#
# This license differs from the rest of public-inbox
#
-# This is a fork of the (for now) unmaintained Danga::Socket 1.61.
-# Unused features will be removed, and updates will be made to take
-# advantage of newer kernels.
+# This is a fork of the unmaintained Danga::Socket (1.61) with
+# significant changes. See Documentation/technical/ds.txt in our
+# source for details.
#
-# API changes to diverge from Danga::Socket will happen to better
-# accomodate new features and improve scalability. Do not expect
-# this to be a stable API like Danga::Socket.
-# Bugs encountered (and likely fixed) are reported to
-# bug-Danga-Socket@rt.cpan.org and visible at:
+# Do not expect this to be a stable API like Danga::Socket,
+# but it will evolve to suite our needs and to take advantage of
+# newer Linux and *BSD features.
+# Bugs encountered were reported to bug-Danga-Socket@rt.cpan.org,
+# fixed in Danga::Socket 1.62 and visible at:
# https://rt.cpan.org/Public/Dist/Display.html?Name=Danga-Socket
package PublicInbox::DS;
use strict;
use bytes;
-use POSIX ();
+use POSIX qw(WNOHANG);
use IO::Handle qw();
use Fcntl qw(SEEK_SET :DEFAULT);
use Time::HiRes qw(clock_gettime CLOCK_MONOTONIC);
our @EXPORT_OK = qw(now msg_more);
use warnings;
use 5.010_001;
+use Scalar::Util qw(blessed);
use PublicInbox::Syscall qw(:epoll);
+use PublicInbox::Tmpfile;
use fields ('sock', # underlying socket
- 'wbuf', # arrayref of coderefs or GLOB refs
+ 'rbuf', # scalarref, usually undef
+ 'wbuf', # arrayref of coderefs or GLOB refs (autovivified)
'wbuf_off', # offset into first element of wbuf to start writing at
);
-use Errno qw(EAGAIN EINVAL EEXIST);
-use Carp qw(croak confess carp);
-require File::Spec;
+use Errno qw(EAGAIN EINVAL);
+use Carp qw(confess carp);
+my $nextq; # queue for next_tick
+my $wait_pids; # list of [ pid, callback, callback_arg ]
+my $later_queue; # list of callbacks to run at some later interval
+my $EXPMAP; # fd -> idle_time
+our $EXPTIME = 180; # 3 minutes
+my ($later_timer, $reap_timer, $exp_timer);
+my $ToClose; # sockets to close when event loop is done
our (
%DescriptorMap, # fd (num) -> PublicInbox::DS object
$Epoll, # Global epoll fd (or DSKQXS ref)
$_io, # IO::Handle for Epoll
- @ToClose, # sockets to close when event loop is done
$PostLoopCallback, # subref to call at the end of each loop, if defined (global)
$LoopTimeout, # timeout of event loop in milliseconds
$DoneInit, # if we've done the one-time module init yet
@Timers, # timers
+ $in_loop,
);
Reset();
=cut
sub Reset {
%DescriptorMap = ();
- @ToClose = ();
+ $wait_pids = $later_queue = undef;
+ $EXPMAP = {};
+ $nextq = $ToClose = $reap_timer = $later_timer = $exp_timer = undef;
$LoopTimeout = -1; # no timeout by default
@Timers = ();
return $LoopTimeout = $_[1] + 0;
}
-=head2 C<< CLASS->AddTimer( $seconds, $coderef ) >>
+=head2 C<< PublicInbox::DS::add_timer( $seconds, $coderef ) >>
Add a timer to occur $seconds from now. $seconds may be fractional, but timers
are not guaranteed to fire at the exact time you ask for.
-Returns a timer object which you can call C<< $timer->cancel >> on if you need to.
-
=cut
-sub AddTimer {
- my ($class, $secs, $coderef) = @_;
-
- if (!$secs) {
- my $timer = bless([0, $coderef], 'PublicInbox::DS::Timer');
- unshift(@Timers, $timer);
- return $timer;
- }
+sub add_timer ($$) {
+ my ($secs, $coderef) = @_;
my $fire_time = now() + $secs;
- my $timer = bless [$fire_time, $coderef], "PublicInbox::DS::Timer";
+ my $timer = [$fire_time, $coderef];
if (!@Timers || $fire_time >= $Timers[-1][0]) {
push @Timers, $timer;
$cls = "PublicInbox::$_";
last if eval "require $cls";
}
- $cls->import;
+ $cls->import(qw(epoll_ctl epoll_wait));
$Epoll = $cls->new;
}
*EventLoop = *EpollEventLoop;
sub now () { clock_gettime(CLOCK_MONOTONIC) }
+sub next_tick () {
+ my $q = $nextq or return;
+ $nextq = undef;
+ for (@$q) {
+ # we avoid "ref" on blessed refs to workaround a Perl 5.16.3 leak:
+ # https://rt.perl.org/Public/Bug/Display.html?id=114340
+ if (blessed($_)) {
+ $_->event_step;
+ } else {
+ $_->();
+ }
+ }
+}
+
# runs timers and returns milliseconds for next one, or next event loop
sub RunTimers {
- return $LoopTimeout unless @Timers;
+ next_tick();
+
+ return (($nextq || $ToClose) ? 0 : $LoopTimeout) unless @Timers;
my $now = now();
$to_run->[1]->($now) if $to_run->[1];
}
+ # timers may enqueue into nextq:
+ return 0 if ($nextq || $ToClose);
+
return $LoopTimeout unless @Timers;
# convert time to an even number of milliseconds, adding 1
return $timeout;
}
+# We can't use waitpid(-1) safely here since it can hit ``, system(),
+# and other things. So we scan the $wait_pids list, which is hopefully
+# not too big. We keep $wait_pids small by not calling dwaitpid()
+# until we've hit EOF when reading the stdout of the child.
