src/Core/Worker.php

   1 <?php
   2 /**
   3  * @file src/Core/Worker.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\BaseObject;
   8 use Friendica\Database\DBA;
   9 use Friendica\Model\Process;
  10 use Friendica\Util\DateTimeFormat;
  11 use Friendica\Util\Network;
  12
  13 /**
  14  * @file src/Core/Worker.php
  15  *
  16  * @brief Contains the class for the worker background job processing
  17  */
  18
  19 /**
  20  * @brief Worker methods
  21  */
  22 class Worker
  23 {
  24         private static $up_start;
  25         private static $db_duration = 0;
  26         private static $db_duration_count = 0;
  27         private static $db_duration_write = 0;
  28         private static $db_duration_stat = 0;
  29         private static $lock_duration = 0;
  30         private static $last_update;
  31
  32         /**
  33          * @brief Processes the tasks that are in the workerqueue table
  34          *
  35          * @param boolean $run_cron Should the cron processes be executed?
  36          * @return void
  37          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  38          */
  39         public static function processQueue($run_cron = true)
  40         {
  41                 $a = \get_app();
  42
  43                 // Ensure that all "strtotime" operations do run timezone independent
  44                 date_default_timezone_set('UTC');
  45
  46                 self::$up_start = microtime(true);
  47
  48                 // At first check the maximum load. We shouldn't continue with a high load
  49                 if ($a->isMaxLoadReached()) {
  50                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  51                         return;
  52                 }
  53
  54                 // We now start the process. This is done after the load check since this could increase the load.
  55                 self::startProcess();
  56
  57                 // Kill stale processes every 5 minutes
  58                 $last_cleanup = Config::get('system', 'worker_last_cleaned', 0);
  59                 if (time() > ($last_cleanup + 300)) {
  60                         Config::set('system', 'worker_last_cleaned', time());
  61                         self::killStaleWorkers();
  62                 }
  63
  64                 // Count active workers and compare them with a maximum value that depends on the load
  65                 if (self::tooMuchWorkers()) {
  66                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  67                         return;
  68                 }
  69
  70                 // Do we have too few memory?
  71                 if ($a->isMinMemoryReached()) {
  72                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  73                         return;
  74                 }
  75
  76                 // Possibly there are too much database connections
  77                 if (self::maxConnectionsReached()) {
  78                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  79                         return;
  80                 }
  81
  82                 // Possibly there are too much database processes that block the system
  83                 if ($a->isMaxProcessesReached()) {
  84                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
  85                         return;
  86                 }
  87
  88                 // Now we start additional cron processes if we should do so
  89                 if ($run_cron) {
  90                         self::runCron();
  91                 }
  92
  93                 $starttime = time();
  94
  95                 $entries = 0;
  96                 $deferred = 0;
  97
  98                 // We fetch the next queue entry that is about to be executed
  99                 while ($r = self::workerProcess($passing_slow, $entries, $deferred)) {
 100                         // When we are processing jobs with a lower priority, we don't refetch new jobs
 101                         // Otherwise fast jobs could wait behind slow ones and could be blocked.
 102                         $refetched = $passing_slow;
 103
 104                         foreach ($r as $entry) {
 105                                 // Assure that the priority is an integer value
 106                                 $entry['priority'] = (int)$entry['priority'];
 107
 108                                 // The work will be done
 109                                 if (!self::execute($entry)) {
 110                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 111                                         return;
 112                                 }
 113
 114                                 // If possible we will fetch new jobs for this worker
 115                                 if (!$refetched) {
 116                                         $entries = self::totalEntries();
 117                                         $deferred = self::deferredEntries();
 118                                         if (Lock::acquire('worker_process', 0)) {
 119                                                 $refetched = self::findWorkerProcesses($passing_slow, $entries, $deferred);
 120                                                 Lock::release('worker_process');
 121                                         }
 122                                 }
 123                         }
 124
 125                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 126                         if (Lock::acquire('worker', 0)) {
 127                                 // Count active workers and compare them with a maximum value that depends on the load
 128                                 if (self::tooMuchWorkers($entries, $deferred)) {
 129                                         Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 130                                         Lock::release('worker');
 131                                         return;
 132                                 }
 133
 134                                 // Check free memory
 135                                 if ($a->isMinMemoryReached()) {
 136                                         Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 137                                         Lock::release('worker');
 138                                         return;
 139                                 }
 140                                 Lock::release('worker');
 141                         }
 142
 143                         // Quit the worker once every 5 minutes
 144                         if (time() > ($starttime + 300)) {
 145                                 Logger::log('Process lifetime reached, quitting.', Logger::DEBUG);
 146                                 return;
 147                         }
 148                 }
 149
 150                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 151                 if (Config::get('system', 'worker_daemon_mode', false)) {
 152                         self::IPCSetJobState(false);
 153                 }
 154                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 155         }
 156
 157         /**
 158          * @brief Check if non executed tasks do exist in the worker queue
 159          *
 160          * @return boolean Returns "true" if tasks are existing
 161          * @throws \Exception
 162          */
 163         private static function entriesExists()
 164         {
 165                 $stamp = (float)microtime(true);
 166                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 167                 self::$db_duration += (microtime(true) - $stamp);
 168                 return $exists;
 169         }
 170
 171         /**
 172          * @brief Returns the number of deferred entries in the worker queue
 173          *
 174          * @return integer Number of deferred entries in the worker queue
 175          * @throws \Exception
 176          */
 177         private static function deferredEntries()
 178         {
 179                 $stamp = (float)microtime(true);
 180                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` > ?", DateTimeFormat::utcNow()]);
 181                 self::$db_duration += (microtime(true) - $stamp);
 182                 self::$db_duration_count += (microtime(true) - $stamp);
 183                 return $count;
 184         }
 185
 186         /**
 187          * @brief Returns the number of non executed entries in the worker queue
 188          *
 189          * @return integer Number of non executed entries in the worker queue
 190          * @throws \Exception
 191          */
 192         private static function totalEntries()
 193         {
 194                 $stamp = (float)microtime(true);
 195                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 196                 self::$db_duration += (microtime(true) - $stamp);
 197                 self::$db_duration_count += (microtime(true) - $stamp);
 198                 return $count;
 199         }
 200
 201         /**
 202          * @brief Returns the highest priority in the worker queue that isn't executed
 203          *
 204          * @return integer Number of active worker processes
 205          * @throws \Exception
 206          */
 207         private static function highestPriority()
 208         {
 209                 $stamp = (float)microtime(true);
 210                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 211                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 212                 self::$db_duration += (microtime(true) - $stamp);
 213                 if (DBA::isResult($workerqueue)) {
 214                         return $workerqueue["priority"];
 215                 } else {
 216                         return 0;
 217                 }
 218         }
 219
 220         /**
 221          * @brief Returns if a process with the given priority is running
 222          *
 223          * @param integer $priority The priority that should be checked
 224          *
 225          * @return integer Is there a process running with that priority?
