]> git.mxchange.org Git - friendica.git/blob - src/Core/Worker.php
Added sharing check for DFRN
[friendica.git] / src / Core / Worker.php
1 <?php
2 /**
3  * @copyright Copyright (C) 2010-2022, the Friendica project
4  *
5  * @license GNU AGPL version 3 or any later version
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU Affero General Public License as
9  * published by the Free Software Foundation, either version 3 of the
10  * License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU Affero General Public License for more details.
16  *
17  * You should have received a copy of the GNU Affero General Public License
18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
19  *
20  */
21
22 namespace Friendica\Core;
23
24 use Friendica\Core\Worker\Entity\Process;
25 use Friendica\Database\DBA;
26 use Friendica\DI;
27 use Friendica\Util\DateTimeFormat;
28
29 /**
30  * Contains the class for the worker background job processing
31  */
32 class Worker
33 {
34         const PRIORITY_UNDEFINED  = PRIORITY_UNDEFINED;
35         const PRIORITY_CRITICAL   = PRIORITY_CRITICAL;
36         const PRIORITY_HIGH       = PRIORITY_HIGH;
37         const PRIORITY_MEDIUM     = PRIORITY_MEDIUM;
38         const PRIORITY_LOW        = PRIORITY_LOW;
39         const PRIORITY_NEGLIGIBLE = PRIORITY_NEGLIGIBLE;
40
41         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
42         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
43         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
44         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
45
46         const FAST_COMMANDS = ['APDelivery', 'Delivery'];
47
48         const LOCK_PROCESS = 'worker_process';
49         const LOCK_WORKER = 'worker';
50
51         private static $up_start;
52         private static $db_duration = 0;
53         private static $db_duration_count = 0;
54         private static $db_duration_write = 0;
55         private static $db_duration_stat = 0;
56         private static $lock_duration = 0;
57         private static $last_update;
58         private static $state;
59         /** @var Process */
60         private static $process;
61
62         /**
63          * Processes the tasks that are in the workerqueue table
64          *
65          * @param boolean $run_cron Should the cron processes be executed?
66          * @param Process $process  The current running process
67          * @return void
68          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
69          */
70         public static function processQueue(bool $run_cron, Process $process)
71         {
72                 self::$up_start = microtime(true);
73
74                 // At first check the maximum load. We shouldn't continue with a high load
75                 if (DI::system()->isMaxLoadReached()) {
76                         Logger::notice('Pre check: maximum load reached, quitting.');
77                         return;
78                 }
79
80                 // We now start the process. This is done after the load check since this could increase the load.
81                 self::$process = $process;
82
83                 // Kill stale processes every 5 minutes
84                 $last_cleanup = DI::config()->get('system', 'worker_last_cleaned', 0);
85                 if (time() > ($last_cleanup + 300)) {
86                         DI::config()->set('system', 'worker_last_cleaned', time());
87                         Worker\Cron::killStaleWorkers();
88                 }
89
90                 // Check if the system is ready
91                 if (!self::isReady()) {
92                         return;
93                 }
94
95                 // Now we start additional cron processes if we should do so
96                 if ($run_cron) {
97                         Worker\Cron::run();
98                 }
99
100                 $last_check = $starttime = time();
101                 self::$state = self::STATE_STARTUP;
102
103                 // We fetch the next queue entry that is about to be executed
104                 while ($r = self::workerProcess()) {
105                         if (Worker\IPC::JobsExists(getmypid())) {
106                                 Worker\IPC::DeleteJobState(getmypid());
107                         }
108
109                         // Don't refetch when a worker fetches tasks for multiple workers
110                         $refetched = DI::config()->get('system', 'worker_multiple_fetch');
111                         foreach ($r as $entry) {
112                                 // The work will be done
113                                 if (!self::execute($entry)) {
114                                         Logger::warning('Process execution failed, quitting.', ['entry' => $entry]);
115                                         return;
116                                 }
117
118                                 // Trying to fetch new processes - but only once when successful
119                                 if (!$refetched && DI::lock()->acquire(self::LOCK_PROCESS, 0)) {
120                                         self::findWorkerProcesses();
121                                         DI::lock()->release(self::LOCK_PROCESS);
122                                         self::$state = self::STATE_REFETCH;
123                                         $refetched = true;
124                                 } else {
125                                         self::$state = self::STATE_SHORT_LOOP;
126                                 }
127                         }
128
129                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
130                         if ((time() > $last_check + 5) && !self::getWaitingJobForPID()) {
131                                 self::$state = self::STATE_LONG_LOOP;
132
133                                 if (DI::lock()->acquire(self::LOCK_WORKER, 0)) {
134                                 // Count active workers and compare them with a maximum value that depends on the load
135                                         if (self::tooMuchWorkers()) {
136                                                 Logger::notice('Active worker limit reached, quitting.');
137                                                 DI::lock()->release(self::LOCK_WORKER);
138                                                 return;
139                                         }
140
141                                         // Check free memory
142                                         if (DI::system()->isMinMemoryReached()) {
143                                                 Logger::warning('Memory limit reached, quitting.');
144                                                 DI::lock()->release(self::LOCK_WORKER);
145                                                 return;
146                                         }
147                                         DI::lock()->release(self::LOCK_WORKER);
148                                 }
149                                 $last_check = time();
150                         }
151
152                         // Quit the worker once every cron interval
153                         if (time() > ($starttime + (DI::config()->get('system', 'cron_interval') * 60)) && !self::systemLimitReached()) {
154                                 Logger::info('Process lifetime reached, respawning.');
155                                 self::unclaimProcess($process);
156                                 if (Worker\Daemon::isMode()) {
157                                         Worker\IPC::SetJobState(true);
158                                 } else {
159                                         self::spawnWorker();
160                                 }
161                                 return;
162                         }
163                 }
164
165                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
166                 if (Worker\Daemon::isMode()) {
167                         Worker\IPC::SetJobState(false);
168                 }
169                 Logger::info("Couldn't select a workerqueue entry, quitting process", ['pid' => getmypid()]);
170         }
171
172         /**
173          * Checks if the system is ready.
