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Differences Between: [Versions 310 and 311] [Versions 311 and 401] [Versions 311 and 402] [Versions 311 and 403] [Versions 39 and 311]

   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              cron_set_process_title("Waiting for next adhoc task");
 200              $taskcount++;
 201              unset($task);
 202          } else {
 203              $timeleft = $finishtime - time();
 204              if ($timeleft <= 0) {
 205                  break;
 206              }
 207              if (!$waiting) {
 208                  mtrace('Waiting for more adhoc tasks to be queued ', '');
 209              } else {
 210                  mtrace('.', '');
 211              }
 212              $waiting = true;
 213              cron_set_process_title("Waiting {$timeleft}s for next adhoc task");
 214              sleep(1);
 215          }
 216      }
 217  
 218      if ($waiting) {
 219          mtrace('');
 220      }
 221  
 222      mtrace("Ran {$taskcount} adhoc tasks found at {$humantimenow}");
 223  
 224      if ($adhoclock) {
 225          // Release the adhoc task runner lock.
 226          $adhoclock->release();
 227      }
 228  }
 229  
 230  /**
 231   * Shared code that handles running of a single scheduled task within the cron.
 232   *
 233   * Not intended for calling directly outside of this library!
 234   *
 235   * @param \core\task\task_base $task
 236   */
 237  function cron_run_inner_scheduled_task(\core\task\task_base $task) {
 238      global $CFG, $DB;
 239  
 240      \core\task\manager::scheduled_task_starting($task);
 241      \core\task\logmanager::start_logging($task);
 242  
 243      $fullname = $task->get_name() . ' (' . get_class($task) . ')';
 244      mtrace('Execute scheduled task: ' . $fullname);
 245      cron_set_process_title('Scheduled task: ' . get_class($task));
 246      cron_trace_time_and_memory();
 247      $predbqueries = null;
 248      $predbqueries = $DB->perf_get_queries();
 249      $pretime = microtime(1);
 250  
 251      // Ensure that we have a clean session with the correct cron user.
 252      cron_setup_user();
 253  
 254      try {
 255          get_mailer('buffer');
 256          cron_prepare_core_renderer();
 257          $task->execute();
 258          if ($DB->is_transaction_started()) {
 259              throw new coding_exception("Task left transaction open");
 260          }
 261          if (isset($predbqueries)) {
 262              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 263              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 264          }
 265          mtrace('Scheduled task complete: ' . $fullname);
 266          \core\task\manager::scheduled_task_complete($task);
 267      } catch (\Throwable $e) {
 268          if ($DB && $DB->is_transaction_started()) {
 269              error_log('Database transaction aborted automatically in ' . get_class($task));
 270              $DB->force_transaction_rollback();
 271          }
 272          if (isset($predbqueries)) {
 273              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 274              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 275          }
 276          mtrace('Scheduled task failed: ' . $fullname . ',' . $e->getMessage());
 277          if ($CFG->debugdeveloper) {
 278              if (!empty($e->debuginfo)) {
 279                  mtrace("Debug info:");
 280                  mtrace($e->debuginfo);
 281              }
 282              mtrace("Backtrace:");
 283              mtrace(format_backtrace($e->getTrace(), true));
 284          }
 285          \core\task\manager::scheduled_task_failed($task);
 286      } finally {
 287          // Reset back to the standard admin user.
 288          cron_setup_user();
 289          cron_set_process_title('Waiting for next scheduled task');
 290          cron_prepare_core_renderer(true);
 291      }
 292      get_mailer('close');
 293  }
 294  
 295  /**
 296   * Shared code that handles running of a single adhoc task within the cron.
 297   *
 298   * @param \core\task\adhoc_task $task
 299   */
 300  function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) {
 301      global $DB, $CFG;
 302  
 303      \core\task\manager::adhoc_task_starting($task);
 304      \core\task\logmanager::start_logging($task);
 305  
 306      mtrace("Execute adhoc task: " . get_class($task));
 307      cron_set_process_title('Adhoc task: ' . $task->get_id() . ' ' . get_class($task));
 308      cron_trace_time_and_memory();
 309      $predbqueries = null;
 310      $predbqueries = $DB->perf_get_queries();
 311      $pretime      = microtime(1);
 312  
 313      if ($userid = $task->get_userid()) {
 314          // This task has a userid specified.
 315          if ($user = \core_user::get_user($userid)) {
 316              // User found. Check that they are suitable.
 317              try {
 318                  \core_user::require_active_user($user, true, true);
 319              } catch (moodle_exception $e) {
 320                  mtrace("User {$userid} cannot be used to run an adhoc task: " . get_class($task) . ". Cancelling task.");
 321                  $user = null;
 322              }
 323          } else {
 324              // Unable to find the user for this task.
