src/Core/Worker.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Core;
  23
  24 use Friendica\Core\Worker\Entity\Process;
  25 use Friendica\Database\DBA;
  26 use Friendica\DI;
  27 use Friendica\Util\DateTimeFormat;
  28
  29 /**
  30  * Contains the class for the worker background job processing
  31  */
  32 class Worker
  33 {
  34         /**
  35          * @name Priority
  36          *
  37          * Process priority for the worker
  38          * @{
  39          */
  40         const PRIORITY_UNDEFINED  = 0;
  41         const PRIORITY_CRITICAL   = 10;
  42         const PRIORITY_HIGH       = 20;
  43         const PRIORITY_MEDIUM     = 30;
  44         const PRIORITY_LOW        = 40;
  45         const PRIORITY_NEGLIGIBLE = 50;
  46         const PRIORITIES          = [self::PRIORITY_CRITICAL, self::PRIORITY_HIGH, self::PRIORITY_MEDIUM, self::PRIORITY_LOW, self::PRIORITY_NEGLIGIBLE];
  47         /* @}*/
  48
  49         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  50         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  51         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  52         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  53
  54         const FAST_COMMANDS = ['APDelivery', 'Delivery'];
  55
  56         const LOCK_PROCESS = 'worker_process';
  57         const LOCK_WORKER = 'worker';
  58
  59         private static $up_start;
  60         private static $db_duration = 0;
  61         private static $db_duration_count = 0;
  62         private static $db_duration_write = 0;
  63         private static $db_duration_stat = 0;
  64         private static $lock_duration = 0;
  65         private static $last_update;
  66         private static $state;
  67         /** @var Process */
  68         private static $process;
  69
  70         /**
  71          * Processes the tasks that are in the workerqueue table
  72          *
  73          * @param boolean $run_cron Should the cron processes be executed?
  74          * @param Process $process  The current running process
  75          * @return void
  76          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  77          */
  78         public static function processQueue(bool $run_cron, Process $process)
  79         {
  80                 self::$up_start = microtime(true);
  81
  82                 // At first check the maximum load. We shouldn't continue with a high load
  83                 if (DI::system()->isMaxLoadReached()) {
  84                         Logger::notice('Pre check: maximum load reached, quitting.');
  85                         return;
  86                 }
  87
  88                 // We now start the process. This is done after the load check since this could increase the load.
  89                 self::$process = $process;
  90
  91                 // Kill stale processes every 5 minutes
  92                 $last_cleanup = DI::config()->get('system', 'worker_last_cleaned', 0);
  93                 if (time() > ($last_cleanup + 300)) {
  94                         DI::config()->set('system', 'worker_last_cleaned', time());
  95                         Worker\Cron::killStaleWorkers();
  96                 }
  97
  98                 // Check if the system is ready
  99                 if (!self::isReady()) {
 100                         return;
 101                 }
 102
 103                 // Now we start additional cron processes if we should do so
 104                 if ($run_cron) {
 105                         Worker\Cron::run();
 106                 }
 107
 108                 $last_check = $starttime = time();
 109                 self::$state = self::STATE_STARTUP;
 110
 111                 // We fetch the next queue entry that is about to be executed
 112                 while ($r = self::workerProcess()) {
 113                         if (Worker\IPC::JobsExists(getmypid())) {
 114                                 Worker\IPC::DeleteJobState(getmypid());
 115                         }
 116
 117                         // Don't refetch when a worker fetches tasks for multiple workers
 118                         $refetched = DI::config()->get('system', 'worker_multiple_fetch');
 119                         foreach ($r as $entry) {
 120                                 // The work will be done
 121                                 if (!self::execute($entry)) {
 122                                         Logger::warning('Process execution failed, quitting.', ['entry' => $entry]);
 123                                         return;
 124                                 }
 125
 126                                 // Trying to fetch new processes - but only once when successful
 127                                 if (!$refetched && DI::lock()->acquire(self::LOCK_PROCESS, 0)) {
 128                                         self::findWorkerProcesses();
 129                                         DI::lock()->release(self::LOCK_PROCESS);
 130                                         self::$state = self::STATE_REFETCH;
 131                                         $refetched = true;
 132                                 } else {
 133                                         self::$state = self::STATE_SHORT_LOOP;
 134                                 }
 135                         }
 136
 137                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 138                         if ((time() > $last_check + 5) && !self::getWaitingJobForPID()) {
 139                                 self::$state = self::STATE_LONG_LOOP;
 140
 141                                 if (DI::lock()->acquire(self::LOCK_WORKER, 0)) {
 142                                 // Count active workers and compare them with a maximum value that depends on the load
 143                                         if (self::tooMuchWorkers()) {
 144                                                 Logger::notice('Active worker limit reached, quitting.');
 145                                                 DI::lock()->release(self::LOCK_WORKER);
 146                                                 return;
 147                                         }
 148
 149                                         // Check free memory
 150                                         if (DI::system()->isMinMemoryReached()) {
 151                                                 Logger::warning('Memory limit reached, quitting.');
 152                                                 DI::lock()->release(self::LOCK_WORKER);
 153                                                 return;
 154                                         }
 155                                         DI::lock()->release(self::LOCK_WORKER);
 156                                 }
 157                                 $last_check = time();
 158                         }
 159
 160                         // Quit the worker once every cron interval
 161                         if (time() > ($starttime + (DI::config()->get('system', 'cron_interval') * 60)) && !self::systemLimitReached()) {
 162                                 Logger::info('Process lifetime reached, respawning.');
 163                                 self::unclaimProcess($process);
 164                                 if (Worker\Daemon::isMode()) {
 165                                         Worker\IPC::SetJobState(true);
 166                                 } else {
 167                                         self::spawnWorker();
 168                                 }
 169                                 return;
 170                         }
 171                 }
 172
 173                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 174                 if (Worker\Daemon::isMode()) {
 175                         Worker\IPC::SetJobState(false);
 176                 }
 177                 Logger::info("Couldn't select a workerqueue entry, quitting process", ['pid' => getmypid()]);
 178         }
 179
 180         /**
 181          * Checks if the system is ready.
 182          *
 183          * Several system parameters like memory, connections and processes are checked.
