send and receive all 3 FDs at once

We'll always be transferring stdin, stdout, and stderr together
for lei.  Perhaps I lack imagination or foresight, but I can't
think of a reason to send more or less FDs.

1 files changed, 14 insertions, 13 deletions

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 6f98c934..3ad5e01a 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -25,7 +25,7 @@ use Text::Wrap qw(wrap);
 use File::Path qw(mkpath);
 use File::Spec;
 our $quit = \&CORE::exit;
-my $recv_fd;
+my $recv_3fds;
 my $GLP = Getopt::Long::Parser->new;
 $GLP->configure(qw(gnu_getopt no_ignore_case auto_abbrev));
 my $GLP_PASS = Getopt::Long::Parser->new;
@@ -614,25 +614,26 @@ sub accept_dispatch { # Listener {post_accept} callback
         my $self = bless { sock => $sock }, __PACKAGE__;
         vec(my $rin = '', fileno($sock), 1) = 1;
         # `say $sock' triggers "die" in lei(1)
-        for my $i (0..2) {
-                if (select(my $rout = $rin, undef, undef, 1)) {
-                        my $fd = $recv_fd->(fileno($sock));
-                        if ($fd >= 0) {
-                                my $rdr = ($fd == 0 ? '<&=' : '>&=');
+        if (select(my $rout = $rin, undef, undef, 1)) {
+                my @fds = $recv_3fds->(fileno($sock));
+                if (scalar(@fds) == 3) {
+                        my $i = 0;
+                        for my $rdr (qw(<&= >&= >&=)) {
+                                my $fd = shift(@fds);
                                 if (open(my $fh, $rdr, $fd)) {
-                                        $self->{$i} = $fh;
-                                } else {
+                                        $self->{$i++} = $fh;
+                                }  else {
                                         say $sock "open($rdr$fd) (FD=$i): $!";
                                         return;
                                 }
-                        } else {
-                                say $sock "recv FD=$i: $!";
-                                return;
                         }
                 } else {
-                        say $sock "timed out waiting to recv FD=$i";
+                        say $sock "recv_3fds failed: $!";
                         return;
                 }
+        } else {
+                say $sock "timed out waiting to recv FDs";
+                return;
         }
         # $ARGV_STR = join("]\0[", @ARGV);
         # $ENV_STR = join('', map { "$_=$ENV{$_}\0" } keys %ENV);
@@ -672,7 +673,7 @@ sub lazy_start {
         my $dev_ino_expect = pack('dd', $st[0], $st[1]); # dev+ino
         pipe(my ($eof_r, $eof_w)) or die "pipe: $!";
         my $oldset = PublicInbox::Sigfd::block_signals();
-        $recv_fd = PublicInbox::Spawn->can('recv_fd') or die
+        $recv_3fds = PublicInbox::Spawn->can('recv_3fds') or die
                 "Inline::C not installed/configured or IO::FDPass missing\n";
         require PublicInbox::Listener;
         require PublicInbox::EOFpipe;