174          *
175          * Several system parameters like memory, connections and processes are checked.
176          *
177          * @return boolean
178          */
179         public static function isReady(): bool
180         {
181                 // Count active workers and compare them with a maximum value that depends on the load
182                 if (self::tooMuchWorkers()) {
183                         Logger::notice('Active worker limit reached, quitting.');
184                         return false;
185                 }
186
187                 // Do we have too few memory?
188                 if (DI::system()->isMinMemoryReached()) {
189                         Logger::warning('Memory limit reached, quitting.');
190                         return false;
191                 }
192
193                 // Possibly there are too much database connections
194                 if (self::maxConnectionsReached()) {
195                         Logger::warning('Maximum connections reached, quitting.');
196                         return false;
197                 }
198
199                 // Possibly there are too much database processes that block the system
200                 if (DI::system()->isMaxProcessesReached()) {
201                         Logger::warning('Maximum processes reached, quitting.');
202                         return false;
203                 }
204
205                 return true;
206         }
207
208         /**
209          * Check if non executed tasks do exist in the worker queue
210          *
211          * @return boolean Returns "true" if tasks are existing
212          * @throws \Exception
213          */
214         public static function entriesExists(): bool
215         {
216                 $stamp = (float)microtime(true);
217                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
218                 self::$db_duration += (microtime(true) - $stamp);
219                 return $exists;
220         }
221
222         /**
223          * Returns the number of deferred entries in the worker queue
224          *
225          * @return integer Number of deferred entries in the worker queue
226          * @throws \Exception
227          */
228         private static function deferredEntries(): int
229         {
230                 $stamp = (float)microtime(true);
231                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
232                 self::$db_duration += (microtime(true) - $stamp);
233                 self::$db_duration_count += (microtime(true) - $stamp);
234                 return $count;
235         }
236
237         /**
238          * Returns the number of non executed entries in the worker queue
239          *
240          * @return integer Number of non executed entries in the worker queue
241          * @throws \Exception
242          */
243         private static function totalEntries(): int
244         {
245                 $stamp = (float)microtime(true);
246                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
247                 self::$db_duration += (microtime(true) - $stamp);
248                 self::$db_duration_count += (microtime(true) - $stamp);
249                 return $count;
250         }
251
252         /**
253          * Returns the highest priority in the worker queue that isn't executed
254          *
255          * @return integer Number of active worker processes
256          * @throws \Exception
257          */
258         private static function highestPriority(): int
259         {
260                 $stamp = (float)microtime(true);
261                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
262                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
263                 self::$db_duration += (microtime(true) - $stamp);
264                 if (DBA::isResult($workerqueue)) {
265                         return $workerqueue['priority'];
266                 } else {
267                         return 0;
268                 }
269         }
270
271         /**
272          * Returns if a process with the given priority is running
273          *
274          * @param integer $priority The priority that should be checked
275          *
276          * @return integer Is there a process running with that priority?
277          * @throws \Exception
278          */
279         private static function processWithPriorityActive(int $priority): int
280         {
281                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
282                 return DBA::exists('workerqueue', $condition);
283         }
284
285         /**
286          * Checks if the given file is valid to be included
287          *
288          * @param mixed $file
289          * @return bool
290          */
291         private static function validateInclude(&$file): bool
292         {
293                 $orig_file = $file;
294
295                 $file = realpath($file);
296
297                 if (strpos($file, getcwd()) !== 0) {
298                         return false;
299                 }
300
301                 $file = str_replace(getcwd() . '/', '', $file, $count);
302                 if ($count != 1) {
303                         return false;
304                 }
305
306                 if ($orig_file !== $file) {
307                         return false;
308                 }
309
310                 $valid = false;
311                 if (strpos($file, 'include/') === 0) {
312                         $valid = true;
313                 }
314
315                 if (strpos($file, 'addon/') === 0) {
316                         $valid = true;
317                 }
318
319                 // Simply return flag
320                 return $valid;
321         }
322
323         /**
324          * Execute a worker entry
325          *
326          * @param array $queue Workerqueue entry
327          *
328          * @return boolean "true" if further processing should be stopped
329          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
330          */
331         public static function execute(array $queue): bool
332         {
333                 $mypid = getmypid();
334
335                 // Quit when in maintenance
336                 if (DI::config()->get('system', 'maintenance', false, true)) {
337                         Logger::notice('Maintenance mode - quit process', ['pid' => $mypid]);
338                         return false;
339                 }
340
341                 // Constantly check the number of parallel database processes
342                 if (DI::system()->isMaxProcessesReached()) {
343                         Logger::warning('Max processes reached for process', ['pid' => $mypid]);
344                         return false;
345                 }
346
347                 // Constantly check the number of available database connections to let the frontend be accessible at any time
348                 if (self::maxConnectionsReached()) {
349                         Logger::warning('Max connection reached for process', ['pid' => $mypid]);
350                         return false;
351                 }
352
353                 $argv = json_decode($queue['parameter'], true);
354                 if (!is_array($argv)) {
355                         $argv = [];
356                 }
357
358                 if (!empty($queue['command'])) {
359                         array_unshift($argv, $queue['command']);
360                 }
361
362                 if (empty($argv)) {
363                         Logger::warning('Parameter is empty', ['queue' => $queue]);
364                         return false;
365                 }
366
367                 // Check for existance and validity of the include file
368                 $include = $argv[0];
369
370                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
371                         // We constantly update the "executed" date every minute to avoid being killed too soon
372                         if (!isset(self::$last_update)) {
373                                 self::$last_update = strtotime($queue['executed']);
374                         }
375
376                         $age = (time() - self::$last_update) / 60;
377                         self::$last_update = time();
378
379                         if ($age > 1) {
380                                 $stamp = (float)microtime(true);
381                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
382                                 self::$db_duration += (microtime(true) - $stamp);
383                                 self::$db_duration_write += (microtime(true) - $stamp);
384                         }
385
386                         array_shift($argv);
387
388                         self::execFunction($queue, $include, $argv, true);
389
