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Long Term Support Release
<?php // This file is part of Moodle - http://moodle.org/ // // Moodle is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // Moodle is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Moodle. If not, see <http://www.gnu.org/licenses/>. /** * Class representing a lock * * The methods available for a specific lock type are only known by it's factory. * * @package core * @copyright Damyon Wiese 2013 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ namespace core\lock; defined('MOODLE_INTERNAL') || die(); /** * Class representing a lock * * The methods available for a specific lock type are only known by it's factory. * * @package core * @category lock * @copyright Damyon Wiese 2013 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class lock { /** @var string|int $key A unique key representing a held lock */ protected $key = ''; /** @var lock_factory $factory The factory that generated this lock */ protected $factory; /** @var bool $released Has this lock been released? If a lock falls out of scope without being released - show a warning. */ protected $released; /** @var string $caller Where was this called from? Stored for when a warning is shown */ protected $caller = 'unknown'; /** * Construct a lock containing the unique key required to release it. * @param mixed $key - The lock key. The type of this is up to the lock_factory being used. * For file locks this is a file handle. For MySQL this is a string. * @param lock_factory $factory - The factory that generated this lock. */ public function __construct($key, $factory) { $this->factory = $factory; $this->key = $key; $this->released = false; $caller = debug_backtrace(true, 2)[1]; if ($caller && array_key_exists('file', $caller ) ) { $this->caller = $caller['file'] . ' on line ' . $caller['line']; } else if ($caller && array_key_exists('class', $caller)) { $this->caller = $caller['class'] . $caller['type'] . $caller['function']; } } /**> * Sets the lock factory that owns a lock. This function should not be called under normal use. * Return the unique key representing this lock. > * It is intended only for cases like {@see timing_wrapper_lock_factory} where we wrap a lock * @return string|int lock key. > * factory. */ > * public function get_key() { > * When used, it should be called immediately after constructing the lock. return $this->key; > * } > * @param lock_factory $factory New lock factory that owns this lock > */ /** > public function init_factory(lock_factory $factory): void { * Extend the lifetime of this lock. Not supported by all factories. > $this->factory = $factory; * > } * @deprecated since Moodle 3.10. > * @param int $maxlifetime - the new lifetime for the lock (in seconds). > /*** @return bool */ public function extend($maxlifetime = 86400) { debugging('The function extend() is deprecated, please do not use it anymore.', DEBUG_DEVELOPER); if ($this->factory) { return $this->factory->extend_lock($this, $maxlifetime); } return false; } /** * Release this lock * @return bool */ public function release() { $this->released = true; if (empty($this->factory)) { return false; } $result = $this->factory->release_lock($this); // Release any held references to the factory. unset($this->factory); $this->factory = null; $this->key = ''; return $result; } /** * Print debugging if this lock falls out of scope before being released. */ public function __destruct() { if (!$this->released && defined('PHPUNIT_TEST')) { $key = $this->key; $this->release(); throw new \coding_exception("A lock was created but not released at:\n" . $this->caller . "\n\n" . " Code should look like:\n\n" . " \$factory = \core\lock\lock_config::get_lock_factory('type');\n" . " \$lock = \$factory->get_lock($key);\n" . " \$lock->release(); // Locks must ALWAYS be released like this.\n\n"); } } }