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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
fee14197 | 4 | | CiviCRM version 5 | |
6a488035 | 5 | +--------------------------------------------------------------------+ |
6b83d5bd | 6 | | Copyright CiviCRM LLC (c) 2004-2019 | |
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 | +--------------------------------------------------------------------+ | |
d25dd0ee | 26 | */ |
6a488035 TO |
27 | |
28 | /** | |
29 | * | |
30 | * @package CRM | |
6b83d5bd | 31 | * @copyright CiviCRM LLC (c) 2004-2019 |
6a488035 TO |
32 | * $Id$ |
33 | * | |
34 | */ | |
10760fa1 | 35 | class CRM_Core_Lock implements \Civi\Core\Lock\LockInterface { |
6a488035 | 36 | |
8bf889ef EM |
37 | /** |
38 | * This variable (despite it's name) roughly translates to 'lock that we actually care about'. | |
39 | * | |
40 | * Prior to version 5.7.5 mysql only supports a single named lock. This variable is | |
41 | * part of the skullduggery involved in 'say it's no so Frank'. | |
42 | * | |
43 | * See further comments on the aquire function. | |
44 | * | |
45 | * @var bool | |
46 | */ | |
518fa0ee | 47 | public static $jobLog = FALSE; |
722ce4f9 | 48 | |
518fa0ee SL |
49 | /** |
50 | * lets have a 3 second timeout for now | |
51 | */ | |
7da04cde | 52 | const TIMEOUT = 3; |
6a488035 | 53 | |
518fa0ee SL |
54 | /** |
55 | * @var bool | |
56 | */ | |
6a488035 TO |
57 | protected $_hasLock = FALSE; |
58 | ||
59 | protected $_name; | |
60 | ||
8bf889ef EM |
61 | protected $_id; |
62 | ||
10760fa1 TO |
63 | /** |
64 | * Use MySQL's GET_LOCK(). Locks are shared across all Civi instances | |
65 | * on the same MySQL server. | |
66 | * | |
67 | * @param string $name | |
68 | * Symbolic name for the lock. Names generally look like | |
69 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
70 | * | |
71 | * Categories: worker|data|cache|... | |
72 | * Component: core|mailing|member|contribute|... | |
73 | * @return \Civi\Core\Lock\LockInterface | |
74 | */ | |
75 | public static function createGlobalLock($name) { | |
76 | return new static($name, NULL, TRUE); | |
77 | } | |
78 | ||
79 | /** | |
80 | * Use MySQL's GET_LOCK(), but apply prefixes to the lock names. | |
81 | * Locks are unique to each instance of Civi. | |
82 | * | |
83 | * @param string $name | |
84 | * Symbolic name for the lock. Names generally look like | |
85 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
86 | * | |
87 | * Categories: worker|data|cache|... | |
88 | * Component: core|mailing|member|contribute|... | |
89 | * @return \Civi\Core\Lock\LockInterface | |
90 | */ | |
91 | public static function createScopedLock($name) { | |
92 | return new static($name); | |
93 | } | |
94 | ||
95 | /** | |
96 | * Use MySQL's GET_LOCK(), but conditionally apply prefixes to the lock names | |
97 | * (if civimail_server_wide_lock is disabled). | |
98 | * | |
99 | * @param string $name | |
100 | * Symbolic name for the lock. Names generally look like | |
101 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
102 | * | |
103 | * Categories: worker|data|cache|... | |
104 | * Component: core|mailing|member|contribute|... | |
105 | * @return \Civi\Core\Lock\LockInterface | |
106 | * @deprecated | |
107 | */ | |
108 | public static function createCivimailLock($name) { | |
aaffa79f | 109 | $serverWideLock = \Civi::settings()->get('civimail_server_wide_lock'); |
10760fa1 TO |
110 | return new static($name, NULL, $serverWideLock); |
111 | } | |
112 | ||
6a488035 TO |
113 | /** |
114 | * Initialize the constants used during lock acquire / release | |
115 | * | |
6a0b768e | 116 | * @param string $name |
10760fa1 TO |
117 | * Symbolic name for the lock. Names generally look like |
118 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
119 | * | |
120 | * Categories: worker|data|cache|... | |
