src/Core/Worker.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   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;
  25 use Friendica\Database\DBA;
  26 use Friendica\DI;
  27 use Friendica\Model\Process;
  28 use Friendica\Util\DateTimeFormat;
  29
  30 /**
  31  * Contains the class for the worker background job processing
  32  */
  33 class Worker
  34 {
  35         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  36         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  37         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  38         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  39
  40         const FAST_COMMANDS = ['APDelivery', 'Delivery', 'CreateShadowEntry'];
  41
  42         const LOCK_PROCESS = 'worker_process';
  43         const LOCK_WORKER = 'worker';
  44
  45         private static $up_start;
  46         private static $db_duration = 0;
  47         private static $db_duration_count = 0;
  48         private static $db_duration_write = 0;
  49         private static $db_duration_stat = 0;
  50         private static $lock_duration = 0;
  51         private static $last_update;
  52         private static $state;
  53
  54         /**
  55          * Processes the tasks that are in the workerqueue table
  56          *
  57          * @param boolean $run_cron Should the cron processes be executed?
  58          * @return void
  59          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  60          */
  61         public static function processQueue($run_cron = true)
  62         {
  63                 // Ensure that all "strtotime" operations do run timezone independent
  64                 date_default_timezone_set('UTC');
  65
  66                 self::$up_start = microtime(true);
  67
  68                 // At first check the maximum load. We shouldn't continue with a high load
  69                 if (DI::process()->isMaxLoadReached()) {
  70                         Logger::info('Pre check: maximum load reached, quitting.');
  71                         return;
  72                 }
  73
  74                 // We now start the process. This is done after the load check since this could increase the load.
  75                 self::startProcess();
  76
  77                 // Kill stale processes every 5 minutes
  78                 $last_cleanup = DI::config()->get('system', 'worker_last_cleaned', 0);
  79                 if (time() > ($last_cleanup + 300)) {
  80                         DI::config()->set('system', 'worker_last_cleaned', time());
  81                         self::killStaleWorkers();
  82                 }
  83
  84                 // Check if the system is ready
  85                 if (!self::isReady()) {
  86                         return;
  87                 }
  88
  89                 // Now we start additional cron processes if we should do so
  90                 if ($run_cron) {
  91                         self::runCron();
  92                 }
  93
  94                 $starttime = time();
  95                 self::$state = self::STATE_STARTUP;
  96
  97                 // We fetch the next queue entry that is about to be executed
  98                 while ($r = self::workerProcess()) {
  99                         $refetched = false;
 100                         foreach ($r as $entry) {
 101                                 // Assure that the priority is an integer value
 102                                 $entry['priority'] = (int)$entry['priority'];
 103
 104                                 // The work will be done
 105                                 if (!self::execute($entry)) {
 106                                         Logger::info('Process execution failed, quitting.');
 107                                         return;
 108                                 }
 109
 110                                 // Trying to fetch new processes - but only once when successful
 111                                 if (!$refetched && DI::lock()->acquire(self::LOCK_PROCESS, 0)) {
 112                                         self::findWorkerProcesses();
 113                                         DI::lock()->release(self::LOCK_PROCESS);
 114                                         self::$state = self::STATE_REFETCH;
 115                                         $refetched = true;
 116                                 } else {
 117                                         self::$state = self::STATE_SHORT_LOOP;
 118                                 }
 119                         }
 120
 121                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 122                         if (!self::getWaitingJobForPID()) {
 123                                 self::$state = self::STATE_LONG_LOOP;
 124
 125                                 if (DI::lock()->acquire(self::LOCK_WORKER, 0)) {
 126                                 // Count active workers and compare them with a maximum value that depends on the load
 127                                         if (self::tooMuchWorkers()) {
 128                                                 Logger::info('Active worker limit reached, quitting.');
 129                                                 DI::lock()->release(self::LOCK_WORKER);
 130                                                 return;
 131                                         }
 132
 133                                         // Check free memory
 134                                         if (DI::process()->isMinMemoryReached()) {
 135                                                 Logger::info('Memory limit reached, quitting.');
 136                                                 DI::lock()->release(self::LOCK_WORKER);
 137                                                 return;
 138                                         }
 139                                         DI::lock()->release(self::LOCK_WORKER);
 140                                 }
 141                         }
 142
 143                         // Quit the worker once every cron interval
 144                         if (time() > ($starttime + (DI::config()->get('system', 'cron_interval') * 60))) {
 145                                 Logger::info('Process lifetime reached, respawning.');
 146                                 self::spawnWorker();
 147                                 return;
 148                         }
 149                 }
 150
 151                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 152                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
 153                         self::IPCSetJobState(false);
 154                 }
 155                 Logger::info("Couldn't select a workerqueue entry, quitting process", ['pid' => getmypid()]);
 156         }
 157
 158         /**
 159          * Checks if the system is ready.
 160          *
 161          * Several system parameters like memory, connections and processes are checked.
 162          *
 163          * @return boolean
 164          */
 165         public static function isReady()
 166         {
 167                 // Count active workers and compare them with a maximum value that depends on the load
 168                 if (self::tooMuchWorkers()) {
 169                         Logger::info('Active worker limit reached, quitting.');
 170                         return false;
 171                 }
 172
 173                 // Do we have too few memory?