 184          *
 185          * @return boolean
 186          */
 187         public static function isReady(): bool
 188         {
 189                 // Count active workers and compare them with a maximum value that depends on the load
 190                 if (self::tooMuchWorkers()) {
 191                         Logger::notice('Active worker limit reached, quitting.');
 192                         return false;
 193                 }
 194
 195                 // Do we have too few memory?
 196                 if (DI::system()->isMinMemoryReached()) {
 197                         Logger::warning('Memory limit reached, quitting.');
 198                         return false;
 199                 }
 200
 201                 // Possibly there are too much database connections
 202                 if (self::maxConnectionsReached()) {
 203                         Logger::warning('Maximum connections reached, quitting.');
 204                         return false;
 205                 }
 206
 207                 // Possibly there are too much database processes that block the system
 208                 if (DI::system()->isMaxProcessesReached()) {
 209                         Logger::warning('Maximum processes reached, quitting.');
 210                         return false;
 211                 }
 212
 213                 return true;
 214         }
 215
 216         /**
 217          * Check if non executed tasks do exist in the worker queue
 218          *
 219          * @return boolean Returns "true" if tasks are existing
 220          * @throws \Exception
 221          */
 222         public static function entriesExists(): bool
 223         {
 224                 $stamp = (float)microtime(true);
 225                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 226                 self::$db_duration += (microtime(true) - $stamp);
 227                 return $exists;
 228         }
 229
 230         /**
 231          * Returns the number of deferred entries in the worker queue
 232          *
 233          * @return integer Number of deferred entries in the worker queue
 234          * @throws \Exception
 235          */
 236         private static function deferredEntries(): int
 237         {
 238                 $stamp = (float)microtime(true);
 239                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 240                 self::$db_duration += (microtime(true) - $stamp);
 241                 self::$db_duration_count += (microtime(true) - $stamp);
 242                 return $count;
 243         }
 244
 245         /**
 246          * Returns the number of non executed entries in the worker queue
 247          *
 248          * @return integer Number of non executed entries in the worker queue
 249          * @throws \Exception
 250          */
 251         private static function totalEntries(): int
 252         {
 253                 $stamp = (float)microtime(true);
 254                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 255                 self::$db_duration += (microtime(true) - $stamp);
 256                 self::$db_duration_count += (microtime(true) - $stamp);
 257                 return $count;
 258         }
 259
 260         /**
 261          * Returns the highest priority in the worker queue that isn't executed
 262          *
 263          * @return integer Number of active worker processes
 264          * @throws \Exception
 265          */
 266         private static function highestPriority(): int
 267         {
 268                 $stamp = (float)microtime(true);
 269                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 270                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 271                 self::$db_duration += (microtime(true) - $stamp);
 272                 if (DBA::isResult($workerqueue)) {
 273                         return $workerqueue['priority'];
 274                 } else {
 275                         return 0;
 276                 }
 277         }
 278
 279         /**
 280          * Returns if a process with the given priority is running
 281          *
 282          * @param integer $priority The priority that should be checked
 283          *
 284          * @return integer Is there a process running with that priority?
 285          * @throws \Exception
 286          */
 287         private static function processWithPriorityActive(int $priority): int
 288         {
 289                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 290                 return DBA::exists('workerqueue', $condition);
 291         }
 292
 293         /**
 294          * Checks if the given file is valid to be included
 295          *
 296          * @param mixed $file
 297          * @return bool
 298          */
 299         private static function validateInclude(&$file): bool
 300         {
 301                 $orig_file = $file;
 302
 303                 $file = realpath($file);
 304
 305                 if (strpos($file, getcwd()) !== 0) {
 306                         return false;
 307                 }
 308
 309                 $file = str_replace(getcwd() . '/', '', $file, $count);
 310                 if ($count != 1) {
 311                         return false;
 312                 }
 313
 314                 if ($orig_file !== $file) {
 315                         return false;
 316                 }
 317
 318                 $valid = false;
 319                 if (strpos($file, 'include/') === 0) {
 320                         $valid = true;
 321                 }
 322
 323                 if (strpos($file, 'addon/') === 0) {
 324                         $valid = true;
 325                 }
 326
 327                 // Simply return flag
 328                 return $valid;
 329         }
 330
 331         /**
 332          * Execute a worker entry
 333          *
 334          * @param array $queue Workerqueue entry
 335          *
 336          * @return boolean "true" if further processing should be stopped
 337          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 338          */
 339         public static function execute(array $queue): bool
 340         {
 341                 $mypid = getmypid();
 342
 343                 // Quit when in maintenance
 344                 if (DI::config()->get('system', 'maintenance', false, true)) {
 345                         Logger::notice('Maintenance mode - quit process', ['pid' => $mypid]);
 346                         return false;
 347                 }
 348
 349                 // Constantly check the number of parallel database processes
 350                 if (DI::system()->isMaxProcessesReached()) {
 351                         Logger::warning('Max processes reached for process', ['pid' => $mypid]);
 352                         return false;
 353                 }
 354
 355                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 356                 if (self::maxConnectionsReached()) {
 357                         Logger::warning('Max connection reached for process', ['pid' => $mypid]);
 358                         return false;
 359                 }
 360
 361                 $argv = json_decode($queue['parameter'], true);
 362                 if (!is_array($argv)) {
 363                         $argv = [];
 364                 }
 365
 366                 if (!empty($queue['command'])) {
 367                         array_unshift($argv, $queue['command']);
 368                 }
 369
 370                 if (empty($argv)) {
 371                         Logger::warning('Parameter is empty', ['queue' => $queue]);
 372                         return false;
 373                 }
 374
 375                 // Check for existance and validity of the include file
 376                 $include = $argv[0];
 377
 378                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 379                         // We constantly update the "executed" date every minute to avoid being killed too soon
 380                         if (!isset(self::$last_update)) {
 381                                 self::$last_update = strtotime($queue['executed']);
 382                         }
 383
 384                         $age = (time() - self::$last_update) / 60;
 385                         self::$last_update = time();
 386
 387                         if ($age > 1) {
 388                                 $stamp = (float)microtime(true);
 389                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 390                                 self::$db_duration += (microtime(true) - $stamp);
 391                                 self::$db_duration_write += (microtime(true) - $stamp);