121 | * Component: core|mailing|member|contribute|... | |
6a0b768e TO |
122 | * @param int $timeout |
123 | * The number of seconds to wait to get the lock. 1 if not set. | |
124 | * @param bool $serverWideLock | |
125 | * Should this lock be applicable across your entire mysql server. | |
10760fa1 TO |
126 | * this is useful if you have multiple sites running on the same |
127 | * mysql server and you want to limit the number of parallel cron | |
128 | * jobs - CRM-91XX | |
6a488035 | 129 | */ |
00be9182 | 130 | public function __construct($name, $timeout = NULL, $serverWideLock = FALSE) { |
e32e3c19 | 131 | $config = CRM_Core_Config::singleton(); |
6a488035 TO |
132 | $dsnArray = DB::parseDSN($config->dsn); |
133 | $database = $dsnArray['database']; | |
134 | $domainID = CRM_Core_Config::domainID(); | |
135 | if ($serverWideLock) { | |
136 | $this->_name = $name; | |
137 | } | |
138 | else { | |
139 | $this->_name = $database . '.' . $domainID . '.' . $name; | |
140 | } | |
8bf889ef EM |
141 | // MySQL 5.7 doesn't like long lock names so creating a lock id |
142 | $this->_id = sha1($this->_name); | |
f2da77e6 | 143 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 144 | CRM_Core_Error::debug_log_message('trying to construct lock for ' . $this->_name . '(' . $this->_id . ')'); |
f2da77e6 | 145 | } |
6a488035 | 146 | $this->_timeout = $timeout !== NULL ? $timeout : self::TIMEOUT; |
6a488035 TO |
147 | } |
148 | ||
00be9182 | 149 | public function __destruct() { |
6a488035 TO |
150 | $this->release(); |
151 | } | |
152 | ||
a0ee3941 | 153 | /** |
ad37ac8e | 154 | * Acquire lock. |
155 | * | |
8bf889ef EM |
156 | * The advantage of mysql locks is that they can be used across processes. However, only one |
157 | * can be used at once within a process. An attempt to use a second one within a process | |
158 | * prior to mysql 5.7.5 results in the first being released. | |
159 | * | |
160 | * The process here is | |
161 | * 1) first attempt to grab a lock for a mailing job - self::jobLog will be populated with the | |
162 | * lock id & a mysql lock will be created for the ID. | |
163 | * | |
164 | * If a second function in the same process attempts to grab the lock it will enter the hackyHandleBrokenCode routine | |
165 | * which says 'I won't break a mailing lock for you but if you are not a civimail send process I'll let you | |
166 | * pretend you have a lock already and you can go ahead with whatever you were doing under the delusion you | |
167 | * have a lock. | |
168 | * | |
169 | * @todo bypass hackyHandleBrokenCode for mysql version 5.7.5+ | |
170 | * | |
171 | * If a second function in a separate process attempts to grab the lock already in use it should be rejected, | |
172 | * but it appears it IS allowed to grab a different lock & unlike in the same process the first lock won't be released. | |
173 | * | |
174 | * All this means CiviMail locks are first class citizens & any other process gets a 'best effort lock'. | |
175 | * | |
176 | * @todo document naming convention for CiviMail locks as this is key to ensuring they work properly. | |
177 | * | |
ad37ac8e | 178 | * @param int $timeout |
179 | * | |
a0ee3941 | 180 | * @return bool |
ad37ac8e | 181 | * @throws \CRM_Core_Exception |
a0ee3941 | 182 | */ |
10760fa1 | 183 | public function acquire($timeout = NULL) { |
6a488035 | 184 | if (!$this->_hasLock) { |
79ee443c | 185 | if (!CRM_Utils_SQL::supportsMultipleLocks() && self::$jobLog && CRM_Core_DAO::singleValueQuery("SELECT IS_USED_LOCK( '" . self::$jobLog . "')")) { |
c1374ea1 TO |
186 | return $this->hackyHandleBrokenCode(self::$jobLog); |
187 | } | |
188 | ||
6a488035 | 189 | $query = "SELECT GET_LOCK( %1, %2 )"; |
be2fb01f CW |
190 | $params = [ |
191 | 1 => [$this->_id, 'String'], | |
192 | 2 => [$timeout ? $timeout : $this->_timeout, 'Integer'], | |
193 | ]; | |
6a488035 TO |