+sub reap_pids {
+ my $tmp = $wait_pids or return;
+ $wait_pids = $reap_timer = undef;
+ foreach my $ary (@$tmp) {
+ my ($pid, $cb, $arg) = @$ary;
+ my $ret = waitpid($pid, WNOHANG);
+ if ($ret == 0) {
+ push @$wait_pids, $ary; # autovivifies @$wait_pids
+ } elsif ($cb) {
+ eval { $cb->($arg, $pid) };
+ }
+ }
+ # we may not be done, yet, and could've missed/masked a SIGCHLD:
+ $reap_timer = add_timer(1, \&reap_pids) if $wait_pids;
+}
+
+# reentrant SIGCHLD handler (since reap_pids is not reentrant)
+sub enqueue_reap ($) { push @$nextq, \&reap_pids }; # autovivifies
+
+sub in_loop () { $in_loop }
+
+# Internal function: run the post-event callback, send read events
+# for pushed-back data, and close pending connections. returns 1
+# if event loop should continue, or 0 to shut it all down.
+sub PostEventLoop () {
+ # now we can close sockets that wanted to close during our event
+ # processing. (we didn't want to close them during the loop, as we
+ # didn't want fd numbers being reused and confused during the event
+ # loop)
+ if (my $close_now = $ToClose) {
+ $ToClose = undef; # will be autovivified on push
+ @$close_now = map { fileno($_) } @$close_now;
+
+ # order matters, destroy expiry times, first:
+ delete @$EXPMAP{@$close_now};
+
+ # ->DESTROY methods may populate ToClose
+ delete @DescriptorMap{@$close_now};
+ }
+
+ # by default we keep running, unless a postloop callback cancels it
+ $PostLoopCallback ? $PostLoopCallback->(\%DescriptorMap) : 1;
+}
+
sub EpollEventLoop {
- while (1) {
+ local $in_loop = 1;
+ do {
my @events;
my $i;
my $timeout = RunTimers();
# in that event.
$DescriptorMap{$events[$i]->[0]}->event_step;
}
- return unless PostEventLoop();
- }
+ } while (PostEventLoop());
+ _run_later();
}
=head2 C<< CLASS->SetPostLoopCallback( CODEREF ) >>
$PostLoopCallback = (defined $ref && ref $ref eq 'CODE') ? $ref : undef;
}
-# Internal function: run the post-event callback, send read events
-# for pushed-back data, and close pending connections. returns 1
-# if event loop should continue, or 0 to shut it all down.
-sub PostEventLoop {
- # now we can close sockets that wanted to close during our event processing.
- # (we didn't want to close them during the loop, as we didn't want fd numbers
- # being reused and confused during the event loop)
- while (my $sock = shift @ToClose) {
- my $fd = fileno($sock);
-
- # close the socket. (not a PublicInbox::DS close)
- CORE::close($sock);
-
- # and now we can finally remove the fd from the map. see
- # comment above in ->close.
- delete $DescriptorMap{$fd};
- }
-
-
- # by default we keep running, unless a postloop callback (either per-object
- # or global) cancels it
- my $keep_running = 1;
-
- # now we're at the very end, call callback if defined
- if (defined $PostLoopCallback) {
- $keep_running &&= $PostLoopCallback->(\%DescriptorMap);
- }
-
- return $keep_running;
-}
-
#####################################################################
### PublicInbox::DS-the-object code
#####################################################################
$self->{sock} = $sock;
my $fd = fileno($sock);
- Carp::cluck("undef sock and/or fd in PublicInbox::DS->new. sock=" . ($sock || "") . ", fd=" . ($fd || ""))
- unless $sock && $fd;
-
_InitPoller();
if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $ev)) {
}
die "couldn't add epoll watch for $fd: $!\n";
}
- Carp::cluck("PublicInbox::DS::new blowing away existing descriptor map for fd=$fd ($DescriptorMap{$fd})")
- if $DescriptorMap{$fd};
+ confess("DescriptorMap{$fd} defined ($DescriptorMap{$fd})")
+ if defined($DescriptorMap{$fd});
$DescriptorMap{$fd} = $self;
- return $self;
}
### I N S T A N C E M E T H O D S
#####################################################################
+sub requeue ($) { push @$nextq, $_[0] } # autovivifies
+
=head2 C<< $obj->close >>
Close the socket.
