daemon: use sigprocmask when respawning workers

[public-inbox.git] / lib / PublicInbox / Daemon.pm

diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index 2b7ac266dfabbccfa83c106c0a114d2f1a446faf..90f111370e9a23b1a740adc7e486add82d977f44 100644 (file)
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2015-2018 all contributors <meta@public-inbox.org>
+# Copyright (C) 2015-2019 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 # contains common daemon code for the nntpd and httpd servers.
 # This may be used for read-only IMAP server if we decide to implement it.
@@ -8,6 +8,7 @@ use warnings;
 use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
 use IO::Handle;
 use IO::Socket;
+use POSIX qw(WNOHANG :signal_h);
 use Socket qw(IPPROTO_TCP SOL_SOCKET);
 sub SO_ACCEPTFILTER () { 0x1000 }
 use Cwd qw/abs_path/;
@@ -15,11 +16,10 @@ STDOUT->autoflush(1);
 STDERR->autoflush(1);
 use PublicInbox::DS qw(now);
 require PublicInbox::EvCleanup;
-require POSIX;
 require PublicInbox::Listener;
 require PublicInbox::ParentPipe;
 my @CMD;
-my $set_user;
+my ($set_user, $oldset, $newset);
 my (@cfg_listen, $stdout, $stderr, $group, $user, $pid_file, $daemonize);
 my $worker_processes = 1;
 my @listeners;
@@ -76,9 +76,11 @@ sub accept_tls_opt ($) {
 
 sub daemon_prepare ($) {
        my ($default_listen) = @_;
+       $oldset = POSIX::SigSet->new();
+       $newset = POSIX::SigSet->new();
+       $newset->fillset or die "fillset: $!";
+       sigprocmask(SIG_SETMASK, $newset, $oldset) or die "sigprocmask: $!";
        @CMD = ($0, @ARGV);
-       $SIG{HUP} = $SIG{USR1} = $SIG{USR2} = $SIG{PIPE} =
-               $SIG{TTIN} = $SIG{TTOU} = $SIG{WINCH} = 'IGNORE';
        my %opts = (
                'l|listen=s' => \@cfg_listen,
                '1|stdout=s' => \$stdout,
@@ -155,9 +157,9 @@ sub daemon_prepare ($) {
                my $s = eval { $sock_pkg->new(%o) };
                warn "error binding $l: $! ($@)\n" unless $s;
                umask $prev;
-
                if ($s) {
                        $listener_names{sockname($s)} = $s;
+                       $s->blocking(0);
                        push @listeners, $s;
                }
        }
@@ -363,6 +365,14 @@ sub inherit () {
        foreach my $fd (3..$end) {
                my $s = IO::Handle->new_from_fd($fd, 'r');
                if (my $k = sockname($s)) {
+                       if ($s->blocking) {
+                               $s->blocking(0);
+                               warn <<"";
+Inherited socket (fd=$fd) is blocking, making it non-blocking.
+Set 'NonBlocking = true' in the systemd.service unit to avoid stalled
+processes when multiple service instances start.
+
+                       }
                        $listener_names{$k} = $s;
                        push @rv, $s;
                } else {
@@ -429,7 +439,7 @@ sub upgrade_aborted ($) {
 
 sub reap_children () {
        while (1) {
-               my $p = waitpid(-1, &POSIX::WNOHANG) or return;
+               my $p = waitpid(-1, WNOHANG) or return;
                if (defined $reexec_pid && $p == $reexec_pid) {
                        upgrade_aborted($p);
                } elsif (defined(my $id = delete $pids{$p})) {
@@ -474,6 +484,7 @@ sub master_loop {
                        syswrite($w, '.');
                };
        }
+       sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!";
        reopen_logs();
        # main loop
        my $quit = 0;
@@ -525,6 +536,7 @@ sub master_loop {
                        }
                        $n = $worker_processes;
                }
+               sigprocmask(SIG_SETMASK, $newset) or die "sigprocmask: $!";
                foreach my $i ($n..($worker_processes - 1)) {
                        my $pid = fork;
                        if (!defined $pid) {
@@ -537,6 +549,7 @@ sub master_loop {
                                $pids{$pid} = $i;
                        }
                }
+               sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!";
                # just wait on signal events here:
                sysread($r, my $buf, 8);
        }
@@ -608,6 +621,7 @@ sub daemon_loop ($$$$) {
                # this calls epoll_create:
                PublicInbox::Listener->new($_, $tls_cb || $post_accept)
        } @listeners;
+       sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!";
        PublicInbox::DS->EventLoop;
        $parent_pipe = undef;
 }