194 | $res = CRM_Core_DAO::singleValueQuery($query, $params); |
195 | if ($res) { | |
722ce4f9 | 196 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 197 | CRM_Core_Error::debug_log_message('acquire lock for ' . $this->_name . '(' . $this->_id . ')'); |
722ce4f9 | 198 | } |
6a488035 | 199 | $this->_hasLock = TRUE; |
c1374ea1 | 200 | if (stristr($this->_name, 'data.mailing.job.')) { |
8bf889ef | 201 | self::$jobLog = $this->_id; |
c1374ea1 | 202 | } |
6a488035 | 203 | } |
722ce4f9 TO |
204 | else { |
205 | if (defined('CIVICRM_LOCK_DEBUG')) { | |
8bf889ef | 206 | CRM_Core_Error::debug_log_message('failed to acquire lock for ' . $this->_name . '(' . $this->_id . ')'); |
722ce4f9 TO |
207 | } |
208 | } | |
6a488035 TO |
209 | } |
210 | return $this->_hasLock; | |
211 | } | |
212 | ||
a0ee3941 EM |
213 | /** |
214 | * @return null|string | |
215 | */ | |
00be9182 | 216 | public function release() { |
6a488035 | 217 | if ($this->_hasLock) { |
10760fa1 | 218 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 219 | CRM_Core_Error::debug_log_message('release lock for ' . $this->_name . '(' . $this->_id . ')'); |
10760fa1 | 220 | } |
6a488035 TO |
221 | $this->_hasLock = FALSE; |
222 | ||
8bf889ef | 223 | if (self::$jobLog == $this->_id) { |
722ce4f9 TO |
224 | self::$jobLog = FALSE; |
225 | } | |
226 | ||
6a488035 | 227 | $query = "SELECT RELEASE_LOCK( %1 )"; |
be2fb01f | 228 | $params = [1 => [$this->_id, 'String']]; |
6a488035 TO |
229 | return CRM_Core_DAO::singleValueQuery($query, $params); |
230 | } | |
231 | } | |
232 | ||
a0ee3941 EM |
233 | /** |
234 | * @return null|string | |
235 | */ | |
00be9182 | 236 | public function isFree() { |
6a488035 | 237 | $query = "SELECT IS_FREE_LOCK( %1 )"; |
be2fb01f | 238 | $params = [1 => [$this->_id, 'String']]; |
6a488035 TO |
239 | return CRM_Core_DAO::singleValueQuery($query, $params); |
240 | } | |
241 | ||
a0ee3941 EM |
242 | /** |
243 | * @return bool | |
244 | */ | |
00be9182 | 245 | public function isAcquired() { |
6a488035 TO |
246 | return $this->_hasLock; |
247 | } | |
f877d534 E |
248 | |
249 | /** | |
250 | * CRM-12856 locks were originally set up for jobs, but the concept was extended to caching & groups without | |
251 | * understanding that would undermine the job locks (because grabbing a lock implicitly releases existing ones) | |
252 | * this is all a big hack to mitigate the impact of that - but should not be seen as a fix. Not sure correct fix | |
253 | * but maybe locks should be used more selectively? Or else we need to handle is some cool way that Tim is yet to write :-) | |
254 | * if we are running in the context of the cron log then we would rather die (or at least let our process die) | |
255 | * than release that lock - so if the attempt is being made by setCache or something relatively trivial | |
256 | * we'll just return TRUE, but if it's another job then we will crash as that seems 'safer' | |
257 | * | |
258 | * @param string $jobLog | |
259 | * @throws CRM_Core_Exception | |
28a04ea9 | 260 | * @return bool |
f877d534 | 261 | */ |
00be9182 | 262 | public function hackyHandleBrokenCode($jobLog) { |
e32e3c19 | 263 | if (stristr($this->_name, 'job')) { |
8bf889ef EM |
264 | CRM_Core_Error::debug_log_message('lock acquisition for ' . $this->_name . '(' . $this->_id . ')' . ' attempted when ' . $jobLog . ' is not released'); |
265 | throw new CRM_Core_Exception('lock acquisition for ' . $this->_name . '(' . $this->_id . ')' . ' attempted when ' . $jobLog . ' is not released'); | |
f877d534 | 266 | } |
f2da77e6 | 267 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 268 | CRM_Core_Error::debug_log_message('(CRM-12856) faking lock for ' . $this->_name . '(' . $this->_id . ')'); |
f2da77e6 | 269 | } |
f877d534 E |
270 | $this->_hasLock = TRUE; |
271 | return TRUE; | |
272 | } | |
96025800 | 273 | |
6a488035 | 274 | } |