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 */ 29function 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 */ 92function 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 */ 142function 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 */ 234function 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 try { 246 get_mailer('buffer'); 247 cron_prepare_core_renderer(); 248 $task->execute(); 249 if ($DB->is_transaction_started()) { 250 throw new coding_exception("Task left transaction open"); 251 } 252 if (isset($predbqueries)) { 253 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries"); 254 mtrace("... used " . (microtime(1) - $pretime) . " seconds"); 255 } 256 mtrace('Scheduled task complete: ' . $fullname); 257 \core\task\manager::scheduled_task_complete($task); 258 } catch (\Throwable $e) { 259 if ($DB && $DB->is_transaction_started()) { 260 error_log('Database transaction aborted automatically in ' . get_class($task)); 261 $DB->force_transaction_rollback(); 262 } 263 if (isset($predbqueries)) { 264 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries"); 265 mtrace("... used " . (microtime(1) - $pretime) . " seconds"); 266 } 267 mtrace('Scheduled task failed: ' . $fullname . ',' . $e->getMessage()); 268 if ($CFG->debugdeveloper) { 269 if (!empty($e->debuginfo)) { 270 mtrace("Debug info:"); 271 mtrace($e->debuginfo); 272 } 273 mtrace("Backtrace:"); 274 mtrace(format_backtrace($e->getTrace(), true)); 275 } 276 \core\task\manager::scheduled_task_failed($task); 277 } finally { 278 // Reset back to the standard admin user. 279 cron_setup_user(); 280 cron_prepare_core_renderer(true); 281 } 282 get_mailer('close'); 283} 284 285/** 286 * Shared code that handles running of a single adhoc task within the cron. 287 * 288 * @param \core\task\adhoc_task $task 289 */ 290function cron_run_inner_adhoc_task(\core\task\adhoc_task $task) { 291 global $DB, $CFG; 292 293 \core\task\logmanager::start_logging($task); 294 295 mtrace("Execute adhoc task: " . get_class($task)); 296 cron_trace_time_and_memory(); 297 $predbqueries = null; 298 $predbqueries = $DB->perf_get_queries(); 299 $pretime = microtime(1); 300 301 if ($userid = $task->get_userid()) { 302 // This task has a userid specified. 303 if ($user = \core_user::get_user($userid)) { 304 // User found. Check that they are suitable. 305 try { 306 \core_user::require_active_user($user, true, true); 307 } catch (moodle_exception $e) { 308 mtrace("User {$userid} cannot be used to run an adhoc task: " . get_class($task) . ". Cancelling task."); 309 $user = null; 310 } 311 } else { 312 // Unable to find the user for this task. 313 // A user missing in the database will never reappear. 314 mtrace("User {$userid} could not be found for adhoc task: " . get_class($task) . ". Cancelling task."); 315 } 316 317 if (empty($user)) { 318 // A user missing in the database will never reappear so the task needs to be failed to ensure that locks are removed, 319 // and then removed to prevent future runs. 320 // A task running as a user should only be run as that user. 321 \core\task\manager::adhoc_task_failed($task); 322 $DB->delete_records('task_adhoc', ['id' => $task->get_id()]); 323 324 return; 325 } 326 327 cron_setup_user($user); 328 } 329 330 try { 331 get_mailer('buffer'); 332 cron_prepare_core_renderer(); 333 $task->execute(); 334 if ($DB->is_transaction_started()) { 335 throw new coding_exception("Task left transaction open"); 336 } 337 if (isset($predbqueries)) { 338 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries"); 339 mtrace("... used " . (microtime(1) - $pretime) . " seconds"); 340 } 341 mtrace("Adhoc task complete: " . get_class($task)); 342 \core\task\manager::adhoc_task_complete($task); 343 } catch (\Throwable $e) { 344 if ($DB && $DB->is_transaction_started()) { 345 error_log('Database transaction aborted automatically in ' . get_class($task)); 346 $DB->force_transaction_rollback(); 347 } 348 if (isset($predbqueries)) { 349 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries"); 350 mtrace("... used " . (microtime(1) - $pretime) . " seconds"); 351 } 352 mtrace("Adhoc task failed: " . get_class($task) . "," . $e->getMessage()); 353 if ($CFG->debugdeveloper) { 354 if (!empty($e->debuginfo)) { 355 mtrace("Debug info:"); 356 mtrace($e->debuginfo); 357 } 358 mtrace("Backtrace:"); 359 mtrace(format_backtrace($e->getTrace(), true)); 360 } 361 \core\task\manager::adhoc_task_failed($task); 362 } finally { 363 // Reset back to the standard admin user. 364 cron_setup_user(); 365 cron_prepare_core_renderer(true); 366 } 367 get_mailer('close'); 368} 369 370/** 371 * Output some standard information during cron runs. Specifically current time 372 * and memory usage. This method also does gc_collect_cycles() (before displaying 373 * memory usage) to try to help PHP manage memory better. 374 */ 375function cron_trace_time_and_memory() { 376 gc_collect_cycles(); 377 mtrace('... started ' . date('H:i:s') . '. Current memory use ' . display_size(memory_get_usage()) . '.'); 378} 379 380/** 381 * Prepare the output renderer for the cron run. 382 * 383 * This involves creating a new $PAGE, and $OUTPUT fresh for each task and prevents any one task from influencing 384 * any other. 385 * 386 * @param bool $restore Whether to restore the original PAGE and OUTPUT 387 */ 388function cron_prepare_core_renderer($restore = false) { 389 global $OUTPUT, $PAGE; 390 391 // Store the original PAGE and OUTPUT values so that they can be reset at a later point to the original. 392 // This should not normally be required, but may be used in places such as the scheduled task tool's "Run now" 393 // functionality. 394 static $page = null; 395 static $output = null; 396 397 if (null === $page) { 398 $page = $PAGE; 399 } 400 401 if (null === $output) { 402 $output = $OUTPUT; 403 } 404 405 if (!empty($restore)) { 406 $PAGE = $page; 407 $page = null; 408 409 $OUTPUT = $output; 410 $output = null; 411 } else { 412 // Setup a new General renderer. 413 // Cron tasks may produce output to be used in web, so we must use the appropriate renderer target. 414 // This allows correct use of templates, etc. 415 $PAGE = new \moodle_page(); 416 $OUTPUT = new \core_renderer($PAGE, RENDERER_TARGET_GENERAL); 417 } 418} 419