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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
bc77d7c0 | 4 | | Copyright CiviCRM LLC. All rights reserved. | |
6a488035 | 5 | | | |
bc77d7c0 TO |
6 | | This work is published under the GNU AGPLv3 license with some | |
7 | | permitted exceptions and without any warranty. For full license | | |
8 | | and copyright information, see https://civicrm.org/licensing | | |
6a488035 | 9 | +--------------------------------------------------------------------+ |
d25dd0ee | 10 | */ |
6a488035 TO |
11 | |
12 | /** | |
13 | * | |
14 | * @package CRM | |
ca5cec67 | 15 | * @copyright CiviCRM LLC https://civicrm.org/licensing |
6a488035 | 16 | */ |
10760fa1 | 17 | class CRM_Core_Lock implements \Civi\Core\Lock\LockInterface { |
6a488035 | 18 | |
8bf889ef EM |
19 | /** |
20 | * This variable (despite it's name) roughly translates to 'lock that we actually care about'. | |
21 | * | |
22 | * Prior to version 5.7.5 mysql only supports a single named lock. This variable is | |
23 | * part of the skullduggery involved in 'say it's no so Frank'. | |
24 | * | |
25 | * See further comments on the aquire function. | |
26 | * | |
27 | * @var bool | |
28 | */ | |
518fa0ee | 29 | public static $jobLog = FALSE; |
722ce4f9 | 30 | |
518fa0ee SL |
31 | /** |
32 | * lets have a 3 second timeout for now | |
33 | */ | |
7da04cde | 34 | const TIMEOUT = 3; |
6a488035 | 35 | |
518fa0ee SL |
36 | /** |
37 | * @var bool | |
38 | */ | |
6a488035 TO |
39 | protected $_hasLock = FALSE; |
40 | ||
41 | protected $_name; | |
42 | ||
8bf889ef EM |
43 | protected $_id; |
44 | ||
10760fa1 TO |
45 | /** |
46 | * Use MySQL's GET_LOCK(). Locks are shared across all Civi instances | |
47 | * on the same MySQL server. | |
48 | * | |
49 | * @param string $name | |
50 | * Symbolic name for the lock. Names generally look like | |
51 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
52 | * | |
53 | * Categories: worker|data|cache|... | |
54 | * Component: core|mailing|member|contribute|... | |
55 | * @return \Civi\Core\Lock\LockInterface | |
56 | */ | |
57 | public static function createGlobalLock($name) { | |
58 | return new static($name, NULL, TRUE); | |
59 | } | |
60 | ||
61 | /** | |
62 | * Use MySQL's GET_LOCK(), but apply prefixes to the lock names. | |
63 | * Locks are unique to each instance of Civi. | |
64 | * | |
65 | * @param string $name | |
66 | * Symbolic name for the lock. Names generally look like | |
67 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
68 | * | |
69 | * Categories: worker|data|cache|... | |
70 | * Component: core|mailing|member|contribute|... | |
71 | * @return \Civi\Core\Lock\LockInterface | |
72 | */ | |
73 | public static function createScopedLock($name) { | |
74 | return new static($name); | |
75 | } | |
76 | ||
77 | /** | |
78 | * Use MySQL's GET_LOCK(), but conditionally apply prefixes to the lock names | |
79 | * (if civimail_server_wide_lock is disabled). | |
80 | * | |
81 | * @param string $name | |
82 | * Symbolic name for the lock. Names generally look like | |
83 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
84 | * | |
85 | * Categories: worker|data|cache|... | |
86 | * Component: core|mailing|member|contribute|... | |
87 | * @return \Civi\Core\Lock\LockInterface | |
88 | * @deprecated | |
89 | */ | |
90 | public static function createCivimailLock($name) { | |
aaffa79f | 91 | $serverWideLock = \Civi::settings()->get('civimail_server_wide_lock'); |
10760fa1 TO |
92 | return new static($name, NULL, $serverWideLock); |
93 | } | |
94 | ||
6a488035 TO |
95 | /** |
96 | * Initialize the constants used during lock acquire / release | |
97 | * | |
6a0b768e | 98 | * @param string $name |
10760fa1 TO |
99 | * Symbolic name for the lock. Names generally look like |
100 | * "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}"). | |
101 | * | |
