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Differences Between: [Versions 39 and 310] [Versions 39 and 311] [Versions 39 and 400] [Versions 39 and 401] [Versions 39 and 402] [Versions 39 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   * Cron functions.
  19   *
  20   * @package    core
  21   * @subpackage admin
  22   * @copyright  1999 onwards Martin Dougiamas  http://dougiamas.com
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  /**
  27   * Execute cron tasks
  28   */
  29  function cron_run() {
  30      global $DB, $CFG, $OUTPUT;
  31  
  32      if (CLI_MAINTENANCE) {
  33          echo "CLI maintenance mode active, cron execution suspended.\n";
  34          exit(1);
  35      }
  36  
  37      if (moodle_needs_upgrading()) {
  38          echo "Moodle upgrade pending, cron execution suspended.\n";
  39          exit(1);
  40      }
  41  
  42      require_once($CFG->libdir.'/adminlib.php');
  43  
  44      if (!empty($CFG->showcronsql)) {
  45          $DB->set_debug(true);
  46      }
  47      if (!empty($CFG->showcrondebugging)) {
  48          set_debugging(DEBUG_DEVELOPER, true);
  49      }
  50  
  51      core_php_time_limit::raise();
  52      $starttime = microtime();
  53  
  54      // Increase memory limit
  55      raise_memory_limit(MEMORY_EXTRA);
  56  
  57      // Emulate normal session - we use admin accoutn by default
  58      cron_setup_user();
  59  
  60      // Start output log
  61      $timenow  = time();
  62      mtrace("Server Time: ".date('r', $timenow)."\n\n");
  63  
  64      // Record start time and interval between the last cron runs.
  65      $laststart = get_config('tool_task', 'lastcronstart');
  66      set_config('lastcronstart', $timenow, 'tool_task');
  67      if ($laststart) {
  68          // Record the interval between last two runs (always store at least 1 second).
  69          set_config('lastcroninterval', max(1, $timenow - $laststart), 'tool_task');
  70      }
  71  
  72      // Run all scheduled tasks.
  73      cron_run_scheduled_tasks($timenow);
  74  
  75      // Run adhoc tasks.
  76      cron_run_adhoc_tasks($timenow);
  77  
  78      mtrace("Cron script completed correctly");
  79  
  80      gc_collect_cycles();
  81      mtrace('Cron completed at ' . date('H:i:s') . '. Memory used ' . display_size(memory_get_usage()) . '.');
  82      $difftime = microtime_diff($starttime, microtime());
  83      mtrace("Execution took ".$difftime." seconds");
  84  }
  85  
  86  /**
  87   * Execute all queued scheduled tasks, applying necessary concurrency limits and time limits.
  88   *
  89   * @param   int     $timenow The time this process started.
  90   * @throws \moodle_exception
  91   */
  92  function cron_run_scheduled_tasks(int $timenow) {
  93      // Allow a restriction on the number of scheduled task runners at once.
  94      $cronlockfactory = \core\lock\lock_config::get_lock_factory('cron');
  95      $maxruns = get_config('core', 'task_scheduled_concurrency_limit');
  96      $maxruntime = get_config('core', 'task_scheduled_max_runtime');
  97  
  98      $scheduledlock = null;
  99      for ($run = 0; $run < $maxruns; $run++) {
 100          // If we can't get a lock instantly it means runner N is already running
 101          // so fail as fast as possible and try N+1 so we don't limit the speed at
 102          // which we bring new runners into the pool.
 103          if ($scheduledlock = $cronlockfactory->get_lock("scheduled_task_runner_{$run}", 0)) {
 104              break;
 105          }
 106      }
 107  
 108      if (!$scheduledlock) {
 109          mtrace("Skipping processing of scheduled tasks. Concurrency limit reached.");
 110          return;
 111      }
 112  
 113      $starttime = time();
 114  
 115      // Run all scheduled tasks.
 116      try {
 117          while (!\core\local\cli\shutdown::should_gracefully_exit() &&
 118                  !\core\task\manager::static_caches_cleared_since($timenow) &&
 119                  $task = \core\task\manager::get_next_scheduled_task($timenow)) {
 120              cron_run_inner_scheduled_task($task);
 121              unset($task);
 122  
 123              if ((time() - $starttime) > $maxruntime) {
 124                  mtrace("Stopping processing of scheduled tasks as time limit has been reached.");
 125                  break;
 126              }
 127          }
 128      } finally {
 129          // Release the scheduled task runner lock.
 130          $scheduledlock->release();
 131      }
 132  }
 133  
 134  /**
 135   * Execute all queued adhoc tasks, applying necessary concurrency limits and time limits.
 136   *
 137   * @param   int     $timenow The time this process started.
 138   * @param   int     $keepalive Keep this function alive for N seconds and poll for new adhoc tasks.
 139   * @param   bool    $checklimits Should we check limits?
 140   * @throws \moodle_exception
 141   */
 142  function cron_run_adhoc_tasks(int $timenow, $keepalive = 0, $checklimits = true) {
 143      // Allow a restriction on the number of adhoc task runners at once.