 226          * @throws \Exception
 227          */
 228         private static function processWithPriorityActive($priority)
 229         {
 230                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 231                 return DBA::exists('workerqueue', $condition);
 232         }
 233
 234         /**
 235          * @brief Execute a worker entry
 236          *
 237          * @param array $queue Workerqueue entry
 238          *
 239          * @return boolean "true" if further processing should be stopped
 240          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 241          */
 242         public static function execute($queue)
 243         {
 244                 $a = \get_app();
 245
 246                 $mypid = getmypid();
 247
 248                 // Quit when in maintenance
 249                 if (Config::get('system', 'maintenance', false, true)) {
 250                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 251                         return false;
 252                 }
 253
 254                 // Constantly check the number of parallel database processes
 255                 if ($a->isMaxProcessesReached()) {
 256                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 257                         return false;
 258                 }
 259
 260                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 261                 if (self::maxConnectionsReached()) {
 262                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 263                         return false;
 264                 }
 265
 266                 $argv = json_decode($queue["parameter"], true);
 267
 268                 // Check for existance and validity of the include file
 269                 $include = $argv[0];
 270
 271                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 272                         // We constantly update the "executed" date every minute to avoid being killed too soon
 273                         if (!isset(self::$last_update)) {
 274                                 self::$last_update = strtotime($queue["executed"]);
 275                         }
 276
 277                         $age = (time() - self::$last_update) / 60;
 278                         self::$last_update = time();
 279
 280                         Logger::alert('last_update', ['age' => $age, 'last_update' => self::$last_update]);
 281
 282                         if ($age > 1) {
 283                                 $stamp = (float)microtime(true);
 284                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 285                                 self::$db_duration += (microtime(true) - $stamp);
 286                                 self::$db_duration_write += (microtime(true) - $stamp);
 287                         }
 288
 289                         array_shift($argv);
 290
 291                         self::execFunction($queue, $include, $argv, true);
 292
 293                         $stamp = (float)microtime(true);
 294                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 295                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 296                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 297                         }
 298                         self::$db_duration = (microtime(true) - $stamp);
 299                         self::$db_duration_write += (microtime(true) - $stamp);
 300
 301                         return true;
 302                 }
 303
 304                 // The script could be provided as full path or only with the function name
 305                 if ($include == basename($include)) {
 306                         $include = "include/".$include.".php";
 307                 }
 308
 309                 if (!validate_include($include)) {
 310                         Logger::log("Include file ".$argv[0]." is not valid!");
 311                         $stamp = (float)microtime(true);
 312                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 313                         self::$db_duration = (microtime(true) - $stamp);
 314                         self::$db_duration_write += (microtime(true) - $stamp);
 315                         return true;
 316                 }
 317
 318                 require_once $include;
 319
 320                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 321
 322                 if (function_exists($funcname)) {
 323                         // We constantly update the "executed" date every minute to avoid being killed too soon
 324                         if (!isset(self::$last_update)) {
 325                                 self::$last_update = strtotime($queue["executed"]);
 326                         }
 327
 328                         $age = (time() - self::$last_update) / 60;
 329                         self::$last_update = time();
 330
 331                         if ($age > 1) {
 332                                 $stamp = (float)microtime(true);
 333                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 334                                 self::$db_duration += (microtime(true) - $stamp);
 335                                 self::$db_duration_write += (microtime(true) - $stamp);
 336                         }
 337
 338                         self::execFunction($queue, $funcname, $argv, false);
 339
 340                         $stamp = (float)microtime(true);
 341                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 342                                 Config::set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 343                         }
 344                         self::$db_duration = (microtime(true) - $stamp);
 345                         self::$db_duration_write += (microtime(true) - $stamp);
 346                 } else {
 347                         Logger::log("Function ".$funcname." does not exist");
 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                 }
 353
 354                 return true;
 355         }
 356
 357         /**
 358          * @brief Execute a function from the queue
 359          *
 360          * @param array   $queue       Workerqueue entry
 361          * @param string  $funcname    name of the function
 362          * @param array   $argv        Array of values to be passed to the function
 363          * @param boolean $method_call boolean
 364          * @return void
 365          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 366          */
 367         private static function execFunction($queue, $funcname, $argv, $method_call)
 368         {
 369                 $a = \get_app();
 370
 371                 $mypid = getmypid();
 372
 373                 $argc = count($argv);
 374
 375                 // Currently deactivated, since the new logger doesn't support this
 376                 //$new_process_id = System::processID("wrk");
 377                 $new_process_id = '';
 378
 379                 Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]." - Process PID: ".$new_process_id);
 380
 381                 $stamp = (float)microtime(true);
 382
 383                 // We use the callstack here to analyze the performance of executed worker entries.