 325              // A user missing in the database will never reappear.
 326              mtrace("User {$userid} could not be found for adhoc task: " . get_class($task) . ". Cancelling task.");
 327          }
 328  
 329          if (empty($user)) {
 330              // A user missing in the database will never reappear so the task needs to be failed to ensure that locks are removed,
 331              // and then removed to prevent future runs.
 332              // A task running as a user should only be run as that user.
 333              \core\task\manager::adhoc_task_failed($task);
 334              $DB->delete_records('task_adhoc', ['id' => $task->get_id()]);
 335  
 336              return;
 337          }
 338  
 339          cron_setup_user($user);
 340      } else {
 341          // No user specified, ensure that we have a clean session with the correct cron user.
 342          cron_setup_user();
 343  
 344      }
 345  
 346      try {
 347          get_mailer('buffer');
 348          cron_prepare_core_renderer();
 349          $task->execute();
 350          if ($DB->is_transaction_started()) {
 351              throw new coding_exception("Task left transaction open");
 352          }
 353          if (isset($predbqueries)) {
 354              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 355              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 356          }
 357          mtrace("Adhoc task complete: " . get_class($task));
 358          \core\task\manager::adhoc_task_complete($task);
 359      } catch (\Throwable $e) {
 360          if ($DB && $DB->is_transaction_started()) {
 361              error_log('Database transaction aborted automatically in ' . get_class($task));
 362              $DB->force_transaction_rollback();
 363          }
 364          if (isset($predbqueries)) {
 365              mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
 366              mtrace("... used " . (microtime(1) - $pretime) . " seconds");
 367          }
 368          mtrace("Adhoc task failed: " . get_class($task) . "," . $e->getMessage());
 369          if ($CFG->debugdeveloper) {
 370              if (!empty($e->debuginfo)) {
 371                  mtrace("Debug info:");
 372                  mtrace($e->debuginfo);
 373              }
 374              mtrace("Backtrace:");
 375              mtrace(format_backtrace($e->getTrace(), true));
 376          }
 377          \core\task\manager::adhoc_task_failed($task);
 378      } finally {
 379          // Reset back to the standard admin user.
 380          cron_setup_user();
 381          cron_prepare_core_renderer(true);
 382      }
 383      get_mailer('close');
 384  }
 385  
 386  /**
 387   * Sets the process title
 388   *
 389   * This makes it very easy for a sysadmin to immediately see what task
 390   * a cron process is running at any given moment.
 391   *
 392   * @param string $title process status title
 393   */
 394  function cron_set_process_title(string $title) {
 395      global $CFG;
 396      if (CLI_SCRIPT) {
 397          require_once($CFG->libdir . '/clilib.php');
 398          $datetime = userdate(time(), '%b %d, %H:%M:%S');
 399          cli_set_process_title_suffix("$datetime $title");
 400      }
 401  }
 402  
 403  /**
 404   * Output some standard information during cron runs. Specifically current time
 405   * and memory usage. This method also does gc_collect_cycles() (before displaying
 406   * memory usage) to try to help PHP manage memory better.
 407   */
 408  function cron_trace_time_and_memory() {
 409      gc_collect_cycles();
 410      mtrace('... started ' . date('H:i:s') . '. Current memory use ' . display_size(memory_get_usage()) . '.');
 411  }
 412  
 413  /**
 414   * Prepare the output renderer for the cron run.
 415   *
 416   * This involves creating a new $PAGE, and $OUTPUT fresh for each task and prevents any one task from influencing
 417   * any other.
 418   *
 419   * @param   bool    $restore Whether to restore the original PAGE and OUTPUT
 420   */
 421  function cron_prepare_core_renderer($restore = false) {
 422      global $OUTPUT, $PAGE;
 423  
 424      // Store the original PAGE and OUTPUT values so that they can be reset at a later point to the original.
 425      // This should not normally be required, but may be used in places such as the scheduled task tool's "Run now"
 426      // functionality.
 427      static $page = null;
 428      static $output = null;
 429  
 430      if (null === $page) {
 431          $page = $PAGE;
 432      }
 433  
 434      if (null === $output) {
 435          $output = $OUTPUT;
 436      }
 437  
 438      if (!empty($restore)) {
 439          $PAGE = $page;
 440          $page = null;
 441  
 442          $OUTPUT = $output;
 443          $output = null;
 444      } else {
 445          // Setup a new General renderer.
 446          // Cron tasks may produce output to be used in web, so we must use the appropriate renderer target.
 447          // This allows correct use of templates, etc.
 448          $PAGE = new \moodle_page();
 449          $OUTPUT = new \core_renderer($PAGE, RENDERER_TARGET_GENERAL);
 450      }
 451  }