ipc: drop dynamic WQ process counts

In retrospect, I don't think it's needed; and trying to wire up
a user interface for lei to manage process counts doesn't seem
worthwhile.  It could be resurrected for public-facing daemon
use in the future, but that's what version control systems are for.

This also lets us automatically avoid setting up broadcast
sockets

Followup-to: 7b7939d47b336fb7 ("lei: lock worker counts")

3 files changed, 10 insertions, 61 deletions

diff --git a/lib/PublicInbox/IPC.pm b/lib/PublicInbox/IPC.pm
index 92f35189..add5f3df 100644
--- a/lib/PublicInbox/IPC.pm
+++ b/lib/PublicInbox/IPC.pm
@@ -262,9 +262,10 @@ sub do_sock_stream { # via wq_io_do, for big requests
 sub wq_broadcast {
         my ($self, $sub, @args) = @_;
         if (my $wkr = $self->{-wq_workers}) {
+                my $buf = ipc_freeze([$sub, @args]);
                 for my $bcast1 (values %$wkr) {
-                        my $buf = ipc_freeze([$sub, @args]);
-                        send($bcast1, $buf, MSG_EOR) // croak "send: $!";
+                        my $sock = $bcast1 // $self->{-wq_s1} // next;
+                        send($sock, $buf, MSG_EOR) // croak "send: $!";
                         # XXX shouldn't have to deal with EMSGSIZE here...
                 }
         } else {
@@ -336,11 +337,10 @@ sub wq_do {
         }
 }
 
-sub _wq_worker_start ($$$) {
-        my ($self, $oldset, $fields) = @_;
+sub _wq_worker_start ($$$$) {
+        my ($self, $oldset, $fields, $one) = @_;
         my ($bcast1, $bcast2);
-        $self->{-wq_no_bcast} or
-                socketpair($bcast1, $bcast2, AF_UNIX, $SEQPACKET, 0) or
+        $one or socketpair($bcast1, $bcast2, AF_UNIX, $SEQPACKET, 0) or
                                                         die "socketpair: $!";
         my $seed = rand(0xffffffff);
         my $pid = fork // die "fork: $!";
@@ -380,66 +380,17 @@ sub wq_workers_start {
         socketpair($self->{-wq_s1}, $self->{-wq_s2}, AF_UNIX, $SEQPACKET, 0) or
                 die "socketpair: $!";
         $self->ipc_atfork_prepare;
-        $nr_workers //= $self->{-wq_nr_workers};
+        $nr_workers //= $self->{-wq_nr_workers}; # was set earlier
         my $sigset = $oldset // PublicInbox::DS::block_signals();
         $self->{-wq_workers} = {};
         $self->{-wq_ident} = $ident;
-        _wq_worker_start($self, $sigset, $fields) for (1..$nr_workers);
+        my $one = $nr_workers == 1;
+        $self->{-wq_nr_workers} = $nr_workers;
+        _wq_worker_start($self, $sigset, $fields, $one) for (1..$nr_workers);
         PublicInbox::DS::sig_setmask($sigset) unless $oldset;
         $self->{-wq_ppid} = $$;
 }
 
-sub wq_worker_incr { # SIGTTIN handler
-        my ($self, $oldset, $fields) = @_;
-        $self->{-wq_s2} or return;
-        die "-wq_nr_workers locked" if defined $self->{-wq_nr_workers};
-        $self->ipc_atfork_prepare;
-        my $sigset = $oldset // PublicInbox::DS::block_signals();
-        _wq_worker_start($self, $sigset, $fields);
-        PublicInbox::DS::sig_setmask($sigset) unless $oldset;
-}
-
-sub wq_exit { # wakes up wq_worker_decr_wait
-        send($_[0]->{-wq_s2}, $$, MSG_EOR) // die "$$ send: $!";
-        exit;
-}
-
-sub wq_worker_decr { # SIGTTOU handler, kills first idle worker
-        my ($self) = @_;
-        return unless wq_workers($self);
-        die "-wq_nr_workers locked" if defined $self->{-wq_nr_workers};
-        $self->wq_io_do('wq_exit');
-        # caller must call wq_worker_decr_wait in main loop
-}
-
-sub wq_worker_decr_wait {
-        my ($self, $timeout, $cb, @args) = @_;
-        return if $self->{-wq_ppid} != $$; # can't reap siblings or parents
-        die "-wq_nr_workers locked" if defined $self->{-wq_nr_workers};
-        my $s1 = $self->{-wq_s1} // croak 'BUG: no wq_s1';
-        vec(my $rin = '', fileno($s1), 1) = 1;
-        select(my $rout = $rin, undef, undef, $timeout) or
-                croak 'timed out waiting for wq_exit';
-        recv($s1, my $pid, 64, 0) // croak "recv: $!";
-        my $workers = $self->{-wq_workers} // croak 'BUG: no wq_workers';
-        delete $workers->{$pid} // croak "BUG: PID:$pid invalid";
-        dwaitpid($pid, $cb // \&ipc_worker_reap, [ $self, @args ]);
-}
-
-# set or retrieve number of workers
-sub wq_workers {
-        my ($self, $nr, $cb, @args) = @_;
-        my $cur = $self->{-wq_workers} or return;
-        if (defined $nr) {
-                while (scalar(keys(%$cur)) > $nr) {
-                        $self->wq_worker_decr;
-                        $self->wq_worker_decr_wait(undef, $cb, @args);
-                }
-                $self->wq_worker_incr while scalar(keys(%$cur)) < $nr;
-        }
-        scalar(keys(%$cur));
-}
-
 sub wq_close {
         my ($self, $nohang, $cb, @args) = @_;
         delete @$self{qw(-wq_s1 -wq_s2)} or return;
diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index f62e82dc..def85ef1 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -627,7 +627,6 @@ sub workers_start {
         my $end = $lei->pkt_op_pair;
         my $ident = $wq->{-wq_ident} // "lei-$lei->{cmd} worker";
         $flds->{lei} = $lei;
-        $wq->{-wq_nr_workers} //= $jobs; # lock, no incrementing
         $wq->wq_workers_start($ident, $jobs, $lei->oldset, $flds);
         delete $lei->{pkt_op_p};
         my $op_c = delete $lei->{pkt_op_c};
diff --git a/lib/PublicInbox/LeiStore.pm b/lib/PublicInbox/LeiStore.pm
index 164a9f2d..b4f40912 100644
--- a/lib/PublicInbox/LeiStore.pm
+++ b/lib/PublicInbox/LeiStore.pm
@@ -565,7 +565,6 @@ sub write_prepare {
                 # Mail we import into lei are private, so headers filtered out
                 # by -mda for public mail are not appropriate
                 local @PublicInbox::MDA::BAD_HEADERS = ();
-                $self->{-wq_no_bcast} = 1;
                 $self->wq_workers_start("lei/store $dir", 1, $lei->oldset, {
                                         lei => $lei,
                                         -err_wr => $w,