(9, 0, $events);
+is($p->ep_del($r, 0), 0, 'EPOLL_CTL_DEL OK');
+$p->ep_wait(9, 0, $events);
 is(scalar @$events, 0, 'nothing ready after EPOLL_CTL_DEL');
 
 done_testing;
diff --git a/t/epoll.t b/t/epoll.t
index f346b387..54dc6f47 100644
--- a/t/epoll.t
+++ b/t/epoll.t
@@ -1,25 +1,22 @@
 #!perl -w
-# Copyright (C) 2020-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
-use strict;
-use v5.10.1;
+use v5.12;
 use Test::More;
-use PublicInbox::Syscall qw(:epoll);
+use autodie;
+use PublicInbox::Syscall qw(EPOLLOUT);
 plan skip_all => 'not Linux' if $^O ne 'linux';
-my $epfd = epoll_create();
-ok($epfd >= 0, 'epoll_create');
-open(my $hnd, '+<&=', $epfd); # for autoclose
-
-pipe(my ($r, $w)) or die "pipe: $!";
-is(epoll_ctl($epfd, EPOLL_CTL_ADD, fileno($w), EPOLLOUT), 0,
-    'epoll_ctl socket EPOLLOUT');
+require_ok 'PublicInbox::Epoll';
+my $ep = PublicInbox::Epoll->new;
+pipe(my $r, my $w);
+is($ep->ep_add($w, EPOLLOUT), 0, 'epoll_ctl pipe EPOLLOUT');
 
 my @events;
-epoll_wait($epfd, 100, 10000, \@events);
+$ep->ep_wait(100, 10000, \@events);
 is(scalar(@events), 1, 'got one event');
 is($events[0], fileno($w), 'got expected FD');
 close $w;
-epoll_wait($epfd, 100, 0, \@events);
+$ep->ep_wait(100, 0, \@events);
 is(scalar(@events), 0, 'epoll_wait timeout');
 
 done_testing;

                 reply	other threads:[~2023-09-11  3:40 UTC|newest]

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