390                         $stamp = (float)microtime(true);
391                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
392                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
393                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
394                         }
395                         self::$db_duration = (microtime(true) - $stamp);
396                         self::$db_duration_write += (microtime(true) - $stamp);
397
398                         return true;
399                 }
400
401                 // The script could be provided as full path or only with the function name
402                 if ($include == basename($include)) {
403                         $include = 'include/' . $include . '.php';
404                 }
405
406                 if (!self::validateInclude($include)) {
407                         Logger::warning('Include file is not valid', ['file' => $argv[0]]);
408                         $stamp = (float)microtime(true);
409                         DBA::delete('workerqueue', ['id' => $queue['id']]);
410                         self::$db_duration = (microtime(true) - $stamp);
411                         self::$db_duration_write += (microtime(true) - $stamp);
412                         return true;
413                 }
414
415                 require_once $include;
416
417                 $funcname = str_replace('.php', '', basename($argv[0])) .'_run';
418
419                 if (function_exists($funcname)) {
420                         // We constantly update the "executed" date every minute to avoid being killed too soon
421                         if (!isset(self::$last_update)) {
422                                 self::$last_update = strtotime($queue['executed']);
423                         }
424
425                         $age = (time() - self::$last_update) / 60;
426                         self::$last_update = time();
427
428                         if ($age > 1) {
429                                 $stamp = (float)microtime(true);
430                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
431                                 self::$db_duration += (microtime(true) - $stamp);
432                                 self::$db_duration_write += (microtime(true) - $stamp);
433                         }
434
435                         self::execFunction($queue, $funcname, $argv, false);
436
437                         $stamp = (float)microtime(true);
438                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue['id']])) {
439                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
440                         }
441                         self::$db_duration = (microtime(true) - $stamp);
442                         self::$db_duration_write += (microtime(true) - $stamp);
443                 } else {
444                         Logger::warning('Function does not exist', ['function' => $funcname]);
445                         $stamp = (float)microtime(true);
446                         DBA::delete('workerqueue', ['id' => $queue['id']]);
447                         self::$db_duration = (microtime(true) - $stamp);
448                         self::$db_duration_write += (microtime(true) - $stamp);
449                 }
450
451                 return true;
452         }
453
454         /**
455          * Checks if system limits are reached.
456          *
457          * @return boolean
458          */
459         private static function systemLimitReached(): bool
460         {
461                 $load_cooldown      = DI::config()->get('system', 'worker_load_cooldown');
462                 $processes_cooldown = DI::config()->get('system', 'worker_processes_cooldown');
463
464                 if (($load_cooldown == 0) && ($processes_cooldown == 0)) {
465                         return false;
466                 }
467
468                 $load = System::getLoadAvg();
469                 if (empty($load)) {
470                         return false;
471                 }
472
473                 if (($load_cooldown > 0) && ($load['average1'] > $load_cooldown)) {
474                         return true;
475                 }
476
477                 if (($processes_cooldown > 0) && ($load['scheduled'] > $processes_cooldown)) {
478                         return true;
479                 }
480
481                 return false;
482         }
483
484         /**
485          * Slow the execution down if the system load is too high
486          *
487          * @return void
488          */
489         public static function coolDown()
490         {
491                 $cooldown = DI::config()->get('system', 'worker_cooldown', 0);
492                 if ($cooldown > 0) {
493                         Logger::debug('Wait for cooldown.', ['cooldown' => $cooldown]);
494                         if ($cooldown < 1) {
495                                 usleep($cooldown * 1000000);
496                         } else {
497                                 sleep($cooldown);
498                         }
499                 }
500
501                 $load_cooldown      = DI::config()->get('system', 'worker_load_cooldown');
502                 $processes_cooldown = DI::config()->get('system', 'worker_processes_cooldown');
503
504                 if (($load_cooldown == 0) && ($processes_cooldown == 0)) {
505                         return;
506                 }
507
508                 $sleeping = false;
509
510                 while ($load = System::getLoadAvg()) {
511                         if (($load_cooldown > 0) && ($load['average1'] > $load_cooldown)) {
512                                 if (!$sleeping) {
513                                         Logger::notice('Load induced pre execution cooldown.', ['max' => $load_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
514                                         $sleeping = true;
515                                 }
516                                 sleep(1);
517                                 continue;
518                         }
519                         if (($processes_cooldown > 0) && ($load['scheduled'] > $processes_cooldown)) {
520                                 if (!$sleeping) {
521                                         Logger::notice('Process induced pre execution cooldown.', ['max' => $processes_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
522                                         $sleeping = true;
523                                 }
524                                 sleep(1);
525                                 continue;
526                         }
527                         break;
528                 }
529
530                 if ($sleeping) {
531                         Logger::notice('Cooldown ended.', ['max-load' => $load_cooldown, 'max-processes' => $processes_cooldown, 'load' => $load, 'called-by' => System::callstack(1)]);
532                 }
533         }
534
535         /**
536          * Execute a function from the queue
537          *
538          * @param array   $queue       Workerqueue entry
539          * @param string  $funcname    name of the function
540          * @param array   $argv        Array of values to be passed to the function
541          * @param boolean $method_call boolean
542          * @return void
543          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
544          */
545         private static function execFunction(array $queue, string $funcname, array $argv, bool $method_call)
546         {
547                 $a = DI::app();
548
549                 self::coolDown();
550
551                 Logger::enableWorker($funcname);
552
553                 Logger::info('Process start.', ['priority' => $queue['priority'], 'id' => $queue['id']]);
554
555                 $stamp = (float)microtime(true);
556
557                 // We use the callstack here to analyze the performance of executed worker entries.
558                 // For this reason the variables have to be initialized.
559                 DI::profiler()->reset();
560
561                 $a->setQueue($queue);
562
563                 $up_duration = microtime(true) - self::$up_start;
564
565                 // Reset global data to avoid interferences
566                 unset($_SESSION);
567
568                 // Set the workerLogger as new default logger
569                 if ($method_call) {
570                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
571                 } else {
572                         $funcname($argv, count($argv));
573                 }
574
575                 Logger::disableWorker();
576
577                 $a->setQueue([]);
578
579                 $duration = (microtime(true) - $stamp);
580
581                 /* With these values we can analyze how effective the worker is.