 174                 if (DI::process()->isMinMemoryReached()) {
 175                         Logger::info('Memory limit reached, quitting.');
 176                         return false;
 177                 }
 178
 179                 // Possibly there are too much database connections
 180                 if (self::maxConnectionsReached()) {
 181                         Logger::info('Maximum connections reached, quitting.');
 182                         return false;
 183                 }
 184
 185                 // Possibly there are too much database processes that block the system
 186                 if (DI::process()->isMaxProcessesReached()) {
 187                         Logger::info('Maximum processes reached, quitting.');
 188                         return false;
 189                 }
 190
 191                 return true;
 192         }
 193
 194         /**
 195          * Check if non executed tasks do exist in the worker queue
 196          *
 197          * @return boolean Returns "true" if tasks are existing
 198          * @throws \Exception
 199          */
 200         public static function entriesExists()
 201         {
 202                 $stamp = (float)microtime(true);
 203                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 204                 self::$db_duration += (microtime(true) - $stamp);
 205                 return $exists;
 206         }
 207
 208         /**
 209          * Returns the number of deferred entries in the worker queue
 210          *
 211          * @return integer Number of deferred entries in the worker queue
 212          * @throws \Exception
 213          */
 214         private static function deferredEntries()
 215         {
 216                 $stamp = (float)microtime(true);
 217                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 218                 self::$db_duration += (microtime(true) - $stamp);
 219                 self::$db_duration_count += (microtime(true) - $stamp);
 220                 return $count;
 221         }
 222
 223         /**
 224          * Returns the number of non executed entries in the worker queue
 225          *
 226          * @return integer Number of non executed entries in the worker queue
 227          * @throws \Exception
 228          */
 229         private static function totalEntries()
 230         {
 231                 $stamp = (float)microtime(true);
 232                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 233                 self::$db_duration += (microtime(true) - $stamp);
 234                 self::$db_duration_count += (microtime(true) - $stamp);
 235                 return $count;
 236         }
 237
 238         /**
 239          * Returns the highest priority in the worker queue that isn't executed
 240          *
 241          * @return integer Number of active worker processes
 242          * @throws \Exception
 243          */
 244         private static function highestPriority()
 245         {
 246                 $stamp = (float)microtime(true);
 247                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 248                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 249                 self::$db_duration += (microtime(true) - $stamp);
 250                 if (DBA::isResult($workerqueue)) {
 251                         return $workerqueue["priority"];
 252                 } else {
 253                         return 0;
 254                 }
 255         }
 256
 257         /**
 258          * Returns if a process with the given priority is running
 259          *
 260          * @param integer $priority The priority that should be checked
 261          *
 262          * @return integer Is there a process running with that priority?
 263          * @throws \Exception
 264          */
 265         private static function processWithPriorityActive($priority)
 266         {
 267                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 268                 return DBA::exists('workerqueue', $condition);
 269         }
 270
 271         /**
 272          * Execute a worker entry
 273          *
 274          * @param array $queue Workerqueue entry
 275          *
 276          * @return boolean "true" if further processing should be stopped
 277          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 278          */
 279         public static function execute($queue)
 280         {
 281                 $mypid = getmypid();
 282
 283                 // Quit when in maintenance
 284                 if (DI::config()->get('system', 'maintenance', false, true)) {
 285                         Logger::info("Maintenance mode - quit process", ['pid' => $mypid]);
 286                         return false;
 287                 }
 288
 289                 // Constantly check the number of parallel database processes
 290                 if (DI::process()->isMaxProcessesReached()) {
 291                         Logger::info("Max processes reached for process", ['pid' => $mypid]);
 292                         return false;
 293                 }
 294
 295                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 296                 if (self::maxConnectionsReached()) {
 297                         Logger::info("Max connection reached for process", ['pid' => $mypid]);
 298                         return false;
 299                 }
 300
 301                 $argv = json_decode($queue["parameter"], true);
 302                 if (empty($argv)) {
 303                         Logger::error('Parameter is empty', ['queue' => $queue]);
 304                         return false;
 305                 }
 306
 307                 // Check for existance and validity of the include file
 308                 $include = $argv[0];
 309
 310                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 311                         // We constantly update the "executed" date every minute to avoid being killed too soon
 312                         if (!isset(self::$last_update)) {
 313                                 self::$last_update = strtotime($queue["executed"]);
 314                         }
 315
 316                         $age = (time() - self::$last_update) / 60;
 317                         self::$last_update = time();
 318
 319                         if ($age > 1) {
 320                                 $stamp = (float)microtime(true);
 321                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 322                                 self::$db_duration += (microtime(true) - $stamp);
 323                                 self::$db_duration_write += (microtime(true) - $stamp);
 324                         }
 325
 326                         array_shift($argv);
 327
 328                         self::execFunction($queue, $include, $argv, true);
 329
 330                         $stamp = (float)microtime(true);
 331                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 332                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 333                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 334                         }
 335                         self::$db_duration = (microtime(true) - $stamp);
 336                         self::$db_duration_write += (microtime(true) - $stamp);
 337
 338                         return true;
 339                 }
 340
 341                 // The script could be provided as full path or only with the function name
 342                 if ($include == basename($include)) {
 343                         $include = "include/".$include.".php";
 344                 }
 345
 346                 if (!validate_include($include)) {
 347                         Logger::log("Include file ".$argv[0]." is not valid!");
 348                         $stamp = (float)microtime(true);
 349                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 350                         self::$db_duration = (microtime(true) - $stamp);
 351                         self::$db_duration_write += (microtime(true) - $stamp);
 352                         return true;
 353                 }
 354
 355                 require_once $include;
 356
 357                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 358
 359                 if (function_exists($funcname)) {
 360                         // We constantly update the "executed" date every minute to avoid being killed too soon
 361                         if (!isset(self::$last_update)) {
 362                                 self::$last_update = strtotime($queue["executed"]);
