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Differences Between: [Versions 310 and 311] [Versions 310 and 400] [Versions 310 and 401] [Versions 310 and 402] [Versions 310 and 403]

   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 = [];
  37      /** @var array list of custom signal callbacks */
  38      protected static $signalcallbacks = [];
  39      /** @var bool is this manager already registered? */
  40      protected static $registered = false;
  41  
  42      /**
  43       * Register self as main shutdown handler.
  44       *
  45       * @private to be called from lib/setup.php only!
  46       */
  47      public static function initialize() {
  48          if (self::$registered) {
  49              debugging('Shutdown manager is already initialised!');
  50          }
  51          self::$registered = true;
  52          register_shutdown_function(array('core_shutdown_manager', 'shutdown_handler'));
  53  
  54          // Signal handlers should only be used when dealing with a CLI script.
  55          // In the case of PHP called in a web server the server is the owning process and should handle the signal chain
  56          // properly itself.
  57          // The 'pcntl' extension is optional and not available on Windows.
  58          if (CLI_SCRIPT && extension_loaded('pcntl') && function_exists('pcntl_async_signals')) {
  59              // We capture and handle SIGINT (Ctrl+C) and SIGTERM (termination requested).
  60              pcntl_async_signals(true);
  61              pcntl_signal(SIGINT, ['core_shutdown_manager', 'signal_handler']);
  62              pcntl_signal(SIGTERM, ['core_shutdown_manager', 'signal_handler']);
  63          }
  64      }
  65  
  66      /**
  67       * Signal handler for SIGINT, and SIGTERM.
  68       *
  69       * @param   int     $signo The signal being handled
  70       */
  71      public static function signal_handler(int $signo) {
  72          // Note: There is no need to manually call the shutdown handler.
  73          // The fact that we are calling exit() in this script means that the standard shutdown handling is performed
  74          // anyway.
  75          switch ($signo) {
  76              case SIGTERM:
  77                  // Replicate native behaviour.
  78                  echo "Terminated: {$signo}\n";
  79  
  80                  // The standard exit code for SIGTERM is 143.
  81                  $exitcode = 143;
  82                  break;
  83              case SIGINT:
  84                  // Replicate native behaviour.
  85                  echo "\n";
  86  
  87                  // The standard exit code for SIGINT (Ctrl+C) is 130.
  88                  $exitcode = 130;
  89                  break;
  90              default:
  91                  // The signal handler was called with a signal it was not expecting.
  92                  // We should exit and complain.
  93                  echo "Warning: \core_shutdown_manager::signal_handler() was called with an unexpected signal ({$signo}).\n";
  94                  $exitcode = 1;
  95          }
  96  
  97          // Normally we should exit unless a callback tells us to wait.
  98          $shouldexit = true;
  99          foreach (self::$signalcallbacks as $data) {
 100              list($callback, $params) = $data;
 101              try {
 102                  array_unshift($params, $signo);
 103                  $shouldexit = call_user_func_array($callback, $params) && $shouldexit;
 104              } catch (Throwable $e) {
 105                  // @codingStandardsIgnoreStart
 106                  error_log('Exception ignored in signal function ' . get_callable_name($callback) . ': ' . $e->getMessage());
 107                  // @codingStandardsIgnoreEnd
 108              }
 109          }
 110  
 111          if ($shouldexit) {
 112              exit ($exitcode);
 113          }
 114      }
 115  
 116      /**
 117       * Register custom signal handler function.
 118       *
 119       * If a handler returns false the signal will be ignored.
 120       *
 121       * @param callable $callback
 122       * @param array $params
 123       * @return void
 124       */
 125      public static function register_signal_handler($callback, array $params = null): void {
 126          if (!is_callable($callback)) {
 127              // @codingStandardsIgnoreStart
 128              error_log('Invalid custom signal function detected ' . var_export($callback, true));
 129              // @codingStandardsIgnoreEnd
 130          }
 131          self::$signalcallbacks[] = [$callback, $params ?? []];
 132      }
 133  
 134      /**
 135       * Register custom shutdown function.