582                  * The database and rest time should be low since this is the unproductive time.
583                  * The execution time is the productive time.
584                  * By changing parameters like the maximum number of workers we can check the effectivness.
585                 */
586                 $dbtotal = round(self::$db_duration, 2);
587                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
588                 $dbcount = round(self::$db_duration_count, 2);
589                 $dbstat  = round(self::$db_duration_stat, 2);
590                 $dbwrite = round(self::$db_duration_write, 2);
591                 $dblock  = round(self::$lock_duration, 2);
592                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
593                 $exec    = round($duration, 2);
594
595                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
596
597                 self::coolDown();
598
599                 self::$up_start = microtime(true);
600                 self::$db_duration = 0;
601                 self::$db_duration_count = 0;
602                 self::$db_duration_stat = 0;
603                 self::$db_duration_write = 0;
604                 self::$lock_duration = 0;
605
606                 if ($duration > 3600) {
607                         Logger::info('Longer than 1 hour.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
608                 } elseif ($duration > 600) {
609                         Logger::info('Longer than 10 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
610                 } elseif ($duration > 300) {
611                         Logger::info('Longer than 5 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
612                 } elseif ($duration > 120) {
613                         Logger::info('Longer than 2 minutes.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration/60, 3)]);
614                 }
615
616                 Logger::info('Process done.', ['priority' => $queue['priority'], 'id' => $queue['id'], 'duration' => round($duration, 3)]);
617
618                 DI::profiler()->saveLog(DI::logger(), 'ID ' . $queue['id'] . ': ' . $funcname);
619         }
620
621         /**
622          * Checks if the number of database connections has reached a critical limit.
623          *
624          * @return bool Are more than 3/4 of the maximum connections used?
625          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
626          */
627         private static function maxConnectionsReached(): bool
628         {
629                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
630                 $max = DI::config()->get('system', 'max_connections');
631
632                 // Fetch the percentage level where the worker will get active
633                 $maxlevel = DI::config()->get('system', 'max_connections_level', 75);
634
635                 if ($max == 0) {
636                         // the maximum number of possible user connections can be a system variable
637                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
638                         if (DBA::isResult($r)) {
639                                 $max = $r['Value'];
640                         }
641                         // Or it can be granted. This overrides the system variable
642                         $stamp = (float)microtime(true);
643                         $r = DBA::p('SHOW GRANTS');
644                         self::$db_duration += (microtime(true) - $stamp);
645                         while ($grants = DBA::fetch($r)) {
646                                 $grant = array_pop($grants);
647                                 if (stristr($grant, "GRANT USAGE ON")) {
648                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
649                                                 $max = $match[1];
650                                         }
651                                 }
652                         }
653                         DBA::close($r);
654                 }
655
656                 // If $max is set we will use the processlist to determine the current number of connections
657                 // The processlist only shows entries of the current user
658                 if ($max != 0) {
659                         $stamp = (float)microtime(true);
660                         $r = DBA::p('SHOW PROCESSLIST');
661                         self::$db_duration += (microtime(true) - $stamp);
662                         $used = DBA::numRows($r);
663                         DBA::close($r);
664
665                         Logger::info('Connection usage (user values)', ['usage' => $used, 'max' => $max]);
666
667                         $level = ($used / $max) * 100;
668
669                         if ($level >= $maxlevel) {
670                                 Logger::warning('Maximum level (' . $maxlevel . '%) of user connections reached: ' . $used .'/' . $max);
671                                 return true;
672                         }
673                 }
674
675                 // We will now check for the system values.
676                 // This limit could be reached although the user limits are fine.
677                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
678                 if (!DBA::isResult($r)) {
679                         return false;
680                 }
681                 $max = intval($r['Value']);
682                 if ($max == 0) {
683                         return false;
684                 }
685                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
686                 if (!DBA::isResult($r)) {
687                         return false;
688                 }
689                 $used = intval($r['Value']);
690                 if ($used == 0) {
691                         return false;
692                 }
693                 Logger::info('Connection usage (system values)', ['used' => $used, 'max' => $max]);
694
695                 $level = $used / $max * 100;
696
697                 if ($level < $maxlevel) {
698                         return false;
699                 }
700                 Logger::warning('Maximum level (' . $level . '%) of system connections reached: ' . $used . '/' . $max);
701                 return true;
702         }
703
704
705         /**
706          * Checks if the number of active workers exceeds the given limits
707          *
708          * @return bool Are there too much workers running?
709          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
710          */
711         private static function tooMuchWorkers(): bool
712         {
713                 $queues = DI::config()->get('system', 'worker_queues', 10);
714
715                 $maxqueues = $queues;
716
717                 $active = self::activeWorkers();
718
719                 // Decrease the number of workers at higher load
720                 $load = System::currentLoad();
721                 if ($load) {
722                         $maxsysload = intval(DI::config()->get('system', 'maxloadavg', 20));
723
724                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
725                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
726                          * For some environments, this rapid decrease is not needed.
