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