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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH] lei: prefer IO::FDPass over our Inline::C recv_3fds
Date: Sun,  3 Jan 2021 20:58:29 +0000	[thread overview]
Message-ID: <20210103205829.8964-1-e@80x24.org> (raw)

While our recv_3fds() implementation is more efficient
syscall-wise, loading Inline takes nearly 50ms on my machine
even after Inline::C memoizes the build.  The current ~20ms in
the fast path is barely acceptable to me, and 50ms would be
unusable.

Eventually, script/lei may invoke tcc(1) or cc(1) directly in
the fast path, but it needs @INC for the slow path, at least.

We'll encode the number of FDs into the socket name allow
parallel installations, for now.
---
 lib/PublicInbox/LEI.pm   | 12 +++++++++---
 lib/PublicInbox/Spawn.pm | 11 -----------
 script/lei               | 18 ++++++++++++------
 t/lei.t                  | 10 ++++++----
 4 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 6f21da35..f41f63ed 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -660,7 +660,7 @@ sub noop {}
 
 # lei(1) calls this when it can't connect
 sub lazy_start {
-	my ($path, $errno) = @_;
+	my ($path, $errno, $nfd) = @_;
 	if ($errno == ECONNREFUSED) {
 		unlink($path) or die "unlink($path): $!";
 	} elsif ($errno != ENOENT) {
@@ -675,8 +675,14 @@ 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();
-	$recv_3fds = PublicInbox::Spawn->can('recv_3fds') or die
-		"Inline::C not installed/configured or IO::FDPass missing\n";
+	if ($nfd == 1) {
+		require IO::FDPass;
+		$recv_3fds = sub { map { IO::FDPass::recv($_[0]) } (0..2) };
+	} elsif ($nfd == 3) {
+		$recv_3fds = PublicInbox::Spawn->can('recv_3fds');
+	}
+	$recv_3fds or die
+		"IO::FDPass missing or Inline::C not installed/configured\n";
 	require PublicInbox::Listener;
 	require PublicInbox::EOFpipe;
 	(-p STDOUT) or die "E: stdout must be a pipe\n";
diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 61e95433..cd94ba96 100644
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -315,17 +315,6 @@ unless ($set_nodatacow) {
 	*nodatacow_fd = \&PublicInbox::NDC_PP::nodatacow_fd;
 	*nodatacow_dir = \&PublicInbox::NDC_PP::nodatacow_dir;
 }
-unless (__PACKAGE__->can('recv_3fds')) {
-	eval { # try the XS IO::FDPass package
-		require IO::FDPass;
-		no warnings 'once';
-		*recv_3fds = sub { map { IO::FDPass::recv($_[0]) } (0..2) };
-		*send_3fds = sub ($$$$) {
-			my $sockfd = shift;
-			IO::FDPass::send($sockfd, shift) for (0..2);
-		};
-	};
-}
 
 undef $set_nodatacow;
 undef $vfork_spawn;
diff --git a/script/lei b/script/lei
index 029881f8..2ea98da4 100755
--- a/script/lei
+++ b/script/lei
@@ -4,11 +4,17 @@
 use strict;
 use v5.10.1;
 use Socket qw(AF_UNIX SOCK_STREAM pack_sockaddr_un);
-my $send_3fds;
+my ($send_3fds, $nfd);
 if (my ($sock, $pwd) = eval {
-	require PublicInbox::Spawn;
-	$send_3fds = PublicInbox::Spawn->can('send_3fds') or die
-		"Inline::C not installed/configured or IO::FDPass missing\n";
+	$send_3fds = eval {
+		require IO::FDPass;
+		$nfd = 1; # 1 FD per-sendmsg
+		sub { IO::FDPass::send($_[0], $_[$_]) for (1..3) }
+	} // do {
+		require PublicInbox::Spawn; # takes ~50ms even if built *sigh*
+		$nfd = 3; # 3 FDs per-sendmsg(2)
+		PublicInbox::Spawn->can('send_3fds');
+	} // die "IO::FDPass missing or Inline::C not installed/configured\n";
 	my $path = do {
 		my $runtime_dir = ($ENV{XDG_RUNTIME_DIR} // '') . '/lei';
 		if ($runtime_dir eq '/lei') {
@@ -19,7 +25,7 @@ if (my ($sock, $pwd) = eval {
 			require File::Path;
 			File::Path::mkpath($runtime_dir, 0, 0700);
 		}
-		"$runtime_dir/sock";
+		"$runtime_dir/$nfd.sock";
 	};
 	my $addr = pack_sockaddr_un($path);
 	socket(my $sock, AF_UNIX, SOCK_STREAM, 0) or die "socket: $!";
@@ -27,7 +33,7 @@ if (my ($sock, $pwd) = eval {
 		local $ENV{PERL5LIB} = join(':', @INC);
 		open(my $daemon, '-|', $^X, qw[-MPublicInbox::LEI
 			-E PublicInbox::LEI::lazy_start(@ARGV)],
-			$path, $! + 0) or die "popen: $!";
+			$path, $! + 0, $nfd) or die "popen: $!";
 		while (<$daemon>) { warn $_ } # EOF when STDERR is redirected
 		close($daemon) or warn <<"";
 lei-daemon could not start, exited with \$?=$?
diff --git a/t/lei.t b/t/lei.t
index 42c0eb8f..5afb8351 100644
--- a/t/lei.t
+++ b/t/lei.t
@@ -193,12 +193,14 @@ if ($ENV{TEST_LEI_ONESHOT}) {
 
 SKIP: { # real socket
 	require_mods(qw(Cwd), my $nr = 46);
-	require PublicInbox::Spawn;
-	skip "Inline::C not installed/configured or IO::FDPass missing", $nr
-		unless PublicInbox::Spawn->can('send_3fds');
+	my $nfd = eval { require IO::FDPass; 1 } // do {
+		require PublicInbox::Spawn;
+		PublicInbox::Spawn->can('send_3fds') ? 3 : undef;
+	} //
+	skip 'IO::FDPass missing or Inline::C not installed/configured', $nr;
 
 	local $ENV{XDG_RUNTIME_DIR} = "$home/xdg_run";
-	my $sock = "$ENV{XDG_RUNTIME_DIR}/lei/sock";
+	my $sock = "$ENV{XDG_RUNTIME_DIR}/lei/$nfd.sock";
 
 	ok($lei->('daemon-pid'), 'daemon-pid');
 	is($err, '', 'no error from daemon-pid');

                 reply	other threads:[~2021-01-03 20:58 UTC|newest]

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