727                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
728                          */
729                         $exponent = intval(DI::config()->get('system', 'worker_load_exponent', 3));
730                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
731                         $queues = intval(ceil($slope * $maxqueues));
732
733                         $processlist = '';
734
735                         if (DI::config()->get('system', 'worker_jpm')) {
736                                 $intervals = explode(',', DI::config()->get('system', 'worker_jpm_range'));
737                                 $jobs_per_minute = [];
738                                 foreach ($intervals as $interval) {
739                                         if ($interval == 0) {
740                                                 continue;
741                                         } else {
742                                                 $interval = (int)$interval;
743                                         }
744
745                                         $stamp = (float)microtime(true);
746                                         $jobs = DBA::count('workerqueue', ["`done` AND `executed` > ?", DateTimeFormat::utc('now - ' . $interval . ' minute')]);
747                                         self::$db_duration += (microtime(true) - $stamp);
748                                         self::$db_duration_stat += (microtime(true) - $stamp);
749                                         $jobs_per_minute[$interval] = number_format($jobs / $interval, 0);
750                                 }
751                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
752                         }
753
754                         // Create a list of queue entries grouped by their priority
755                         $listitem = [0 => ''];
756
757                         $idle_workers = $active;
758
759                         $deferred = self::deferredEntries();
760
761                         if (DI::config()->get('system', 'worker_debug')) {
762                                 $waiting_processes = 0;
763                                 // Now adding all processes with workerqueue entries
764                                 $stamp = (float)microtime(true);
765                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
766                                 self::$db_duration += (microtime(true) - $stamp);
767                                 self::$db_duration_stat += (microtime(true) - $stamp);
768                                 while ($entry = DBA::fetch($jobs)) {
769                                         $stamp = (float)microtime(true);
770                                         $running = DBA::count('workerqueue-view', ['priority' => $entry['priority']]);
771                                         self::$db_duration += (microtime(true) - $stamp);
772                                         self::$db_duration_stat += (microtime(true) - $stamp);
773                                         $idle_workers -= $running;
774                                         $waiting_processes += $entry['entries'];
775                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $running . '/' . $entry['entries'];
776                                 }
777                                 DBA::close($jobs);
778                         } else {
779                                 $waiting_processes =  self::totalEntries();
780                                 $stamp = (float)microtime(true);
781                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority` ORDER BY `priority`");
782                                 self::$db_duration += (microtime(true) - $stamp);
783                                 self::$db_duration_stat += (microtime(true) - $stamp);
784
785                                 while ($entry = DBA::fetch($jobs)) {
786                                         $idle_workers -= $entry['running'];
787                                         $listitem[$entry['priority']] = $entry['priority'] . ':' . $entry['running'];
788                                 }
789                                 DBA::close($jobs);
790                         }
791
792                         $waiting_processes -= $deferred;
793
794                         $listitem[0] = '0:' . max(0, $idle_workers);
795
796                         $processlist .= ' ('.implode(', ', $listitem).')';
797
798                         if (DI::config()->get('system', 'worker_fastlane', false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
799                                 $top_priority = self::highestPriority();
800                                 $high_running = self::processWithPriorityActive($top_priority);
801
802                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
803                                         Logger::info('Jobs with a higher priority are waiting but none is executed. Open a fastlane.', ['priority' => $top_priority]);
804                                         $queues = $active + 1;
805                                 }
806                         }
807
808                         Logger::notice('Load: ' . $load . '/' . $maxsysload . ' - processes: ' . $deferred . '/' . $active . '/' . $waiting_processes . $processlist . ' - maximum: ' . $queues . '/' . $maxqueues);
809
810                         // Are there fewer workers running as possible? Then fork a new one.
811                         if (!DI::config()->get('system', 'worker_dont_fork', false) && ($queues > ($active + 1)) && self::entriesExists() && !self::systemLimitReached()) {
812                                 Logger::info('There are fewer workers as possible, fork a new worker.', ['active' => $active, 'queues' => $queues]);
813                                 if (Worker\Daemon::isMode()) {
814                                         Worker\IPC::SetJobState(true);
815                                 } else {
816                                         self::spawnWorker();
817                                 }
818                         }
819                 }
820
821                 // if there are too much worker, we don't spawn a new one.
822                 if (Worker\Daemon::isMode() && ($active > $queues)) {
823                         Worker\IPC::SetJobState(false);
824                 }
825
826                 return $active > $queues;
827         }
828
829         /**
830          * Returns the number of active worker processes
831          *
832          * @return integer Number of active worker processes
833          * @throws \Exception
834          */
835         private static function activeWorkers(): int
836         {
837                 $stamp = (float)microtime(true);
838                 $count = DI::process()->countCommand('Worker.php');
839                 self::$db_duration += (microtime(true) - $stamp);
840                 self::$db_duration_count += (microtime(true) - $stamp);
841                 return $count;
842         }
843
844         /**
845          * Returns the number of active worker processes
846          *
847          * @return array List of worker process ids
848          * @throws \Exception
849          */
850         private static function getWorkerPIDList(): array
851         {
852                 $ids = [];
853                 $stamp = (float)microtime(true);
854
855                 $queues = DBA::p("SELECT `process`.`pid`, COUNT(`workerqueue`.`pid`) AS `entries` FROM `process`
856                         LEFT JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `workerqueue`.`done`
857                         GROUP BY `process`.`pid`");
858                 while ($queue = DBA::fetch($queues)) {
859                         $ids[$queue['pid']] = $queue['entries'];
860                 }
861                 DBA::close($queues);
862
863                 self::$db_duration += (microtime(true) - $stamp);
864                 self::$db_duration_count += (microtime(true) - $stamp);
865                 return $ids;
866         }
867
868         /**
869          * Returns waiting jobs for the current process id
870          *
871          * @return array|bool waiting workerqueue jobs or FALSE on failture
872          * @throws \Exception
873          */
874         private static function getWaitingJobForPID()
875         {
876                 $stamp = (float)microtime(true);
877                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
878                 self::$db_duration += (microtime(true) - $stamp);
879                 if (DBA::isResult($r)) {
880                         return DBA::toArray($r);
881                 }
882                 DBA::close($r);
883
884                 return false;
885         }
886
887         /**
888          * Returns the next jobs that should be executed
889          * @param int $limit
890          * @return array array with next jobs
891          * @throws \Exception
892          */
893         private static function nextProcess(int $limit): array
894         {
895                 $priority = self::nextPriority();
896                 if (empty($priority)) {
897                         Logger::info('No tasks found');
898                         return [];
899                 }
900
901                 $ids = [];
902                 $stamp = (float)microtime(true);
903                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
904                 $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['retrial', 'created']]);
905                 self::$db_duration += (microtime(true) - $stamp);
906                 while ($task = DBA::fetch($tasks)) {
907                         $ids[] = $task['id'];
908                         // Only continue that loop while we are storing commands that can be processed quickly
