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Diffstat (limited to 'lib/PublicInbox/IPC.pm')
| -rw-r--r-- | lib/PublicInbox/IPC.pm | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/lib/PublicInbox/IPC.pm b/lib/PublicInbox/IPC.pm new file mode 100644 index 00000000..ed6d27fd --- /dev/null +++ b/lib/PublicInbox/IPC.pm @@ -0,0 +1,452 @@ +# Copyright (C) all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> + +# base class for remote IPC calls and workqueues, requires Storable or Sereal +# - ipc_do and ipc_worker_* is for a single worker/producer and uses pipes +# - wq_io_do and wq_worker* is for a single producer and multiple workers, +# using SOCK_SEQPACKET for work distribution +# use ipc_do when you need work done on a certain process +# use wq_io_do when your work can be done on any idle worker +package PublicInbox::IPC; +use v5.12; +use parent qw(Exporter); +use autodie qw(close pipe read socketpair sysread); +use Carp qw(croak); +use PublicInbox::DS qw(awaitpid); +use PublicInbox::Spawn; +use PublicInbox::OnDestroy; +use PublicInbox::WQWorker; +use Socket qw(AF_UNIX SOCK_STREAM SOCK_SEQPACKET); +my $MY_MAX_ARG_STRLEN = 4096 * 33; # extra 4K for serialization +our @EXPORT_OK = qw(ipc_freeze ipc_thaw nproc_shards); +my ($enc, $dec); +# ->imports at BEGIN turns sereal_*_with_object into custom ops on 5.14+ +# and eliminate method call overhead +BEGIN { + eval { + require Sereal::Encoder; + require Sereal::Decoder; + Sereal::Encoder->import('sereal_encode_with_object'); + Sereal::Decoder->import('sereal_decode_with_object'); + ($enc, $dec) = (Sereal::Encoder->new, Sereal::Decoder->new); + }; +}; + +if ($enc && $dec) { # should be custom ops + *ipc_freeze = sub ($) { sereal_encode_with_object $enc, $_[0] }; + *ipc_thaw = sub ($) { sereal_decode_with_object $dec, $_[0], my $ret }; +} else { + require Storable; + *ipc_freeze = \&Storable::freeze; + *ipc_thaw = \&Storable::thaw; +} + +our $recv_cmd = PublicInbox::Spawn->can('recv_cmd4'); +our $send_cmd = PublicInbox::Spawn->can('send_cmd4') // do { + require PublicInbox::CmdIPC4; + $recv_cmd //= PublicInbox::CmdIPC4->can('recv_cmd4'); + PublicInbox::CmdIPC4->can('send_cmd4'); +} // do { + require PublicInbox::Syscall; + $recv_cmd //= PublicInbox::Syscall->can('recv_cmd4'); + PublicInbox::Syscall->can('send_cmd4'); +}; + +sub _get_rec ($) { + my ($r) = @_; + my $len = <$r> // return; + chop($len) eq "\n" or croak "no LF byte in $len"; + my $n = read($r, my $buf, $len); + $n == $len or croak "short read: $n != $len"; + ipc_thaw($buf); +} + +sub _send_rec ($$) { + my ($w, $ref) = @_; + my $buf = ipc_freeze($ref); + print $w length($buf), "\n", $buf or croak "print: $!"; +} + +sub ipc_return ($$$) { + my ($w, $ret, $exc) = @_; + _send_rec($w, $exc ? bless(\$exc, 'PublicInbox::IPC::Die') : $ret); +} + +sub ipc_worker_loop ($$$) { + my ($self, $r_req, $w_res) = @_; + my ($rec, $wantarray, $sub, @args); + local $/ = "\n"; + while ($rec = _get_rec($r_req)) { + ($wantarray, $sub, @args) = @$rec; + # no waiting if client doesn't care, + # this is the overwhelmingly likely case + if (!defined($wantarray)) { + eval { $self->$sub(@args) }; + warn "$$ die: $@ (from nowait $sub)\n" if $@; + } elsif ($wantarray) { + my @ret = eval { $self->$sub(@args) }; + ipc_return($w_res, \@ret, $@); + } else { # '' => wantscalar + my $ret = eval { $self->$sub(@args) }; + ipc_return($w_res, \$ret, $@); + } + } +} + +sub exit_exception { exit(!!