include/poller.php

   1 <?php
   2
   3 use Friendica\App;
   4 use Friendica\Core\Config;
   5 use Friendica\Util\Lock;
   6
   7 if (!file_exists("boot.php") && (sizeof($_SERVER["argv"]) != 0)) {
   8         $directory = dirname($_SERVER["argv"][0]);
   9
  10         if (substr($directory, 0, 1) != "/") {
  11                 $directory = $_SERVER["PWD"]."/".$directory;
  12         }
  13         $directory = realpath($directory."/..");
  14
  15         chdir($directory);
  16 }
  17
  18 require_once("boot.php");
  19
  20 function poller_run($argv, $argc){
  21         global $a, $db;
  22
  23         $a = new App(dirname(__DIR__));
  24
  25         @include(".htconfig.php");
  26         require_once("include/dba.php");
  27         $db = new dba($db_host, $db_user, $db_pass, $db_data);
  28         unset($db_host, $db_user, $db_pass, $db_data);
  29
  30         Config::load();
  31
  32         // Quit when in maintenance
  33         if (Config::get('system', 'maintenance', true)) {
  34                 return;
  35         }
  36
  37         $a->set_baseurl(Config::get('system', 'url'));
  38
  39         load_hooks();
  40
  41         // At first check the maximum load. We shouldn't continue with a high load
  42         if ($a->maxload_reached()) {
  43                 logger('Pre check: maximum load reached, quitting.', LOGGER_DEBUG);
  44                 return;
  45         }
  46
  47         // We now start the process. This is done after the load check since this could increase the load.
  48         $a->start_process();
  49
  50         // At first we check the number of workers and quit if there are too much of them
  51         // This is done at the top to avoid that too much code is executed without a need to do so,
  52         // since the poller mostly quits here.
  53         if (poller_too_much_workers()) {
  54                 poller_kill_stale_workers();
  55                 logger('Pre check: Active worker limit reached, quitting.', LOGGER_DEBUG);
  56                 return;
  57         }
  58
  59         // Do we have too few memory?
  60         if ($a->min_memory_reached()) {
  61                 logger('Pre check: Memory limit reached, quitting.', LOGGER_DEBUG);
  62                 return;
  63         }
  64
  65         // Possibly there are too much database connections
  66         if (poller_max_connections_reached()) {
  67                 logger('Pre check: maximum connections reached, quitting.', LOGGER_DEBUG);
  68                 return;
  69         }
  70
  71         // Possibly there are too much database processes that block the system
  72         if ($a->max_processes_reached()) {
  73                 logger('Pre check: maximum processes reached, quitting.', LOGGER_DEBUG);
  74                 return;
  75         }
  76
  77         // Now we start additional cron processes if we should do so
  78         if (($argc <= 1) || ($argv[1] != "no_cron")) {
  79                 poller_run_cron();
  80         }
  81
  82         $starttime = time();
  83
  84         // We fetch the next queue entry that is about to be executed
  85         while ($r = poller_worker_process()) {
  86
  87                 // If we got that queue entry we claim it for us
  88                 if (!poller_claim_process($r[0])) {
  89                         continue;
  90                 }
  91
  92                 // To avoid the quitting of multiple pollers only one poller at a time will execute the check
  93                 if (Lock::set('poller_worker', 0)) {
  94                         // Count active workers and compare them with a maximum value that depends on the load
  95                         if (poller_too_much_workers()) {
  96                                 logger('Active worker limit reached, quitting.', LOGGER_DEBUG);
  97                                 return;
  98                         }
  99
 100                         // Check free memory
 101                         if ($a->min_memory_reached()) {
 102                                 logger('Memory limit reached, quitting.', LOGGER_DEBUG);
 103                                 return;
 104                         }
 105                         Lock::remove('poller_worker');
 106                 }
 107
 108                 // finally the work will be done
 109                 if (!poller_execute($r[0])) {
 110                         logger('Process execution failed, quitting.', LOGGER_DEBUG);
 111                         return;
 112                 }
 113
 114                 // Quit the poller once every hour
 115                 if (time() > ($starttime + 3600)) {
 116                         logger('Process lifetime reached, quitting.', LOGGER_DEBUG);
 117                         return;
 118                 }
 119         }
 120         logger("Couldn't select a workerqueue entry, quitting.", LOGGER_DEBUG);
 121 }
 122
 123 /**
 124  * @brief Execute a worker entry
 125  *
 126  * @param array $queue Workerqueue entry
 127  *
 128  * @return boolean "true" if further processing should be stopped
 129  */
 130 function poller_execute($queue) {
 131
 132         $a = get_app();
 133
 134         $mypid = getmypid();
 135
 136         // Quit when in maintenance
 137         if (Config::get('system', 'maintenance', true)) {
 138                 logger("Maintenance mode - quit process ".$mypid, LOGGER_DEBUG);
 139                 return false;
 140         }
 141
 142         // Constantly check the number of parallel database processes
 143         if ($a->max_processes_reached()) {
 144                 logger("Max processes reached for process ".$mypid, LOGGER_DEBUG);
 145                 return false;
 146         }
 147