 384                 // For this reason the variables have to be initialized.
 385                 $a->getProfiler()->reset();
 386
 387                 // For better logging create a new process id for every worker call
 388                 // But preserve the old one for the worker
 389                 $old_process_id = $a->process_id;
 390                 $a->process_id = $new_process_id;
 391                 $a->queue = $queue;
 392
 393                 $up_duration = microtime(true) - self::$up_start;
 394
 395                 // Reset global data to avoid interferences
 396                 unset($_SESSION);
 397
 398                 if ($method_call) {
 399                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 400                 } else {
 401                         $funcname($argv, $argc);
 402                 }
 403
 404                 $a->process_id = $old_process_id;
 405                 unset($a->queue);
 406
 407                 $duration = (microtime(true) - $stamp);
 408
 409                 /* With these values we can analyze how effective the worker is.
 410                  * The database and rest time should be low since this is the unproductive time.
 411                  * The execution time is the productive time.
 412                  * By changing parameters like the maximum number of workers we can check the effectivness.
 413                 */
 414                 Logger::log(
 415                         'DB: '.number_format(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 4).
 416                         ' - DB-Count: '.number_format(self::$db_duration_count, 4).
 417                         ' - DB-Stat: '.number_format(self::$db_duration_stat, 4).
 418                         ' - DB-Write: '.number_format(self::$db_duration_write, 4).
 419                         ' - Lock: '.number_format(self::$lock_duration, 4).
 420                         ' - Rest: '.number_format(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 4).
 421                         ' - Execution: '.number_format($duration, 4),
 422                         Logger::DEBUG
 423                 );
 424
 425                 self::$up_start = microtime(true);
 426                 self::$db_duration = 0;
 427                 self::$db_duration_count = 0;
 428                 self::$db_duration_stat = 0;
 429                 self::$db_duration_write = 0;
 430                 self::$lock_duration = 0;
 431
 432                 if ($duration > 3600) {
 433                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", Logger::DEBUG);
 434                 } elseif ($duration > 600) {
 435                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 436                 } elseif ($duration > 300) {
 437                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 438                 } elseif ($duration > 120) {
 439                         Logger::log("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", Logger::DEBUG);
 440                 }
 441
 442                 Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".number_format($duration, 4)." seconds. Process PID: ".$new_process_id);
 443
 444                 $a->getProfiler()->saveLog("ID " . $queue["id"] . ": " . $funcname);
 445
 446                 $cooldown = Config::get("system", "worker_cooldown", 0);
 447
 448                 if ($cooldown > 0) {
 449                         Logger::log("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 450                         sleep($cooldown);
 451                 }
 452         }
 453
 454         /**
 455          * @brief Checks if the number of database connections has reached a critical limit.
 456          *
 457          * @return bool Are more than 3/4 of the maximum connections used?
 458          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 459          */
 460         private static function maxConnectionsReached()
 461         {
 462                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 463                 $max = Config::get("system", "max_connections");
 464
 465                 // Fetch the percentage level where the worker will get active
 466                 $maxlevel = Config::get("system", "max_connections_level", 75);
 467
 468                 if ($max == 0) {
 469                         // the maximum number of possible user connections can be a system variable
 470                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 471                         if (DBA::isResult($r)) {
 472                                 $max = $r["Value"];
 473                         }
 474                         // Or it can be granted. This overrides the system variable
 475                         $stamp = (float)microtime(true);
 476                         $r = DBA::p('SHOW GRANTS');
 477                         self::$db_duration += (microtime(true) - $stamp);
 478                         while ($grants = DBA::fetch($r)) {
 479                                 $grant = array_pop($grants);
 480                                 if (stristr($grant, "GRANT USAGE ON")) {
 481                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 482                                                 $max = $match[1];
 483                                         }
 484                                 }
 485                         }
 486                         DBA::close($r);
 487                 }
 488
 489                 // If $max is set we will use the processlist to determine the current number of connections
 490                 // The processlist only shows entries of the current user
 491                 if ($max != 0) {
 492                         $stamp = (float)microtime(true);
 493                         $r = DBA::p('SHOW PROCESSLIST');
 494                         self::$db_duration += (microtime(true) - $stamp);
 495                         $used = DBA::numRows($r);
 496                         DBA::close($r);
 497
 498                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 499
 500                         $level = ($used / $max) * 100;
 501
 502                         if ($level >= $maxlevel) {
 503                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 504                                 return true;
 505                         }
 506                 }
 507
 508                 // We will now check for the system values.
 509                 // This limit could be reached although the user limits are fine.
