| 
                    1
                 | 
                                    
                                                     | 
                
                 | 
                <?php  | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    2
                 | 
                                    
                                                     | 
                
                 | 
                    /**  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    3
                 | 
                                    
                                                     | 
                
                 | 
                     * @package     Freemius  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    4
                 | 
                                    
                                                     | 
                
                 | 
                     * @copyright   Copyright (c) 2015, Freemius, Inc.  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    5
                 | 
                                    
                                                     | 
                
                 | 
                     * @license     https://www.gnu.org/licenses/gpl-3.0.html GNU General Public License Version 3  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    6
                 | 
                                    
                                                     | 
                
                 | 
                     * @since       2.1.0  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    7
                 | 
                                    
                                                     | 
                
                 | 
                     */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    8
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    9
                 | 
                                    
                                                     | 
                
                 | 
                    if ( ! defined( 'ABSPATH' ) ) { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    10
                 | 
                                    
                                                     | 
                
                 | 
                        exit;  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    11
                 | 
                                    
                                                     | 
                
                 | 
                    }  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    12
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    13
                 | 
                                    
                                                     | 
                
                 | 
                    /**  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    14
                 | 
                                    
                                                     | 
                
                 | 
                     * Class FS_User_Lock  | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    15
                 | 
                                    
                                                     | 
                
                 | 
                     */  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    16
                 | 
                                    
                                                     | 
                
                 | 
                    class FS_User_Lock { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                                                                        
                        
                         
                                                                                        
                                                                                            
                                                                                     
                     | 
                
            
                                                                        
                            
            
                                    
            
            
                | 
                    17
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    18
                 | 
                                    
                                                     | 
                
                 | 
                         * @var int  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    19
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    20
                 | 
                                    
                                                     | 
                
                 | 
                        private $_wp_user_id;  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    21
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    22
                 | 
                                    
                                                     | 
                
                 | 
                         * @var int  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    23
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    24
                 | 
                                    
                                                     | 
                
                 | 
                        private $_thread_id;  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    25
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    26
                 | 
                                    
                                                     | 
                
                 | 
                        #--------------------------------------------------------------------------------  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    27
                 | 
                                    
                                                     | 
                
                 | 
                        #region Singleton  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    28
                 | 
                                    
                                                     | 
                
                 | 
                        #--------------------------------------------------------------------------------  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    29
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    30
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    31
                 | 
                                    
                                                     | 
                
                 | 
                         * @var FS_User_Lock  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    32
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    33
                 | 
                                    
                                                     | 
                
                 | 
                        private static $_instance;  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    34
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    35
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    36
                 | 
                                    
                                                     | 
                
                 | 
                         * @author Vova Feldman (@svovaf)  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    37
                 | 
                                    
                                                     | 
                
                 | 
                         * @since  2.1.0  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    38
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    39
                 | 
                                    
                                                     | 
                
                 | 
                         * @return FS_User_Lock  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    40
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    41
                 | 
                                    
                                                     | 
                
                 | 
                        static function instance() { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    42
                 | 
                                    
                                                     | 
                
                 | 
                            if ( ! isset( self::$_instance ) ) { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    43
                 | 
                                    
                                                     | 
                
                 | 
                                self::$_instance = new self();  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    44
                 | 
                                    
                                                     | 
                
                 | 
                            }  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    45
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    46
                 | 
                                    
                                                     | 
                
                 | 
                            return self::$_instance;  | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    47
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    48
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    49
                 | 
                                    
                                                     | 
                
                 | 
                        #endregion  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    50
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    51
                 | 
                                    
                                                     | 
                
                 | 
                        private function __construct() { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    52
                 | 
                                    
                                                     | 
                
                 | 
                            $this->_wp_user_id = Freemius::get_current_wp_user_id();  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    53
                 | 
                                    
                                                     | 
                
                 | 
                            $this->_thread_id  = mt_rand( 0, 32000 );  | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    54
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    55
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    56
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    57
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    58
                 | 
                                    
                                                     | 
                
                 | 
                         * Try to acquire lock. If the lock is already set or is being acquired by another locker, don't do anything.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    59
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    60
                 | 
                                    
                                                     | 
                
                 | 
                         * @author Vova Feldman (@svovaf)  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    61
                 | 
                                    
                                                     | 
                
                 | 
                         * @since  2.1.0  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    62
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    63
                 | 
                                    
                                                     | 
                
                 | 
                         * @param int $expiration  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    64
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    65
                 | 
                                    
                                                     | 
                
                 | 
                         * @return bool TRUE if successfully acquired lock.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    66
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    67
                 | 
                                    
                                                     | 
                
                 | 
                        function try_lock( $expiration = 0 ) { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    68
                 | 
                                    
                                                     | 
                
                 | 
                            if ( $this->is_locked() ) { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    69
                 | 
                                    
                                                     | 
                
                 | 
                                // Already locked.  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    70
                 | 
                                    
