[PATCH 18/22] lei: get rid of client {pid} field

[Eric Wong <e@80x24.org>]

Using kill(2) is too dangerous since extremely long
queries may mean the original PID of the aborted lei(1)
client process to be recycled by a new process.  It would
be bad if the lei_xsearch worker process issued a kill
on the wrong process.

So just rely on sending the exit message via socket.
---
 lib/PublicInbox/LEI.pm      | 18 +++++++-----------
 lib/PublicInbox/LeiQuery.pm |  2 +-
 script/lei                  |  2 +-
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index f8b8cd4a..0cbf342c 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -240,15 +240,12 @@ my %CONFIG_KEYS = (
 sub x_it ($$) { # pronounced "exit"
 	my ($self, $code) = @_;
 	$self->{1}->autoflush(1); # make sure client sees stdout before exit
-	if (my $sig = ($code & 127)) {
-		kill($sig, $self->{pid} // $$);
-	} else {
-		$code >>= 8;
-		if (my $sock = $self->{sock}) {
-			say $sock "exit=$code";
-		} else { # for oneshot
-			$quit->($code);
-		}
+	my $sig = ($code & 127);
+	$code >>= 8 unless $sig;
+	if (my $sock = $self->{sock}) {
+		say $sock "exit=$code";
+	} else { # for oneshot
+		$quit->($code);
 	}
 }
 
@@ -675,13 +672,12 @@ sub accept_dispatch { # Listener {post_accept} callback
 		say $sock "request command truncated";
 		return;
 	}
-	my ($client_pid, $argc, @argv) = split(/\0/, $buf, -1);
+	my ($argc, @argv) = split(/\0/, $buf, -1);
 	undef $buf;
 	my %env = map { split(/=/, $_, 2) } splice(@argv, $argc);
 	if (chdir($env{PWD})) {
 		local %ENV = %env;
 		$self->{env} = \%env;
-		$self->{pid} = $client_pid + 0;
 		eval { dispatch($self, @argv) };
 		say $sock $@ if $@;
 	} else {
diff --git a/lib/PublicInbox/LeiQuery.pm b/lib/PublicInbox/LeiQuery.pm
index 040c284d..d5376be5 100644
--- a/lib/PublicInbox/LeiQuery.pm
+++ b/lib/PublicInbox/LeiQuery.pm
@@ -76,7 +76,7 @@ sub lei_q {
 	}
 	my $j = $opt->{jobs} // scalar(@srcs) > 4 ? 4 : scalar(@srcs);
 	$j = 1 if !$opt->{thread};
-	if ($self->{pid}) {
+	if ($self->{sock}) {
 		$lxs->wq_workers_start('lei_xsearch', $j, $self->oldset)
 			// $self->wq_workers($j);
 	}
diff --git a/script/lei b/script/lei
index 5e30f4d7..bea06b2c 100755
--- a/script/lei
+++ b/script/lei
@@ -62,7 +62,7 @@ Falling back to (slow) one-shot mode
 	1;
 }) { # (Socket::MsgHdr|IO::FDPass|Inline::C), $sock, $pwd are all available:
 	local $ENV{PWD} = $pwd;
-	my $buf = join("\0", $$, scalar(@ARGV), @ARGV);
+	my $buf = join("\0", scalar(@ARGV), @ARGV);
 	while (my ($k, $v) = each %ENV) { $buf .= "\0$k=$v" }
 	$buf .= "\0\0";
 	select $sock;