-# 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.
sub lock_acquire {
my ($self) = @_;
- croak 'already locked' if $self->{lockfh};
- my $lock_path = $self->{lock_path} or return;
- sysopen(my $lockfh, $lock_path, O_WRONLY|O_CREAT) or
- die "failed to open lock $lock_path: $!\n";
- flock($lockfh, LOCK_EX) or die "lock failed: $!\n";
+ 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_RDWR|O_CREAT) or
+ croak "failed to open $lock_path: $!\n";
+ flock($lockfh, LOCK_EX) or croak "lock $lock_path failed: $!\n";
$self->{lockfh} = $lockfh;
}
sub lock_release {
my ($self, $wake) = @_;
- return unless $self->{lock_path};
- my $lockfh = delete $self->{lockfh} or croak 'not locked';
+ defined(my $lock_path = $self->{lock_path}) or return;
+ my $lockfh = delete $self->{lockfh} or croak "not locked: $lock_path";
syswrite($lockfh, '.') if $wake;
- flock($lockfh, LOCK_UN) or die "unlock failed: $!\n";
- close $lockfh or die "close failed: $!\n";
+ flock($lockfh, LOCK_UN) or croak "unlock $lock_path failed: $!\n";
+ 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;