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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
06b69b18 | 4 | | CiviCRM version 4.5 | |
6a488035 | 5 | +--------------------------------------------------------------------+ |
06b69b18 | 6 | | Copyright CiviCRM LLC (c) 2004-2014 | |
6a488035 TO |
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 | |
06b69b18 | 31 | * @copyright CiviCRM LLC (c) 2004-2014 |
6a488035 TO |
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 | * | |
77b97be7 | 47 | * @param string $name name of the lock. Please prefix with component / functionality |
6a488035 | 48 | * e.g. civimail.cronjob.JOB_ID |
77b97be7 | 49 | * @param int $timeout the number of seconds to wait to get the lock. 1 if not set |
6a488035 | 50 | * @param boolean $serverWideLock should this lock be applicable across your entire mysql server |
da3c7979 | 51 | * this is useful if you have multiple sites running on the same |
6a488035 TO |
52 | * mysql server and you want to limit the number of parallel cron |
53 | * jobs - CRM-91XX | |
54 | * | |
77b97be7 | 55 | * @return \CRM_Core_Lock the lock object |
6a488035 | 56 | */ |
e32e3c19 TO |
57 | function __construct($name, $timeout = NULL, $serverWideLock = FALSE) { |
58 | $config = CRM_Core_Config::singleton(); | |
6a488035 TO |
59 | $dsnArray = DB::parseDSN($config->dsn); |
60 | $database = $dsnArray['database']; | |
61 | $domainID = CRM_Core_Config::domainID(); | |
62 | if ($serverWideLock) { | |
63 | $this->_name = $name; | |
64 | } | |
65 | else { | |
66 | $this->_name = $database . '.' . $domainID . '.' . $name; | |
67 | } | |
f2da77e6 TO |
68 | if (defined('CIVICRM_LOCK_DEBUG')) { |
69 | CRM_Core_Error::debug_log_message('trying to construct lock for ' . $this->_name); | |
70 | } | |
f877d534 | 71 | static $jobLog = FALSE; |
e32e3c19 | 72 | if ($jobLog && CRM_Core_DAO::singleValueQuery("SELECT IS_USED_LOCK( '{$jobLog}')")) { |
f877d534 E |
73 | return $this->hackyHandleBrokenCode($jobLog); |
74 | } | |
e32e3c19 | 75 | if (stristr($name, 'civimail.job.')) { |
f877d534 E |
76 | $jobLog = $this->_name; |
77 | } | |
6a488035 TO |
78 | $this->_timeout = $timeout !== NULL ? $timeout : self::TIMEOUT; |
79 | ||
80 | $this->acquire(); | |
81 | } | |
82 | ||
83 | function __destruct() { | |
84 | $this->release(); | |
85 | } | |
86 | ||
a0ee3941 EM |
87 | /** |
88 | * @return bool | |
89 | */ | |
6a488035 | 90 | function acquire() { |
f2da77e6 TO |
91 | if (defined('CIVICRM_LOCK_DEBUG')) { |
92 | CRM_Core_Error::debug_log_message('acquire lock for ' . $this->_name); | |
93 | } | |
6a488035 TO |
94 | if (!$this->_hasLock) { |
95 | $query = "SELECT GET_LOCK( %1, %2 )"; | |
e32e3c19 TO |
96 | $params = array( |
97 | 1 => array($this->_name, 'String'), | |
6a488035 TO |
98 | 2 => array($this->_timeout, 'Integer'), |
99 | ); | |
100 | $res = CRM_Core_DAO::singleValueQuery($query, $params); | |
101 | if ($res) { | |
102 | $this->_hasLock = TRUE; | |
103 | } | |
104 | } | |
105 | return $this->_hasLock; | |
106 | } | |
107 | ||
a0ee3941 EM |
108 | /** |
109 | * @return null|string | |
110 | */ | |
6a488035 TO |
111 | function release() { |
112 | if ($this->_hasLock) { | |
113 | $this->_hasLock = FALSE; | |
114 | ||
115 | $query = "SELECT RELEASE_LOCK( %1 )"; | |
116 | $params = array(1 => array($this->_name, 'String')); | |
117 | return CRM_Core_DAO::singleValueQuery($query, $params); | |
118 | } | |
119 | } | |
120 | ||
a0ee3941 EM |
121 | /** |
122 | * @return null|string | |
123 | */ | |
6a488035 TO |
124 | function isFree() { |
125 | $query = "SELECT IS_FREE_LOCK( %1 )"; | |
126 | $params = array(1 => array($this->_name, 'String')); | |
127 | return CRM_Core_DAO::singleValueQuery($query, $params); | |
128 | } | |
129 | ||
a0ee3941 EM |
130 | /** |
131 | * @return bool | |
132 | */ | |
6a488035 TO |
133 | function isAcquired() { |
134 | return $this->_hasLock; | |
135 | } | |
f877d534 E |
136 | |
137 | /** | |
138 | * CRM-12856 locks were originally set up for jobs, but the concept was extended to caching & groups without | |
139 | * understanding that would undermine the job locks (because grabbing a lock implicitly releases existing ones) | |
140 | * this is all a big hack to mitigate the impact of that - but should not be seen as a fix. Not sure correct fix | |
141 | * but maybe locks should be used more selectively? Or else we need to handle is some cool way that Tim is yet to write :-) | |
142 | * if we are running in the context of the cron log then we would rather die (or at least let our process die) | |
143 | * than release that lock - so if the attempt is being made by setCache or something relatively trivial | |
144 | * we'll just return TRUE, but if it's another job then we will crash as that seems 'safer' | |
145 | * | |
146 | * @param string $jobLog | |
147 | * @throws CRM_Core_Exception | |
148 | * @return boolean | |
149 | */ | |
150 | function hackyHandleBrokenCode($jobLog) { | |
e32e3c19 | 151 | if (stristr($this->_name, 'job')) { |
f877d534 E |
152 | throw new CRM_Core_Exception('lock aquisition for ' . $this->_name . 'attempted when ' . $jobLog . 'is not released'); |
153 | } | |
f2da77e6 TO |
154 | if (defined('CIVICRM_LOCK_DEBUG')) { |
155 | CRM_Core_Error::debug_log_message('(CRM-12856) faking lock for ' . $this->_name); | |
156 | } | |
f877d534 E |
157 | $this->_hasLock = TRUE; |
158 | return TRUE; | |
159 | } | |
6a488035 TO |
160 | } |
161 |