909                         if (!empty($task['command'])) {
910                                 $command = $task['command'];
911                         } else {
912                                 $command = json_decode($task['parameter'])[0];
913                         }
914
915                         if (!in_array($command, self::FAST_COMMANDS)) {
916                                 break;
917                         }
918                 }
919                 DBA::close($tasks);
920
921                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
922                 return $ids;
923         }
924
925         /**
926          * Returns the priority of the next workerqueue job
927          *
928          * @return string|bool priority or FALSE on failure
929          * @throws \Exception
930          */
931         private static function nextPriority()
932         {
933                 $waiting = [];
934                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
935                 foreach ($priorities as $priority) {
936                         $stamp = (float)microtime(true);
937                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
938                                 $waiting[$priority] = true;
939                         }
940                         self::$db_duration += (microtime(true) - $stamp);
941                 }
942
943                 if (!empty($waiting[PRIORITY_CRITICAL])) {
944                         return PRIORITY_CRITICAL;
945                 }
946
947                 $running = [];
948                 $running_total = 0;
949                 $stamp = (float)microtime(true);
950                 $processes = DBA::p("SELECT COUNT(DISTINCT(`pid`)) AS `running`, `priority` FROM `workerqueue-view` GROUP BY `priority`");
951                 self::$db_duration += (microtime(true) - $stamp);
952                 while ($process = DBA::fetch($processes)) {
953                         $running[$process['priority']] = $process['running'];
954                         $running_total += $process['running'];
955                 }
956                 DBA::close($processes);
957
958                 foreach ($priorities as $priority) {
959                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
960                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
961                                 return $priority;
962                         }
963                 }
964
965                 $active = max(self::activeWorkers(), $running_total);
966                 $priorities = max(count($waiting), count($running));
967                 $exponent = 2;
968
969                 $total = 0;
970                 for ($i = 1; $i <= $priorities; ++$i) {
971                         $total += pow($i, $exponent);
972                 }
973
974                 $limit = [];
975                 for ($i = 1; $i <= $priorities; ++$i) {
976                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
977                 }
978
979                 $i = 0;
980                 foreach ($running as $priority => $workers) {
981                         if ($workers < $limit[$i++]) {
982                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
983                                 return $priority;
984                         }
985                 }
986
987                 if (!empty($waiting)) {
988                         $priority = array_keys($waiting)[0];
989                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
990                         return $priority;
991                 }
992
993                 return false;
994         }
995
996         /**
997          * Find and claim the next worker process for us
998          *
999          * @return void
1000          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1001          */
1002         private static function findWorkerProcesses()
1003         {
1004                 $fetch_limit = DI::config()->get('system', 'worker_fetch_limit', 1);
1005
1006                 if (DI::config()->get('system', 'worker_multiple_fetch')) {
1007                         $pids = [];
1008                         foreach (self::getWorkerPIDList() as $pid => $count) {
1009                                 if ($count <= $fetch_limit) {
1010                                         $pids[] = $pid;
1011                                 }
1012                         }
1013                         if (empty($pids)) {
1014                                 return;
1015                         }
1016                         $limit = $fetch_limit * count($pids);
1017                 } else {
1018                         $pids = [getmypid()];
1019                         $limit = $fetch_limit;
1020                 }
1021
1022                 $ids = self::nextProcess($limit);
1023                 $limit -= count($ids);
1024
1025                 // If there is not enough results we check without priority limit
1026                 if ($limit > 0) {
1027                         $stamp = (float)microtime(true);
1028                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
1029                         $tasks = DBA::select('workerqueue', ['id', 'command', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'retrial', 'created']]);
1030                         self::$db_duration += (microtime(true) - $stamp);
1031
1032                         while ($task = DBA::fetch($tasks)) {
1033                                 $ids[] = $task['id'];
1034                                 // Only continue that loop while we are storing commands that can be processed quickly
1035                                 if (!empty($task['command'])) {
1036                                         $command = $task['command'];
1037                                 } else {
1038                                         $command = json_decode($task['parameter'])[0];
1039                                 }
1040                                 if (!in_array($command, self::FAST_COMMANDS)) {
1041                                         break;
1042                                 }
1043                         }
1044                         DBA::close($tasks);
1045                 }
1046
1047                 if (empty($ids)) {
1048                         return;
1049                 }
1050
1051                 // Assign the task ids to the workers
1052                 $worker = [];
1053                 foreach (array_unique($ids) as $id) {
1054                         $pid = next($pids);
1055                         if (!$pid) {
1056                                 $pid = reset($pids);
1057                         }
1058                         $worker[$pid][] = $id;
1059                 }
1060
1061                 $stamp = (float)microtime(true);
1062                 foreach ($worker as $worker_pid => $worker_ids) {
1063                         Logger::info('Set queue entry', ['pid' => $worker_pid, 'ids' => $worker_ids]);
1064                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $worker_pid],
1065                                 ['id' => $worker_ids, 'done' => false, 'pid' => 0]);
1066                 }
1067                 self::$db_duration += (microtime(true) - $stamp);
1068                 self::$db_duration_write += (microtime(true) - $stamp);
1069         }
1070
1071         /**
1072          * Returns the next worker process
1073          *
1074          * @return array worker processes
1075          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1076          */
1077         public static function workerProcess(): array
1078         {
1079                 // There can already be jobs for us in the queue.
1080                 $waiting = self::getWaitingJobForPID();
1081                 if (!empty($waiting)) {
1082                         return $waiting;
1083                 }
1084
1085                 $stamp = (float)microtime(true);
1086                 if (!DI::lock()->acquire(self::LOCK_PROCESS)) {
1087                         return [];
1088                 }
1089                 self::$lock_duration += (microtime(true) - $stamp);
1090
1091                 self::findWorkerProcesses();
1092
1093                 DI::lock()->release(self::LOCK_PROCESS);
1094
1095                 // Prevents "Return value of Friendica\Core\Worker::workerProcess() must be of the type array, bool returned"
1096                 $process = self::getWaitingJobForPID();
1097                 return (is_array($process) ? $process : []);
1098         }
1099
1100         /**
1101          * Removes a workerqueue entry from the current process
1102          *
1103          * @param Process $process the process behind the workerqueue
1104          *
1105          * @return void
1106          * @throws \Exception
1107          */
1108         public static function unclaimProcess(Process $process)
1109         {
1110                 $stamp = (float)microtime(true);
1111                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $process->pid, 'done' => false]);
1112                 self::$db_duration += (microtime(true) - $stamp);
1113                 self::$db_duration_write += (microtime(true) - $stamp);
1114         }
1115
1116         /**
1117          * Fork a child process
1118          *
1119          * @param boolean $do_cron
1120          * @return void
1121          */
1122         private static function forkProcess(bool $do_cron)
1123         {
1124                 if (DI::system()->isMinMemoryReached()) {
1125                         Logger::warning('Memory limit reached - quitting');
1126                         return;
1127                 }
1128
1129                 // Children inherit their parent's database connection.
