KinoSearch::Store::LocUser Contributed Perl DocumentKinoSearch::Store::Lock(3)NAMEKinoSearch::Store::Lock - Abstract class representing an interprocess
mutex lock.
SYNOPSIS
my $lock = $lock_factory->make_lock(
name => 'write',
timeout => 5000,
);
$lock->obtain or die "can't get lock for " . $lock->get_name;
do_stuff();
$lock->release;
DESCRIPTION
The Lock class produces an interprocess mutex lock. The default
subclass uses dot-lock files, but alternative implementations are
possible.
Each lock must have a name which is unique per resource to be locked.
Each lock also has a "host" id which should be unique per machine; it
is used to help clear away stale locks.
CONSTRUCTORS
new( [labeled params] )
my $lock = KinoSearch::Store::Lock->new(
name => 'commit', # required
folder => $folder, # required
host => $hostname, # required
timeout => 5000, # default: 0
interval => 1000, # default: 100
);
Abstract constructor.
· folder - A Folder.
· name - String identifying the resource to be locked, which must
consist solely of characters matching [-_.A-Za-z0-9].
· host - A unique per-machine identifier.
· timeout - Time in milliseconds to keep retrying before abandoning
the attempt to obtain() a lock.
· interval - Time in milliseconds between retries.
ABSTRACT METHODSrequest()
Make one attempt to acquire the lock.
The semantics of request() differ depending on whether shared() returns
true. If the Lock is shared(), then request() should not fail if
another lock is held against the resource identified by "name" (though
it might fail for other reasons). If it is not shared()-- i.e. it's
an exclusive (write) lock -- then other locks should cause request() to
fail.
Returns: true on success, false on failure (sets KinoSearch->error).
release()
Release the lock.
is_locked()
Indicate whether the resource identified by this lock's name is
currently locked.
Returns: true if the resource is locked, false otherwise.
clear_stale()
Release all locks that meet the following three conditions: the lock
name matches, the host id matches, and the process id that the lock was
created under no longer identifies an active process.
METHODSobtain()
Call request() once per "interval" until request() returns success or
the "timeout" has been reached.
Returns: true on success, false on failure (sets KinoSearch->error).
INHERITANCEKinoSearch::Store::Lock isa KinoSearch::Object::Obj.
COPYRIGHT AND LICENSE
Copyright 2005-2010 Marvin Humphrey
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1 2011-06-20 KinoSearch::Store::Lock(3)