 363                         }
 364
 365                         $age = (time() - self::$last_update) / 60;
 366                         self::$last_update = time();
 367
 368                         if ($age > 1) {
 369                                 $stamp = (float)microtime(true);
 370                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 371                                 self::$db_duration += (microtime(true) - $stamp);
 372                                 self::$db_duration_write += (microtime(true) - $stamp);
 373                         }
 374
 375                         self::execFunction($queue, $funcname, $argv, false);
 376
 377                         $stamp = (float)microtime(true);
 378                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 379                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 380                         }
 381                         self::$db_duration = (microtime(true) - $stamp);
 382                         self::$db_duration_write += (microtime(true) - $stamp);
 383                 } else {
 384                         Logger::log("Function ".$funcname." does not exist");
 385                         $stamp = (float)microtime(true);
 386                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 387                         self::$db_duration = (microtime(true) - $stamp);
 388                         self::$db_duration_write += (microtime(true) - $stamp);
 389                 }
 390
 391                 return true;
 392         }
 393
 394         /**
 395          * Execute a function from the queue
 396          *
 397          * @param array   $queue       Workerqueue entry
 398          * @param string  $funcname    name of the function
 399          * @param array   $argv        Array of values to be passed to the function
 400          * @param boolean $method_call boolean
 401          * @return void
 402          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 403          */
 404         private static function execFunction($queue, $funcname, $argv, $method_call)
 405         {
 406                 $a = DI::app();
 407
 408                 Logger::enableWorker($funcname);
 409
 410                 Logger::info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 411
 412                 $stamp = (float)microtime(true);
 413
 414                 // We use the callstack here to analyze the performance of executed worker entries.
 415                 // For this reason the variables have to be initialized.
 416                 DI::profiler()->reset();
 417
 418                 $a->queue = $queue;
 419
 420                 $up_duration = microtime(true) - self::$up_start;
 421
 422                 // Reset global data to avoid interferences
 423                 unset($_SESSION);
 424
 425                 // Set the workerLogger as new default logger
 426                 if ($method_call) {
 427                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 428                 } else {
 429                         $funcname($argv, count($argv));
 430                 }
 431
 432                 Logger::disableWorker();
 433
 434                 unset($a->queue);
 435
 436                 $duration = (microtime(true) - $stamp);
 437
 438                 /* With these values we can analyze how effective the worker is.
 439                  * The database and rest time should be low since this is the unproductive time.
 440                  * The execution time is the productive time.
 441                  * By changing parameters like the maximum number of workers we can check the effectivness.
 442                 */
 443                 $dbtotal = round(self::$db_duration, 2);
 444                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 445                 $dbcount = round(self::$db_duration_count, 2);
 446                 $dbstat  = round(self::$db_duration_stat, 2);
 447                 $dbwrite = round(self::$db_duration_write, 2);
 448                 $dblock  = round(self::$lock_duration, 2);
 449                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 450                 $exec    = round($duration, 2);
 451
 452                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 453
 454                 self::$up_start = microtime(true);
 455                 self::$db_duration = 0;
 456                 self::$db_duration_count = 0;
 457                 self::$db_duration_stat = 0;
 458                 self::$db_duration_write = 0;
 459                 self::$lock_duration = 0;
 460
 461                 if ($duration > 3600) {
 462                         Logger::info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 463                 } elseif ($duration > 600) {
 464                         Logger::info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 465                 } elseif ($duration > 300) {
 466                         Logger::info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 467                 } elseif ($duration > 120) {
 468                         Logger::info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 469                 }
 470
 471                 Logger::info('Process done.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration, 3)]);
 472
 473                 DI::profiler()->saveLog(DI::logger(), "ID " . $queue["id"] . ": " . $funcname);
 474
 475                 $cooldown = DI::config()->get("system", "worker_cooldown", 0);
 476
 477                 if ($cooldown > 0) {
 478                         Logger::info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 479                         sleep($cooldown);
 480                 }
 481         }
 482
 483         /**
 484          * Checks if the number of database connections has reached a critical limit.
 485          *
 486          * @return bool Are more than 3/4 of the maximum connections used?
 487          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 488          */
 489         private static function maxConnectionsReached()
 490         {
 491                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 492                 $max = DI::config()->get("system", "max_connections");
 493
 494                 // Fetch the percentage level where the worker will get active
 495                 $maxlevel = DI::config()->get("system", "max_connections_level", 75);
 496
 497                 if ($max == 0) {
 498                         // the maximum number of possible user connections can be a system variable
 499                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 500                         if (DBA::isResult($r)) {
 501                                 $max = $r["Value"];
 502                         }
 503                         // Or it can be granted. This overrides the system variable
 504                         $stamp = (float)microtime(true);
 505                         $r = DBA::p('SHOW GRANTS');
 506                         self::$db_duration += (microtime(true) - $stamp);
 507                         while ($grants = DBA::fetch($r)) {
 508                                 $grant = array_pop($grants);
 509                                 if (stristr($grant, "GRANT USAGE ON")) {
 510                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 511                                                 $max = $match[1];
 512                                         }
 513                                 }
 514                         }
 515                         DBA::close($r);
 516                 }
 517
 518                 // If $max is set we will use the processlist to determine the current number of connections
 519                 // The processlist only shows entries of the current user
 520                 if ($max != 0) {
 521                         $stamp = (float)microtime(true);
 522                         $r = DBA::p('SHOW PROCESSLIST');
 523                         self::$db_duration += (microtime(true) - $stamp);
 524                         $used = DBA::numRows($r);
 525                         DBA::close($r);
 526
 527                         Logger::info("Connection usage (user values)", ['usage' => $used, 'max' => $max]);
 528
 529                         $level = ($used / $max) * 100;
 530
 531                         if ($level >= $maxlevel) {
 532                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 533                                 return true;
 534                         }
 535                 }
 536
 537                 // We will now check for the system values.
