lei: fork + FD cleanup

Do a better job of closing FDs that we don't want shared with
the work queue workers.  We'll also fix naming and use
"atfork_prepare" instead of "atfork_parent" to match
pthread_atfork(3) naming.

diff --git a/lib/PublicInbox/IPC.pm b/lib/PublicInbox/IPC.pm
index 4db4b8ea26e3b87dd9ce408ee21620883186b4de..88f81e477ec07d58c97f80f8ccb091d88f7f6d2d 100644 (file)
--- a/lib/PublicInbox/IPC.pm
+++ b/lib/PublicInbox/IPC.pm
@@ -126,7 +126,7 @@ sub ipc_worker_spawn {
        pipe(my ($r_res, $w_res)) or die "pipe: $!";
        my $sigset = $oldset // PublicInbox::DS::block_signals();
        my $parent = $$;
-       $self->ipc_atfork_parent;
+       $self->ipc_atfork_prepare;
        defined(my $pid = fork) or die "fork: $!";
        if ($pid == 0) {
                eval { PublicInbox::DS->Reset };
@@ -155,8 +155,14 @@ sub ipc_worker_reap { # dwaitpid callback
 }
 
 # for base class, override in sub classes
-sub ipc_atfork_parent {}
-sub ipc_atfork_child {}
+sub ipc_atfork_prepare {}
+
+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 {
@@ -251,14 +257,21 @@ sub ipc_sibling_atfork_child {
        $pid == $$ and die "BUG: $$ ipc_atfork_child called on itself";
 }
 
+sub _close_recvd ($) {
+       my ($self) = @_;
+       close($_) for (grep { defined } (delete @$self{0..2}));
+}
+
 sub wq_worker_loop ($) {
        my ($self) = @_;
        my $buf;
        my $len = $self->{wq_req_len} // (4096 * 33);
-       my ($rec, $sub, @args);
+       my ($sub, $args);
        my $s2 = $self->{-wq_s2} // die 'BUG: no -wq_s2';
        local $SIG{PIPE} = sub {
-               die(bless(\"$_[0]", __PACKAGE__.'::PIPE')) if $sub;
+               my $cur_sub = $sub;
+               _close_recvd($self);
+               die(bless(\$cur_sub, __PACKAGE__.'::PIPE')) if $cur_sub;
        };
        my $rcv = $self->{-wq_recv_cmd} // $recv_cmd;
        while (1) {
@@ -267,22 +280,25 @@ sub wq_worker_loop ($) {
                my @m = @{$self->{wq_open_modes} // [qw( +<&= >&= >&= )]};
                for my $fd (@fds) {
                        my $mode = shift(@m);
-                       if (open(my $fh, $mode, $fd)) {
-                               $self->{$i++} = $fh;
-                               $fh->autoflush(1);
+                       if (open(my $cmdfh, $mode, $fd)) {
+                               $self->{$i++} = $cmdfh;
+                               $cmdfh->autoflush(1);
                        } else {
                                die "$$ open($mode$fd) (FD:$i): $!";
                        }
                }
-               # Sereal dies, Storable returns undef
-               $rec = thaw($buf) //
+               # Sereal dies on truncated data, Storable returns undef
+               $args = thaw($buf) //
                        die "thaw error on buffer of size:".length($buf);
-               ($sub, @args) = @$rec;
-               eval { $self->$sub(@args) };
+               eval {
+                       $sub = shift @$args;
+                       eval { $self->$sub(@$args) };
+                       undef $sub; # quiet SIG{PIPE} handler
+                       die $@ if $@;
+               };
                warn "$$ wq_worker: $@" if $@ && ref $@ ne __PACKAGE__.'::PIPE';
-               undef $sub; # quiet SIG{PIPE} handler
                # need to close explicitly to avoid warnings after SIGPIPE
-               close($_) for (delete(@$self{0..2}));
+               _close_recvd($self);
        }
 }
 