                                                     | 
                
                 | 
                                return false;  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    71
                 | 
                                    
                                                     | 
                
                 | 
                            }  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    72
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    73
                 | 
                                    
                                                     | 
                
                 | 
                            set_site_transient( "locked_{$this->_wp_user_id}", $this->_thread_id, $expiration ); | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    74
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    75
                 | 
                                    
                                                     | 
                
                 | 
                            if ( $this->has_lock() ) { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    76
                 | 
                                    
                                                     | 
                
                 | 
                                set_site_transient( "locked_{$this->_wp_user_id}", true, $expiration ); | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    77
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    78
                 | 
                                    
                                                     | 
                
                 | 
                                return true;  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    79
                 | 
                                    
                                                     | 
                
                 | 
                            }  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    80
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    81
                 | 
                                    
                                                     | 
                
                 | 
                            return false;  | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    82
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    83
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    84
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    85
                 | 
                                    
                                                     | 
                
                 | 
                         * Acquire lock regardless if it's already acquired by another locker or not.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    86
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    87
                 | 
                                    
                                                     | 
                
                 | 
                         * @author Vova Feldman (@svovaf)  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    88
                 | 
                                    
                                                     | 
                
                 | 
                         * @since  2.1.0  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    89
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    90
                 | 
                                    
                                                     | 
                
                 | 
                         * @param int $expiration  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    91
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    92
                 | 
                                    
                                                     | 
                
                 | 
                        function lock( $expiration = 0 ) { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    93
                 | 
                                    
                                                     | 
                
                 | 
                            set_site_transient( "locked_{$this->_wp_user_id}", true, $expiration ); | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    94
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    95
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    96
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    97
                 | 
                                    
                                                     | 
                
                 | 
                         * Checks if lock is currently acquired.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    98
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    99
                 | 
                                    
                                                     | 
                
                 | 
                         * @author Vova Feldman (@svovaf)  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    100
                 | 
                                    
                                                     | 
                
                 | 
                         * @since  2.1.0  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    101
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    102
                 | 
                                    
                                                     | 
                
                 | 
                         * @return bool  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    103
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    104
                 | 
                                    
                                                     | 
                
                 | 
                        function is_locked() { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    105
                 | 
                                    
                                                     | 
                
                 | 
                            return ( false !== get_site_transient( "locked_{$this->_wp_user_id}" ) ); | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    106
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    107
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    108
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    109
                 | 
                                    
                                                     | 
                
                 | 
                         * Unlock the lock.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    110
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    111
                 | 
                                    
                                                     | 
                
                 | 
                         * @author Vova Feldman (@svovaf)  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    112
                 | 
                                    
                                                     | 
                
                 | 
                         * @since  2.1.0  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    113
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    114
                 | 
                                    
                                                     | 
                
                 | 
                        function unlock() { | 
            
                            
                    | 
                        
                     | 
                     | 
                     | 
                    
                                                                                                    
                        
                         
                                                                                        
                                                                                     
                     | 
                
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    115
                 | 
                                    
                                                     | 
                
                 | 
                            delete_site_transient( "locked_{$this->_wp_user_id}" ); | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    116
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    117
                 | 
                                    
                                                     | 
                
                 | 
                 | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    118
                 | 
                                    
                                                     | 
                
                 | 
                        /**  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    119
                 | 
                                    
                                                     | 
                
                 | 
                         * Checks if lock is currently acquired by the current locker.  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    120
                 | 
                                    
                                                     | 
                
                 | 
                         *  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    121
                 | 
                                    
                                                     | 
                
                 | 
                         * @return bool  | 
            
            
                                                                        
                            
            
                                    
            
            
                | 
                    122
                 | 
                                    
                                                     | 
                
                 | 
                         */  | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    123
                 | 
                                    
                                                     | 
                
                 | 
                        private function has_lock() { | 
            
            
                                                                                                            
                            
            
                                    
            
            
                | 
                    124
                 | 
                                    
                                                     | 
                
                 | 
                            return ( $this->_thread_id == get_site_transient( "locked_{$this->_wp_user_id}" ) ); | 
            
            
                                                                                                            
                                                                
            
                                    
            
            
                | 
                    125
                 | 
                                    
                                                     | 
                
                 | 
                        }  | 
            
            
                                                        
            
                                    
            
            
                | 
                    126
                 | 
                                    
                                                     | 
                
                 | 
                    }  | 
            
            
                        
The PSR-1: Basic Coding Standard recommends that a file should either introduce new symbols, that is classes, functions, constants or similar, or have side effects. Side effects are anything that executes logic, like for example printing output, changing ini settings or writing to a file.
The idea behind this recommendation is that merely auto-loading a class should not change the state of an application. It also promotes a cleaner style of programming and makes your code less prone to errors, because the logic is not spread out all over the place.
To learn more about the PSR-1, please see the PHP-FIG site on the PSR-1.