 144      $cronlockfactory = \core\lock\lock_config::get_lock_factory('cron');
 145      $maxruns = get_config('core', 'task_adhoc_concurrency_limit');
 146      $maxruntime = get_config('core', 'task_adhoc_max_runtime');
 147  
 148      if ($checklimits) {
 149          $adhoclock = null;
 150          for ($run = 0; $run < $maxruns; $run++) {
 151              // If we can't get a lock instantly it means runner N is already running
 152              // so fail as fast as possible and try N+1 so we don't limit the speed at
 153              // which we bring new runners into the pool.
 154              if ($adhoclock = $cronlockfactory->get_lock("adhoc_task_runner_{$run}", 0)) {
 155                  break;
 156              }
 157          }
 158  
 159          if (!$adhoclock) {
 160              mtrace("Skipping processing of adhoc tasks. Concurrency limit reached.");
 161              return;
 162          }
 163      }
 164  
 165      $humantimenow = date('r', $timenow);
 166      $finishtime = $timenow + $keepalive;
 167      $waiting = false;
 168      $taskcount = 0;
 169  
 170      // Run all adhoc tasks.
 171      while (!\core\local\cli\shutdown::should_gracefully_exit() &&
 172              !\core\task\manager::static_caches_cleared_since($timenow)) {
 173  
 174          if ($checklimits && (time() - $timenow) >= $maxruntime) {
 175              if ($waiting) {
 176                  $waiting = false;
 177                  mtrace('');
 178              }
 179              mtrace("Stopping processing of adhoc tasks as time limit has been reached.");
 180              break;
 181          }
 182  
 183          try {
 184              $task = \core\task\manager::get_next_adhoc_task(time(), $checklimits);
 185          } catch (\Throwable $e) {
 186              if ($adhoclock) {
 187                  // Release the adhoc task runner lock.
 188                  $adhoclock->release();
 189              }
 190              throw $e;
 191          }
 192  
 193          if ($task) {
 194              if ($waiting) {
 195                  mtrace('');
 196              }
 197              $waiting = false;
 198              cron_run_inner_adhoc_task($task);
 199              $taskcount++;
 200              unset($task);
 201          } else {
 202              if (time() >= $finishtime) {
 203                  break;
 204              }
 205              if (!$waiting) {
 206                  mtrace('Waiting for more adhoc tasks to be queued ', '');
 207              } else {
 208                  mtrace('.', '');
 209              }
 210              $waiting = true;
 211              sleep(1);
 212          }
 213      }
 214  
 215      if ($waiting) {
 216          mtrace('');
 217      }
 218  
 219      mtrace("Ran {$taskcount} adhoc tasks found at {$humantimenow}");
 220  
 221      if ($adhoclock) {
 222          // Release the adhoc task runner lock.
 223          $adhoclock->release();
 224      }
 225  }
 226  
 227  /**
 228   * Shared code that handles running of a single scheduled task within the cron.
 229   *
 230   * Not intended for calling directly outside of this library!
 231   *
 232   * @param \core\task\task_base $task
 233   */
 234  function cron_run_inner_scheduled_task(\core\task\task_base $task) {
 235      global $CFG, $DB;
 236  
 237      \core\task\logmanager::start_logging($task);
 238  
 239      $fullname = $task->get_name() . ' (' . get_class($task) . ')';
 240      mtrace('Execute scheduled task: ' . $fullname);
 241      cron_trace_time_and_memory();
 242      $predbqueries = null;
 243      $predbqueries = $DB->perf_get_queries();
 244      $pretime = microtime(1);
 245  
 246      // Ensure that we have a clean session with the correct cron user.
 247      cron_setup_user();
 248  
 249      try {
 250          get_mailer('buffer');
 251          cron_prepare_core_renderer();
 252          $task->execute();
 253          if ($DB->is_transaction_started()) {
 254              throw new coding_exception("Task left transaction open");
 255          }
 256          if (isset($predbqueries)) {
 257              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 258              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 259          }
 260          mtrace('Scheduled task complete: ' . $fullname);
 261          \core\task\manager::scheduled_task_complete($task);
 262      } catch (\Throwable $e) {
 263          if ($DB && $DB->is_transaction_started()) {
 264              error_log('Database transaction aborted automatically in ' . get_class($task));
 265              $DB->force_transaction_rollback();
 266          }
 267          if (isset($predbqueries)) {
 268              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 269              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 270          }
 271          mtrace('Scheduled task failed: ' . $fullname . ',' . $e->getMessage());
 272          if ($CFG->debugdeveloper) {
 273              if (!empty($e->debuginfo)) {
 274                  mtrace("Debug info:");
 275                  mtrace($e->debuginfo);
 276              }
 277              mtrace("Backtrace:");
 278              mtrace(format_backtrace($e->getTrace(), true));
 279          }
 280          \core\task\manager::scheduled_task_failed($task);
 281      } finally {
 282          // Reset back to the standard admin user.
 283          cron_setup_user();
 284          cron_prepare_core_renderer(true);
 285      }
 286      get_mailer('close');
 287  }
 288  
 289  /**
 290   * Shared code that handles running of a single adhoc task within the cron.
