lib/classes/shutdown_manager.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Shutdown management class.
  19  *
  20  * @package    core
  21  * @copyright  2013 Petr Skoda {@link http://skodak.org}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 /**
  28  * Shutdown management class.
  29  *
  30  * @package    core
  31  * @copyright  2013 Petr Skoda {@link http://skodak.org}
  32  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  33  */
  34 class core_shutdown_manager {
  35     /** @var array list of custom callbacks */
  36     protected static $callbacks = array();
  37     /** @var bool is this manager already registered? */
  38     protected static $registered = false;
  39
  40     /**
  41      * Register self as main shutdown handler.
  42      *
  43      * @private to be called from lib/setup.php only!
  44      */
  45     public static function initialize() {
  46         if (self::$registered) {
  47             debugging('Shutdown manager is already initialised!');
  48         }
  49         self::$registered = true;
  50         register_shutdown_function(array('core_shutdown_manager', 'shutdown_handler'));
  51     }
  52
  53     /**
  54      * Register custom shutdown function.
  55      *
  56      * @param callable $callback
  57      * @param array $params
  58      */
  59     public static function register_function($callback, array $params = null) {
  60         self::$callbacks[] = array($callback, $params);
  61     }
  62
  63     /**
  64      * @private - do NOT call directly.
  65      */
  66     public static function shutdown_handler() {
  67         global $DB;
  68
  69         // Custom stuff first.
  70         foreach (self::$callbacks as $data) {
  71             list($callback, $params) = $data;
  72             try {
  73                 if (!is_callable($callback)) {
  74                     error_log('Invalid custom shutdown function detected '.var_export($callback, true));
  75                     continue;
  76                 }
  77                 if ($params === null) {
  78                     call_user_func($callback);
  79                 } else {
  80                     call_user_func_array($callback, $params);
  81                 }
  82             } catch (Exception $e) {
  83                 error_log('Exception ignored in shutdown function '.var_export($callback, true).':'.$e->getMessage());
  84             } catch (Throwable $e) {
  85                 // Engine errors in PHP7 throw exceptions of type Throwable (this "catch" will be ignored in PHP5).
  86                 error_log('Exception ignored in shutdown function '.var_export($callback, true).':'.$e->getMessage());
  87             }
  88         }
  89
  90         // Handle DB transactions, session need to be written afterwards
  91         // in order to maintain consistency in all session handlers.
  92         if ($DB->is_transaction_started()) {
  93             if (!defined('PHPUNIT_TEST') or !PHPUNIT_TEST) {
  94                 // This should not happen, it usually indicates wrong catching of exceptions,
  95                 // because all transactions should be finished manually or in default exception handler.
  96                 $backtrace = $DB->get_transaction_start_backtrace();
  97                 error_log('Potential coding error - active database transaction detected during request shutdown:'."\n".format_backtrace($backtrace, true));
  98             }
  99             $DB->force_transaction_rollback();
 100         }
 101
 102         // Close sessions - do it here to make it consistent for all session handlers.
 103         \core\session\manager::write_close();
 104
 105         // Other cleanup.
 106         self::request_shutdown();
 107
 108         // Stop profiling.
 109         if (function_exists('profiling_is_running')) {
 110             if (profiling_is_running()) {
 111                 profiling_stop();
 112             }
 113         }
 114
 115         // NOTE: do not dispose $DB and MUC here, they might be used from legacy shutdown functions.
 116     }
 117
 118     /**
 119      * Standard shutdown sequence.
 120      */
 121     protected static function request_shutdown() {
 122         global $CFG;
 123
 124         // Help apache server if possible.
 125         $apachereleasemem = false;
 126         if (function_exists('apache_child_terminate') && function_exists('memory_get_usage') && ini_get_bool('child_terminate')) {
 127             $limit = (empty($CFG->apachemaxmem) ? 64*1024*1024 : $CFG->apachemaxmem); // 64MB default.
 128             if (memory_get_usage() > get_real_size($limit)) {
 129                 $apachereleasemem = $limit;
 130                 @apache_child_terminate();
 131             }
 132         }
 133
 134         // Deal with perf logging.
 135         if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
 136             if ($apachereleasemem) {
 137                 error_log('Mem usage over '.$apachereleasemem.': marking Apache child for reaping.');
 138             }
 139             if (defined('MDL_PERFTOLOG')) {
 140                 $perf = get_performance_info();
 141                 error_log("PERF: " . $perf['txt']);
 142             }
 143             if (defined('MDL_PERFINC')) {
 144                 $inc = get_included_files();
 145                 $ts  = 0;
 146                 foreach ($inc as $f) {
 147                     if (preg_match(':^/:', $f)) {
 148                         $fs = filesize($f);
 149                         $ts += $fs;
 150                         $hfs = display_size($fs);
 151                         error_log(substr($f, strlen($CFG->dirroot)) . " size: $fs ($hfs)", null, null, 0);
 152                     } else {
 153                         error_log($f , null, null, 0);
 154                     }
 155                 }
 156                 if ($ts > 0 ) {
 157                     $hts = display_size($ts);
 158                     error_log("Total size of files included: $ts ($hts)");
 159                 }
 160             }
 161         }
 162     }
 163 }