 392                         }
 393
 394                         array_shift($argv);
 395
 396                         self::execFunction($queue, $include, $argv, true);
 397
 398                         $stamp = (float)microtime(true);
 399                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 400                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 401                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 402                         }
 403                         self::$db_duration = (microtime(true) - $stamp);
 404                         self::$db_duration_write += (microtime(true) - $stamp);
 405
 406                         return true;
 407                 }
 408
 409                 // The script could be provided as full path or only with the function name
 410                 if ($include == basename($include)) {
 411                         $include = 'include/' . $include . '.php';
 412                 }
 413
 414                 if (!self::validateInclude($include)) {
 415                         Logger::warning('Include file is not valid', ['file' => $argv[0]]);
 416                         $stamp = (float)microtime(true);
 417                         DBA::delete('workerqueue', ['id' => $queue['id']]);
 418                         self::$db_duration = (microtime(true) - $stamp);
 419                         self::$db_duration_write += (microtime(true) - $stamp);
 420                         return true;
 421                 }
 422
 423                 require_once $include;
 424
 425                 $funcname = str_replace('.php', '', basename($argv[0])) .'_run';
 426
 427                 if (function_exists($funcname)) {
 428                         // We constantly update the "executed" date every minute to avoid being killed too soon
 429                         if (!isset(self::$last_update)) {
 430                                 self::$last_update = strtotime($queue['executed']);
 431                         }
 432
 433                         $age = (time() - self::$last_update) / 60;
 434                         self::$last_update = time();
 435
 436                         if ($age > 1) {
 437                                 $stamp = (float)microtime(true);
 438                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 439                                 self::$db_duration += (microtime(true) - $stamp);
 440                                 self::$db_duration_write += (microtime(true) - $stamp);
 441                         }
 442
 443                         self::execFunction($queue, $funcname, $argv, false);
 444
 445                         $stamp = (float)microtime(true);
 446                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue['id']])) {
 447                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 448                         }
 449                         self::$db_duration = (microtime(true) - $stamp);
 450                         self::$db_duration_write += (microtime(true) - $stamp);
 451                 } else {
 452                         Logger::warning('Function does not exist', ['function' => $funcname]);
 453                         $stamp = (float)microtime(true);
 454                         DBA::delete('workerqueue', ['id' => $queue['id']]);
 455                         self::$db_duration = (microtime(true) - $stamp);
 456                         self::$db_duration_write += (microtime(true) - $stamp);
 457                 }
 458
 459                 return true;
 460         }
 461
 462         /**
 463          * Checks if system limits are reached.
 464          *
 465          * @return boolean
 466          */
 467         private static function systemLimitReached(): bool
 468         {
 469                 $load_cooldown      = DI::config()->get('system', 'worker_load_cooldown');
 470                 $processes_cooldown = DI::config()->get('system', 'worker_processes_cooldown');
 471
 472                 if ($load_cooldown == 0) {
 473                         $load_cooldown = DI::config()->get('system', 'maxloadavg');
 474                 }
 475
 476                 if (($load_cooldown == 0) && ($processes_cooldown == 0)) {
 477                         return false;
 478                 }
 479
 480                 $load = System::getLoadAvg();
 481                 if (empty($load)) {
 482                         return false;
 483                 }
 484
 485                 if (($load_cooldown > 0) && ($load['average1'] > $load_cooldown)) {
 486                         return true;
 487                 }
 488
 489                 if (($processes_cooldown > 0) && ($load['scheduled'] > $processes_cooldown)) {
 490                         return true;
 491                 }
 492
 493                 return false;
 494         }
 495
 496         /**
 497          * Slow the execution down if the system load is too high
 498          *
 499          * @return void
 500          */
 501         public static function coolDown()
 502         {
 503                 $cooldown = DI::config()->get('system', 'worker_cooldown', 0);
 504                 if ($cooldown > 0) {
 505                         Logger::debug('Wait for cooldown.', ['cooldown' => $cooldown]);
 506                         if ($cooldown < 1) {
 507                                 usleep($cooldown * 1000000);
 508                         } else {
 509                                 sleep($cooldown);
 510                         }
 511                 }
 512
 513                 $load_cooldown      = DI::config()->get('system', 'worker_load_cooldown');
 514                 $processes_cooldown = DI::config()->get('system', 'worker_processes_cooldown');
 515
 516                 if ($load_cooldown == 0) {
 517                         $load_cooldown = DI::config()->get('system', 'maxloadavg');
 518                 }
 519
 520                 if (($load_cooldown == 0) && ($processes_cooldown == 0)) {
 521                         return;
 522                 }
 523
 524                 $sleeping = false;
 525
 526                 while ($load = System::getLoadAvg()) {
 527                         if (($load_cooldown > 0) && ($load['average1'] > $load_cooldown)) {
 528                                 if (!$sleeping) {
 529                                         Logger::notice('Load induced pre execution cooldown.', ['max' => $load_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
 530                                         $sleeping = true;
 531                                 }
 532                                 sleep(1);
 533                                 continue;
 534                         }
 535                         if (($processes_cooldown > 0) && ($load['scheduled'] > $processes_cooldown)) {
 536                                 if (!$sleeping) {
 537                                         Logger::notice('Process induced pre execution cooldown.', ['max' => $processes_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
 538                                         $sleeping = true;
 539                                 }
 540                                 sleep(1);
 541                                 continue;
 542                         }
 543                         break;
 544                 }
 545
 546                 if ($sleeping) {
 547                         Logger::notice('Cooldown ended.', ['max-load' => $load_cooldown, 'max-processes' => $processes_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
 548                 }
 549         }
 550
 551         /**
 552          * Execute a function from the queue
 553          *
 554          * @param array   $queue       Workerqueue entry
 555          * @param string  $funcname    name of the function
 556          * @param array   $argv        Array of values to be passed to the function
 557          * @param boolean $method_call boolean
 558          * @return void
 559          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 560          */
 561         private static function execFunction(array $queue, string $funcname, array $argv, bool $method_call)
 562         {
 563                 $a = DI::app();
 564
 565                 self::coolDown();
 566
 567                 Logger::enableWorker($funcname);
 568
 569                 Logger::info('Process start.', ['priority' => $queue['priority'], 'id' => $queue['id']]);
 570
 571                 $stamp = (float)microtime(true);
 572
 573                 // We use the callstack here to analyze the performance of executed worker entries.
 574                 // For this reason the variables have to be initialized.