@@ -306,14 +322,17 @@ sub _wq_worker_start ($$) {
                eval { PublicInbox::DS->Reset };
                close(delete $self->{-wq_s1});
                delete $self->{qw(-wq_workers -wq_ppid)};
-               $SIG{$_} = 'IGNORE' for (qw(TTOU TTIN));
-               $SIG{$_} = 'DEFAULT' for (qw(TERM QUIT INT));
+               $SIG{$_} = 'IGNORE' for (qw(PIPE TTOU TTIN));
+               $SIG{$_} = 'DEFAULT' for (qw(TERM QUIT INT CHLD));
                local $0 = $self->{-wq_ident};
                PublicInbox::DS::sig_setmask($oldset);
+               # ensure we properly exit even if warn() dies:
+               my $end = PublicInbox::OnDestroy->new($$, sub { exit(!!$@) });
                my $on_destroy = $self->ipc_atfork_child;
                eval { wq_worker_loop($self) };
                warn "worker $self->{-wq_ident} PID:$$ died: $@" if $@;
-               exit($@ ? 1 : 0);
+               undef $on_destroy;
+               undef $end; # trigger exit
        } else {
                $self->{-wq_workers}->{$pid} = \undef;
        }
@@ -326,7 +345,7 @@ sub wq_workers_start {
        return if $self->{-wq_s1}; # idempotent
        my ($s1, $s2);
        socketpair($s1, $s2, AF_UNIX, $SEQPACKET, 0) or die "socketpair: $!";
-       $self->ipc_atfork_parent;
+       $self->ipc_atfork_prepare;
        $nr_workers //= 4;
        $nr_workers = $WQ_MAX_WORKERS if $nr_workers > $WQ_MAX_WORKERS;
        my $sigset = $oldset // PublicInbox::DS::block_signals();
@@ -343,7 +362,7 @@ sub wq_worker_incr { # SIGTTIN handler
        my ($self, $oldset) = @_;
        $self->{-wq_s2} or return;
        return if wq_workers($self) >= $WQ_MAX_WORKERS;
-       $self->ipc_atfork_parent;
+       $self->ipc_atfork_prepare;
        my $sigset = $oldset // PublicInbox::DS::block_signals();
        _wq_worker_start($self, $sigset);
        PublicInbox::DS::sig_setmask($sigset) unless $oldset;

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 0cbf342cd52583eab8f6fda6fa2b83160cea9a38..1ef0cbecc2c3793a4a71f6df0d0dbaabb4912e79 100644 (file)
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -33,6 +33,7 @@ my $GLP_PASS = Getopt::Long::Parser->new;
 $GLP_PASS->configure(qw(gnu_getopt no_ignore_case auto_abbrev pass_through));
 
 our %PATH2CFG; # persistent for socket daemon
+our @TO_CLOSE_ATFORK_CHILD;
 
 # TBD: this is a documentation mechanism to show a subcommand
 # (may) pass options through to another command:
@@ -266,12 +267,20 @@ sub fail ($$;$) {
        undef;
 }
 
+sub atfork_prepare_wq {
+       my ($self, $wq) = @_;
+       push @{$wq->{-ipc_atfork_child_close}}, @TO_CLOSE_ATFORK_CHILD,
+                               grep { defined } @$self{qw(0 1 2 sock)}
+}
+
 # usage: local %SIG = (%SIG, $lei->atfork_child_wq($wq));
 sub atfork_child_wq {
        my ($self, $wq) = @_;
        $self->{sock} //= $wq->{0};
        $self->{$_} //= $wq->{$_} for (0..2);
        my $oldpipe = $SIG{PIPE};
+       %PATH2CFG = ();
+       @TO_CLOSE_ATFORK_CHILD = ();
        (
                __WARN__ => sub { err($self, @_) },
                PIPE => sub {
@@ -281,11 +290,14 @@ sub atfork_child_wq {
        );
 }
 
-# usage: ($lei, @io) = $lei->atfork_prepare_wq($wq);
-sub atfork_prepare_wq {
+# usage: ($lei, @io) = $lei->atfork_parent_wq($wq);
+sub atfork_parent_wq {
        my ($self, $wq) = @_;
        if ($wq->wq_workers) {
+               my $env = delete $self->{env}; # env is inherited at fork
                my $ret = bless { %$self }, ref($self);
+               $self->{env} = $env;
+               delete @$ret{qw(-lei_store cfg)};
                my $in = delete $ret->{0};
                ($ret, delete($ret->{sock}) // $in, delete @$ret{1, 2});
        } else {
@@ -738,6 +750,7 @@ sub lazy_start {
        return if $pid;
        $0 = "lei-daemon $path";
        local %PATH2CFG;
+       local @TO_CLOSE_ATFORK_CHILD = ($l, $eof_r, $eof_w);
        $_->blocking(0) for ($l, $eof_r, $eof_w);
        $l = PublicInbox::Listener->new($l, \&accept_dispatch, $l);
        my $exit_code;
@@ -764,6 +777,7 @@ sub lazy_start {
        local %SIG = (%SIG, %$sig) if !$sigfd;
        local $SIG{PIPE} = 'IGNORE';
        if ($sigfd) { # TODO: use inotify/kqueue to detect unlinked sockets
+               push @TO_CLOSE_ATFORK_CHILD, $sigfd->{sock};
                PublicInbox::DS->SetLoopTimeout(5000);
        } else {
                # wake up every second to accept signals if we don't