1130                 // To avoid problems we disconnect and connect both parent and child
1131                 DBA::disconnect();
1132                 $pid = pcntl_fork();
1133                 if ($pid == -1) {
1134                         DBA::connect();
1135                         Logger::warning('Could not spawn worker');
1136                         return;
1137                 } elseif ($pid) {
1138                         // The parent process continues here
1139                         DBA::connect();
1140
1141                         Worker\IPC::SetJobState(true, $pid);
1142                         Logger::info('Spawned new worker', ['pid' => $pid]);
1143
1144                         $cycles = 0;
1145                         while (Worker\IPC::JobsExists($pid) && (++$cycles < 100)) {
1146                                 usleep(10000);
1147                         }
1148
1149                         Logger::info('Spawned worker is ready', ['pid' => $pid, 'wait_cycles' => $cycles]);
1150                         return;
1151                 }
1152
1153                 // We now are in the new worker
1154                 DBA::connect();
1155
1156                 DI::flushLogger();
1157                 $process = DI::process()->create(getmypid(), basename(__FILE__));
1158
1159                 $cycles = 0;
1160                 while (!Worker\IPC::JobsExists($process->pid) && (++$cycles < 100)) {
1161                         usleep(10000);
1162                 }
1163
1164                 Logger::info('Worker spawned', ['pid' => $process->pid, 'wait_cycles' => $cycles]);
1165
1166                 self::processQueue($do_cron, $process);
1167
1168                 self::unclaimProcess($process);
1169
1170                 Worker\IPC::SetJobState(false, $process->pid);
1171                 DI::process()->delete($process);
1172                 Logger::info('Worker ended', ['pid' => $process->pid]);
1173                 exit();
1174         }
1175
1176         /**
1177          * Spawns a new worker
1178          *
1179          * @param bool $do_cron
1180          * @return void
1181          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1182          */
1183         public static function spawnWorker(bool $do_cron = false)
1184         {
1185                 if (Worker\Daemon::isMode() && DI::config()->get('system', 'worker_fork')) {
1186                         self::forkProcess($do_cron);
1187                 } else {
1188                         DI::system()->run('bin/worker.php', ['no_cron' => !$do_cron]);
1189                 }
1190                 if (Worker\Daemon::isMode()) {
1191                         Worker\IPC::SetJobState(false);
1192                 }
1193         }
1194
1195         /**
1196          * Adds tasks to the worker queue
1197          *
1198          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1199          *
1200          * next args are passed as $cmd command line
1201          * or: Worker::add(PRIORITY_HIGH, 'Notifier', Delivery::DELETION, $drop_id);
1202          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), 'Delivery', $post_id);
1203          *
1204          * @return int '0' if worker queue entry already existed or there had been an error, otherwise the ID of the worker task
1205          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1206          * @note $cmd and string args are surrounded with ''
1207          *
1208          * @hooks 'proc_run'
1209          *    array $arr
1210          *
1211          */
1212         public static function add(...$args)
1213         {
1214                 if (!count($args)) {
1215                         return 0;
1216                 }
1217
1218                 $arr = ['args' => $args, 'run_cmd' => true];
1219
1220                 Hook::callAll('proc_run', $arr);
1221                 if (!$arr['run_cmd'] || !count($args)) {
1222                         return 1;
1223                 }
1224
1225                 $priority = PRIORITY_MEDIUM;
1226                 // Don't fork from frontend tasks by default
1227                 $dont_fork = DI::config()->get('system', 'worker_dont_fork', false) || !DI::mode()->isBackend();
1228                 $created = DateTimeFormat::utcNow();
1229                 $delayed = DBA::NULL_DATETIME;
1230                 $force_priority = false;
1231
1232                 $run_parameter = array_shift($args);
1233
1234                 if (is_int($run_parameter)) {
1235                         $priority = $run_parameter;
1236                 } elseif (is_array($run_parameter)) {
1237                         if (isset($run_parameter['delayed'])) {
1238                                 $delayed = $run_parameter['delayed'];
1239                         }
1240                         if (isset($run_parameter['priority'])) {
1241                                 $priority = $run_parameter['priority'];
1242                         }
1243                         if (isset($run_parameter['created'])) {
1244                                 $created = $run_parameter['created'];
1245                         }
1246                         if (isset($run_parameter['dont_fork'])) {
1247                                 $dont_fork = $run_parameter['dont_fork'];
1248                         }
1249                         if (isset($run_parameter['force_priority'])) {
1250                                 $force_priority = $run_parameter['force_priority'];
1251                         }
1252                 } else {
1253                         throw new \InvalidArgumentException('Priority number or task parameter array expected as first argument');
1254                 }
1255
1256                 $command = array_shift($args);
1257                 $parameters = json_encode($args);
1258                 $found = DBA::exists('workerqueue', ['command' => $command, 'parameter' => $parameters, 'done' => false]);
1259                 $added = 0;
1260
1261                 if (!is_int($priority) || !in_array($priority, PRIORITIES)) {
1262                         Logger::warning('Invalid priority', ['priority' => $priority, 'command' => $command, 'callstack' => System::callstack(20)]);
1263                         $priority = PRIORITY_MEDIUM;
1264                 }
1265
1266                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1267                 if (DBA::errorNo() != 0) {
1268                         return 0;
1269                 }
1270
1271                 if (!$found) {
1272                         if (!DBA::insert('workerqueue', ['command' => $command, 'parameter' => $parameters, 'created' => $created,
1273                                 'priority' => $priority, 'next_try' => $delayed])) {
1274                                 return 0;
1275                         }
1276                         $added = DBA::lastInsertId();
1277                 } elseif ($force_priority) {
1278                         DBA::update('workerqueue', ['priority' => $priority], ['command' => $command, 'parameter' => $parameters, 'done' => false, 'pid' => 0]);
1279                 }
1280
1281                 // Set the IPC flag to ensure an immediate process execution via daemon
1282                 if (Worker\Daemon::isMode()) {
1283                         Worker\IPC::SetJobState(true);
1284                 }
1285
1286                 Worker\Daemon::checkState();
1287
1288                 // Should we quit and wait for the worker to be called as a cronjob?