 538                 // This limit could be reached although the user limits are fine.
 539                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 540                 if (!DBA::isResult($r)) {
 541                         return false;
 542                 }
 543                 $max = intval($r["Value"]);
 544                 if ($max == 0) {
 545                         return false;
 546                 }
 547                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 548                 if (!DBA::isResult($r)) {
 549                         return false;
 550                 }
 551                 $used = intval($r["Value"]);
 552                 if ($used == 0) {
 553                         return false;
 554                 }
 555                 Logger::info("Connection usage (system values)", ['used' => $used, 'max' => $max]);
 556
 557                 $level = $used / $max * 100;
 558
 559                 if ($level < $maxlevel) {
 560                         return false;
 561                 }
 562                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 563                 return true;
 564         }
 565
 566         /**
 567          * fix the queue entry if the worker process died
 568          *
 569          * @return void
 570          * @throws \Exception
 571          */
 572         private static function killStaleWorkers()
 573         {
 574                 $stamp = (float)microtime(true);
 575                 $entries = DBA::select(
 576                         'workerqueue',
 577                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 578                         ['NOT `done` AND `pid` != 0'],
 579                         ['order' => ['priority', 'created']]
 580                 );
 581                 self::$db_duration += (microtime(true) - $stamp);
 582
 583                 while ($entry = DBA::fetch($entries)) {
 584                         if (!posix_kill($entry["pid"], 0)) {
 585                                 $stamp = (float)microtime(true);
 586                                 DBA::update(
 587                                         'workerqueue',
 588                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 589                                         ['id' => $entry["id"]]
 590                                 );
 591                                 self::$db_duration += (microtime(true) - $stamp);
 592                                 self::$db_duration_write += (microtime(true) - $stamp);
 593                         } else {
 594                                 // Kill long running processes
 595                                 // Check if the priority is in a valid range
 596                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 597                                         $entry["priority"] = PRIORITY_MEDIUM;
 598                                 }
 599
 600                                 // Define the maximum durations
 601                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 602                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 603
 604                                 $argv = json_decode($entry["parameter"], true);
 605                                 if (empty($argv)) {
 606                                         return;
 607                                 }
 608
 609                                 $argv[0] = basename($argv[0]);
 610
 611                                 // How long is the process already running?
 612                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 613                                 if ($duration > $max_duration) {
 614                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 615                                         posix_kill($entry["pid"], SIGTERM);
 616
 617                                         // We killed the stale process.
 618                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 619                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 620                                         $new_priority = $entry["priority"];
 621                                         if ($entry["priority"] == PRIORITY_HIGH) {
 622                                                 $new_priority = PRIORITY_MEDIUM;
 623                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 624                                                 $new_priority = PRIORITY_LOW;
 625                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 626                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 627                                         }
 628                                         $stamp = (float)microtime(true);
 629                                         DBA::update(
 630                                                 'workerqueue',
 631                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 632                                                 ['id' => $entry["id"]]
 633                                         );
 634                                         self::$db_duration += (microtime(true) - $stamp);
 635                                         self::$db_duration_write += (microtime(true) - $stamp);
 636                                 } else {
 637                                         Logger::info('Process runtime is okay', ['pid' => $entry["pid"], 'duration' => $duration, 'max' => $max_duration, 'command' => substr(json_encode($argv), 0, 50)]);
 638                                 }
 639                         }
 640                 }
 641                 DBA::close($entries);
 642         }
 643
 644         /**
 645          * Checks if the number of active workers exceeds the given limits
 646          *
 647          * @return bool Are there too much workers running?
 648          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 649          */
 650         private static function tooMuchWorkers()
 651         {
 652                 $queues = DI::config()->get("system", "worker_queues", 10);
 653
 654                 $maxqueues = $queues;
 655
 656                 $active = self::activeWorkers();
 657
 658                 // Decrease the number of workers at higher load
 659                 $load = System::currentLoad();
 660                 if ($load) {
 661                         $maxsysload = intval(DI::config()->get("system", "maxloadavg", 20));
 662
 663                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 664                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 665                          * For some environments, this rapid decrease is not needed.
