on_destroy: support PID owner guard

Since we'll be forking for Xapian indexing and maybe
other places, having a simple guard in place to ensure
OnDestroy doesn't unexpectedly unlink files or similar
is a safer option.

3 files changed, 9 insertions, 5 deletions

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index b84e24ef..4af85d49 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -745,9 +745,8 @@ sub lazy_start {
         # reading the <$daemon> pipe.
         openlog($path, 'pid', 'user');
         local $SIG{__WARN__} = sub { syslog('warning', "@_") };
-        my $owner_pid = $$;
-        my $on_destroy = PublicInbox::OnDestroy->new(sub {
-                syslog('crit', "$@") if $@ && $$ == $owner_pid;
+        my $on_destroy = PublicInbox::OnDestroy->new($$, sub {
+                syslog('crit', "$@") if $@;
         });
         open STDERR, '>&STDIN' or die "redirect stderr failed: $!";
         open STDOUT, '>&STDIN' or die "redirect stdout failed: $!";
diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index f6eaa5ce..1d0b4f9c 100644
--- a/lib/PublicInbox/Lock.pm
+++ b/lib/PublicInbox/Lock.pm
@@ -36,9 +36,9 @@ sub lock_release {
 
 # caller must use return value
 sub lock_for_scope {
-        my ($self) = @_;
+        my ($self, @single_pid) = @_;
         $self->lock_acquire;
-        PublicInbox::OnDestroy->new(\&lock_release, $self);
+        PublicInbox::OnDestroy->new(@single_pid, \&lock_release, $self);
 }
 
 sub new_tmp {
diff --git a/lib/PublicInbox/OnDestroy.pm b/lib/PublicInbox/OnDestroy.pm
index 841f87d4..65ebd7dc 100644
--- a/lib/PublicInbox/OnDestroy.pm
+++ b/lib/PublicInbox/OnDestroy.pm
@@ -10,6 +10,11 @@ sub new {
 
 sub DESTROY {
         my ($cb, @args) = @{$_[0]};
+        if (!ref($cb)) {
+                my $pid = $cb;
+                return if $pid != $$;
+                $cb = shift @args;
+        }
         $cb->(@args) if $cb;
 }