PHPXRef 0.7.1 : Unnamed Project : Detail view of db_record_lock

This is a db record locking factory.

Copyright:	Damyon Wiese 2013
License:	http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
File Size:	222 lines (7 kb)
Included or required:	0 times
Referenced:	0 times
Includes or requires:	0 files

Defines 1 class

db_record_lock_factory:: (10 methods):
  is_available()
  __construct()
  supports_timeout()
  supports_auto_release()
  supports_recursion()
  generate_unique_token()
  get_lock()
  release_lock()
  extend_lock()
  auto_release()

Class: db_record_lock_factory - X-Ref

This is a db record locking factory.

This lock factory uses record locks relying on sql of the form "SET XXX where YYY" and checking if the
value was set. It supports timeouts, autorelease and can work on any DB. The downside - is this
will always be slower than some shared memory type locking function.

is_available() X-Ref

Is available.

return: boolean - True if this lock type is available in this environment.

__construct($type) X-Ref

Almighty constructor.

param: string $type - Used to prefix lock keys.

supports_timeout() X-Ref

Return information about the blocking behaviour of the lock type on this platform.

return: boolean - True

supports_auto_release() X-Ref

Will this lock type will be automatically released when a process ends.

return: boolean - True (shutdown handler)

supports_recursion() X-Ref

Multiple locks for the same resource can be held by a single process.

return: boolean - False - not process specific.

generate_unique_token() X-Ref

This function generates a unique token for the lock to use.
It is important that this token is not solely based on time as this could lead
to duplicates in a clustered environment (especially on VMs due to poor time precision).

get_lock($resource, $timeout, $maxlifetime = 86400) X-Ref

Create and get a lock

param: string $resource - The identifier for the lock. Should use frankenstyle prefix.
param: int $timeout - The number of seconds to wait for a lock before giving up.
param: int $maxlifetime - Unused by this lock type.
return: boolean - true if a lock was obtained.

release_lock(lock $lock) X-Ref

Release a lock that was previously obtained with @lock.

param: lock $lock - a lock obtained from this factory.
return: boolean - true if the lock is no longer held (including if it was never held).

extend_lock(lock $lock, $maxlifetime = 86400) X-Ref

Extend a lock that was previously obtained with @lock.

param: lock $lock - a lock obtained from this factory.
param: int $maxlifetime - the new lifetime for the lock (in seconds).
return: boolean - true if the lock was extended.

auto_release() X-Ref

Auto release any open locks on shutdown.
This is required, because we may be using persistent DB connections.

PHP Cross Reference of Unnamed Project

/lib/classes/lock/ -> db_record_lock_factory.php (summary)

Defines 1 class