daemon: use DESTROY for unlinking --pid-file

This gets rid of the last "END{}" block in our code and cleans
up a (temporary) circular reference.

Furthermore, ensure the cleanup code still works in all
configurations by adding tests and testing both the -W1
(default, 1 worker) and -W0 (no workers) code paths.

2 files changed, 33 insertions, 33 deletions

diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index c2c05b96..dd9e7780 100644
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -28,10 +28,8 @@ my %pids;
 my %listener_names; # sockname => IO::Handle
 my %tls_opt; # scheme://sockname => args for IO::Socket::SSL->start_SSL
 my $reexec_pid;
-my $cleanup;
 my ($uid, $gid);
 my ($default_cert, $default_key);
-END { $cleanup->() if $cleanup };
 my %KNOWN_TLS = ( 443 => 'https', 563 => 'nntps' );
 my %KNOWN_STARTTLS = ( 119 => 'nntp' );
 
@@ -245,14 +243,11 @@ sub daemonize () {
                 die "could not fork: $!\n" unless defined $pid;
                 exit if $pid;
         }
-        if (defined $pid_file) {
-                write_pid($pid_file);
-                my $unlink_pid = $$;
-                $cleanup = sub {
-                        $cleanup = undef; # avoid cyclic reference
-                        unlink_pid_file_safe_ish($unlink_pid, $pid_file);
-                };
-        }
+        return unless defined $pid_file;
+
+        write_pid($pid_file);
+        # for ->DESTROY:
+        bless { pid => $$, pid_file => $pid_file }, __PACKAGE__;
 }
 
 sub worker_quit { # $_[0] = signal name or number (unused)
@@ -631,16 +626,16 @@ sub daemon_loop ($$$$) {
                 PublicInbox::DS->SetLoopTimeout(1000);
         }
         PublicInbox::DS->EventLoop;
-        $parent_pipe = undef;
 }
 
-
 sub run ($$$;$) {
         my ($default, $refresh, $post_accept, $nntpd) = @_;
         daemon_prepare($default);
         my $af_default = $default =~ /:8080\z/ ? 'httpready' : undef;
-        daemonize();
+        my $for_destroy = daemonize();
         daemon_loop($refresh, $post_accept, $nntpd, $af_default);
+        PublicInbox::DS->Reset;
+        # ->DESTROY runs when $for_destroy goes out-of-scope
 }
 
 sub do_chown ($) {
@@ -656,4 +651,8 @@ sub write_pid ($) {
         do_chown($path);
 }
 
+sub DESTROY {
+        unlink_pid_file_safe_ish($_[0]->{pid}, $_[0]->{pid_file});
+}
+
 1;
diff --git a/t/httpd-unix.t b/t/httpd-unix.t
index ceec127c..2c8f8d6b 100644
--- a/t/httpd-unix.t
+++ b/t/httpd-unix.t
@@ -22,7 +22,6 @@ my $td;
 
 my $spawn_httpd = sub {
         my (@args) = @_;
-        push @args, '-W0';
         my $cmd = [ '-httpd', @args, "--stdout=$out", "--stderr=$err", $psgi ];
         $td = start_script($cmd);
 };
@@ -36,7 +35,7 @@ my $spawn_httpd = sub {
 }
 
 ok(!-S $unix, 'UNIX socket does not exist, yet');
-$spawn_httpd->("-l$unix");
+$spawn_httpd->("-l$unix", '-W0');
 my %o = (Peer => $unix, Type => SOCK_STREAM);
 for (1..1000) {
         last if -S $unix && IO::Socket::UNIX->new(%o);
@@ -87,26 +86,28 @@ check_sock($unix);
 
 SKIP: {
         eval 'require Net::Server::Daemonize';
-        skip('Net::Server missing for pid-file/daemonization test', 10) if $@;
+        skip('Net::Server missing for pid-file/daemonization test', 20) if $@;
+        my $pid_file = "$tmpdir/pid";
+        for my $w (qw(-W0 -W1)) {
+                # wait for daemonization
+                $spawn_httpd->("-l$unix", '-D', '-P', $pid_file, $w);
+                $td->join;
+                is($?, 0, "daemonized $w process");
+                check_sock($unix);
 
-        # wait for daemonization
-        $spawn_httpd->("-l$unix", '-D', '-P', "$tmpdir/pid");
-        $td->join;
-        is($?, 0, 'daemonized process OK');
-        check_sock($unix);
-
-        ok(-f "$tmpdir/pid", 'pid file written');
-        open my $fh, '<', "$tmpdir/pid" or die "open failed: $!";
-        local $/ = "\n";
-        my $rpid = <$fh>;
-        chomp $rpid;
-        like($rpid, qr/\A\d+\z/s, 'pid file looks like a pid');
-        is(kill('TERM', $rpid), 1, 'signalled daemonized process');
-        for (1..100) {
-                kill(0, $rpid) or last;
-                select undef, undef, undef, 0.02;
+                ok(-f $pid_file, "$w pid file written");
+                open my $fh, '<', "$tmpdir/pid" or die "open failed: $!";
+                my $rpid = do { local $/; <$fh> };
+                chomp $rpid;
+                like($rpid, qr/\A\d+\z/s, "$w pid file looks like a pid");
+                is(kill('TERM', $rpid), 1, "signaled daemonized $w process");
+                for (1..100) {
+                        kill(0, $rpid) or last;
+                        select undef, undef, undef, 0.02;
+                }
+                is(kill(0, $rpid), 0, "daemonized $w process exited");
+                ok(!-e $pid_file, "$w pid file unlinked at exit");
         }
-        is(kill(0, $rpid), 0, 'daemonized process exited')
 }
 
 done_testing();