 575                 DI::profiler()->reset();
 576
 577                 $a->setQueue($queue);
 578
 579                 $up_duration = microtime(true) - self::$up_start;
 580
 581                 // Reset global data to avoid interferences
 582                 unset($_SESSION);
 583
 584                 // Set the workerLogger as new default logger
 585                 if ($method_call) {
 586                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 587                 } else {
 588                         $funcname($argv, count($argv));
 589                 }
 590
 591                 Logger::disableWorker();
 592
 593                 $a->setQueue([]);
 594
 595                 $duration = (microtime(true) - $stamp);
 596
 597                 /* With these values we can analyze how effective the worker is.
 598                  * The database and rest time should be low since this is the unproductive time.
 599                  * The execution time is the productive time.
 600                  * By changing parameters like the maximum number of workers we can check the effectivness.
 601                 */
 602                 $dbtotal = round(self::$db_duration, 2);
 603                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 604                 $dbcount = round(self::$db_duration_count, 2);
 605                 $dbstat  = round(self::$db_duration_stat, 2);
 606                 $dbwrite = round(self::$db_duration_write, 2);
 607                 $dblock  = round(self::$lock_duration, 2);
 608                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 609                 $exec    = round($duration, 2);
 610
 611                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 612
 613                 self::coolDown();
 614
 615                 self::$up_start = microtime(true);
 616                 self::$db_duration = 0;
 617                 self::$db_duration_count = 0;
 618                 self::$db_duration_stat = 0;
 619                 self::$db_duration_write = 0;
 620                 self::$lock_duration = 0;
 621
 622                 if ($duration > 3600) {
 623                         Logger::info('Longer than 1 hour.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 624                 } elseif ($duration > 600) {
 625                         Logger::info('Longer than 10 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 626                 } elseif ($duration > 300) {
 627                         Logger::info('Longer than 5 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 628                 } elseif ($duration > 120) {
 629                         Logger::info('Longer than 2 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
 630                 }
 631
 632                 Logger::info('Process done.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration, 3)]);
 633
 634                 DI::profiler()->saveLog(DI::logger(), 'ID ' . $queue['id'] . ': ' . $funcname);
 635         }
 636
 637         /**
 638          * Checks if the number of database connections has reached a critical limit.
 639          *
 640          * @return bool Are more than 3/4 of the maximum connections used?
 641          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 642          */
 643         private static function maxConnectionsReached(): bool
 644         {
 645                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 646                 $max = DI::config()->get('system', 'max_connections');
 647
 648                 // Fetch the percentage level where the worker will get active
 649                 $maxlevel = DI::config()->get('system', 'max_connections_level', 75);
 650
 651                 if ($max == 0) {
 652                         // the maximum number of possible user connections can be a system variable
 653                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 654                         if (DBA::isResult($r)) {
 655                                 $max = $r['Value'];
 656                         }
 657                         // Or it can be granted. This overrides the system variable
 658                         $stamp = (float)microtime(true);
 659                         $r = DBA::p('SHOW GRANTS');
 660                         self::$db_duration += (microtime(true) - $stamp);
 661                         while ($grants = DBA::fetch($r)) {
 662                                 $grant = array_pop($grants);
 663                                 if (stristr($grant, "GRANT USAGE ON")) {
 664                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 665                                                 $max = $match[1];
 666                                         }
 667                                 }
 668                         }
 669                         DBA::close($r);
 670                 }
 671
 672                 // If $max is set we will use the processlist to determine the current number of connections
 673                 // The processlist only shows entries of the current user
 674                 if ($max != 0) {
 675                         $stamp = (float)microtime(true);
 676                         $r = DBA::p('SHOW PROCESSLIST');
 677                         self::$db_duration += (microtime(true) - $stamp);
 678                         $used = DBA::numRows($r);
 679                         DBA::close($r);
 680
 681                         Logger::info('Connection usage (user values)', ['usage' => $used, 'max' => $max]);
 682
 683                         $level = ($used / $max) * 100;
 684
 685                         if ($level >= $maxlevel) {
 686                                 Logger::warning('Maximum level (' . $maxlevel . '%) of user connections reached: ' . $used .'/' . $max);
 687                                 return true;
 688                         }
 689                 }
 690
 691                 // We will now check for the system values.
 692                 // This limit could be reached although the user limits are fine.
 693                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 694                 if (!DBA::isResult($r)) {
 695                         return false;
 696                 }
 697                 $max = intval($r['Value']);
 698                 if ($max == 0) {
 699                         return false;
 700                 }
 701                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 702                 if (!DBA::isResult($r)) {
 703                         return false;
 704                 }
 705                 $used = intval($r['Value']);
 706                 if ($used == 0) {
 707                         return false;
 708                 }
 709                 Logger::info('Connection usage (system values)', ['used' => $used, 'max' => $max]);
 710
 711                 $level = $used / $max * 100;
 712
 713                 if ($level < $maxlevel) {
 714                         return false;
 715                 }
 716                 Logger::warning('Maximum level (' . $level . '%) of system connections reached: ' . $used . '/' . $max);
 717                 return true;
 718         }
 719
 720
 721         /**
 722          * Checks if the number of active workers exceeds the given limits
 723          *
 724          * @return bool Are there too much workers running?
 725          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 726          */
 727         private static function tooMuchWorkers(): bool
 728         {
 729                 $queues = DI::config()->get('system', 'worker_queues', 10);
 730
 731                 $maxqueues = $queues;
 732
 733                 $active = self::activeWorkers();
 734
 735                 // Decrease the number of workers at higher load
 736                 $load = System::currentLoad();
 737                 if ($load) {
 738                         $maxsysload = intval(DI::config()->get('system', 'maxloadavg', 20));
 739
 740                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 741                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 742                          * For some environments, this rapid decrease is not needed.