 510                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 511                 if (!DBA::isResult($r)) {
 512                         return false;
 513                 }
 514                 $max = intval($r["Value"]);
 515                 if ($max == 0) {
 516                         return false;
 517                 }
 518                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 519                 if (!DBA::isResult($r)) {
 520                         return false;
 521                 }
 522                 $used = intval($r["Value"]);
 523                 if ($used == 0) {
 524                         return false;
 525                 }
 526                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 527
 528                 $level = $used / $max * 100;
 529
 530                 if ($level < $maxlevel) {
 531                         return false;
 532                 }
 533                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 534                 return true;
 535         }
 536
 537         /**
 538          * @brief fix the queue entry if the worker process died
 539          * @return void
 540          * @throws \Exception
 541          */
 542         private static function killStaleWorkers()
 543         {
 544                 $stamp = (float)microtime(true);
 545                 $entries = DBA::select(
 546                         'workerqueue',
 547                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 548                         ['NOT `done` AND `pid` != 0'],
 549                         ['order' => ['priority', 'created']]
 550                 );
 551                 self::$db_duration += (microtime(true) - $stamp);
 552
 553                 while ($entry = DBA::fetch($entries)) {
 554                         if (!posix_kill($entry["pid"], 0)) {
 555                                 $stamp = (float)microtime(true);
 556                                 DBA::update(
 557                                         'workerqueue',
 558                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 559                                         ['id' => $entry["id"]]
 560                                 );
 561                                 self::$db_duration += (microtime(true) - $stamp);
 562                                 self::$db_duration_write += (microtime(true) - $stamp);
 563                         } else {
 564                                 // Kill long running processes
 565                                 // Check if the priority is in a valid range
 566                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 567                                         $entry["priority"] = PRIORITY_MEDIUM;
 568                                 }
 569
 570                                 // Define the maximum durations
 571                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 572                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 573
 574                                 $argv = json_decode($entry["parameter"], true);
 575                                 $argv[0] = basename($argv[0]);
 576
 577                                 // How long is the process already running?
 578                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 579                                 if ($duration > $max_duration) {
 580                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 581                                         posix_kill($entry["pid"], SIGTERM);
 582
 583                                         // We killed the stale process.
 584                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 585                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 586                                         $new_priority = $entry["priority"];
 587                                         if ($entry["priority"] == PRIORITY_HIGH) {
 588                                                 $new_priority = PRIORITY_MEDIUM;
 589                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 590                                                 $new_priority = PRIORITY_LOW;
 591                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 592                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 593                                         }
 594                                         $stamp = (float)microtime(true);
 595                                         DBA::update(
 596                                                 'workerqueue',
 597                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 598                                                 ['id' => $entry["id"]]
 599                                         );
 600                                         self::$db_duration += (microtime(true) - $stamp);
 601                                         self::$db_duration_write += (microtime(true) - $stamp);
 602                                 } else {
 603                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 604                                 }
 605                         }
 606                 }
 607         }
 608
 609         /**
 610          * @brief Checks if the number of active workers exceeds the given limits
 611          *
 612          * @param integer $entries Total number of queue entries
 613          * @param integer $deferred Number of deferred queue entries
 614          *
 615          * @return bool Are there too much workers running?
 616          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 617          */
 618         public static function tooMuchWorkers($entries = 0, $deferred = 0)
 619         {
 620                 $queues = Config::get("system", "worker_queues", 4);
 621
 622                 $maxqueues = $queues;
 623
 624                 $active = self::activeWorkers();
 625
 626                 // Decrease the number of workers at higher load
 627                 $load = System::currentLoad();
 628                 if ($load) {
 629                         $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 630
 631                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 632                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 633                          * For some environments, this rapid decrease is not needed.
 634                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 635                          */
 636                         $exponent = intval(Config::get('system', 'worker_load_exponent', 3));
 637                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 638                         $queues = intval(ceil($slope * $maxqueues));
 639
 640                         $processlist = '';
 641
 642                         if (Config::get('system', 'worker_jpm')) {
 643                                 $intervals = explode(',', Config::get('system', 'worker_jpm_range'));
 644                                 $jobs_per_minute = [];
 645                                 foreach ($intervals as $interval) {
 646                                         if ($interval == 0) {
 647                                                 continue;
 648                                         } else {
 649                                                 $interval = (int)$interval;
 650                                         }
 651
 652                                         $stamp = (float)microtime(true);
 653                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 654                                         self::$db_duration += (microtime(true) - $stamp);
 655                                         self::$db_duration_stat += (microtime(true) - $stamp);
 656                                         if ($job = DBA::fetch($jobs)) {
 657                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 658                                         }
 659                                         DBA::close($jobs);
 660                                 }
 661                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 662                         }
 663