# defer closing the actual socket until the event loop is done
# processing this round of events. (otherwise we might reuse fds)
- push @ToClose, $sock;
+ push @$ToClose, $sock; # autovivifies $ToClose
return 0;
}
$written;
}
+sub epbit ($$) { # (sock, default)
+ ref($_[0]) eq 'IO::Socket::SSL' ? PublicInbox::TLS::epollbit() : $_[1];
+}
+
# returns 1 if done, 0 if incomplete
sub flush_write ($) {
my ($self) = @_;
goto next_buf;
}
} elsif ($! == EAGAIN) {
+ epwait($sock, epbit($sock, EPOLLOUT) | EPOLLONESHOT);
$self->{wbuf_off} = $off;
- watch($self, EPOLLOUT|EPOLLONESHOT);
return 0;
} else {
return $self->close;
1; # all done
}
-sub do_read ($$$$) {
+sub rbuf_idle ($$) {
+ my ($self, $rbuf) = @_;
+ if ($$rbuf eq '') { # who knows how long till we can read again
+ delete $self->{rbuf};
+ } else {
+ $self->{rbuf} = $rbuf;
+ }
+}
+
+sub do_read ($$$;$) {
my ($self, $rbuf, $len, $off) = @_;
- my $r = sysread($self->{sock}, $$rbuf, $len, $off);
+ my $r = sysread(my $sock = $self->{sock}, $$rbuf, $len, $off // 0);
return ($r == 0 ? $self->close : $r) if defined $r;
# common for clients to break connections without warning,
# would be too noisy to log here:
- if (ref($self) eq 'IO::Socket::SSL') {
- my $ev = PublicInbox::TLS::epollbit() or return $self->close;
- watch($self, $ev | EPOLLONESHOT);
- } elsif ($! == EAGAIN) {
- watch($self, EPOLLIN | EPOLLONESHOT);
+ if ($! == EAGAIN) {
+ epwait($sock, epbit($sock, EPOLLIN) | EPOLLONESHOT);
+ rbuf_idle($self, $rbuf);
+ 0;
} else {
$self->close;
}
# PerlIO::mmap or PerlIO::scalar if needed
sub tmpio ($$$) {
my ($self, $bref, $off) = @_;
- my $fh; # open(my $fh, '+>>', undef) doesn't set O_APPEND
- do {
- my $fn = File::Spec->tmpdir . '/wbuf-' . rand;
- if (sysopen($fh, $fn, O_RDWR|O_CREAT|O_EXCL|O_APPEND, 0600)) { # likely
- unlink($fn) or return drop($self, "unlink($fn) $!");
- } elsif ($! != EEXIST) { # EMFILE/ENFILE/ENOSPC/ENOMEM
- return drop($self, "open: $!");
- }
- } until (defined $fh);
+ my $fh = tmpfile('wbuf', $self->{sock}, 1) or
+ return drop($self, "tmpfile $!");
$fh->autoflush(1);
my $len = bytes::length($$bref) - $off;
$fh->write($$bref, $len, $off) or return drop($self, "write ($len): $!");
if (defined $written) {
return 1 if $written == $to_write;
+ requeue($self); # runs: event_step -> flush_write
} elsif ($! == EAGAIN) {
+ epwait($sock, epbit($sock, EPOLLOUT) | EPOLLONESHOT);
$written = 0;
} else {
return $self->close;
}
+
+ # deal with EAGAIN or partial write:
my $tmpio = tmpio($self, $bref, $written) or return 0;
- $self->{wbuf} = [ $tmpio ];
- watch($self, EPOLLOUT|EPOLLONESHOT);
+
+ # wbuf may be an empty array if we're being called inside
+ # ->flush_write via CODE bref:
+ push @{$self->{wbuf}}, $tmpio; # autovivifies
return 0;
}
}
sub msg_more ($$) {
my $self = $_[0];
my $sock = $self->{sock} or return 1;
+ my $wbuf = $self->{wbuf};
- if (MSG_MORE && !$self->{wbuf} && ref($sock) ne 'IO::Socket::SSL') {
+ if (MSG_MORE && (!defined($wbuf) || !scalar(@$wbuf)) &&
+ ref($sock) ne 'IO::Socket::SSL') {
my $n = send($sock, $_[1], MSG_MORE);
if (defined $n) {
my $nlen = bytes::length($_[1]) - $n;
return 1 if $nlen == 0; # all done!