 743                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 744                          */
 745                         $exponent = intval(DI::config()->get('system', 'worker_load_exponent', 3));
 746                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 747                         $queues = intval(ceil($slope * $maxqueues));
 748
 749                         $processlist = '';
 750
 751                         if (DI::config()->get('system', 'worker_jpm')) {
 752                                 $intervals = explode(',', DI::config()->get('system', 'worker_jpm_range'));
 753                                 $jobs_per_minute = [];
 754                                 foreach ($intervals as $interval) {
 755                                         if ($interval == 0) {
 756                                                 continue;
 757                                         } else {
 758                                                 $interval = (int)$interval;
 759                                         }
 760
 761                                         $stamp = (float)microtime(true);
 762                                         $jobs = DBA::count('workerqueue', ["`done` AND `executed` > ?", DateTimeFormat::utc('now - ' . $interval . ' minute')]);
 763                                         self::$db_duration += (microtime(true) - $stamp);
 764                                         self::$db_duration_stat += (microtime(true) - $stamp);
 765                                         $jobs_per_minute[$interval] = number_format($jobs / $interval, 0);
 766                                 }
 767                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 768                         }
 769
 770                         // Create a list of queue entries grouped by their priority
 771                         $listitem = [0 => ''];
 772
 773                         $idle_workers = $active;
 774
 775                         $deferred = self::deferredEntries();
 776
 777                         if (DI::config()->get('system', 'worker_debug')) {
 778                                 $waiting_processes = 0;
 779                                 // Now adding all processes with workerqueue entries
 780                                 $stamp = (float)microtime(true);
 781                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 782                                 self::$db_duration += (microtime(true) - $stamp);
 783                                 self::$db_duration_stat += (microtime(true) - $stamp);
 784                                 while ($entry = DBA::fetch($jobs)) {
 785                                         $stamp = (float)microtime(true);
 786                                         $running = DBA::count('workerqueue-view', ['priority' => $entry['priority']]);
 787                                         self::$db_duration += (microtime(true) - $stamp);
 788                                         self::$db_duration_stat += (microtime(true) - $stamp);
 789                                         $idle_workers -= $running;
 790                                         $waiting_processes += $entry['entries'];
 791                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $running . '/' . $entry['entries'];
 792                                 }
 793                                 DBA::close($jobs);
 794                         } else {
 795                                 $waiting_processes =  self::totalEntries();
 796                                 $stamp = (float)microtime(true);
 797                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority` ORDER BY `priority`");
 798                                 self::$db_duration += (microtime(true) - $stamp);
 799                                 self::$db_duration_stat += (microtime(true) - $stamp);
 800
 801                                 while ($entry = DBA::fetch($jobs)) {
 802                                         $idle_workers -= $entry['running'];
 803                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $entry['running'];
 804                                 }
 805                                 DBA::close($jobs);
 806                         }
 807
 808                         $waiting_processes -= $deferred;
 809
 810                         $listitem[0] = '0:' . max(0, $idle_workers);
 811
 812                         $processlist .= ' ('.implode(', ', $listitem).')';
 813
 814                         if (DI::config()->get('system', 'worker_fastlane', false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 815                                 $top_priority = self::highestPriority();
 816                                 $high_running = self::processWithPriorityActive($top_priority);
 817
 818                                 if (!$high_running && ($top_priority > self::PRIORITY_UNDEFINED) && ($top_priority < self::PRIORITY_NEGLIGIBLE)) {
 819                                         Logger::info('Jobs with a higher priority are waiting but none is executed. Open a fastlane.', ['priority' => $top_priority]);
 820                                         $queues = $active + 1;
 821                                 }
 822                         }
 823
 824                         Logger::notice('Load: ' . $load . '/' . $maxsysload . ' - processes: ' . $deferred . '/' . $active . '/' . $waiting_processes . $processlist . ' - maximum: ' . $queues . '/' . $maxqueues);
 825
 826                         // Are there fewer workers running as possible? Then fork a new one.
 827                         if (!DI::config()->get('system', 'worker_dont_fork', false) && ($queues > ($active + 1)) && self::entriesExists() && !self::systemLimitReached()) {
 828                                 Logger::info('There are fewer workers as possible, fork a new worker.', ['active' => $active, 'queues' => $queues]);
 829                                 if (Worker\Daemon::isMode()) {
 830                                         Worker\IPC::SetJobState(true);
 831                                 } else {
 832                                         self::spawnWorker();
 833                                 }
 834                         }
 835                 }
 836
 837                 // if there are too much worker, we don't spawn a new one.
 838                 if (Worker\Daemon::isMode() && ($active > $queues)) {
 839                         Worker\IPC::SetJobState(false);
 840                 }
 841
 842                 return $active > $queues;
 843         }
 844
 845         /**
 846          * Returns the number of active worker processes
 847          *
 848          * @return integer Number of active worker processes
 849          * @throws \Exception
 850          */
 851         private static function activeWorkers(): int
 852         {
 853                 $stamp = (float)microtime(true);
 854                 $count = DI::process()->countCommand('Worker.php');
 855                 self::$db_duration += (microtime(true) - $stamp);
 856                 self::$db_duration_count += (microtime(true) - $stamp);
 857                 return $count;
 858         }
 859
 860         /**
 861          * Returns the number of active worker processes
 862          *
 863          * @return array List of worker process ids
 864          * @throws \Exception
 865          */
 866         private static function getWorkerPIDList(): array
 867         {
 868                 $ids = [];
 869                 $stamp = (float)microtime(true);
 870
 871                 $queues = DBA::p("SELECT `process`.`pid`, COUNT(`workerqueue`.`pid`) AS `entries` FROM `process`
 872                         LEFT JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `workerqueue`.`done`
 873                         GROUP BY `process`.`pid`");
 874                 while ($queue = DBA::fetch($queues)) {
 875                         $ids[$queue['pid']] = $queue['entries'];
 876                 }
 877                 DBA::close($queues);
 878
 879                 self::$db_duration += (microtime(true) - $stamp);
 880                 self::$db_duration_count += (microtime(true) - $stamp);
 881                 return $ids;
 882         }
 883
 884         /**
 885          * Returns waiting jobs for the current process id
 886          *
 887          * @return array|bool waiting workerqueue jobs or FALSE on failture
 888          * @throws \Exception
 889          */
 890         private static function getWaitingJobForPID()
 891         {
 892                 $stamp = (float)microtime(true);
 893                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 894                 self::$db_duration += (microtime(true) - $stamp);
 895                 if (DBA::isResult($r)) {
 896                         return DBA::toArray($r);
 897                 }
 898                 DBA::close($r);
 899