 666                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 667                          */
 668                         $exponent = intval(DI::config()->get('system', 'worker_load_exponent', 3));
 669                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 670                         $queues = intval(ceil($slope * $maxqueues));
 671
 672                         $processlist = '';
 673
 674                         if (DI::config()->get('system', 'worker_jpm')) {
 675                                 $intervals = explode(',', DI::config()->get('system', 'worker_jpm_range'));
 676                                 $jobs_per_minute = [];
 677                                 foreach ($intervals as $interval) {
 678                                         if ($interval == 0) {
 679                                                 continue;
 680                                         } else {
 681                                                 $interval = (int)$interval;
 682                                         }
 683
 684                                         $stamp = (float)microtime(true);
 685                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 686                                         self::$db_duration += (microtime(true) - $stamp);
 687                                         self::$db_duration_stat += (microtime(true) - $stamp);
 688                                         if ($job = DBA::fetch($jobs)) {
 689                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 690                                         }
 691                                         DBA::close($jobs);
 692                                 }
 693                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 694                         }
 695
 696                         // Create a list of queue entries grouped by their priority
 697                         $listitem = [0 => ''];
 698
 699                         $idle_workers = $active;
 700
 701                         $deferred = self::deferredEntries();
 702
 703                         if (DI::config()->get('system', 'worker_debug')) {
 704                                 $waiting_processes = 0;
 705                                 // Now adding all processes with workerqueue entries
 706                                 $stamp = (float)microtime(true);
 707                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 708                                 self::$db_duration += (microtime(true) - $stamp);
 709                                 self::$db_duration_stat += (microtime(true) - $stamp);
 710                                 while ($entry = DBA::fetch($jobs)) {
 711                                         $stamp = (float)microtime(true);
 712                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `workerqueue-view` WHERE `priority` = ?", $entry["priority"]);
 713                                         self::$db_duration += (microtime(true) - $stamp);
 714                                         self::$db_duration_stat += (microtime(true) - $stamp);
 715                                         if ($process = DBA::fetch($processes)) {
 716                                                 $idle_workers -= $process["running"];
 717                                                 $waiting_processes += $entry["entries"];
 718                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 719                                         }
 720                                         DBA::close($processes);
 721                                 }
 722                                 DBA::close($jobs);
 723                         } else {
 724                                 $waiting_processes =  self::totalEntries();
 725                                 $stamp = (float)microtime(true);
 726                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority` ORDER BY `priority`");
 727                                 self::$db_duration += (microtime(true) - $stamp);
 728                                 self::$db_duration_stat += (microtime(true) - $stamp);
 729
 730                                 while ($entry = DBA::fetch($jobs)) {
 731                                         $idle_workers -= $entry["running"];
 732                                         $listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 733                                 }
 734                                 DBA::close($jobs);
 735                         }
 736
 737                         $waiting_processes -= $deferred;
 738
 739                         $listitem[0] = "0:" . max(0, $idle_workers);
 740
 741                         $processlist .= ' ('.implode(', ', $listitem).')';
 742
 743                         if (DI::config()->get("system", "worker_fastlane", false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 744                                 $top_priority = self::highestPriority();
 745                                 $high_running = self::processWithPriorityActive($top_priority);
 746
 747                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 748                                         Logger::info("Jobs with a higher priority are waiting but none is executed. Open a fastlane.", ['priority' => $top_priority]);
 749                                         $queues = $active + 1;
 750                                 }
 751                         }
 752
 753                         Logger::notice("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues);
 754
 755                         // Are there fewer workers running as possible? Then fork a new one.
 756                         if (!DI::config()->get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && self::entriesExists()) {
 757                                 Logger::info("There are fewer workers as possible, fork a new worker.", ['active' => $active, 'queues' => $queues]);
 758                                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
 759                                         self::IPCSetJobState(true);
 760                                 } else {
 761                                         self::spawnWorker();
 762                                 }
 763                         }
 764                 }
 765
 766                 // if there are too much worker, we don't spawn a new one.
 767                 if (DI::config()->get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 768                         self::IPCSetJobState(false);
 769                 }
 770
 771                 return $active > $queues;
 772         }
 773
 774         /**
 775          * Returns the number of active worker processes
 776          *
 777          * @return integer Number of active worker processes
 778          * @throws \Exception
 779          */
 780         private static function activeWorkers()
 781         {
 782                 $stamp = (float)microtime(true);
 783                 $count = DBA::count('process', ['command' => 'Worker.php']);
 784                 self::$db_duration += (microtime(true) - $stamp);
 785                 return $count;
 786         }
 787
 788         /**
 789          * Returns the number of active worker processes
 790          *
 791          * @return array List of worker process ids
 792          * @throws \Exception
 793          */
 794         private static function getWorkerPIDList()
 795         {
 796                 $ids = [];
 797                 $stamp = (float)microtime(true);
 798
 799                 $queues = DBA::p("SELECT `process`.`pid`, COUNT(`workerqueue`.`pid`) AS `entries` FROM `process`
 800                         LEFT JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `workerqueue`.`done`
 801                         GROUP BY `process`.`pid`");
 802                 while ($queue = DBA::fetch($queues)) {
 803                         $ids[$queue['pid']] = $queue['entries'];
 804                 }
 805                 DBA::close($queues);
 806
 807                 self::$db_duration += (microtime(true) - $stamp);
 808                 return $ids;
 809         }
 810
 811         /**
 812          * Returns waiting jobs for the current process id
 813          *
 814          * @return array waiting workerqueue jobs
 815          * @throws \Exception
 816          */
 817         private static function getWaitingJobForPID()
 818         {
 819                 $stamp = (float)microtime(true);
 820                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 821                 self::$db_duration += (microtime(true) - $stamp);
