# Copyright (C) 2016-2021 all contributors
# License: AGPL-3.0+
# Pure-Perl implementation of "spawn". This can't take advantage
# of vfork, so no speedups under Linux for spawning from large processes.
package PublicInbox::SpawnPP;
use strict;
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, $pgid) = @_;
my $old = POSIX::SigSet->new();
my $set = POSIX::SigSet->new();
$set->fillset or die "fillset failed: $!";
sigprocmask(SIG_SETMASK, $set, $old) or die "can't block signals: $!";
my $syserr;
pipe(my ($r, $w));
my $pid = fork;
unless (defined $pid) { # compat with Inline::C version
$syserr = $!;
$pid = -1;
}
if ($pid == 0) {
close $r;
$SIG{__DIE__} = sub {
warn(@_);
syswrite($w, my $num = $! + 0);
_exit(1);
};
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): $!";
}
if ($pgid >= 0 && !defined(setpgid(0, $pgid))) {
die "setpgid(0, $pgid): $!";
}
for (keys %SIG) {
$SIG{$_} = 'DEFAULT' if substr($_, 0, 1) ne '_';
}
if ($cd ne '') {
chdir $cd or die "chdir $cd: $!";
}
while (@$rlim) {
my ($r, $soft, $hard) = splice(@$rlim, 0, 3);
BSD::Resource::setrlimit($r, $soft, $hard) or
die "setrlimit($r=[$soft,$hard]: $!)";
}
$old->delset(POSIX::SIGCHLD) or die "delset SIGCHLD: $!";
sigprocmask(SIG_SETMASK, $old) or die "SETMASK: ~SIGCHLD: $!";
$cmd->[0] = $f;
if ($ENV{MOD_PERL}) {
@$cmd = (which('env'), '-i', @$env, @$cmd);
} else {
%ENV = map { split(/=/, $_, 2) } @$env;
}
undef $r;
exec { $f } @$cmd;
die "exec @$cmd failed: $!";
}
close $w;
sigprocmask(SIG_SETMASK, $old) or die "can't unblock signals: $!";
if (my $cerrnum = do { local $/, <$r> }) {
$pid = -1;
$! = $cerrnum;
} else {
$! = $syserr;
}
$pid;
}
1;