 664                         // Create a list of queue entries grouped by their priority
 665                         $listitem = [0 => ''];
 666
 667                         $idle_workers = $active;
 668
 669                         if (empty($deferred) && empty($entries)) {
 670                                 $deferred = self::deferredEntries();
 671                                 $entries = max(self::totalEntries() - $deferred, 0);
 672                         }
 673
 674                         $waiting_processes = max(0, $entries - $deferred);
 675
 676                         if (Config::get('system', 'worker_debug')) {
 677                                 $waiting_processes = 0;
 678                                 // Now adding all processes with workerqueue entries
 679                                 $stamp = (float)microtime(true);
 680                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` AND `next_try` < ? GROUP BY `priority`", DateTimeFormat::utcNow());
 681                                 self::$db_duration += (microtime(true) - $stamp);
 682                                 self::$db_duration_stat += (microtime(true) - $stamp);
 683                                 while ($entry = DBA::fetch($jobs)) {
 684                                         $stamp = (float)microtime(true);
 685                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
 686                                         self::$db_duration += (microtime(true) - $stamp);
 687                                         self::$db_duration_stat += (microtime(true) - $stamp);
 688                                         if ($process = DBA::fetch($processes)) {
 689                                                 $idle_workers -= $process["running"];
 690                                                 $waiting_processes += $entry["entries"];
 691                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 692                                         }
 693                                         DBA::close($processes);
 694                                 }
 695                                 DBA::close($jobs);
 696                         } else {
 697                                 $stamp = (float)microtime(true);
 698                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` GROUP BY `priority` ORDER BY `priority`");
 699                                 self::$db_duration += (microtime(true) - $stamp);
 700
 701                                 while ($entry = DBA::fetch($jobs)) {
 702                                         $idle_workers -= $entry["running"];
 703                                         $listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 704                                 }
 705                                 DBA::close($jobs);
 706                         }
 707
 708                         $listitem[0] = "0:" . max(0, $idle_workers);
 709
 710                         $processlist .= ' ('.implode(', ', $listitem).')';
 711
 712                         if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && self::entriesExists() && ($active >= $queues)) {
 713                                 $top_priority = self::highestPriority();
 714                                 $high_running = self::processWithPriorityActive($top_priority);
 715
 716                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 717                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 718                                         $queues = $active + 1;
 719                                 }
 720                         }
 721
 722                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 723
 724                         // Are there fewer workers running as possible? Then fork a new one.
 725                         if (!Config::get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && ($entries > 1)) {
 726                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 727                                 if (Config::get('system', 'worker_daemon_mode', false)) {
 728                                         self::IPCSetJobState(true);
 729                                 } else {
 730                                         self::spawnWorker();
 731                                 }
 732                         }
 733                 }
 734
 735                 // if there are too much worker, we don't spawn a new one.
 736                 if (Config::get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 737                         self::IPCSetJobState(false);
 738                 }
 739
 740                 return $active > $queues;
 741         }
 742
 743         /**
 744          * @brief Returns the number of active worker processes
 745          *
 746          * @return integer Number of active worker processes
 747          * @throws \Exception
 748          */
 749         private static function activeWorkers()
 750         {
 751                 $stamp = (float)microtime(true);
 752                 $count = DBA::count('process', ['command' => 'Worker.php']);
 753                 self::$db_duration += (microtime(true) - $stamp);
 754                 return $count;
 755         }
 756
 757         /**
 758          * @brief Check if we should pass some slow processes
 759          *
 760          * When the active processes of the highest priority are using more than 2/3
 761          * of all processes, we let pass slower processes.
 762          *
 763          * @param string $highest_priority Returns the currently highest priority
 764          * @return bool We let pass a slower process than $highest_priority
 765          * @throws \Exception
 766          */
 767         private static function passingSlow(&$highest_priority)
 768         {
 769                 $highest_priority = 0;
 770
 771                 $stamp = (float)microtime(true);
 772                 $r = DBA::p(
 773                         "SELECT `priority`
 774                                 FROM `process`
 775                                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done`"
 776                 );
 777                 self::$db_duration += (microtime(true) - $stamp);
 778
 779                 // No active processes at all? Fine
 780                 if (!DBA::isResult($r)) {
 781                         return false;
 782                 }
 783                 $priorities = [];
 784                 while ($line = DBA::fetch($r)) {
 785                         $priorities[] = $line["priority"];
 786                 }
 787                 DBA::close($r);
 788
 789                 // Should not happen
 790                 if (count($priorities) == 0) {
 791                         return false;
 792                 }
 793                 $highest_priority = min($priorities);
 794
 795                 // The highest process is already the slowest one?
 796                 // Then we quit
 797                 if ($highest_priority == PRIORITY_NEGLIGIBLE) {
 798                         return false;
 799                 }
 800                 $high = 0;
 801                 foreach ($priorities as $priority) {
 802                         if ($priority == $highest_priority) {
 803                                 ++$high;
 804                         }
 805                 }
 806                 Logger::log("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, Logger::DEBUG);
 807                 $passing_slow = (($high/count($priorities)) > (2/3));
 808
 809                 if ($passing_slow) {
 810                         Logger::log("Passing slower processes than priority ".$highest_priority, Logger::DEBUG);
 811                 }
 812                 return $passing_slow;
 813         }
 814
 815         /**
 816          * @brief Find and claim the next worker process for us
 817          *
 818          * @param boolean $passing_slow Returns if we had passed low priority processes
 819          * @param integer $entries Total number of queue entries
 820          * @param integer $deferred Number of deferred queue entries
 821          * @return boolean Have we found something?