 900                 return false;
 901         }
 902
 903         /**
 904          * Returns the next jobs that should be executed
 905          * @param int $limit
 906          * @return array array with next jobs
 907          * @throws \Exception
 908          */
 909         private static function nextProcess(int $limit): array
 910         {
 911                 $priority = self::nextPriority();
 912                 if (empty($priority)) {
 913                         Logger::info('No tasks found');
 914                         return [];
 915                 }
 916
 917                 $ids = [];
 918                 $stamp = (float)microtime(true);
 919                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 920                 $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['retrial', 'created']]);
 921                 self::$db_duration += (microtime(true) - $stamp);
 922                 while ($task = DBA::fetch($tasks)) {
 923                         $ids[] = $task['id'];
 924                         // Only continue that loop while we are storing commands that can be processed quickly
 925                         if (!empty($task['command'])) {
 926                                 $command = $task['command'];
 927                         } else {
 928                                 $command = json_decode($task['parameter'])[0];
 929                         }
 930
 931                         if (!in_array($command, self::FAST_COMMANDS)) {
 932                                 break;
 933                         }
 934                 }
 935                 DBA::close($tasks);
 936
 937                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 938                 return $ids;
 939         }
 940
 941         /**
 942          * Returns the priority of the next workerqueue job
 943          *
 944          * @return string|bool priority or FALSE on failure
 945          * @throws \Exception
 946          */
 947         private static function nextPriority()
 948         {
 949                 $waiting = [];
 950                 $priorities = [self::PRIORITY_CRITICAL, self::PRIORITY_HIGH, self::PRIORITY_MEDIUM, self::PRIORITY_LOW, self::PRIORITY_NEGLIGIBLE];
 951                 foreach ($priorities as $priority) {
 952                         $stamp = (float)microtime(true);
 953                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 954                                 $waiting[$priority] = true;
 955                         }
 956                         self::$db_duration += (microtime(true) - $stamp);
 957                 }
 958
 959                 if (!empty($waiting[self::PRIORITY_CRITICAL])) {
 960                         return self::PRIORITY_CRITICAL;
 961                 }
 962
 963                 $running = [];
 964                 $running_total = 0;
 965                 $stamp = (float)microtime(true);
 966                 $processes = DBA::p("SELECT COUNT(DISTINCT(`pid`)) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority`");
 967                 self::$db_duration += (microtime(true) - $stamp);
 968                 while ($process = DBA::fetch($processes)) {
 969                         $running[$process['priority']] = $process['running'];
 970                         $running_total += $process['running'];
 971                 }
 972                 DBA::close($processes);
 973
 974                 foreach ($priorities as $priority) {
 975                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 976                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 977                                 return $priority;
 978                         }
 979                 }
 980
 981                 $active = max(self::activeWorkers(), $running_total);
 982                 $priorities = max(count($waiting), count($running));
 983                 $exponent = 2;
 984
 985                 $total = 0;
 986                 for ($i = 1; $i <= $priorities; ++$i) {
 987                         $total += pow($i, $exponent);
 988                 }
 989
 990                 $limit = [];
 991                 for ($i = 1; $i <= $priorities; ++$i) {
 992                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 993                 }
 994
 995                 $i = 0;
 996                 foreach ($running as $priority => $workers) {
 997                         if ($workers < $limit[$i++]) {
 998                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 999                                 return $priority;
1000                         }
1001                 }
1002
1003                 if (!empty($waiting)) {
1004                         $priority = array_keys($waiting)[0];
1005                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
1006                         return $priority;
1007                 }
1008
1009                 return false;
1010         }
1011
1012         /**
1013          * Find and claim the next worker process for us
1014          *
1015          * @return void
1016          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1017          */
1018         private static function findWorkerProcesses()
1019         {
1020                 $fetch_limit = DI::config()->get('system', 'worker_fetch_limit', 1);
1021
1022                 if (DI::config()->get('system', 'worker_multiple_fetch')) {
1023                         $pids = [];
1024                         foreach (self::getWorkerPIDList() as $pid => $count) {
1025                                 if ($count <= $fetch_limit) {
1026                                         $pids[] = $pid;
1027                                 }
1028                         }
1029                         if (empty($pids)) {
1030                                 return;
1031                         }
1032                         $limit = $fetch_limit * count($pids);
1033                 } else {
1034                         $pids = [getmypid()];
1035                         $limit = $fetch_limit;
1036                 }
1037
1038                 $ids = self::nextProcess($limit);
1039                 $limit -= count($ids);
1040
1041                 // If there is not enough results we check without priority limit
1042                 if ($limit > 0) {
1043                         $stamp = (float)microtime(true);
1044                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
1045                         $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'retrial', 'created']]);
1046                         self::$db_duration += (microtime(true) - $stamp);
1047
1048                         while ($task = DBA::fetch($tasks)) {
1049                                 $ids[] = $task['id'];
1050                                 // Only continue that loop while we are storing commands that can be processed quickly
1051                                 if (!empty($task['command'])) {
1052                                         $command = $task['command'];
1053                                 } else {
1054                                         $command = json_decode($task['parameter'])[0];
1055                                 }
1056                                 if (!in_array($command, self::FAST_COMMANDS)) {
1057                                         break;
1058                                 }
1059                         }
1060                         DBA::close($tasks);
1061                 }
1062
1063                 if (empty($ids)) {
1064                         return;
1065                 }
1066
1067                 // Assign the task ids to the workers
1068                 $worker = [];
1069                 foreach (array_unique($ids) as $id) {
1070                         $pid = next($pids);
1071                         if (!$pid) {
1072                                 $pid = reset($pids);
1073                         }
1074                         $worker[$pid][] = $id;
1075                 }
1076
1077                 $stamp = (float)microtime(true);
1078                 foreach ($worker as $worker_pid => $worker_ids) {
1079                         Logger::info('Set queue entry', ['pid' => $worker_pid, 'ids' => $worker_ids]);
1080                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $worker_pid],
1081                                 ['id' => $worker_ids, 'done' => false, 'pid' => 0]);
1082                 }
1083                 self::$db_duration += (microtime(true) - $stamp);
1084                 self::$db_duration_write += (microtime(true) - $stamp);
1085         }
1086
1087         /**
1088          * Returns the next worker process
1089          *
1090          * @return array worker processes
1091          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1092          */
1093         public static function workerProcess(): array
1094         {
1095                 // There can already be jobs for us in the queue.
