It's a bit inefficient to use a pipe, here. However, using dwaitpid() on a process that's not expected to exit soon is also inefficient as it causes excessive wakeups as most of our inbox-writing code expects synchronous waitpid().
This only affects -watch instances configured for NNTP and IMAP clients. --- MANIFEST | 1 + lib/PublicInbox/EOFpipe.pm | 24 ++++++++++++++++++++++++ lib/PublicInbox/Watch.pm | 25 +++++++++++++++++++++---- 3 files changed, 46 insertions(+), 4 deletions(-) create mode 100644 lib/PublicInbox/EOFpipe.pm diff --git a/MANIFEST b/MANIFEST index f090175e..0b3835d8 100644 --- a/MANIFEST +++ b/MANIFEST @@ -114,6 +114,7 @@ lib/PublicInbox/DSPoll.pm lib/PublicInbox/Daemon.pm lib/PublicInbox/DirIdle.pm lib/PublicInbox/DummyInbox.pm +lib/PublicInbox/EOFpipe.pm lib/PublicInbox/Emergency.pm lib/PublicInbox/Eml.pm lib/PublicInbox/EmlContentFoo.pm diff --git a/lib/PublicInbox/EOFpipe.pm b/lib/PublicInbox/EOFpipe.pm new file mode 100644 index 00000000..489caf82 --- /dev/null +++ b/lib/PublicInbox/EOFpipe.pm @@ -0,0 +1,24 @@ +# Copyright (C) 2020 all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> + +package PublicInbox::EOFpipe; +use strict; +use parent qw(PublicInbox::DS); +use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT); + +sub new { + my (undef, $rd, $cb, $arg) = @_; + my $self = bless { cb => $cb, arg => $arg }, __PACKAGE__; + # 1031: F_SETPIPE_SZ, 4096: page size + fcntl($rd, 1031, 4096) if $^O eq 'linux'; + $self->SUPER::new($rd, EPOLLIN|EPOLLONESHOT); +} + +sub event_step { + my ($self) = @_; + if ($self->do_read(my $buf, 1) == 0) { # auto-closed + $self->{cb}->($self->{arg}); + } +} + +1; diff --git a/lib/PublicInbox/Watch.pm b/lib/PublicInbox/Watch.pm index db8d0396..17786377 100644 --- a/lib/PublicInbox/Watch.pm +++ b/lib/PublicInbox/Watch.pm @@ -14,7 +14,8 @@ use PublicInbox::Sigfd; use PublicInbox::DS qw(now); use PublicInbox::MID qw(mids); use PublicInbox::ContentHash qw(content_hash); -use POSIX qw(_exit); +use PublicInbox::EOFpipe; +use POSIX qw(_exit WNOHANG); sub compile_watchheaders ($) { my ($ibx) = @_; @@ -611,17 +612,30 @@ sub imap_idle_reap { # PublicInbox::DS::dwaitpid callback \&imap_idle_requeue, [ $self, $url_intvl ]); } +sub reap { # callback for EOFpipe + my ($pid, $cb, $self) = @{$_[0]}; + my $ret = waitpid($pid, 0); + if ($ret == $pid) { + $cb->($self, $pid); # poll_fetch_reap || imap_idle_reap + } else { + warn "W: waitpid($pid) => ", $ret // "($!)", "\n"; + } +} + sub imap_idle_fork ($$) { my ($self, $url_intvl) = @_; my ($url, $intvl) = @$url_intvl; + pipe(my ($r, $w)) or die "pipe: $!"; defined(my $pid = fork) or die "fork: $!"; if ($pid == 0) { + close $r; watch_atfork_child($self); watch_imap_idle_1($self, $url, $intvl); + close $w; _exit(0); } $self->{idle_pids}->{$pid} = $url_intvl; - PublicInbox::DS::dwaitpid($pid, \&imap_idle_reap, $self); + PublicInbox::EOFpipe->new($r, \&reap, [$pid, \&imap_idle_reap, $self]); } sub event_step { @@ -689,24 +703,27 @@ sub watch_nntp_fetch_all ($$) { sub poll_fetch_fork ($) { # DS::add_timer callback my ($self, $intvl, $urls) = @{$_[0]}; return if $self->{quit}; + pipe(my ($r, $w)) or die "pipe: $!"; my $oldset = watch_atfork_parent($self); my $pid = fork; if (defined($pid) && $pid == 0) { + close $r; watch_atfork_child($self); if ($urls->[0] =~ m!\Aimaps?://!i) { watch_imap_fetch_all($self, $urls); } else { watch_nntp_fetch_all($self, $urls); } + close $w; _exit(0); } PublicInbox::Sigfd::sig_setmask($oldset); die "fork: $!" unless defined $pid; $self->{poll_pids}->{$pid} = [ $intvl, $urls ]; - PublicInbox::DS::dwaitpid($pid, \&poll_fetch_reap, $self); + PublicInbox::EOFpipe->new($r, \&reap, [$pid, \&poll_fetch_reap, $self]); } -sub poll_fetch_reap { # PublicInbox::DS::dwaitpid callback +sub poll_fetch_reap { my ($self, $pid) = @_; my $intvl_urls = delete $self->{poll_pids}->{$pid} or die "BUG: PID=$pid (unknown) reaped: \$?=$?\n"; -- unsubscribe: one-click, see List-Unsubscribe header archive: https://public-inbox.org/meta/
