From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00 shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 6F2751F5AE for ; Sat, 4 Jul 2020 21:33:13 +0000 (UTC) From: Eric Wong To: meta@public-inbox.org Subject: [PATCH] watch: don't burn CPU on IDLE failures Date: Sat, 4 Jul 2020 21:33:13 +0000 Message-Id: <20200704213313.4441-1-e@yhbt.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: Network connections fail and need to be detected sooner rather than later during IDLE to avoid backtrace floods. In case the IDLE process dies completely, don't respawn right away, either, to avoid entering a respawn loop. There's also a typo fix :P --- lib/PublicInbox/WatchMaildir.pm | 23 ++++++++++++++++++----- t/imapd.t | 29 +++++++++++++++++++++++++++-- 2 files changed, 45 insertions(+), 7 deletions(-) diff --git a/lib/PublicInbox/WatchMaildir.pm b/lib/PublicInbox/WatchMaildir.pm index 23b2e9f11..7547f6e47 100644 --- a/lib/PublicInbox/WatchMaildir.pm +++ b/lib/PublicInbox/WatchMaildir.pm @@ -497,7 +497,8 @@ sub imap_idle_once ($$$$) { } $self->{idle_mic} = $mic; # for ->quit my @res; - until ($self->{quit} || grep(/^\* [0-9]+ EXISTS/, @res) || $i <= 0) { + until ($self->{quit} || !$mic->IsConnected || + grep(/^\* [0-9]+ EXISTS/, @res) || $i <= 0) { @res = $mic->idle_data($i); $i = $end - now(); } @@ -520,8 +521,13 @@ sub watch_imap_idle_1 ($$$) { local $0 = $uri->mailbox." $sec"; until ($self->{quit}) { $mic //= PublicInbox::IMAPClient->new(%$mic_arg); - my $err = imap_fetch_all($self, $mic, $url); - $err //= imap_idle_once($self, $mic, $intvl, $url); + my $err; + if ($mic && $mic->IsConnected) { + $err = imap_fetch_all($self, $mic, $url); + $err //= imap_idle_once($self, $mic, $intvl, $url); + } else { + $err = "not connected: $!"; + } if ($err && !$self->{quit}) { warn $err, "\n"; $mic = undef; @@ -545,6 +551,13 @@ sub watch_atfork_parent ($) { _done_for_now($self); } +sub imap_idle_requeue ($) { # DS::add_timer callback + my ($self, $url_intvl) = @{$_[0]}; + return if $self->{quit}; + push @{$self->{idle_todo}}, $url_intvl; + event_step($self); +} + sub imap_idle_reap { # PublicInbox::DS::dwaitpid callback my ($self, $pid) = @_; my $url_intvl = delete $self->{idle_pids}->{$pid} or @@ -553,8 +566,8 @@ sub imap_idle_reap { # PublicInbox::DS::dwaitpid callback my ($url, $intvl) = @$url_intvl; return if $self->{quit}; warn "W: PID=$pid on $url died: \$?=$?\n" if $?; - push @{$self->{idle_todo}}, $url_intvl; - PubicInbox::DS::requeue($self); # call ->event_step to respawn + PublicInbox::DS::add_timer(60, + \&imap_idle_requeue, [ $self, $url_intvl ]); } sub imap_idle_fork ($$) { diff --git a/t/imapd.t b/t/imapd.t index cf327e9fb..1ac6a4ab6 100644 --- a/t/imapd.t +++ b/t/imapd.t @@ -468,7 +468,7 @@ SKIP: { my $obj = bless \$cb, 'PublicInbox::TestCommon::InboxWakeup'; $cfg->each_inbox(sub { $_[0]->subscribe_unlock('ident', $obj) }); my $watcherr = "$tmpdir/watcherr"; - open my $err_wr, '>', $watcherr or BAIL_OUT $!; + open my $err_wr, '>>', $watcherr or BAIL_OUT $!; open my $err, '<', $watcherr or BAIL_OUT $!; my $w = start_script(['-watch'], undef, { 2 => $err_wr }); @@ -512,11 +512,36 @@ SKIP: { seek($err, 0, 0); my @err = grep(!/^I:/, <$err>); is(@err, 0, 'no warnings/errors from -watch'.join(' ', @err)); + + if ($ENV{TEST_KILL_IMAPD}) { # not sure how reliable this test can be + xsys(qw(git config), "--file=$home/.public-inbox/config", + qw(--unset imap.PollInterval)) == 0 + or BAIL_OUT "git config $?"; + truncate($err_wr, 0) or BAIL_OUT $!; + my @t0 = times; + $w = start_script(['-watch'], undef, { 2 => $err_wr }); + seek($err, 0, 0); + tick until (grep(/I: \S+ idling/, <$err>)); + diag 'killing imapd, waiting for CPU spins'; + my $delay = 0.11; + $td->kill(9); + tick $delay; + $w->kill; + $w->join; + is($?, 0, 'no error in exited -watch process'); + my @t1 = times; + my $c = $t1[2] + $t1[3] - $t0[2] - $t0[3]; + my $thresh = (0.9 * $delay); + diag "c=$c, threshold=$thresh"; + ok($c < $thresh, 'did not burn much CPU'); + is_deeply([grep(/ line \d+$/m, <$err>)], [], + 'no backtraces from errors'); + } } $td->kill; $td->join; -is($?, 0, 'no error in exited process'); +is($?, 0, 'no error in exited process') if !$ENV{TEST_KILL_IMAPD}; open my $fh, '<', $err or BAIL_OUT("open $err failed: $!"); my $eout = do { local $/; <$fh> }; unlike($eout, qr/wide/i, 'no Wide character warnings');