From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH v2 2/2] test_common: avoid needless fcntl in start_script
Date: Sat, 24 Dec 2022 10:40:47 +0000 [thread overview]
Message-ID: <20221224104047.M132580@dcvr> (raw)
In-Reply-To: <20221224071708.1222828-3-e@80x24.org>
POSIX::dup2 does not do anything in addition to dup2(2) and is
thus immune to Perl automatically setting FD_CLOEXEC on FDs it
makes into IO objects/globs. We only need to account for the
case when both args for dup2 are identical, in which case the
kernel treats it as a no-op and then thus we need to clear
FD_CLOEXEC ourselves.
---
v2 now accounts for oldfd == newfd for dup2(2).
Interdiff:
diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 179f8bae..b36c71a6 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -6,7 +6,7 @@ package PublicInbox::TestCommon;
use strict;
use parent qw(Exporter);
use v5.10.1;
-use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD :seek);
+use Fcntl qw(F_SETFD :seek);
use POSIX qw(dup2);
use IO::Socket::INET;
use File::Spec;
@@ -481,7 +481,12 @@ sub start_script {
my $fd;
for ($fd = 0; $fd < 3 || defined($opt->{$fd}); $fd++) {
my $io = $opt->{$fd} // next;
- dup2(fileno($io), $fd) or die "dup2($io, $fd): $!";
+ my $old = fileno($io);
+ if ($old == $fd) {
+ fcntl($io, F_SETFD, 0) // die "F_SETFD: $!";
+ } else {
+ dup2($old, $fd) // die "dup2($old, $fd): $!";
+ }
}
%ENV = (%ENV, %$env) if $env;
my $fds = $fd - 3;
lib/PublicInbox/TestCommon.pm | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 888c1f1e..b36c71a6 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -6,7 +6,7 @@ package PublicInbox::TestCommon;
use strict;
use parent qw(Exporter);
use v5.10.1;
-use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD :seek);
+use Fcntl qw(F_SETFD :seek);
use POSIX qw(dup2);
use IO::Socket::INET;
use File::Spec;
@@ -479,16 +479,14 @@ sub start_script {
# pretend to be systemd (cf. sd_listen_fds(3))
# 3 == SD_LISTEN_FDS_START
my $fd;
- for ($fd = 0; 1; $fd++) {
- my $s = $opt->{$fd};
- last if $fd >= 3 && !defined($s);
- next unless $s;
- my $fl = fcntl($s, F_GETFD, 0);
- if (($fl & FD_CLOEXEC) != FD_CLOEXEC) {
- warn "got FD:".fileno($s)." w/o CLOEXEC\n";
+ for ($fd = 0; $fd < 3 || defined($opt->{$fd}); $fd++) {
+ my $io = $opt->{$fd} // next;
+ my $old = fileno($io);
+ if ($old == $fd) {
+ fcntl($io, F_SETFD, 0) // die "F_SETFD: $!";
+ } else {
+ dup2($old, $fd) // die "dup2($old, $fd): $!";
}
- fcntl($s, F_SETFD, $fl &= ~FD_CLOEXEC);
- dup2(fileno($s), $fd) or die "dup2 failed: $!\n";
}
%ENV = (%ENV, %$env) if $env;
my $fds = $fd - 3;
prev parent reply other threads:[~2022-12-24 10:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-24 7:17 [PATCH 0/2] spawning-related cleanups Eric Wong
2022-12-24 7:17 ` [PATCH 1/2] spawn_pp: cleanup, error checks and descriptive errors Eric Wong
2022-12-24 7:17 ` [PATCH 2/2] test_common: avoid needless fcntl in start_script Eric Wong
2022-12-24 10:40 ` Eric Wong [this message]
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