$@) } + +# starts a worker if Sereal or Storable is installed +sub ipc_worker_spawn { + my ($self, $ident, $oldset, $fields, @cb_args) = @_; + return if ($self->{-ipc_ppid} // -1) == $$; # idempotent + delete(@$self{qw(-ipc_req -ipc_res -ipc_ppid -ipc_pid)}); + pipe(my $r_req, my $w_req); + pipe(my $r_res, my $w_res); + my $sigset = $oldset // PublicInbox::DS::block_signals(); + $self->ipc_atfork_prepare; + my $pid = PublicInbox::DS::fork_persist; + if ($pid == 0) { + delete @$self{qw(-wq_s1 -wq_s2 -wq_workers -wq_ppid)}; + $w_req = $r_res = undef; + $w_res->autoflush(1); + $SIG{$_} = 'IGNORE' for (qw(TERM INT QUIT)); + local $0 = $ident; + # ensure we properly exit even if warn() dies: + my $end = on_destroy \&exit_exception; + eval { + $fields //= {}; + local @$self{keys %$fields} = values(%$fields); + my $on_destroy = $self->ipc_atfork_child; + local @SIG{keys %SIG} = values %SIG; + PublicInbox::DS::sig_setmask($sigset); + ipc_worker_loop($self, $r_req, $w_res); + }; + warn "worker $ident PID:$$ died: $@\n" if $@; + undef $end; # trigger exit + } + PublicInbox::DS::sig_setmask($sigset) unless $oldset; + $r_req = $w_res = undef; + $w_req->autoflush(1); + $self->{-ipc_req} = $w_req; + $self->{-ipc_res} = $r_res; + $self->{-ipc_ppid} = $$; + awaitpid($pid, \&ipc_worker_reap, $self, @cb_args); + $self->{-ipc_pid} = $pid; +} + +sub ipc_worker_reap { # awaitpid callback + my ($pid, $self, $cb, @args) = @_; + delete $self->{-wq_workers}->{$pid}; + return $cb->($pid, $self, @args) if $cb; + return if !$?; + my $s = $? & 127; + # TERM(15) is our default exit signal, PIPE(13) is likely w/ pager + warn "$self->{-wq_ident} PID:$pid died \$?=$?\n" if $s != 15 && $s != 13 +} + +# for base class, override in sub classes +sub ipc_atfork_prepare {} + +sub wq_atexit_child {} + +sub ipc_atfork_child { + my ($self) = @_; + my $io = delete($self->{-ipc_atfork_child_close}) or return; + close($_) for @$io; + undef; +} + +# idempotent, can be called regardless of whether worker is active or not +sub ipc_worker_stop { + my ($self) = @_; + my ($pid, $ppid) = delete(@$self{qw(-ipc_pid -ipc_ppid)}); + my ($w_req, $r_res) = delete(@$self{qw(-ipc_req -ipc_res)}); + if (!$w_req && !$r_res) { + die "unexpected PID:$pid without IPC pipes" if $pid; + return; # idempotent + } + die 'no PID with IPC pipes' unless $pid; + $w_req = $r_res = undef; + awaitpid($pid) if $$ == $ppid; # for non-event loop +} + +sub _wait_return ($$) { + my ($r_res, $sub) = @_; + my $ret = _get_rec($r_res) // die "no response on $sub"; + die $$ret if ref($ret) eq 'PublicInbox::IPC::Die'; + wantarray ? @$ret : $$ret; +} + +# call $self->$sub(@args), on a worker if ipc_worker_spawn was used +sub ipc_do { + my ($self, $sub, @args) = @_; + if (my $w_req = $self->{-ipc_req}) { # run in worker + if (defined(wantarray)) { + my $r_res = $self->{-ipc_res} or die 'no ipc_res'; + _send_rec($w_req, [ wantarray, $sub, @args ]); + _wait_return($r_res, $sub); + } else { # likely, fire-and-forget into pipe + _send_rec($w_req, [ undef , $sub, @args ]); + } + } else { # run locally + $self->$sub(@args); + } +} + +# needed when there's multiple IPC workers and the parent forking +# causes newer siblings to inherit older siblings sockets +sub ipc_sibling_atfork_child { + my ($self) = @_; + my ($pid, undef) = delete(@$self{qw(-ipc_pid -ipc_ppid)}); + delete(@$self{qw(-ipc_req -ipc_res)}); + $pid == $$ and die "BUG: $$ ipc_atfork_child called on itself"; +} + +sub recv_and_run { + my ($self, $s2, $len, $full_stream) = @_; + my @fds = $recv_cmd->($s2, my $buf, $len // $MY_MAX_ARG_STRLEN); + return if scalar(@fds) && !defined($fds[0]); + my $n = length($buf) or return 0; + my $nfd = 0; + for my $fd (@fds) { + open(my $cmdfh, '+<&=', $fd); + $self->{$nfd++} = $cmdfh; + $cmdfh->autoflush(1); + } + while ($full_stream && $n < $len) { + my $r = sysread($s2, $buf, $len - $n, $n); + croak "read EOF after $n/$len bytes" if $r == 0; + $n = length($buf); + } + # Sereal dies on truncated data, Storable returns undef + my $args = ipc_thaw($buf) // die "thaw error on buffer of size: $n"; + undef $buf; + my $sub = shift @$args; + eval { $self->$sub(@$args) }; + warn "$$ $0 wq_worker: $sub: $@" if $@; + delete @$self{0..