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 B25241F4B4 for ; Sun, 27 Sep 2020 22:12:48 +0000 (UTC) From: Eric Wong To: meta@public-inbox.org Subject: [PATCH] gcf2: improve error handling and do not ->fail on wbuf Date: Sun, 27 Sep 2020 22:12:48 +0000 Message-Id: <20200927221248.28815-1-e@80x24.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: For historical reasons, both Danga::Socket::write and PublicInbox::DS::write will return 0 when data is buffered; so we Gcf2Client must not call ->fail when DS::write returns 0. We'll also improve robustness by recreating the entire Gcf2Client object if it does die for other reasons, instead of risking mismatched fields. We also need to ensure we only get one EPOLLERR wakeup and issue EPOLL_CTL_DEL if ->event_step is triggered by a dying Gcf2 process. --- lib/PublicInbox/Daemon.pm | 10 ++-------- lib/PublicInbox/Gcf2Client.pm | 31 +++++++++++++++++++------------ lib/PublicInbox/GitAsyncCat.pm | 11 +++++++++-- 3 files changed, 30 insertions(+), 22 deletions(-) diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm index 1520f8f2..155707e1 100644 --- a/lib/PublicInbox/Daemon.pm +++ b/lib/PublicInbox/Daemon.pm @@ -654,14 +654,8 @@ sub run ($$$;$) { my $af_default = $default =~ /:8080\z/ ? 'httpready' : undef; my $for_destroy = daemonize(); - # this wastes a bit of memory for non-PublicInbox::WWW -httpd users - # oh well... - eval { - require PublicInbox::Gcf2; - require PublicInbox::Gcf2Client; - }; - local $PublicInbox::GitAsyncCat::GCF2C = - PublicInbox::Gcf2Client::new() if !$@; + # localize GCF2C for tests: + local $PublicInbox::GitAsyncCat::GCF2C; daemon_loop($refresh, $post_accept, $tlsd, $af_default); PublicInbox::DS->Reset; diff --git a/lib/PublicInbox/Gcf2Client.pm b/lib/PublicInbox/Gcf2Client.pm index 42ff1bf3..ab486de5 100644 --- a/lib/PublicInbox/Gcf2Client.pm +++ b/lib/PublicInbox/Gcf2Client.pm @@ -8,27 +8,28 @@ use parent qw(PublicInbox::DS); use PublicInbox::Git; use PublicInbox::Spawn qw(popen_rd); use IO::Handle (); -use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLOUT); +use PublicInbox::Syscall qw(EPOLLONESHOT); # fields: # async_cat => GitAsyncCat ref (read-only pipe) # sock => writable pipe to Gcf2::loop -sub new { bless($_[0] // {}, __PACKAGE__) } -sub gcf2c_begin ($) { - my ($self) = @_; +sub new { + my ($rdr) = @_; + my $self = bless {}, __PACKAGE__; # ensure the child process has the same @INC we do: my $env = { PERL5LIB => join(':', @INC) }; my ($out_r, $out_w); pipe($out_r, $out_w) or die "pipe failed: $!"; - my $rdr = { 0 => $out_r, 2 => $self->{2} }; + $rdr //= {}; + $rdr->{0} = $out_r; my $cmd = [$^X, qw[-MPublicInbox::Gcf2 -e PublicInbox::Gcf2::loop()]]; @$self{qw(in pid)} = popen_rd($cmd, $env, $rdr); fcntl($out_w, 1031, 4096) if $^O eq 'linux'; # 1031: F_SETPIPE_SZ $out_w->autoflush(1); $out_w->blocking(0); - $self->SUPER::new($out_w, 0); # EPOLL_CTL_ADD (a bit wasteful :x) $self->{inflight} = []; + $self->SUPER::new($out_w, EPOLLONESHOT); # detect errors once } sub fail { @@ -39,22 +40,28 @@ sub fail { sub cat_async ($$$;$) { my ($self, $req, $cb, $arg) = @_; - my $inflight = $self->{inflight} // gcf2c_begin($self); + my $inflight = $self->{inflight}; - # rare, I hope: + # {wbuf} is rare, I hope: cat_async_step($self, $inflight) if $self->{wbuf}; - $self->write(\"$req\n") or $self->fail("gcf2c write: $!"); + if (!$self->write(\"$req\n")) { + $self->fail("gcf2c write: $!") if !$self->{sock}; + } push @$inflight, $req, $cb, $arg; } # ensure PublicInbox::Git::cat_async_step never calls cat_async_retry sub alternates_changed {} -no warnings 'once'; - # this is the write-only end of a pipe, DS->EventLoop will call this -*event_step = \&PublicInbox::DS::flush_write; +sub event_step { + my ($self) = @_; + $self->flush_write; + $self->close if !$self->{in}; # process died +} + +no warnings 'once'; # used by GitAsyncCat *cat_async_step = \&PublicInbox::Git::cat_async_step; diff --git a/lib/PublicInbox/GitAsyncCat.pm b/lib/PublicInbox/GitAsyncCat.pm index b9dbe0cc..be51f673 100644 --- a/lib/PublicInbox/GitAsyncCat.pm +++ b/lib/PublicInbox/GitAsyncCat.pm @@ -53,14 +53,21 @@ sub event_step { sub git_async_cat ($$$$) { my ($git, $oid, $cb, $arg) = @_; - my $gitish = $GCF2C; - if ($gitish) { + my $gitish = $GCF2C //= eval { + require PublicInbox::Gcf2; + require PublicInbox::Gcf2Client; + PublicInbox::Gcf2Client::new(); + } // 0; # 0: do not retry if libgit2 or Inline::C are missing + if ($gitish) { # Gcf2 active, {inflight} may be unset due to errors + $GCF2C->{inflight} or + $gitish = $GCF2C = PublicInbox::Gcf2Client::new(); $oid .= " $git->{git_dir}"; } else { $gitish = $git; } $gitish->cat_async($oid, $cb, $arg); $gitish->{async_cat} //= do { + # read-only end of pipe (Gcf2Client is write-only end) my $self = bless { gitish => $gitish }, __PACKAGE__; $self->SUPER::new($gitish->{in}, EPOLLIN|EPOLLET); \undef; # this is a true ref()