 822          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 823          */
 824         private static function findWorkerProcesses(&$passing_slow, $entries, $deferred)
 825         {
 826                 $mypid = getmypid();
 827
 828                 // Check if we should pass some low priority process
 829                 $highest_priority = 0;
 830                 $found = false;
 831                 $passing_slow = false;
 832
 833                 // The higher the number of parallel workers, the more we prefetch to prevent concurring access
 834                 // We decrease the limit with the number of entries left in the queue
 835                 $worker_queues = Config::get("system", "worker_queues", 4);
 836                 $queue_length = Config::get('system', 'worker_fetch_limit', 1);
 837                 $lower_job_limit = $worker_queues * $queue_length * 2;
 838                 $entries = max($entries - $deferred, 0);
 839
 840                 // Now do some magic
 841                 $exponent = 2;
 842                 $slope = $queue_length / pow($lower_job_limit, $exponent);
 843                 $limit = min($queue_length, ceil($slope * pow($entries, $exponent)));
 844
 845                 Logger::log('Deferred: ' . $deferred . ' - Total: ' . $entries . ' - Maximum: ' . $queue_length . ' - jobs per queue: ' . $limit, Logger::DEBUG);
 846                 $ids = [];
 847                 if (self::passingSlow($highest_priority)) {
 848                         // Are there waiting processes with a higher priority than the currently highest?
 849                         $stamp = (float)microtime(true);
 850                         $result = DBA::select(
 851                                 'workerqueue',
 852                                 ['id'],
 853                                 ["`pid` = 0 AND `priority` < ? AND NOT `done` AND `next_try` < ?",
 854                                 $highest_priority, DateTimeFormat::utcNow()],
 855                                 ['limit' => 1, 'order' => ['priority', 'created']]
 856                         );
 857                         self::$db_duration += (microtime(true) - $stamp);
 858
 859                         while ($id = DBA::fetch($result)) {
 860                                 $ids[] = $id["id"];
 861                         }
 862                         DBA::close($result);
 863
 864                         $found = (count($ids) > 0);
 865
 866                         if (!$found) {
 867                                 // Give slower processes some processing time
 868                                 $stamp = (float)microtime(true);
 869                                 $result = DBA::select(
 870                                         'workerqueue',
 871                                         ['id'],
 872                                         ["`pid` = 0 AND `priority` > ? AND NOT `done` AND `next_try` < ?",
 873                                         $highest_priority, DateTimeFormat::utcNow()],
 874                                         ['limit' => 1, 'order' => ['priority', 'created']]
 875                                 );
 876                                 self::$db_duration += (microtime(true) - $stamp);
 877
 878                                 while ($id = DBA::fetch($result)) {
 879                                         $ids[] = $id["id"];
 880                                 }
 881                                 DBA::close($result);
 882
 883                                 $found = (count($ids) > 0);
 884                                 $passing_slow = $found;
 885                         }
 886                 }
 887
 888                 // At first try to fetch a bunch of high or medium tasks
 889                 if (!$found && ($limit > 1)) {
 890                         $stamp = (float)microtime(true);
 891                         $result = DBA::select(
 892                                 'workerqueue',
 893                                 ['id'],
 894                                 ["`pid` = 0 AND NOT `done` AND `priority` <= ? AND `next_try` < ? AND `retrial` = 0",
 895                                 PRIORITY_MEDIUM, DateTimeFormat::utcNow()],
 896                                 ['limit' => $limit, 'order' => ['created']]
 897                         );
 898                         self::$db_duration += (microtime(true) - $stamp);
 899
 900                         while ($id = DBA::fetch($result)) {
 901                                 $ids[] = $id["id"];
 902                         }
 903                         DBA::close($result);
 904
 905                         $found = (count($ids) > 0);
 906                 }
 907
 908                 // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 909                 if (!$found) {
 910                         $stamp = (float)microtime(true);
 911                         $result = DBA::select(
 912                                 'workerqueue',
 913                                 ['id'],
 914                                 ["`pid` = 0 AND NOT `done` AND `next_try` < ?",
 915                                 DateTimeFormat::utcNow()],
 916                                 ['limit' => 1, 'order' => ['priority', 'created']]
 917                         );
 918                         self::$db_duration += (microtime(true) - $stamp);
 919
 920                         while ($id = DBA::fetch($result)) {
 921                                 $ids[] = $id["id"];
 922                         }
 923                         DBA::close($result);
 924
 925                         $found = (count($ids) > 0);
 926                 }
 927
 928                 if ($found) {
 929                         $stamp = (float)microtime(true);
 930                         $condition = "`id` IN (".substr(str_repeat("?, ", count($ids)), 0, -2).") AND `pid` = 0 AND NOT `done`";
 931                         array_unshift($ids, $condition);
 932                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $ids);
 933                         self::$db_duration += (microtime(true) - $stamp);
 934                         self::$db_duration_write += (microtime(true) - $stamp);
 935                 }
 936
 937                 return $found;
 938         }
 939
 940         /**
 941          * @brief Returns the next worker process
 942          *
 943          * @param boolean $passing_slow Returns if we had passed low priority processes
 944          * @param integer $entries Returns total number of queue entries
 945          * @param integer $deferred Returns number of deferred queue entries
 946          *
 947          * @return string SQL statement
 948          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 949          */
 950         public static function workerProcess(&$passing_slow, &$entries, &$deferred)
 951         {
 952                 // There can already be jobs for us in the queue.
