lei: restore default __DIE__ handler for event loop

The kqueue code paths will trigger exceptions which are caught
by eval{}, so we can't be calling exit() from the __DIE__
handler and expect eval to catch it.

We only need the __DIE__ handler to deal with fork or open
failures at startup (since stderr is pointed to /dev/null).
After that we can rely on OnDestroy writing errors to syslog
when it goes out of scope.

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 5399fadeefa641094ee4aeab04d8c515f4557192..95b48095ef6af108d67aad827d5acb6583f2482f 100644 (file)
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -20,6 +20,7 @@ use PublicInbox::Syscall qw($SFD_NONBLOCK EPOLLIN EPOLLONESHOT);
 use PublicInbox::Sigfd;
 use PublicInbox::DS qw(now);
 use PublicInbox::Spawn qw(spawn);
+use PublicInbox::OnDestroy;
 use Text::Wrap qw(wrap);
 use File::Path qw(mkpath);
 use File::Spec;
@@ -386,7 +387,6 @@ sub optparse ($$$) {
 sub dispatch {
        my ($self, $cmd, @argv) = @_;
        local $SIG{__WARN__} = sub { err($self, "@_") };
-       local $SIG{__DIE__} = 'DEFAULT';
        return _help($self, 'no command given') unless defined($cmd);
        my $func = "lei_$cmd";
        $func =~ tr/-/_/;
@@ -602,12 +602,12 @@ sub lazy_start {
        my $oldset = PublicInbox::Sigfd::block_signals();
        my $pid = fork // die "fork: $!";
        return if $pid;
+       require PublicInbox::Listener;
+       require PublicInbox::EOFpipe;
        openlog($path, 'pid', 'user');
        local $SIG{__DIE__} = sub {
                syslog('crit', "@_");
-               exit $! if $!;
-               exit $? >> 8 if $? >> 8;
-               exit 255;
+               die; # calls the default __DIE__ handler
        };
        local $SIG{__WARN__} = sub { syslog('warning', "@_") };
        open(STDIN, '+<', '/dev/null') or die "redirect stdin failed: $!\n";
@@ -616,10 +616,13 @@ sub lazy_start {
        setsid();
        $pid = fork // die "fork: $!";
        return if $pid;
+       $SIG{__DIE__} = 'DEFAULT';
+       my $on_destroy = PublicInbox::OnDestroy->new(sub {
+               my ($owner_pid) = @_;
+               syslog('crit', "$@") if $@ && $$ == $owner_pid;
+       }, $$);
        $0 = "lei-daemon $path";
        local %PATH2CFG;
-       require PublicInbox::Listener;
-       require PublicInbox::EOFpipe;
        $l->blocking(0);
        $eof_w->blocking(0);
        $eof_r->blocking(0);
@@ -680,6 +683,7 @@ sub lazy_start {
                $n; # true: continue, false: stop
        });
        PublicInbox::DS->EventLoop;
+       $@ = undef if $on_destroy; # quiet OnDestroy if we got here
        exit($exit_code // 0);
 }