 291   *
 292   * @param \core\task\adhoc_task $task
 293   */
 294  function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) {
 295      global $DB, $CFG;
 296  
 297      \core\task\logmanager::start_logging($task);
 298  
 299      mtrace("Execute adhoc task: " . get_class($task));
 300      cron_trace_time_and_memory();
 301      $predbqueries = null;
 302      $predbqueries = $DB->perf_get_queries();
 303      $pretime      = microtime(1);
 304  
 305      if ($userid = $task->get_userid()) {
 306          // This task has a userid specified.
 307          if ($user = \core_user::get_user($userid)) {
 308              // User found. Check that they are suitable.
 309              try {
 310                  \core_user::require_active_user($user, true, true);
 311              } catch (moodle_exception $e) {
 312                  mtrace("User {$userid} cannot be used to run an adhoc task: " . get_class($task) . ". Cancelling task.");
 313                  $user = null;
 314              }
 315          } else {
 316              // Unable to find the user for this task.
 317              // A user missing in the database will never reappear.
 318              mtrace("User {$userid} could not be found for adhoc task: " . get_class($task) . ". Cancelling task.");
 319          }
 320  
 321          if (empty($user)) {
 322              // A user missing in the database will never reappear so the task needs to be failed to ensure that locks are removed,
 323              // and then removed to prevent future runs.
 324              // A task running as a user should only be run as that user.
 325              \core\task\manager::adhoc_task_failed($task);
 326              $DB->delete_records('task_adhoc', ['id' => $task->get_id()]);
 327  
 328              return;
 329          }
 330  
 331          cron_setup_user($user);
 332      } else {
 333          // No user specified, ensure that we have a clean session with the correct cron user.
 334          cron_setup_user();
 335  
 336      }
 337  
 338      try {
 339          get_mailer('buffer');
 340          cron_prepare_core_renderer();
 341          $task->execute();
 342          if ($DB->is_transaction_started()) {
 343              throw new coding_exception("Task left transaction open");
 344          }
 345          if (isset($predbqueries)) {
 346              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 347              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 348          }
 349          mtrace("Adhoc task complete: " . get_class($task));
 350          \core\task\manager::adhoc_task_complete($task);
 351      } catch (\Throwable $e) {
 352          if ($DB && $DB->is_transaction_started()) {
 353              error_log('Database transaction aborted automatically in ' . get_class($task));
 354              $DB->force_transaction_rollback();
 355          }
 356          if (isset($predbqueries)) {
 357              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 358              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 359          }
 360          mtrace("Adhoc task failed: " . get_class($task) . "," . $e->getMessage());
 361          if ($CFG->debugdeveloper) {
 362              if (!empty($e->debuginfo)) {
 363                  mtrace("Debug info:");
 364                  mtrace($e->debuginfo);
 365              }
 366              mtrace("Backtrace:");
 367              mtrace(format_backtrace($e->getTrace(), true));
 368          }
 369          \core\task\manager::adhoc_task_failed($task);
 370      } finally {
 371          // Reset back to the standard admin user.
 372          cron_setup_user();
 373          cron_prepare_core_renderer(true);
 374      }
 375      get_mailer('close');
 376  }
 377  
 378  /**
 379   * Output some standard information during cron runs. Specifically current time
 380   * and memory usage. This method also does gc_collect_cycles() (before displaying
 381   * memory usage) to try to help PHP manage memory better.
 382   */
 383  function cron_trace_time_and_memory() {
 384      gc_collect_cycles();
 385      mtrace('... started ' . date('H:i:s') . '. Current memory use ' . display_size(memory_get_usage()) . '.');
 386  }
 387  
 388  /**
 389   * Prepare the output renderer for the cron run.
 390   *
 391   * This involves creating a new $PAGE, and $OUTPUT fresh for each task and prevents any one task from influencing
 392   * any other.
 393   *
 394   * @param   bool    $restore Whether to restore the original PAGE and OUTPUT
 395   */
 396  function cron_prepare_core_renderer($restore = false) {
 397      global $OUTPUT, $PAGE;
 398  
 399      // Store the original PAGE and OUTPUT values so that they can be reset at a later point to the original.
 400      // This should not normally be required, but may be used in places such as the scheduled task tool's "Run now"
 401      // functionality.
 402      static $page = null;
 403      static $output = null;
 404  
 405      if (null === $page) {
 406          $page = $PAGE;
 407      }
 408  
 409      if (null === $output) {
 410          $output = $OUTPUT;
 411      }
 412  
 413      if (!empty($restore)) {
 414          $PAGE = $page;
 415          $page = null;
 416  
 417          $OUTPUT = $output;
 418          $output = null;
 419      } else {
 420          // Setup a new General renderer.
 421          // Cron tasks may produce output to be used in web, so we must use the appropriate renderer target.
 422          // This allows correct use of templates, etc.
 423          $PAGE = new \moodle_page();
 424          $OUTPUT = new \core_renderer($PAGE, RENDERER_TARGET_GENERAL);
 425      }
 426  }