sharedkv: use lock_for_scope_fast

This allows us to avoid repeated open() and close() syscalls
and speeds up the new xt/stress-sharedkv.t maintainer test
by roughly 7%.

1 files changed, 17 insertions, 0 deletions

diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index bb213de4..c0c4c15c 100644
--- a/lib/PublicInbox/Lock.pm
+++ b/lib/PublicInbox/Lock.pm
@@ -41,6 +41,23 @@ sub lock_for_scope {
         PublicInbox::OnDestroy->new(@single_pid, \&lock_release, $self);
 }
 
+sub lock_acquire_fast {
+        $_[0]->{lockfh} or return lock_acquire($_[0]);
+        flock($_[0]->{lockfh}, LOCK_EX) or croak "lock (fast) failed: $!";
+}
+
+sub lock_release_fast {
+        flock($_[0]->{lockfh} // return, LOCK_UN) or
+                        croak "unlock (fast) $_[0]->{lock_path}: $!";
+}
+
+# caller must use return value
+sub lock_for_scope_fast {
+        my ($self, @single_pid) = @_;
+        lock_acquire_fast($self) or return; # lock_path not set
+        PublicInbox::OnDestroy->new(@single_pid, \&lock_release_fast, $self);
+}
+
 sub new_tmp {
         my ($cls, $ident) = @_;
         my $tmp = File::Temp->new("$ident.lock-XXXXXX", TMPDIR => 1);