lei: All Local Externals: bare git dir for alternates

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

diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index b2c8227f0a66c8940d9be8e60afb8571015f0fc0..0ee2a8bd60bd964a13c0c24f958f43e0ca9a6b5b 100644 (file)
--- a/lib/PublicInbox/Lock.pm
+++ b/lib/PublicInbox/Lock.pm
@@ -1,12 +1,13 @@
-# Copyright (C) 2018-2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2018-2021 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # Base class for per-inbox locking
 package PublicInbox::Lock;
 use strict;
-use warnings;
+use v5.10.1;
 use Fcntl qw(:flock :DEFAULT);
 use Carp qw(croak);
+use PublicInbox::OnDestroy;
 
 # we only acquire the flock if creating or reindexing;
 # PublicInbox::Import already has the lock on its own.
@@ -15,7 +16,7 @@ sub lock_acquire {
        my $lock_path = $self->{lock_path};
        croak 'already locked '.($lock_path // '(undef)') if $self->{lockfh};
        return unless defined($lock_path);
-       sysopen(my $lockfh, $lock_path, O_WRONLY|O_CREAT) or
+       sysopen(my $lockfh, $lock_path, O_RDWR|O_CREAT) or
                croak "failed to open $lock_path: $!\n";
        flock($lockfh, LOCK_EX) or croak "lock $lock_path failed: $!\n";
        $self->{lockfh} = $lockfh;
@@ -32,4 +33,28 @@ sub lock_release {
        close $lockfh or croak "close $lock_path failed: $!\n";
 }
 
+# caller must use return value
+sub lock_for_scope {
+       my ($self, @single_pid) = @_;
+       lock_acquire($self) or return; # lock_path not set
+       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);
+}
+
 1;