/usr/share/perl5/Mail/Box/Locker/POSIX.pm is in libmail-box-perl 3.004-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 | # Copyrights 2001-2017 by [Mark Overmeer].
# For other contributors see ChangeLog.
# See the manual pages for details on the licensing terms.
# Pod stripped from pm file by OODoc 2.02.
use strict;
package Mail::Box::Locker::POSIX;
use vars '$VERSION';
$VERSION = '3.004';
use base 'Mail::Box::Locker';
use Fcntl;
use IO::File;
use Errno qw/EAGAIN/;
# fcntl() should not be used without XS: the below is sensitive
# for changes in the structure. However, at the moment it seems
# there are only two options: either SysV-style or BSD-style
my $pack_pattern = $^O =~ /bsd|darwin/i ? '@20 s @256' : 's @256';
sub init($)
{ my ($self, $args) = @_;
$args->{file} = $args->{posix_file} if $args->{posix_file};
$self->SUPER::init($args);
}
sub name() {'POSIX'}
sub _try_lock($)
{ my ($self, $file) = @_;
my $p = pack $pack_pattern, F_WRLCK;
$? = fcntl($file, F_SETLK, $p) || ($!+0);
$?==0;
}
sub _unlock($)
{ my ($self, $file) = @_;
my $p = pack $pack_pattern, F_UNLCK;
fcntl $file, F_SETLK, $p;
$self;
}
sub lock()
{ my $self = shift;
if($self->hasLock)
{ my $folder = $self->folder;
$self->log(WARNING => "Folder $folder already lockf'd");
return 1;
}
my $filename = $self->filename;
my $folder = $self->folder;
my $file = IO::File->new($filename, 'r+');
unless(defined $file)
{ $self->log(ERROR =>
"Unable to open POSIX lock file $filename for $folder: $!");
return 0;
}
my $timeout = $self->timeout;
my $end = $timeout eq 'NOTIMEOUT' ? -1 : $timeout;
while(1)
{ if($self->_try_lock($file))
{ $self->{MBLF_filehandle} = $file;
return $self->SUPER::lock;
}
unless($!==EAGAIN)
{ $self->log(ERROR =>
"Will never get a POSIX lock on $filename for $folder: $!");
last;
}
last unless --$end;
sleep 1;
}
return 0;
}
sub isLocked()
{ my $self = shift;
my $filename = $self->filename;
my $file = IO::File->new($filename, "r");
unless($file)
{ my $folder = $self->folder;
$self->log(ERROR => "Unable to check lock file $filename for $folder: $!");
return 0;
}
$self->_try_lock($file)==0 or return 0;
$self->_unlock($file);
$file->close;
$self->SUPER::unlock;
1;
}
sub unlock()
{ my $self = shift;
$self->_unlock(delete $self->{MBLF_filehandle})
if $self->hasLock;
$self->SUPER::unlock;
$self;
}
1;
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