From 5244475c94d9f80b0a76b6bfa9185bdff5a8a0d8 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Sun, 7 Feb 2021 08:51:44 +0000
Subject: spawn: pi_fork_exec: support "pgid"

We'll be using this to allow the "git clone" process hierarchy
to be killed via Ctrl-C.  This also fixes a long-standing bug
in error reporting for the Inline::C version, because we're
actually testing for errors, now!

n.b. strlen(3) is officially async-signal-safe as of
POSIX.1-2016, but I can't think of a reason any previous
implementation prior to that wouldn't be.
---
 lib/PublicInbox/SpawnPP.pm | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

(limited to 'lib/PublicInbox/SpawnPP.pm')

diff --git a/lib/PublicInbox/SpawnPP.pm b/lib/PublicInbox/SpawnPP.pm
index f64b95dc..401cb78d 100644
--- a/lib/PublicInbox/SpawnPP.pm
+++ b/lib/PublicInbox/SpawnPP.pm
@@ -5,12 +5,12 @@
 # of vfork, so no speedups under Linux for spawning from large processes.
 package PublicInbox::SpawnPP;
 use strict;
-use warnings;
-use POSIX qw(dup2 :signal_h);
+use v5.10.1;
+use POSIX qw(dup2 _exit setpgid :signal_h);
 
 # Pure Perl implementation for folks that do not use Inline::C
-sub pi_fork_exec ($$$$$$) {
-	my ($redir, $f, $cmd, $env, $rlim, $cd) = @_;
+sub pi_fork_exec ($$$$$$$) {
+	my ($redir, $f, $cmd, $env, $rlim, $cd, $pgid) = @_;
 	my $old = POSIX::SigSet->new();
 	my $set = POSIX::SigSet->new();
 	$set->fillset or die "fillset failed: $!";
@@ -22,21 +22,25 @@ sub pi_fork_exec ($$$$$$) {
 		$pid = -1;
 	}
 	if ($pid == 0) {
-		while (@$rlim) {
-			my ($r, $soft, $hard) = splice(@$rlim, 0, 3);
-			BSD::Resource::setrlimit($r, $soft, $hard) or
-			  warn "failed to set $r=[$soft,$hard]\n";
-		}
 		for my $child_fd (0..$#$redir) {
 			my $parent_fd = $redir->[$child_fd];
 			next if $parent_fd == $child_fd;
 			dup2($parent_fd, $child_fd) or
 				die "dup2($parent_fd, $child_fd): $!\n";
 		}
+		if ($pgid >= 0 && !defined(setpgid(0, $pgid))) {
+			warn "setpgid: $!";
+			_exit(1);
+		}
+		$SIG{$_} = 'DEFAULT' for keys %SIG;
 		if ($cd ne '') {
 			chdir $cd or die "chdir $cd: $!";
 		}
-		$SIG{$_} = 'DEFAULT' for keys %SIG;
+		while (@$rlim) {
+			my ($r, $soft, $hard) = splice(@$rlim, 0, 3);
+			BSD::Resource::setrlimit($r, $soft, $hard) or
+			  warn "failed to set $r=[$soft,$hard]\n";
+		}
 		$old->delset(POSIX::SIGCHLD) or die "delset SIGCHLD: $!";
 		sigprocmask(SIG_SETMASK, $old) or die "SETMASK: ~SIGCHLD: $!";
 		if ($ENV{MOD_PERL}) {
-- 
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