 953                 $stamp = (float)microtime(true);
 954                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 955                 self::$db_duration += (microtime(true) - $stamp);
 956                 if (DBA::isResult($r)) {
 957                         return DBA::toArray($r);
 958                 }
 959                 DBA::close($r);
 960
 961                 // Counting the rows outside the lock reduces the lock time
 962                 $entries = self::totalEntries();
 963                 $deferred = self::deferredEntries();
 964
 965                 $stamp = (float)microtime(true);
 966                 if (!Lock::acquire('worker_process')) {
 967                         return false;
 968                 }
 969                 self::$lock_duration += (microtime(true) - $stamp);
 970
 971                 $found = self::findWorkerProcesses($passing_slow, $entries, $deferred);
 972
 973                 Lock::release('worker_process');
 974
 975                 if ($found) {
 976                         $stamp = (float)microtime(true);
 977                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 978                         self::$db_duration += (microtime(true) - $stamp);
 979                         return DBA::toArray($r);
 980                 }
 981                 return false;
 982         }
 983
 984         /**
 985          * @brief Removes a workerqueue entry from the current process
 986          * @return void
 987          * @throws \Exception
 988          */
 989         public static function unclaimProcess()
 990         {
 991                 $mypid = getmypid();
 992
 993                 $stamp = (float)microtime(true);
 994                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 995                 self::$db_duration += (microtime(true) - $stamp);
 996                 self::$db_duration_write += (microtime(true) - $stamp);
 997         }
 998
 999         /**
1000          * @brief Call the front end worker
1001          * @return void
1002          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1003          */
1004         public static function callWorker()
1005         {
1006                 if (!Config::get("system", "frontend_worker")) {
1007                         return;
1008                 }
1009
1010                 $url = System::baseUrl()."/worker";
1011                 Network::fetchUrl($url, false, $redirects, 1);
1012         }
1013
1014         /**
1015          * @brief Call the front end worker if there aren't any active
1016          * @return void
1017          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1018          */
1019         public static function executeIfIdle()
1020         {
1021                 if (!Config::get("system", "frontend_worker")) {
1022                         return;
1023                 }
1024
1025                 // Do we have "proc_open"? Then we can fork the worker
1026                 if (function_exists("proc_open")) {
1027                         // When was the last time that we called the worker?
1028                         // Less than one minute? Then we quit
1029                         if ((time() - Config::get("system", "worker_started")) < 60) {
1030                                 return;
1031                         }
1032
1033                         Config::set("system", "worker_started", time());
1034
1035                         // Do we have enough running workers? Then we quit here.
1036                         if (self::tooMuchWorkers()) {
1037                                 // Cleaning dead processes
1038                                 self::killStaleWorkers();
1039                                 Process::deleteInactive();
1040
1041                                 return;
1042                         }
1043
1044                         self::runCron();
1045
1046                         Logger::log('Call worker', Logger::DEBUG);
1047                         self::spawnWorker();
1048                         return;
1049                 }
1050
1051                 // We cannot execute background processes.
1052                 // We now run the processes from the frontend.
1053                 // This won't work with long running processes.
1054                 self::runCron();
1055
1056                 self::clearProcesses();
1057
1058                 $workers = self::activeWorkers();
1059
1060                 if ($workers == 0) {
1061                         self::callWorker();
1062                 }
1063         }
1064
1065         /**
1066          * @brief Removes long running worker processes
1067          * @return void
1068          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1069          */
1070         public static function clearProcesses()
1071         {
1072                 $timeout = Config::get("system", "frontend_worker_timeout", 10);
1073
1074                 /// @todo We should clean up the corresponding workerqueue entries as well
1075                 $stamp = (float)microtime(true);
1076                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1077                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1078                 DBA::delete('process', $condition);
1079                 self::$db_duration = (microtime(true) - $stamp);
1080                 self::$db_duration_write += (microtime(true) - $stamp);
1081         }
1082
1083         /**
1084          * @brief Runs the cron processes
1085          * @return void
1086          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1087          */
1088         private static function runCron()
1089         {
1090                 Logger::log('Add cron entries', Logger::DEBUG);
1091
1092                 // Check for spooled items
1093                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1094
1095                 // Run the cron job that calls all other jobs
1096                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1097
1098                 // Cleaning dead processes
1099                 self::killStaleWorkers();
1100         }
1101
1102         /**
1103          * @brief Spawns a new worker
1104          * @param bool $do_cron
1105          * @return void
1106          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1107          */
1108         public static function spawnWorker($do_cron = false)
1109         {
1110                 $command = 'bin/worker.php';
1111
1112                 $args = ['no_cron' => !$do_cron];
1113
1114                 get_app()->proc_run($command, $args);
1115
1116                 // after spawning we have to remove the flag.