 822                 if (DBA::isResult($r)) {
 823                         return DBA::toArray($r);
 824                 }
 825                 DBA::close($r);
 826
 827                 return false;
 828         }
 829
 830         /**
 831          * Returns the next jobs that should be executed
 832          * @param int $limit
 833          * @return array array with next jobs
 834          * @throws \Exception
 835          */
 836         private static function nextProcess(int $limit)
 837         {
 838                 $priority = self::nextPriority();
 839                 if (empty($priority)) {
 840                         Logger::info('No tasks found');
 841                         return [];
 842                 }
 843
 844                 $ids = [];
 845                 $stamp = (float)microtime(true);
 846                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 847                 $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['created']]);
 848                 self::$db_duration += (microtime(true) - $stamp);
 849                 while ($task = DBA::fetch($tasks)) {
 850                         $ids[] = $task['id'];
 851                         // Only continue that loop while we are storing commands that can be processed quickly
 852                         $command = json_decode($task['parameter'])[0];
 853                         if (!in_array($command, self::FAST_COMMANDS)) {
 854                                 break;
 855                         }
 856                 }
 857                 DBA::close($tasks);
 858
 859                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 860                 return $ids;
 861         }
 862
 863         /**
 864          * Returns the priority of the next workerqueue job
 865          *
 866          * @return string priority
 867          * @throws \Exception
 868          */
 869         private static function nextPriority()
 870         {
 871                 $waiting = [];
 872                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 873                 foreach ($priorities as $priority) {
 874                         $stamp = (float)microtime(true);
 875                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 876                                 $waiting[$priority] = true;
 877                         }
 878                         self::$db_duration += (microtime(true) - $stamp);
 879                 }
 880
 881                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 882                         return PRIORITY_CRITICAL;
 883                 }
 884
 885                 $running = [];
 886                 $running_total = 0;
 887                 $stamp = (float)microtime(true);
 888                 $processes = DBA::p("SELECT COUNT(DISTINCT(`pid`)) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority`");
 889                 self::$db_duration += (microtime(true) - $stamp);
 890                 while ($process = DBA::fetch($processes)) {
 891                         $running[$process['priority']] = $process['running'];
 892                         $running_total += $process['running'];
 893                 }
 894                 DBA::close($processes);
 895
 896                 foreach ($priorities as $priority) {
 897                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 898                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 899                                 return $priority;
 900                         }
 901                 }
 902
 903                 $active = max(self::activeWorkers(), $running_total);
 904                 $priorities = max(count($waiting), count($running));
 905                 $exponent = 2;
 906
 907                 $total = 0;
 908                 for ($i = 1; $i <= $priorities; ++$i) {
 909                         $total += pow($i, $exponent);
 910                 }
 911
 912                 $limit = [];
 913                 for ($i = 1; $i <= $priorities; ++$i) {
 914                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 915                 }
 916
 917                 $i = 0;
 918                 foreach ($running as $priority => $workers) {
 919                         if ($workers < $limit[$i++]) {
 920                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 921                                 return $priority;
 922                         }
 923                 }
 924
 925                 if (!empty($waiting)) {
 926                         $priority = array_keys($waiting)[0];
 927                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 928                         return $priority;
 929                 }
 930
 931                 return false;
 932         }
 933
 934         /**
 935          * Find and claim the next worker process for us
 936          *
 937          * @return boolean Have we found something?
 938          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 939          */
 940         private static function findWorkerProcesses()
 941         {
 942                 $fetch_limit = DI::config()->get('system', 'worker_fetch_limit', 1);
 943
 944                 if (DI::config()->get('system', 'worker_multiple_fetch')) {
 945                         $pids = [];
 946                         $worker_pids = self::getWorkerPIDList();
 947                         foreach ($worker_pids as $pid => $count) {
 948                                 if ($count <= $fetch_limit) {
 949                                         $pids[] = $pid;
 950                                 }
 951                         }
 952                         if (empty($pids)) {
 953                                 return;
 954                         }
 955                         $limit = $fetch_limit * count($pids);
 956                 } else {
 957                         $pids = [getmypid()];
 958                         $limit = $fetch_limit;
 959                 }
 960
 961                 $ids = self::nextProcess($limit);
 962                 $limit -= count($ids);
 963
 964                 // If there is not enough results we check without priority limit
 965                 if ($limit > 0) {
 966                         $stamp = (float)microtime(true);
 967                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 968                         $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'created']]);
 969                         self::$db_duration += (microtime(true) - $stamp);
 970
 971                         while ($task = DBA::fetch($tasks)) {
 972                                 $ids[] = $task['id'];
 973                                 // Only continue that loop while we are storing commands that can be processed quickly
 974                                 $command = json_decode($task['parameter'])[0];
 975                                 if (!in_array($command, self::FAST_COMMANDS)) {
 976                                         break;
 977                                 }
 978                         }
 979                         DBA::close($tasks);
 980                 }
 981
 982                 if (!empty($ids)) {
 983                         $worker = [];
 984                         foreach (array_unique($ids) as $id) {
 985                                 $pid = next($pids);
 986                                 if (!$pid) {
 987                                         $pid = reset($pids);
 988                                 }
 989                                 $worker[$pid][] = $id;
 990                         }
 991
 992                         $stamp = (float)microtime(true);
 993                         foreach ($worker as $worker_pid => $worker_ids) {
 994                                 Logger::info('Set queue entry', ['pid' => $worker_pid, 'ids' => $worker_ids]);
 995                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $worker_pid],
 996                                         ['id' => $worker_ids, 'done' => false, 'pid' => 0]);
 997                         }
 998                         self::$db_duration += (microtime(true) - $stamp);
 999                         self::$db_duration_write += (microtime(true) - $stamp);
1000                 }
1001
1002                 return !empty($ids);
1003         }
1004
1005         /**
1006          * Returns the next worker process
1007          *
1008          * @return array worker processes
1009          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1010          */
1011         public static function workerProcess()
1012         {
1013                 // There can already be jobs for us in the queue.