($nfd-1)}; + $n; +} + +sub sock_defined { # PublicInbox::DS::post_loop_do CB + my ($wqw) = @_; + defined($wqw->{sock}); +} + +sub wq_worker_loop ($$$) { + my ($self, $bcast2, $oldset) = @_; + my $wqw = PublicInbox::WQWorker->new($self, $self->{-wq_s2}); + PublicInbox::WQWorker->new($self, $bcast2) if $bcast2; + local @PublicInbox::DS::post_loop_do = (\&sock_defined, $wqw); + my $sig = delete($self->{wq_sig}); + $sig->{CHLD} //= \&PublicInbox::DS::enqueue_reap; + PublicInbox::DS::event_loop($sig, $oldset); + PublicInbox::DS->Reset; +} + +sub do_sock_stream { # via wq_io_do, for big requests + my ($self, $len) = @_; + recv_and_run($self, my $s2 = delete $self->{0}, $len, 1); +} + +sub wq_broadcast { + my ($self, $sub, @args) = @_; + my $wkr = $self->{-wq_workers} or Carp::confess('no -wq_workers'); + my $buf = ipc_freeze([$sub, @args]); + for my $bcast1 (values %$wkr) { + my $sock = $bcast1 // $self->{-wq_s1} // next; + send($sock, $buf, 0) // croak "send: $!"; + # XXX shouldn't have to deal with EMSGSIZE here... + } +} + +sub stream_in_full ($$$) { + my ($s1, $fds, $buf) = @_; + socketpair(my $r, my $w, AF_UNIX, SOCK_STREAM, 0); + my $n = $send_cmd->($s1, [ fileno($r) ], + ipc_freeze(['do_sock_stream', length($buf)]), + 0) // croak "sendmsg: $!"; + undef $r; + $n = $send_cmd->($w, $fds, $buf, 0) // croak "sendmsg: $!"; + print $w substr($buf, $n) if $n < length($buf); # need > 2G on Linux + close $w; # autodies +} + +sub wq_io_do { # always async + my ($self, $sub, $ios, @args) = @_; + my $s1 = $self->{-wq_s1} or Carp::confess('no -wq_s1'); + my $fds = [ map { fileno($_) } @$ios ]; + my $buf = ipc_freeze([$sub, @args]); + if (length($buf) > $MY_MAX_ARG_STRLEN) { + stream_in_full($s1, $fds, $buf); + } else { + my $n = $send_cmd->($s1, $fds, $buf, 0); + return if defined($n); # likely + $!{ETOOMANYREFS} and croak "sendmsg: $! (check RLIMIT_NOFILE)"; + $!{EMSGSIZE} ? stream_in_full($s1, $fds, $buf) : + croak("sendmsg: $!"); + } +} + +sub wq_sync_run { + my ($self, $wantarray, $sub, @args) = @_; + if ($wantarray) { + my @ret = eval { $self->$sub(@args) }; + ipc_return($self->{0}, \@ret, $@); + } else { # '' => wantscalar + my $ret = eval { $self->$sub(@args) }; + ipc_return($self->{0}, \$ret, $@); + } +} + +sub wq_do { + my ($self, $sub, @args) = @_; + if (defined(wantarray)) { + pipe(my $r, my $w); + wq_io_do($self, 'wq_sync_run', [ $w ], wantarray, $sub, @args); + undef $w; + _wait_return($r, $sub); + } else { + wq_io_do($self, $sub, [], @args); + } +} + +sub prepare_nonblock { + ($_[0]->{-wq_s1} // die 'BUG: no {-wq_s1}')->blocking(0); + require PublicInbox::WQBlocked; +} + +sub wq_nonblock_do { # always async + my ($self, $sub, @args) = @_; + my $buf = ipc_freeze([$sub, @args]); + if ($self->{wqb}) { # saturated once, assume saturated forever + $self->{wqb}->flush_send($buf); + } else { + $send_cmd->($self->{-wq_s1}, [], $buf, 0) // + ($!