# Copyright (C) 2016 all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+#
+# This allows vfork to be used for spawning subprocesses if
+# PERL_INLINE_DIRECTORY is explicitly defined in the environment.
+# Under Linux, vfork can make a big difference in spawning performance
+# as process size increases (fork still needs to mark pages for CoW use).
+# Currently, we only use this for code intended for long running
+# daemons (inside the PSGI code (-httpd) and -nntpd). The short-lived
+# scripts (-mda, -index, -learn, -init) either use IPC::run or standard
+# Perl routines.
+
package PublicInbox::Spawn;
use strict;
use warnings;
use base qw(Exporter);
-our @EXPORT_OK = qw/which spawn/;
+use Symbol qw(gensym);
+use PublicInbox::ProcessPipe;
+our @EXPORT_OK = qw/which spawn popen_rd/;
my $vfork_spawn = <<'VFORK_SPAWN';
#include <sys/types.h>
public_inbox_fork_exec($in, $out, $err, $f, $cmd, \@env);
}
+sub popen_rd {
+ my ($cmd, $env, $opts) = @_;
+ unless (wantarray || defined $vfork_spawn || defined $env) {
+ open my $fh, '-|', @$cmd or
+ die('open `'.join(' ', @$cmd) . " pipe failed: $!\n");
+ return $fh
+ }
+ pipe(my ($r, $w)) or die "pipe: $!\n";
+ $opts ||= {};
+ my $blocking = $opts->{Blocking};
+ $r->blocking($blocking) if defined $blocking;
+ $opts->{1} = fileno($w);
+ my $pid = spawn($cmd, $env, $opts);
+ close $w;
+ return ($r, $pid) if wantarray;
+ my $ret = gensym;
+ tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r;
+ $ret;
+}
+
1;