1014                 $waiting = self::getWaitingJobForPID();
1015                 if (!empty($waiting)) {
1016                         return $waiting;
1017                 }
1018
1019                 $stamp = (float)microtime(true);
1020                 if (!DI::lock()->acquire(self::LOCK_PROCESS)) {
1021                         return false;
1022                 }
1023                 self::$lock_duration += (microtime(true) - $stamp);
1024
1025                 $found = self::findWorkerProcesses();
1026
1027                 DI::lock()->release(self::LOCK_PROCESS);
1028
1029                 if ($found) {
1030                         $stamp = (float)microtime(true);
1031                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
1032                         self::$db_duration += (microtime(true) - $stamp);
1033                         return DBA::toArray($r);
1034                 }
1035                 return false;
1036         }
1037
1038         /**
1039          * Removes a workerqueue entry from the current process
1040          *
1041          * @return void
1042          * @throws \Exception
1043          */
1044         public static function unclaimProcess()
1045         {
1046                 $mypid = getmypid();
1047
1048                 $stamp = (float)microtime(true);
1049                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
1050                 self::$db_duration += (microtime(true) - $stamp);
1051                 self::$db_duration_write += (microtime(true) - $stamp);
1052         }
1053
1054         /**
1055          * Call the front end worker
1056          *
1057          * @return void
1058          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1059          */
1060         public static function callWorker()
1061         {
1062                 if (!DI::config()->get("system", "frontend_worker")) {
1063                         return;
1064                 }
1065
1066                 $url = DI::baseUrl() . '/worker';
1067                 DI::httpRequest()->fetch($url, false, 1);
1068         }
1069
1070         /**
1071          * Call the front end worker if there aren't any active
1072          *
1073          * @return void
1074          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1075          */
1076         public static function executeIfIdle()
1077         {
1078                 if (!DI::config()->get("system", "frontend_worker")) {
1079                         return;
1080                 }
1081
1082                 // Do we have "proc_open"? Then we can fork the worker
1083                 if (function_exists("proc_open")) {
1084                         // When was the last time that we called the worker?
1085                         // Less than one minute? Then we quit
1086                         if ((time() - DI::config()->get("system", "worker_started")) < 60) {
1087                                 return;
1088                         }
1089
1090                         DI::config()->set("system", "worker_started", time());
1091
1092                         // Do we have enough running workers? Then we quit here.
1093                         if (self::tooMuchWorkers()) {
1094                                 // Cleaning dead processes
1095                                 self::killStaleWorkers();
1096                                 Process::deleteInactive();
1097
1098                                 return;
1099                         }
1100
1101                         self::runCron();
1102
1103                         Logger::info('Call worker');
1104                         self::spawnWorker();
1105                         return;
1106                 }
1107
1108                 // We cannot execute background processes.
1109                 // We now run the processes from the frontend.
1110                 // This won't work with long running processes.
1111                 self::runCron();
1112
1113                 self::clearProcesses();
1114
1115                 $workers = self::activeWorkers();
1116
1117                 if ($workers == 0) {
1118                         self::callWorker();
1119                 }
1120         }
1121
1122         /**
1123          * Removes long running worker processes
1124          *
1125          * @return void
1126          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1127          */
1128         public static function clearProcesses()
1129         {
1130                 $timeout = DI::config()->get("system", "frontend_worker_timeout", 10);
1131
1132                 /// @todo We should clean up the corresponding workerqueue entries as well
1133                 $stamp = (float)microtime(true);
1134                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1135                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1136                 DBA::delete('process', $condition);
1137                 self::$db_duration = (microtime(true) - $stamp);
1138                 self::$db_duration_write += (microtime(true) - $stamp);
1139         }
1140
1141         /**
1142          * Runs the cron processes
1143          *
1144          * @return void
1145          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1146          */
1147         private static function runCron()
1148         {
1149                 Logger::info('Add cron entries');
1150
1151                 // Check for spooled items
1152                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1153
1154                 // Run the cron job that calls all other jobs
1155                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1156
1157                 // Cleaning dead processes
1158                 self::killStaleWorkers();
1159         }
1160
1161         /**
1162          * Spawns a new worker
1163          *
1164          * @param bool $do_cron
1165          * @return void
1166          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1167          */
1168         public static function spawnWorker($do_cron = false)
1169         {
1170                 $command = 'bin/worker.php';
1171
1172                 $args = ['no_cron' => !$do_cron];
1173
1174                 $a = DI::app();
1175                 $process = new Core\Process(DI::logger(), DI::mode(), DI::config(), $a->getBasePath());
1176                 $process->run($command, $args);
1177
1178                 // after spawning we have to remove the flag.
1179                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
1180                         self::IPCSetJobState(false);
1181                 }
1182         }
1183
1184         /**
1185          * Adds tasks to the worker queue
1186          *
1187          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1188          *
1189          * next args are passed as $cmd command line
1190          * or: Worker::add(PRIORITY_HIGH, "Notifier", Delivery::DELETION, $drop_id);
1191          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1192          *
1193          * @return boolean "false" if worker queue entry already existed or there had been an error
1194          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1195          * @note $cmd and string args are surrounded with ""
1196          *
1197          * @hooks 'proc_run'
1198          *    array $arr
1199          *
1200          */
1201         public static function add($cmd)
1202         {
1203                 $args = func_get_args();
1204
1205                 if (!count($args)) {
1206                         return false;
1207                 }
1208
1209                 $arr = ['args' => $args, 'run_cmd' => true];
1210
1211                 Hook::callAll("proc_run", $arr);
1212                 if (!$arr['run_cmd'] || !count($args)) {
1213                         return true;
1214                 }
1215
1216                 $priority = PRIORITY_MEDIUM;
1217                 // Don't fork from frontend tasks by default
1218                 $dont_fork = DI::config()->get("system", "worker_dont_fork", false) || !DI::mode()->isBackend();
1219                 $created = DateTimeFormat::utcNow();
1220                 $force_priority = false;
1221
1222                 $run_parameter = array_shift($args);
1223
1224                 if (is_int($run_parameter)) {
1225                         $priority = $run_parameter;
1226                 } elseif (is_array($run_parameter)) {
1227                         if (isset($run_parameter['priority'])) {
1228                                 $priority = $run_parameter['priority'];
1229                         }
1230                         if (isset($run_parameter['created'])) {
1231                                 $created = $run_parameter['created'];
1232                         }
1233                         if (isset($run_parameter['dont_fork'])) {
1234                                 $dont_fork = $run_parameter['dont_fork'];
1235                         }
1236                         if (isset($run_parameter['force_priority'])) {
1237                                 $force_priority = $run_parameter['force_priority'];
1238                         }
1239                 }
1240
1241                 $parameters = json_encode($args);
1242                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1243                 $added = false;
1244
1245                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1246                 if (DBA::errorNo() != 0) {
1247                         return false;
1248                 }
1249
1250                 if (!$found) {
1251                         $added = DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1252                         if (!$added) {
1253                                 return false;
1254                         }
1255                 } elseif ($force_priority) {
1256                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1257                 }
1258
1259                 // Should we quit and wait for the worker to be called as a cronjob?