1289                 if ($dont_fork || self::systemLimitReached()) {
1290                         return $added;
1291                 }
1292
1293                 // If there is a lock then we don't have to check for too much worker
1294                 if (!DI::lock()->acquire(self::LOCK_WORKER, 0)) {
1295                         return $added;
1296                 }
1297
1298                 // If there are already enough workers running, don't fork another one
1299                 $quit = self::tooMuchWorkers();
1300                 DI::lock()->release(self::LOCK_WORKER);
1301
1302                 if ($quit) {
1303                         return $added;
1304                 }
1305
1306                 // Quit on daemon mode
1307                 if (Worker\Daemon::isMode()) {
1308                         return $added;
1309                 }
1310
1311                 // Now call the worker to execute the jobs that we just added to the queue
1312                 self::spawnWorker();
1313
1314                 return $added;
1315         }
1316
1317         public static function countWorkersByCommand(string $command): int
1318         {
1319                 return DBA::count('workerqueue', ['done' => false, 'pid' => 0, 'command' => $command]);
1320         }
1321
1322         /**
1323          * Returns the next retrial level for worker jobs.
1324          * This function will skip levels when jobs are older.
1325          *
1326          * @param array $queue Worker queue entry
1327          * @param integer $max_level maximum retrial level
1328          * @return integer the next retrial level value
1329          */
1330         private static function getNextRetrial(array $queue, int $max_level): int
1331         {
1332                 $created = strtotime($queue['created']);
1333                 $retrial_time = time() - $created;
1334
1335                 $new_retrial = $queue['retrial'] + 1;
1336                 $total = 0;
1337                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1338                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1339                         $total += $delay;
1340                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1341                                 $new_retrial = $retrial;
1342                         }
1343                 }
1344                 Logger::notice('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1345                 return $new_retrial;
1346         }
1347
1348         /**
1349          * Defers the current worker entry
1350          *
1351          * @return boolean had the entry been deferred?
1352          * @throws \Exception
1353          */
1354         public static function defer(): bool
1355         {
1356                 $queue = DI::app()->getQueue();
1357
1358                 if (empty($queue)) {
1359                         return false;
1360                 }
1361
1362                 $id = $queue['id'];
1363                 $priority = $queue['priority'];
1364
1365                 $max_level = DI::config()->get('system', 'worker_defer_limit');
1366
1367                 $new_retrial = self::getNextRetrial($queue, $max_level);
1368
1369                 if ($new_retrial > $max_level) {
1370                         Logger::notice('The task exceeded the maximum retry count', ['id' => $id, 'created' => $queue['created'], 'old_prio' => $queue['priority'], 'old_retrial' => $queue['retrial'], 'max_level' => $max_level, 'retrial' => $new_retrial]);
1371                         return false;
1372                 }
1373
1374                 // Calculate the delay until the next trial
1375                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1376                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1377
1378                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1379                         $priority = PRIORITY_MEDIUM;
1380                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1381                         $priority = PRIORITY_LOW;
1382                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1383                         $priority = PRIORITY_NEGLIGIBLE;
1384                 }
1385
1386                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1387
1388                 $stamp = (float)microtime(true);
1389                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1390                 DBA::update('workerqueue', $fields, ['id' => $id]);
1391                 self::$db_duration += (microtime(true) - $stamp);
1392                 self::$db_duration_write += (microtime(true) - $stamp);
1393
1394                 return true;
1395         }
1396
1397         /**
1398          * Check if the system is inside the defined maintenance window
1399          *
1400          * @param bool $check_last_execution Whether check last execution
1401          * @return boolean
1402          */
1403         public static function isInMaintenanceWindow(bool $check_last_execution = false): bool
1404         {
1405                 // Calculate the seconds of the start end end of the maintenance window
1406                 $start = strtotime(DI::config()->get('system', 'maintenance_start')) % 86400;
1407                 $end = strtotime(DI::config()->get('system', 'maintenance_end')) % 86400;
1408
1409                 Logger::info('Maintenance window', ['start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1410
1411                 if ($check_last_execution) {
1412                         // Calculate the window duration
1413                         $duration = max($start, $end) - min($start, $end);
1414
1415                         // Quit when the last cron execution had been after the previous window
1416                         $last_cron = DI::config()->get('system', 'last_cron_daily');
1417                         if ($last_cron + $duration > time()) {
1418                                 Logger::info('The Daily cron had been executed recently', ['last' => date(DateTimeFormat::MYSQL, $last_cron), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1419                                 return false;
1420                         }
1421                 }
1422
1423                 $current = time() % 86400;
1424
1425                 if ($start < $end) {
1426                         // Execute if we are inside the window
1427                         $execute = ($current >= $start) && ($current <= $end);
1428                 } else {
1429                         // Don't execute if we are outside the window
1430                         $execute = !(($current > $end) && ($current < $start));
1431                 }
1432
1433                 if ($execute) {
1434                         Logger::info('We are inside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1435                 } else {
1436                         Logger::info('We are outside the maintenance window', ['current' => date('H:i:s', $current), 'start' => date('H:i:s', $start), 'end' => date('H:i:s', $end)]);
1437                 }
1438
1439                 return $execute;
1440         }
1441 }