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