| 1 | <?php |
| 2 | /* |
| 3 | +--------------------------------------------------------------------+ |
| 4 | | CiviCRM version 4.5 | |
| 5 | +--------------------------------------------------------------------+ |
| 6 | | Copyright CiviCRM LLC (c) 2004-2014 | |
| 7 | +--------------------------------------------------------------------+ |
| 8 | | This file is a part of CiviCRM. | |
| 9 | | | |
| 10 | | CiviCRM is free software; you can copy, modify, and distribute it | |
| 11 | | under the terms of the GNU Affero General Public License | |
| 12 | | Version 3, 19 November 2007 and the CiviCRM Licensing Exception. | |
| 13 | | | |
| 14 | | CiviCRM is distributed in the hope that it will be useful, but | |
| 15 | | WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 16 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
| 17 | | See the GNU Affero General Public License for more details. | |
| 18 | | | |
| 19 | | You should have received a copy of the GNU Affero General Public | |
| 20 | | License and the CiviCRM Licensing Exception along | |
| 21 | | with this program; if not, contact CiviCRM LLC | |
| 22 | | at info[AT]civicrm[DOT]org. If you have questions about the | |
| 23 | | GNU Affero General Public License or the licensing of CiviCRM, | |
| 24 | | see the CiviCRM license FAQ at http://civicrm.org/licensing | |
| 25 | +--------------------------------------------------------------------+ |
| 26 | */ |
| 27 | |
| 28 | /** |
| 29 | * |
| 30 | * @package CRM |
| 31 | * @copyright CiviCRM LLC (c) 2004-2014 |
| 32 | * $Id$ |
| 33 | * |
| 34 | */ |
| 35 | class CRM_Core_Lock { |
| 36 | |
| 37 | // lets have a 3 second timeout for now |
| 38 | CONST TIMEOUT = 3; |
| 39 | |
| 40 | protected $_hasLock = FALSE; |
| 41 | |
| 42 | protected $_name; |
| 43 | |
| 44 | /** |
| 45 | * Initialize the constants used during lock acquire / release |
| 46 | * |
| 47 | * @param string $name name of the lock. Please prefix with component / functionality |
| 48 | * e.g. civimail.cronjob.JOB_ID |
| 49 | * @param int $timeout the number of seconds to wait to get the lock. 1 if not set |
| 50 | * @param boolean $serverWideLock should this lock be applicable across your entire mysql server |
| 51 | * this is useful if you have mutliple sites running on the same |
| 52 | * mysql server and you want to limit the number of parallel cron |
| 53 | * jobs - CRM-91XX |
| 54 | * |
| 55 | * @return object the lock object |
| 56 | * |
| 57 | */ |
| 58 | function __construct($name, $timeout = NULL, $serverWideLock = FALSE) { |
| 59 | $config = CRM_Core_Config::singleton(); |
| 60 | $dsnArray = DB::parseDSN($config->dsn); |
| 61 | $database = $dsnArray['database']; |
| 62 | $domainID = CRM_Core_Config::domainID(); |
| 63 | if ($serverWideLock) { |
| 64 | $this->_name = $name; |
| 65 | } |
| 66 | else { |
| 67 | $this->_name = $database . '.' . $domainID . '.' . $name; |
| 68 | } |
| 69 | $this->_timeout = $timeout !== NULL ? $timeout : self::TIMEOUT; |
| 70 | |
| 71 | $this->acquire(); |
| 72 | } |
| 73 | |
| 74 | function __destruct() { |
| 75 | $this->release(); |
| 76 | } |
| 77 | |
| 78 | function acquire() { |
| 79 | if (!$this->_hasLock) { |
| 80 | $query = "SELECT GET_LOCK( %1, %2 )"; |
| 81 | $params = array(1 => array($this->_name, 'String'), |
| 82 | 2 => array($this->_timeout, 'Integer'), |
| 83 | ); |
| 84 | $res = CRM_Core_DAO::singleValueQuery($query, $params); |
| 85 | if ($res) { |
| 86 | $this->_hasLock = TRUE; |
| 87 | } |
| 88 | } |
| 89 | return $this->_hasLock; |
| 90 | } |
| 91 | |
| 92 | function release() { |
| 93 | if ($this->_hasLock) { |
| 94 | $this->_hasLock = FALSE; |
| 95 | |
| 96 | $query = "SELECT RELEASE_LOCK( %1 )"; |
| 97 | $params = array(1 => array($this->_name, 'String')); |
| 98 | return CRM_Core_DAO::singleValueQuery($query, $params); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | function isFree() { |
| 103 | $query = "SELECT IS_FREE_LOCK( %1 )"; |
| 104 | $params = array(1 => array($this->_name, 'String')); |
| 105 | return CRM_Core_DAO::singleValueQuery($query, $params); |
| 106 | } |
| 107 | |
| 108 | function isAcquired() { |
| 109 | return $this->_hasLock; |
| 110 | } |
| 111 | } |
| 112 | |