1117                 if (Config::get('system', 'worker_daemon_mode', false)) {
1118                         self::IPCSetJobState(false);
1119                 }
1120         }
1121
1122         /**
1123          * @brief Adds tasks to the worker queue
1124          *
1125          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1126          *
1127          * next args are passed as $cmd command line
1128          * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
1129          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1130          *
1131          * @return boolean "false" if proc_run couldn't be executed
1132          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1133          * @note $cmd and string args are surrounded with ""
1134          *
1135          * @hooks 'proc_run'
1136          *    array $arr
1137          *
1138          */
1139         public static function add($cmd)
1140         {
1141                 $args = func_get_args();
1142
1143                 if (!count($args)) {
1144                         return false;
1145                 }
1146
1147                 $arr = ['args' => $args, 'run_cmd' => true];
1148
1149                 Hook::callAll("proc_run", $arr);
1150                 if (!$arr['run_cmd'] || !count($args)) {
1151                         return true;
1152                 }
1153
1154                 $priority = PRIORITY_MEDIUM;
1155                 $dont_fork = Config::get("system", "worker_dont_fork", false);
1156                 $created = DateTimeFormat::utcNow();
1157                 $force_priority = false;
1158
1159                 $run_parameter = array_shift($args);
1160
1161                 if (is_int($run_parameter)) {
1162                         $priority = $run_parameter;
1163                 } elseif (is_array($run_parameter)) {
1164                         if (isset($run_parameter['priority'])) {
1165                                 $priority = $run_parameter['priority'];
1166                         }
1167                         if (isset($run_parameter['created'])) {
1168                                 $created = $run_parameter['created'];
1169                         }
1170                         if (isset($run_parameter['dont_fork'])) {
1171                                 $dont_fork = $run_parameter['dont_fork'];
1172                         }
1173                         if (isset($run_parameter['force_priority'])) {
1174                                 $force_priority = $run_parameter['force_priority'];
1175                         }
1176                 }
1177
1178                 $parameters = json_encode($args);
1179                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1180
1181                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1182                 if (DBA::errorNo() != 0) {
1183                         return false;
1184                 }
1185
1186                 if (!$found) {
1187                         DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1188                 } elseif ($force_priority) {
1189                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1190                 }
1191
1192                 // Should we quit and wait for the worker to be called as a cronjob?
1193                 if ($dont_fork) {
1194                         return true;
1195                 }
1196
1197                 // If there is a lock then we don't have to check for too much worker
1198                 if (!Lock::acquire('worker', 0)) {
1199                         return true;
1200                 }
1201
1202                 // If there are already enough workers running, don't fork another one
1203                 $quit = self::tooMuchWorkers();
1204                 Lock::release('worker');
1205
1206                 if ($quit) {
1207                         return true;
1208                 }
1209
1210                 // We tell the daemon that a new job entry exists
1211                 if (Config::get('system', 'worker_daemon_mode', false)) {
1212                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1213                         return true;
1214                 }
1215
1216                 // Now call the worker to execute the jobs that we just added to the queue
1217                 self::spawnWorker();
1218
1219                 return true;
1220         }
1221
1222         /**
1223          * Defers the current worker entry
1224          */
1225         public static function defer()
1226         {
1227                 if (empty(BaseObject::getApp()->queue)) {
1228                         return;
1229                 }
1230
1231                 $queue = BaseObject::getApp()->queue;
1232
1233                 $retrial = $queue['retrial'];
1234                 $id = $queue['id'];
1235                 $priority = $queue['priority'];
1236
1237                 if ($retrial > 14) {
1238                         Logger::log('Id ' . $id . ' had been tried 14 times. We stop now.', Logger::DEBUG);
1239                         return;
1240                 }
1241
1242                 // Calculate the delay until the next trial
1243                 $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1244                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1245
1246                 if (($priority < PRIORITY_MEDIUM) && ($retrial > 2)) {
1247                         $priority = PRIORITY_MEDIUM;
1248                 } elseif (($priority < PRIORITY_LOW) && ($retrial > 5)) {
1249                         $priority = PRIORITY_LOW;
1250                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($retrial > 7)) {
1251                         $priority = PRIORITY_NEGLIGIBLE;
1252                 }
1253
1254                 Logger::log('Defer execution ' . $retrial . ' of id ' . $id . ' to ' . $next . ' - priority old/new: ' . $queue['priority'] . '/' . $priority, Logger::DEBUG);
1255
1256                 $stamp = (float)microtime(true);
1257                 $fields = ['retrial' => $retrial + 1, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1258                 DBA::update('workerqueue', $fields, ['id' => $id]);
1259                 self::$db_duration += (microtime(true) - $stamp);
1260                 self::$db_duration_write += (microtime(true) - $stamp);
1261         }
1262
1263         /**
1264          * Log active processes into the "process" table
1265          *
1266          * @brief Log active processes into the "process" table
1267          */
1268         public static function startProcess()
1269         {
1270                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1271
1272                 $command = basename($trace[0]['file']);
1273
1274                 Process::deleteInactive();
1275
1276                 Process::insert($command);
1277         }
1278
1279         /**
1280          * Remove the active process from the "process" table
1281          *
1282          * @brief Remove the active process from the "process" table
1283          * @return bool
1284          * @throws \Exception
1285          */
1286         public static function endProcess()
1287         {
1288                 return Process::deleteByPid();
1289         }
1290
1291         /**
1292          * Set the flag if some job is waiting
1293          *
1294          * @brief Set the flag if some job is waiting
1295          * @param boolean $jobs Is there a waiting job?
1296          * @throws \Exception
1297          */
1298         public static function IPCSetJobState($jobs)
1299         {
1300                 $stamp = (float)microtime(true);
1301                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1302                 self::$db_duration += (microtime(true) - $stamp);
1303                 self::$db_duration_write += (microtime(true) - $stamp);
1304         }
1305
1306         /**
1307          * Checks if some worker job waits to be executed
1308          *
1309          * @brief Checks if some worker job waits to be executed
1310          * @return bool
1311          * @throws \Exception
1312          */
1313         public static function IPCJobsExists()
1314         {
1315                 $stamp = (float)microtime(true);
1316                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1317                 self::$db_duration += (microtime(true) - $stamp);
1318
1319                 // When we don't have a row, no job is running
1320                 if (!DBA::isResult($row)) {
1321                         return false;
1322                 }
1323
1324                 return (bool)$row['jobs'];
1325         }
1326 }