1096                 $waiting = self::getWaitingJobForPID();
1097                 if (!empty($waiting)) {
1098                         return $waiting;
1099                 }
1100
1101                 $stamp = (float)microtime(true);
1102                 if (!DI::lock()->acquire(self::LOCK_PROCESS)) {
1103                         return [];
1104                 }
1105                 self::$lock_duration += (microtime(true) - $stamp);
1106
1107                 self::findWorkerProcesses();
1108
1109                 DI::lock()->release(self::LOCK_PROCESS);
1110
1111                 // Prevents "Return value of Friendica\Core\Worker::workerProcess() must be of the type array, bool returned"
1112                 $process = self::getWaitingJobForPID();
1113                 return (is_array($process) ? $process : []);
1114         }
1115
1116         /**
1117          * Removes a workerqueue entry from the current process
1118          *
1119          * @param Process $process the process behind the workerqueue
1120          *
1121          * @return void
1122          * @throws \Exception
1123          */
1124         public static function unclaimProcess(Process $process)
1125         {
1126                 $stamp = (float)microtime(true);
1127                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $process->pid, 'done' => false]);
1128                 self::$db_duration += (microtime(true) - $stamp);
1129                 self::$db_duration_write += (microtime(true) - $stamp);
1130         }
1131
1132         /**
1133          * Fork a child process
1134          *
1135          * @param boolean $do_cron
1136          * @return void
1137          */
1138         private static function forkProcess(bool $do_cron)
1139         {
1140                 if (DI::system()->isMinMemoryReached()) {
1141                         Logger::warning('Memory limit reached - quitting');
1142                         return;
1143                 }
1144
1145                 // Children inherit their parent's database connection.
1146                 // To avoid problems we disconnect and connect both parent and child
1147                 DBA::disconnect();
1148                 $pid = pcntl_fork();
1149                 if ($pid == -1) {
1150                         DBA::connect();
1151                         Logger::warning('Could not spawn worker');
1152                         return;
1153                 } elseif ($pid) {
1154                         // The parent process continues here
1155                         DBA::connect();
1156
1157                         Worker\IPC::SetJobState(true, $pid);
1158                         Logger::info('Spawned new worker', ['pid' => $pid]);
1159
1160                         $cycles = 0;
1161                         while (Worker\IPC::JobsExists($pid) && (++$cycles < 100)) {
1162                                 usleep(10000);
1163                         }
1164
1165                         Logger::info('Spawned worker is ready', ['pid' => $pid, 'wait_cycles' => $cycles]);
1166                         return;
1167                 }
1168
1169                 // We now are in the new worker
1170                 DBA::connect();
1171
1172                 DI::flushLogger();
1173                 $process = DI::process()->create(getmypid(), basename(__FILE__));
1174
1175                 $cycles = 0;
1176                 while (!Worker\IPC::JobsExists($process->pid) && (++$cycles < 100)) {
1177                         usleep(10000);
1178                 }
1179
1180                 Logger::info('Worker spawned', ['pid' => $process->pid, 'wait_cycles' => $cycles]);
1181
1182                 self::processQueue($do_cron, $process);
1183
1184                 self::unclaimProcess($process);
1185
1186                 Worker\IPC::SetJobState(false, $process->pid);
1187                 DI::process()->delete($process);
1188                 Logger::info('Worker ended', ['pid' => $process->pid]);
1189                 exit();
1190         }
1191
1192         /**
1193          * Spawns a new worker
1194          *
1195          * @param bool $do_cron
1196          * @return void
1197          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1198          */
1199         public static function spawnWorker(bool $do_cron = false)
1200         {
1201                 if (Worker\Daemon::isMode() && DI::config()->get('system', 'worker_fork')) {
1202                         self::forkProcess($do_cron);
1203                 } else {
1204                         DI::system()->run('bin/worker.php', ['no_cron' => !$do_cron]);
1205                 }
1206                 if (Worker\Daemon::isMode()) {
1207                         Worker\IPC::SetJobState(false);
1208                 }
1209         }
1210
1211         /**
1212          * Adds tasks to the worker queue
1213          *
1214          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1215          *
1216          * next args are passed as $cmd command line
1217          * or: Worker::add(Worker::PRIORITY_HIGH, 'Notifier', Delivery::DELETION, $drop_id);
1218          * or: Worker::add(array('priority' => Worker::PRIORITY_HIGH, 'dont_fork' => true), 'Delivery', $post_id);
1219          *
1220          * @return int '0' if worker queue entry already existed or there had been an error, otherwise the ID of the worker task
1221          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1222          * @note $cmd and string args are surrounded with ''
1223          *
1224          * @hooks 'proc_run'
1225          *    array $arr
1226          *
1227          */
1228         public static function add(...$args)
1229         {
1230                 if (!count($args)) {
1231                         return 0;
1232                 }
1233
1234                 $arr = ['args' => $args, 'run_cmd' => true];
1235
1236                 Hook::callAll('proc_run', $arr);
1237                 if (!$arr['run_cmd'] || !count($args)) {
1238                         return 1;
1239                 }
1240
1241                 $priority = self::PRIORITY_MEDIUM;
1242                 // Don't fork from frontend tasks by default
1243                 $dont_fork = DI::config()->get('system', 'worker_dont_fork', false) || !DI::mode()->isBackend();
1244                 $created = DateTimeFormat::utcNow();
1245                 $delayed = DBA::NULL_DATETIME;
1246                 $force_priority = false;
1247
1248                 $run_parameter = array_shift($args);
1249
1250                 if (is_int($run_parameter)) {
1251                         $priority = $run_parameter;
1252                 } elseif (is_array($run_parameter)) {
1253                         if (isset($run_parameter['delayed'])) {
1254                                 $delayed = $run_parameter['delayed'];
1255                         }
1256                         if (isset($run_parameter['priority'])) {
1257                                 $priority = $run_parameter['priority'];
1258                         }
1259                         if (isset($run_parameter['created'])) {
1260                                 $created = $run_parameter['created'];
1261                         }
1262                         if (isset($run_parameter['dont_fork'])) {
1263                                 $dont_fork = $run_parameter['dont_fork'];
1264                         }
1265                         if (isset($run_parameter['force_priority'])) {
1266                                 $force_priority = $run_parameter['force_priority'];
1267                         }
1268                 } else {
1269                         throw new \InvalidArgumentException('Priority number or task parameter array expected as first argument');
1270                 }
1271
1272                 $command = array_shift($args);
1273                 $parameters = json_encode($args);
1274                 $found = DBA::exists('workerqueue', ['command' => $command, 'parameter' => $parameters, 'done' => false]);
1275                 $added = 0;
1276
1277                 if (!is_int($priority) || !in_array($priority, self::PRIORITIES)) {
1278                         Logger::warning('Invalid priority', ['priority' => $priority, 'command' => $command, 'callstack' => System::callstack(20)]);
1279                         $priority = self::PRIORITY_MEDIUM;
1280                 }
1281
1282                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1283                 if (DBA::errorNo() != 0) {
1284                         return 0;
1285                 }
1286
1287                 if (!$found) {
1288                         if (!DBA::insert('workerqueue', ['command' => $command, 'parameter' => $parameters, 'created' => $created,
1289                                 'priority' => $priority, 'next_try' => $delayed])) {
1290                                 return 0;
1291                         }
1292                         $added = DBA::lastInsertId();
1293                 } elseif ($force_priority) {
1294                         DBA::update('workerqueue', ['priority' => $priority], ['command' => $command, 'parameter' => $parameters, 'done' => false, 'pid' => 0]);
1295                 }
1296
1297                 // Set the IPC flag to ensure an immediate process execution via daemon
1298                 if (Worker\Daemon::isMode()) {
1299                         Worker\IPC::SetJobState(true);
1300                 }
1301
1302                 Worker\Daemon::checkState();
1303
1304                 // Should we quit and wait for the worker to be called as a cronjob?
