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