diff --git a/lib/PublicInbox/LeiQuery.pm b/lib/PublicInbox/LeiQuery.pm
index d5376be51f59cd630293f1e3d6b823edc3af9ae3..9a383cef0ea98ef928d145c1869052cd8a21b82a 100644 (file)
--- a/lib/PublicInbox/LeiQuery.pm
+++ b/lib/PublicInbox/LeiQuery.pm
@@ -66,7 +66,7 @@ sub lei_q {
 
        # --local is enabled by default
        # src: LeiXSearch || LeiSearch || Inbox
-       my @srcs = $opt->{'local'} ? ($sto->search) : ();
+       my @srcs;
        require PublicInbox::LeiXSearch;
        my $lxs = PublicInbox::LeiXSearch->new;
 
@@ -74,12 +74,15 @@ sub lei_q {
        if ($opt->{external} // 1) {
                $self->_externals_each(\&_vivify_external, \@srcs);
        }
-       my $j = $opt->{jobs} // scalar(@srcs) > 4 ? 4 : scalar(@srcs);
+       my $j = $opt->{jobs} // scalar(@srcs) > 3 ? 3 : scalar(@srcs);
        $j = 1 if !$opt->{thread};
+       $j++ if $opt->{'local'}; # for sto->search below
        if ($self->{sock}) {
+               $self->atfork_prepare_wq($lxs);
                $lxs->wq_workers_start('lei_xsearch', $j, $self->oldset)
                        // $self->wq_workers($j);
        }
+       unshift(@srcs, $sto->search) if $opt->{'local'};
        my $out = $opt->{output} // '-';
        $out = 'json:/dev/stdout' if $out eq '-';
        my $isatty = -t $self->{1};

diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
index c0df21a8155cb13193a0177b14a347a75e09b9e2..b41727342de7c1e65a95c360ec0bf300c27f705f 100644 (file)
--- a/lib/PublicInbox/LeiXSearch.pm
+++ b/lib/PublicInbox/LeiXSearch.pm
@@ -9,6 +9,7 @@ use strict;
 use v5.10.1;
 use parent qw(PublicInbox::LeiSearch PublicInbox::IPC);
 use PublicInbox::Search qw(get_pct);
+use Sys::Syslog qw(syslog);
 
 sub new {
        my ($class) = @_;
@@ -92,13 +93,13 @@ sub _mset_more ($$) {
 
 sub query_thread_mset { # for --thread
        my ($self, $lei, $ibxish) = @_;
+       local %SIG = (%SIG, $lei->atfork_child_wq($self));
        my ($srch, $over) = ($ibxish->search, $ibxish->over);
        unless ($srch && $over) {
                my $desc = $ibxish->{inboxdir} // $ibxish->{topdir};
                warn "$desc not indexed by Xapian\n";
                return;
        }
-       local %SIG = (%SIG, $lei->atfork_child_wq($self));
        my $mo = { %{$lei->{mset_opt}} };
        my $mset;
        do {
@@ -145,7 +146,7 @@ sub query_mset { # non-parallel for non-"--thread" users
 
 sub do_query {
        my ($self, $lei_orig, $srcs) = @_;
-       my ($lei, @io) = $lei_orig->atfork_prepare_wq($self);
+       my ($lei, @io) = $lei_orig->atfork_parent_wq($self);
        $io[1]->autoflush(1);
        $io[2]->autoflush(1);
        if ($lei->{opt}->{thread}) {
@@ -161,4 +162,10 @@ sub do_query {
        }
 }
 
+sub ipc_atfork_child {
+       my ($self) = @_;
+       $SIG{__WARN__} = sub { syslog('warning', "@_") };
+       $self->SUPER::ipc_atfork_child; # PublicInbox::IPC
+}
+
 1;