1305                 if ($dont_fork || self::systemLimitReached()) {
1306                         return $added;
1307                 }
1308
1309                 // If there is a lock then we don't have to check for too much worker
1310                 if (!DI::lock()->acquire(self::LOCK_WORKER, 0)) {
1311                         return $added;
1312                 }
1313
1314                 // If there are already enough workers running, don't fork another one
1315                 $quit = self::tooMuchWorkers();
1316                 DI::lock()->release(self::LOCK_WORKER);
1317
1318                 if ($quit) {
1319                         return $added;
1320                 }
1321
1322                 // Quit on daemon mode
1323                 if (Worker\Daemon::isMode()) {
1324                         return $added;
1325                 }
1326
1327                 // Now call the worker to execute the jobs that we just added to the queue
1328                 self::spawnWorker();
1329
1330                 return $added;
1331         }
1332
1333         public static function countWorkersByCommand(string $command): int
1334         {
1335                 return DBA::count('workerqueue', ['done' => false, 'pid' => 0, 'command' => $command]);
1336         }
1337
1338         /**
1339          * Returns the next retrial level for worker jobs.
1340          * This function will skip levels when jobs are older.
1341          *
1342          * @param array $queue Worker queue entry
1343          * @param integer $max_level maximum retrial level
1344          * @return integer the next retrial level value
1345          */
1346         private static function getNextRetrial(array $queue, int $max_level): int
1347         {
1348                 $created = strtotime($queue['created']);
1349                 $retrial_time = time() - $created;
1350
1351                 $new_retrial = $queue['retrial'] + 1;
1352                 $total = 0;
1353                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1354                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1355                         $total += $delay;
1356                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1357                                 $new_retrial = $retrial;
1358                         }
1359                 }
1360                 Logger::notice('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1361                 return $new_retrial;
1362         }
1363
1364         /**
1365          * Defers the current worker entry
1366          *
1367          * @return boolean had the entry been deferred?
1368          * @throws \Exception
1369          */
1370         public static function defer(): bool
1371         {
1372                 $queue = DI::app()->getQueue();
1373
1374                 if (empty($queue)) {
1375                         return false;
1376                 }
1377
1378                 $id = $queue['id'];
1379                 $priority = $queue['priority'];
1380
1381                 $max_level = DI::config()->get('system', 'worker_defer_limit');
1382
1383                 $new_retrial = self::getNextRetrial($queue, $max_level);
1384
1385                 if ($new_retrial > $max_level) {
1386                         Logger::notice('The task exceeded the maximum retry count', ['id' => $id, 'created' => $queue['created'], 'old_prio' => $queue['priority'], 'old_retrial' => $queue['retrial'], 'max_level' => $max_level, 'retrial' => $new_retrial]);
1387                         return false;
1388                 }
1389
1390                 // Calculate the delay until the next trial
1391                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1392                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1393
1394                 if (($priority < self::PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1395                         $priority = self::PRIORITY_MEDIUM;
1396                 } elseif (($priority < self::PRIORITY_LOW) && ($new_retrial > 6)) {
1397                         $priority = self::PRIORITY_LOW;
1398                 } elseif (($priority < self::PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1399                         $priority = self::PRIORITY_NEGLIGIBLE;
1400                 }
1401
1402                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1403
1404                 $stamp = (float)microtime(true);
1405                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1406                 DBA::update('workerqueue', $fields, ['id' => $id]);
1407                 self::$db_duration += (microtime(true) - $stamp);
1408                 self::$db_duration_write += (microtime(true) - $stamp);
1409
1410                 return true;
1411         }
1412
1413         /**
1414          * Check if the system is inside the defined maintenance window
1415          *
1416          * @param bool $check_last_execution Whether check last execution
1417          * @return boolean
1418          */
1419         public static function isInMaintenanceWindow(bool $check_last_execution = false): bool
1420         {
1421                 // Calculate the seconds of the start end end of the maintenance window
1422                 $start = strtotime(DI::config()->get('system', 'maintenance_start')) % 86400;
1423                 $end = strtotime(DI::config()->get('system', 'maintenance_end')) % 86400;
1424
1425                 Logger::info('Maintenance window', ['start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1426
1427                 if ($check_last_execution) {
1428                         // Calculate the window duration
1429                         $duration = max($start, $end) - min($start, $end);
1430
1431                         // Quit when the last cron execution had been after the previous window
1432                         $last_cron = DI::config()->get('system', 'last_cron_daily');
1433                         if ($last_cron + $duration > time()) {
1434                                 Logger::info('The Daily cron had been executed recently', ['last' => date(DateTimeFormat::MYSQL, $last_cron), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1435                                 return false;
1436                         }
1437                 }
1438
1439                 $current = time() % 86400;
1440
1441                 if ($start < $end) {
1442                         // Execute if we are inside the window
1443                         $execute = ($current >= $start) && ($current <= $end);
1444                 } else {
1445                         // Don't execute if we are outside the window
1446                         $execute = !(($current > $end) && ($current < $start));
1447                 }
1448
1449                 if ($execute) {
1450                         Logger::info('We are inside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1451                 } else {
1452                         Logger::info('We are outside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1453                 }
1454
1455                 return $execute;
1456         }
1457 }