102 | * Categories: worker|data|cache|... | |
103 | * Component: core|mailing|member|contribute|... | |
6a0b768e TO |
104 | * @param int $timeout |
105 | * The number of seconds to wait to get the lock. 1 if not set. | |
106 | * @param bool $serverWideLock | |
107 | * Should this lock be applicable across your entire mysql server. | |
10760fa1 TO |
108 | * this is useful if you have multiple sites running on the same |
109 | * mysql server and you want to limit the number of parallel cron | |
110 | * jobs - CRM-91XX | |
6a488035 | 111 | */ |
00be9182 | 112 | public function __construct($name, $timeout = NULL, $serverWideLock = FALSE) { |
e32e3c19 | 113 | $config = CRM_Core_Config::singleton(); |
6a488035 TO |
114 | $dsnArray = DB::parseDSN($config->dsn); |
115 | $database = $dsnArray['database']; | |
116 | $domainID = CRM_Core_Config::domainID(); | |
117 | if ($serverWideLock) { | |
118 | $this->_name = $name; | |
119 | } | |
120 | else { | |
121 | $this->_name = $database . '.' . $domainID . '.' . $name; | |
122 | } | |
8bf889ef EM |
123 | // MySQL 5.7 doesn't like long lock names so creating a lock id |
124 | $this->_id = sha1($this->_name); | |
f2da77e6 | 125 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 126 | CRM_Core_Error::debug_log_message('trying to construct lock for ' . $this->_name . '(' . $this->_id . ')'); |
f2da77e6 | 127 | } |
6a488035 | 128 | $this->_timeout = $timeout !== NULL ? $timeout : self::TIMEOUT; |
6a488035 TO |
129 | } |
130 | ||
00be9182 | 131 | public function __destruct() { |
6a488035 TO |
132 | $this->release(); |
133 | } | |
134 | ||
a0ee3941 | 135 | /** |
ad37ac8e | 136 | * Acquire lock. |
137 | * | |
8bf889ef EM |
138 | * The advantage of mysql locks is that they can be used across processes. However, only one |
139 | * can be used at once within a process. An attempt to use a second one within a process | |
140 | * prior to mysql 5.7.5 results in the first being released. | |
141 | * | |
142 | * The process here is | |
143 | * 1) first attempt to grab a lock for a mailing job - self::jobLog will be populated with the | |
144 | * lock id & a mysql lock will be created for the ID. | |
145 | * | |
146 | * If a second function in the same process attempts to grab the lock it will enter the hackyHandleBrokenCode routine | |
147 | * which says 'I won't break a mailing lock for you but if you are not a civimail send process I'll let you | |
148 | * pretend you have a lock already and you can go ahead with whatever you were doing under the delusion you | |
149 | * have a lock. | |
150 | * | |
151 | * @todo bypass hackyHandleBrokenCode for mysql version 5.7.5+ | |
152 | * | |
153 | * If a second function in a separate process attempts to grab the lock already in use it should be rejected, | |
154 | * but it appears it IS allowed to grab a different lock & unlike in the same process the first lock won't be released. | |
155 | * | |
156 | * All this means CiviMail locks are first class citizens & any other process gets a 'best effort lock'. | |
157 | * | |
158 | * @todo document naming convention for CiviMail locks as this is key to ensuring they work properly. | |
159 | * | |
ad37ac8e | 160 | * @param int $timeout |
161 | * | |
a0ee3941 | 162 | * @return bool |
ad37ac8e | 163 | * @throws \CRM_Core_Exception |
a0ee3941 | 164 | */ |
10760fa1 | 165 | public function acquire($timeout = NULL) { |
6a488035 | 166 | if (!$this->_hasLock) { |
79ee443c | 167 | if (!CRM_Utils_SQL::supportsMultipleLocks() && self::$jobLog && CRM_Core_DAO::singleValueQuery("SELECT IS_USED_LOCK( '" . self::$jobLog . "')")) { |
c1374ea1 TO |
168 | return $this->hackyHandleBrokenCode(self::$jobLog); |
169 | } | |
170 | ||
6a488035 | 171 | $query = "SELECT GET_LOCK( %1, %2 )"; |
be2fb01f CW |
172 | $params = [ |
173 | 1 => [$this->_id, 'String'], | |
174 | 2 => [$timeout ? $timeout : $this->_timeout, 'Integer'], | |
175 | ]; | |