1260                 if ($dont_fork) {
1261                         return $added;
1262                 }
1263
1264                 // If there is a lock then we don't have to check for too much worker
1265                 if (!DI::lock()->acquire(self::LOCK_WORKER, 0)) {
1266                         return $added;
1267                 }
1268
1269                 // If there are already enough workers running, don't fork another one
1270                 $quit = self::tooMuchWorkers();
1271                 DI::lock()->release(self::LOCK_WORKER);
1272
1273                 if ($quit) {
1274                         return $added;
1275                 }
1276
1277                 // We tell the daemon that a new job entry exists
1278                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
1279                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1280                         return $added;
1281                 }
1282
1283                 // Now call the worker to execute the jobs that we just added to the queue
1284                 self::spawnWorker();
1285
1286                 return $added;
1287         }
1288
1289         /**
1290          * Returns the next retrial level for worker jobs.
1291          * This function will skip levels when jobs are older.
1292          *
1293          * @param array $queue Worker queue entry
1294          * @param integer $max_level maximum retrial level
1295          * @return integer the next retrial level value
1296          */
1297         private static function getNextRetrial($queue, $max_level)
1298         {
1299                 $created = strtotime($queue['created']);
1300                 $retrial_time = time() - $created;
1301
1302                 $new_retrial = $queue['retrial'] + 1;
1303                 $total = 0;
1304                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1305                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1306                         $total += $delay;
1307                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1308                                 $new_retrial = $retrial;
1309                         }
1310                 }
1311                 Logger::info('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1312                 return $new_retrial;
1313         }
1314
1315         /**
1316          * Defers the current worker entry
1317          *
1318          * @return boolean had the entry been deferred?
1319          */
1320         public static function defer()
1321         {
1322                 if (empty(DI::app()->queue)) {
1323                         return false;
1324                 }
1325
1326                 $queue = DI::app()->queue;
1327
1328                 $retrial = $queue['retrial'];
1329                 $id = $queue['id'];
1330                 $priority = $queue['priority'];
1331
1332                 $max_level = DI::config()->get('system', 'worker_defer_limit');
1333
1334                 $new_retrial = self::getNextRetrial($queue, $max_level);
1335
1336                 if ($new_retrial > $max_level) {
1337                         Logger::info('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]);
1338                         return false;
1339                 }
1340
1341                 // Calculate the delay until the next trial
1342                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1343                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1344
1345                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1346                         $priority = PRIORITY_MEDIUM;
1347                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1348                         $priority = PRIORITY_LOW;
1349                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1350                         $priority = PRIORITY_NEGLIGIBLE;
1351                 }
1352
1353                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1354
1355                 $stamp = (float)microtime(true);
1356                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1357                 DBA::update('workerqueue', $fields, ['id' => $id]);
1358                 self::$db_duration += (microtime(true) - $stamp);
1359                 self::$db_duration_write += (microtime(true) - $stamp);
1360
1361                 return true;
1362         }
1363
1364         /**
1365          * Log active processes into the "process" table
1366          */
1367         public static function startProcess()
1368         {
1369                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1370
1371                 $command = basename($trace[0]['file']);
1372
1373                 Process::deleteInactive();
1374
1375                 Process::insert($command);
1376         }
1377
1378         /**
1379          * Remove the active process from the "process" table
1380          *
1381          * @return bool
1382          * @throws \Exception
1383          */
1384         public static function endProcess()
1385         {
1386                 return Process::deleteByPid();
1387         }
1388
1389         /**
1390          * Set the flag if some job is waiting
1391          *
1392          * @param boolean $jobs Is there a waiting job?
1393          * @throws \Exception
1394          */
1395         public static function IPCSetJobState($jobs)
1396         {
1397                 $stamp = (float)microtime(true);
1398                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1399                 self::$db_duration += (microtime(true) - $stamp);
1400                 self::$db_duration_write += (microtime(true) - $stamp);
1401         }
1402
1403         /**
1404          * Checks if some worker job waits to be executed
1405          *
1406          * @return bool
1407          * @throws \Exception
1408          */
1409         public static function IPCJobsExists()
1410         {
1411                 $stamp = (float)microtime(true);
1412                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1413                 self::$db_duration += (microtime(true) - $stamp);
1414
1415                 // When we don't have a row, no job is running
1416                 if (!DBA::isResult($row)) {
1417                         return false;
1418                 }
1419
1420                 return (bool)$row['jobs'];
1421         }
1422 }