 136       *
 137       * @param callable $callback
 138       * @param array $params
 139       * @return void
 140       */
 141      public static function register_function($callback, array $params = null): void {
 142          if (!is_callable($callback)) {
 143              // @codingStandardsIgnoreStart
 144              error_log('Invalid custom shutdown function detected '.var_export($callback, true));
 145              // @codingStandardsIgnoreEnd
 146          }
 147          self::$callbacks[] = [$callback, $params ?? []];
 148      }
 149  
 150      /**
 151       * @private - do NOT call directly.
 152       */
 153      public static function shutdown_handler() {
 154          global $DB;
 155  
 156          // Custom stuff first.
 157          foreach (self::$callbacks as $data) {
 158              list($callback, $params) = $data;
 159              try {
 160                  call_user_func_array($callback, $params);
 161              } catch (Throwable $e) {
 162                  // @codingStandardsIgnoreStart
 163                  error_log('Exception ignored in shutdown function '.get_callable_name($callback).': '.$e->getMessage());
 164                  // @codingStandardsIgnoreEnd
 165              }
 166          }
 167  
 168          // Handle DB transactions, session need to be written afterwards
 169          // in order to maintain consistency in all session handlers.
 170          if ($DB->is_transaction_started()) {
 171              if (!defined('PHPUNIT_TEST') or !PHPUNIT_TEST) {
 172                  // This should not happen, it usually indicates wrong catching of exceptions,
 173                  // because all transactions should be finished manually or in default exception handler.
 174                  $backtrace = $DB->get_transaction_start_backtrace();
 175                  error_log('Potential coding error - active database transaction detected during request shutdown:'."\n".format_backtrace($backtrace, true));
 176              }
 177              $DB->force_transaction_rollback();
 178          }
 179  
 180          // Close sessions - do it here to make it consistent for all session handlers.
 181          \core\session\manager::write_close();
 182  
 183          // Other cleanup.
 184          self::request_shutdown();
 185  
 186          // Stop profiling.
 187          if (function_exists('profiling_is_running')) {
 188              if (profiling_is_running()) {
 189                  profiling_stop();
 190              }
 191          }
 192  
 193          // NOTE: do not dispose $DB and MUC here, they might be used from legacy shutdown functions.
 194      }
 195  
 196      /**
 197       * Standard shutdown sequence.
 198       */
 199      protected static function request_shutdown() {
 200          global $CFG;
 201  
 202          // Help apache server if possible.
 203          $apachereleasemem = false;
 204          if (function_exists('apache_child_terminate') && function_exists('memory_get_usage') && ini_get_bool('child_terminate')) {
 205              $limit = (empty($CFG->apachemaxmem) ? 64*1024*1024 : $CFG->apachemaxmem); // 64MB default.
 206              if (memory_get_usage() > get_real_size($limit)) {
 207                  $apachereleasemem = $limit;
 208                  @apache_child_terminate();
 209              }
 210          }
 211  
 212          // Deal with perf logging.
 213          if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
 214              if ($apachereleasemem) {
 215                  error_log('Mem usage over '.$apachereleasemem.': marking Apache child for reaping.');
 216              }
 217              if (defined('MDL_PERFTOLOG')) {
 218                  $perf = get_performance_info();
 219                  error_log("PERF: " . $perf['txt']);
 220              }
 221              if (defined('MDL_PERFINC')) {
 222                  $inc = get_included_files();
 223                  $ts  = 0;
 224                  foreach ($inc as $f) {
 225                      if (preg_match(':^/:', $f)) {
 226                          $fs = filesize($f);
 227                          $ts += $fs;
 228                          $hfs = display_size($fs);
 229                          error_log(substr($f, strlen($CFG->dirroot)) . " size: $fs ($hfs)", null, null, 0);
 230                      } else {
 231                          error_log($f , null, null, 0);
 232                      }
 233                  }
 234                  if ($ts > 0 ) {
 235                      $hts = display_size($ts);
 236                      error_log("Total size of files included: $ts ($hts)");
 237                  }
 238              }
 239          }
 240      }
 241  }