6a488035 TO |
176 | $res = CRM_Core_DAO::singleValueQuery($query, $params); |
177 | if ($res) { | |
722ce4f9 | 178 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 179 | CRM_Core_Error::debug_log_message('acquire lock for ' . $this->_name . '(' . $this->_id . ')'); |
722ce4f9 | 180 | } |
6a488035 | 181 | $this->_hasLock = TRUE; |
c1374ea1 | 182 | if (stristr($this->_name, 'data.mailing.job.')) { |
8bf889ef | 183 | self::$jobLog = $this->_id; |
c1374ea1 | 184 | } |
6a488035 | 185 | } |
722ce4f9 TO |
186 | else { |
187 | if (defined('CIVICRM_LOCK_DEBUG')) { | |
8bf889ef | 188 | CRM_Core_Error::debug_log_message('failed to acquire lock for ' . $this->_name . '(' . $this->_id . ')'); |
722ce4f9 TO |
189 | } |
190 | } | |
6a488035 TO |
191 | } |
192 | return $this->_hasLock; | |
193 | } | |
194 | ||
a0ee3941 EM |
195 | /** |
196 | * @return null|string | |
197 | */ | |
00be9182 | 198 | public function release() { |
6a488035 | 199 | if ($this->_hasLock) { |
10760fa1 | 200 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 201 | CRM_Core_Error::debug_log_message('release lock for ' . $this->_name . '(' . $this->_id . ')'); |
10760fa1 | 202 | } |
6a488035 TO |
203 | $this->_hasLock = FALSE; |
204 | ||
8bf889ef | 205 | if (self::$jobLog == $this->_id) { |
722ce4f9 TO |
206 | self::$jobLog = FALSE; |
207 | } | |
208 | ||
6a488035 | 209 | $query = "SELECT RELEASE_LOCK( %1 )"; |
be2fb01f | 210 | $params = [1 => [$this->_id, 'String']]; |
6a488035 TO |
211 | return CRM_Core_DAO::singleValueQuery($query, $params); |
212 | } | |
213 | } | |
214 | ||
a0ee3941 EM |
215 | /** |
216 | * @return null|string | |
217 | */ | |
00be9182 | 218 | public function isFree() { |
6a488035 | 219 | $query = "SELECT IS_FREE_LOCK( %1 )"; |
be2fb01f | 220 | $params = [1 => [$this->_id, 'String']]; |
6a488035 TO |
221 | return CRM_Core_DAO::singleValueQuery($query, $params); |
222 | } | |
223 | ||
a0ee3941 EM |
224 | /** |
225 | * @return bool | |
226 | */ | |
00be9182 | 227 | public function isAcquired() { |
6a488035 TO |
228 | return $this->_hasLock; |
229 | } | |
f877d534 E |
230 | |
231 | /** | |
232 | * CRM-12856 locks were originally set up for jobs, but the concept was extended to caching & groups without | |
233 | * understanding that would undermine the job locks (because grabbing a lock implicitly releases existing ones) | |
234 | * this is all a big hack to mitigate the impact of that - but should not be seen as a fix. Not sure correct fix | |
235 | * but maybe locks should be used more selectively? Or else we need to handle is some cool way that Tim is yet to write :-) | |
236 | * if we are running in the context of the cron log then we would rather die (or at least let our process die) | |
237 | * than release that lock - so if the attempt is being made by setCache or something relatively trivial | |
238 | * we'll just return TRUE, but if it's another job then we will crash as that seems 'safer' | |
239 | * | |
240 | * @param string $jobLog | |
241 | * @throws CRM_Core_Exception | |
28a04ea9 | 242 | * @return bool |
f877d534 | 243 | */ |
00be9182 | 244 | public function hackyHandleBrokenCode($jobLog) { |
e32e3c19 | 245 | if (stristr($this->_name, 'job')) { |
8bf889ef EM |
246 | CRM_Core_Error::debug_log_message('lock acquisition for ' . $this->_name . '(' . $this->_id . ')' . ' attempted when ' . $jobLog . ' is not released'); |
247 | throw new CRM_Core_Exception('lock acquisition for ' . $this->_name . '(' . $this->_id . ')' . ' attempted when ' . $jobLog . ' is not released'); | |
f877d534 | 248 | } |
f2da77e6 | 249 | if (defined('CIVICRM_LOCK_DEBUG')) { |
8bf889ef | 250 | CRM_Core_Error::debug_log_message('(CRM-12856) faking lock for ' . $this->_name . '(' . $this->_id . ')'); |
f2da77e6 | 251 | } |
f877d534 E |
252 | $this->_hasLock = TRUE; |
253 | return TRUE; | |
254 | } | |
96025800 | 255 | |
6a488035 | 256 | } |