# queue up the unwritten substring:
my $tmpio = tmpio($self, \($_[1]), $n) or return 0;
- $self->{wbuf} = [ $tmpio ];
- watch($self, EPOLLOUT|EPOLLONESHOT);
+ push @{$self->{wbuf}}, $tmpio; # autovivifies
+ epwait($sock, EPOLLOUT|EPOLLONESHOT);
return 0;
}
}
- $self->write(\($_[1]));
+
+ # don't redispatch into NNTPdeflate::write
+ PublicInbox::DS::write($self, \($_[1]));
}
-sub watch ($$) {
- my ($self, $ev) = @_;
- my $sock = $self->{sock} or return;
+sub epwait ($$) {
+ my ($sock, $ev) = @_;
epoll_ctl($Epoll, EPOLL_CTL_MOD, fileno($sock), $ev) and
confess("EPOLL_CTL_MOD $!");
- 0;
}
-sub watch_in1 ($) { watch($_[0], EPOLLIN | EPOLLONESHOT) }
-
# return true if complete, false if incomplete (or failure)
sub accept_tls_step ($) {
my ($self) = @_;
my $sock = $self->{sock} or return;
return 1 if $sock->accept_SSL;
return $self->close if $! != EAGAIN;
- if (my $ev = PublicInbox::TLS::epollbit()) {
- unshift @{$self->{wbuf} ||= []}, \&accept_tls_step;
- return watch($self, $ev | EPOLLONESHOT);
- }
- drop($self, 'BUG? EAGAIN but '.PublicInbox::TLS::err());
+ epwait($sock, PublicInbox::TLS::epollbit() | EPOLLONESHOT);
+ unshift(@{$self->{wbuf}}, \&accept_tls_step); # autovivifies
+ 0;
}
+# return true if complete, false if incomplete (or failure)
sub shutdn_tls_step ($) {
my ($self) = @_;
my $sock = $self->{sock} or return;
return $self->close if $sock->stop_SSL(SSL_fast_shutdown => 1);
return $self->close if $! != EAGAIN;
- if (my $ev = PublicInbox::TLS::epollbit()) {
- unshift @{$self->{wbuf} ||= []}, \&shutdn_tls_step;
- return watch($self, $ev | EPOLLONESHOT);
- }
- drop($self, 'BUG? EAGAIN but '.PublicInbox::TLS::err());
+ epwait($sock, PublicInbox::TLS::epollbit() | EPOLLONESHOT);
+ unshift(@{$self->{wbuf}}, \&shutdn_tls_step); # autovivifies
+ 0;
}
# don't bother with shutdown($sock, 2), we don't fork+exec w/o CLOEXEC
}
}
-package PublicInbox::DS::Timer;
-# [$abs_float_firetime, $coderef];
-sub cancel {
- $_[0][1] = undef;
+# must be called with eval, PublicInbox::DS may not be loaded (see t/qspawn.t)
+sub dwaitpid ($$$) {
+ die "Not in EventLoop\n" unless $in_loop;
+ push @$wait_pids, [ @_ ]; # [ $pid, $cb, $arg ]
+
+ # We could've just missed our SIGCHLD, cover it, here:
+ requeue(\&reap_pids);
+}
+
+sub _run_later () {
+ my $run = $later_queue or return;
+ $later_timer = $later_queue = undef;
+ $_->() for @$run;
+}
+
+sub later ($) {
+ push @$later_queue, $_[0]; # autovivifies @$later_queue
+ $later_timer //= add_timer(60, \&_run_later);
+}
+
+sub expire_old () {
+ my $now = now();
+ my $exp = $EXPTIME;
+ my $old = $now - $exp;
+ my %new;
+ while (my ($fd, $idle_at) = each %$EXPMAP) {
+ if ($idle_at < $old) {
+ my $ds_obj = $DescriptorMap{$fd};
+ $new{$fd} = $idle_at if !$ds_obj->shutdn;
+ } else {
+ $new{$fd} = $idle_at;
+ }
+ }
+ $EXPMAP = \%new;
+ $exp_timer = scalar(keys %new) ? later(\&expire_old) : undef;
+}
+
+sub update_idle_time {
+ my ($self) = @_;
+ my $sock = $self->{sock} or return;
+ $EXPMAP->{fileno($sock)} = now();
+ $exp_timer //= later(\&expire_old);
+}
+
+sub not_idle_long {
+ my ($self, $now) = @_;
+ my $sock = $self->{sock} or return;
+ my $idle_at = $EXPMAP->{fileno($sock)} or return;
+ ($idle_at + $EXPTIME) > $now;
}
1;