{EAGAIN} ? PublicInbox::WQBlocked->new($self, $buf) + : croak("sendmsg: $!")); + } +} + +sub _wq_worker_start { + my ($self, $oldset, $fields, $one, @cb_args) = @_; + my ($bcast1, $bcast2); + $one or socketpair($bcast1, $bcast2, AF_UNIX, SOCK_SEQPACKET, 0); + my $pid = PublicInbox::DS::fork_persist; + if ($pid == 0) { + undef $bcast1; + delete @$self{qw(-wq_s1 -wq_ppid)}; + $self->{-wq_worker_nr} = + keys %{delete($self->{-wq_workers}) // {}}; + $SIG{$_} = 'DEFAULT' for (qw(TTOU TTIN TERM QUIT INT CHLD)); + local $0 = $one ? $self->{-wq_ident} : + "$self->{-wq_ident} $self->{-wq_worker_nr}"; + # ensure we properly exit even if warn() dies: + my $end = on_destroy \&exit_exception; + eval { + $fields //= {}; + local @$self{keys %$fields} = values(%$fields); + my $on_destroy = $self->ipc_atfork_child; + local @SIG{keys %SIG} = values %SIG; + wq_worker_loop($self, $bcast2, $oldset); + }; + warn "worker $self->{-wq_ident} PID:$$ died: $@" if $@; + undef $end; # trigger exit + } else { + $self->{-wq_workers}->{$pid} = $bcast1; + awaitpid($pid, \&ipc_worker_reap, $self, @cb_args); + } +} + +# starts workqueue workers if Sereal or Storable is installed +sub wq_workers_start { + my ($self, $ident, $nr_workers, $oldset, $fields, @cb_args) = @_; + ($send_cmd && $recv_cmd) or return; + return if $self->{-wq_s1}; # idempotent + socketpair($self->{-wq_s1}, $self->{-wq_s2},AF_UNIX, SOCK_SEQPACKET, 0); + $self->ipc_atfork_prepare; + $nr_workers //= $self->{-wq_nr_workers}; # was set earlier + my $sigset = $oldset // PublicInbox::DS::block_signals(); + $self->{-wq_workers} = {}; + $self->{-wq_ident} = $ident; + my $one = $nr_workers == 1; + $self->{-wq_nr_workers} = $nr_workers; + for (1..$nr_workers) { + _wq_worker_start($self, $sigset, $fields, $one, @cb_args); + } + PublicInbox::DS::sig_setmask($sigset) unless $oldset; + $self->{-wq_ppid} = $$; +} + +sub wq_close { + my ($self) = @_; + if (my $wqb = delete $self->{wqb}) { + $wqb->enq_close; + } + delete @$self{qw(-wq_s1 -wq_s2)} or return; + return if ($self->{-wq_ppid} // -1) != $$; + awaitpid($_) for keys %{$self->{-wq_workers}}; +} + +sub wq_kill { + my ($self, $sig) = @_; + kill($sig // 'TERM', keys %{$self->{-wq_workers}}); +} + +sub DESTROY { + my ($self) = @_; + my $ppid = $self->{-wq_ppid}; + wq_kill($self) if $ppid && $ppid == $$; + wq_close($self); + ipc_worker_stop($self); +} + +# _SC_NPROCESSORS_ONLN = 84 on both Linux glibc and musl, +# emitted using: $^X devel/sysdefs-list +my %NPROCESSORS_ONLN = ( + linux => 84, + freebsd => 58, + dragonfly => 58, + openbsd => 503, + netbsd => 1002 +); + +sub detect_nproc () { + my $n = $NPROCESSORS_ONLN{$^O}; + return POSIX::sysconf($n) if defined $n; + + # getconf(1) is POSIX, but *NPROCESSORS* vars are not even if + # glibc, {Free,Net,Open}BSD all support them. + for (qw(_NPROCESSORS_ONLN NPROCESSORS_ONLN)) { + `getconf $_ 2>/dev/null` =~ /^(\d+)$/ and return $1; + } + # note: GNU nproc(1) checks CPU affinity, which is nice but + # isn't remotely portable + undef +} + +# SATA storage lags behind what CPUs are capable of, so relying on +# nproc(1) can be misleading and having extra Xapian shards is a +# waste of FDs and space. It can also lead to excessive IO latency +# and slow things down. Users on NVME or other fast storage can +# use the NPROC env or switches in our script/public-inbox-* programs +# to increase Xapian shards +our $NPROC_MAX_DEFAULT = 4; + +sub nproc_shards ($) { + my ($creat_opt) = @_; + my $n = $creat_opt->{nproc} if ref($creat_opt) eq 'HASH'; + $n //= $ENV{NPROC}; + if (!$n) { + # assume 2 cores if not detectable or zero + state $NPROC_DETECTED = PublicInbox::IPC::detect_nproc() || 2; + $n = $NPROC_DETECTED; + $n = $NPROC_MAX_DEFAULT if $n > $NPROC_MAX_DEFAULT; + } + + # subtract for the main process and git-fast-import + $n -= 1; + $n < 1 ? 1 : $n; +} + +1; |