 148         // Constantly check the number of available database connections to let the frontend be accessible at any time
 149         if (poller_max_connections_reached()) {
 150                 logger("Max connection reached for process ".$mypid, LOGGER_DEBUG);
 151                 return false;
 152         }
 153
 154         $argv = json_decode($queue["parameter"]);
 155
 156         // Check for existance and validity of the include file
 157         $include = $argv[0];
 158
 159         if (!validate_include($include)) {
 160                 logger("Include file ".$argv[0]." is not valid!");
 161                 dba::delete('workerqueue', array('id' => $queue["id"]));
 162                 return true;
 163         }
 164
 165         require_once($include);
 166
 167         $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 168
 169         if (function_exists($funcname)) {
 170                 poller_exec_function($queue, $funcname, $argv);
 171                 dba::delete('workerqueue', array('id' => $queue["id"]));
 172         } else {
 173                 logger("Function ".$funcname." does not exist");
 174         }
 175
 176         return true;
 177 }
 178
 179 /**
 180  * @brief Execute a function from the queue
 181  *
 182  * @param array $queue Workerqueue entry
 183  * @param string $funcname name of the function
 184  * @param array $argv Array of values to be passed to the function
 185  */
 186 function poller_exec_function($queue, $funcname, $argv) {
 187
 188         $a = get_app();
 189
 190         $mypid = getmypid();
 191
 192         $argc = count($argv);
 193
 194         logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]);
 195
 196         $stamp = (float)microtime(true);
 197
 198         // We use the callstack here to analyze the performance of executed worker entries.
 199         // For this reason the variables have to be initialized.
 200         if (Config::get("system", "profiler")) {
 201                 $a->performance["start"] = microtime(true);
 202                 $a->performance["database"] = 0;
 203                 $a->performance["database_write"] = 0;
 204                 $a->performance["network"] = 0;
 205                 $a->performance["file"] = 0;
 206                 $a->performance["rendering"] = 0;
 207                 $a->performance["parser"] = 0;
 208                 $a->performance["marktime"] = 0;
 209                 $a->performance["markstart"] = microtime(true);
 210                 $a->callstack = array();
 211         }
 212
 213         // For better logging create a new process id for every worker call
 214         // But preserve the old one for the worker
 215         $old_process_id = $a->process_id;
 216         $a->process_id = uniqid("wrk", true);
 217
 218         $funcname($argv, $argc);
 219
 220         $a->process_id = $old_process_id;
 221
 222         $duration = number_format(microtime(true) - $stamp, 3);
 223
 224         if ($duration > 3600) {
 225                 logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
 226         } elseif ($duration > 600) {
 227                 logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 228         } elseif ($duration > 300) {
 229                 logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 230         } elseif ($duration > 120) {
 231                 logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
 232         }
 233
 234         logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds.");
 235
 236         // Write down the performance values into the log
 237         if (Config::get("system", "profiler")) {
 238                 $duration = microtime(true)-$a->performance["start"];
 239
 240                 if (Config::get("rendertime", "callstack")) {
 241                         if (isset($a->callstack["database"])) {
 242                                 $o = "\nDatabase Read:\n";
 243                                 foreach ($a->callstack["database"] AS $func => $time) {
 244                                         $time = round($time, 3);
 245                                         if ($time > 0) {
 246                                                 $o .= $func.": ".$time."\n";
 247                                         }
 248                                 }
 249                         }
 250                         if (isset($a->callstack["database_write"])) {
 251                                 $o .= "\nDatabase Write:\n";
 252                                 foreach ($a->callstack["database_write"] AS $func => $time) {
 253                                         $time = round($time, 3);
 254                                         if ($time > 0) {
 255                                                 $o .= $func.": ".$time."\n";
 256                                         }
 257                                 }
 258                         }
 259                         if (isset($a->callstack["network"])) {
 260                                 $o .= "\nNetwork:\n";
 261                                 foreach ($a->callstack["network"] AS $func => $time) {
 262                                         $time = round($time, 3);
 263                                         if ($time > 0) {
 264                                                 $o .= $func.": ".$time."\n";
 265                                         }
 266                                 }
 267                         }
 268                 } else {
 269                         $o = '';
 270                 }
 271
 272                 logger("ID ".$queue["id"].": ".$funcname.": ".sprintf("DB: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
 273                         number_format($a->performance["database"] - $a->performance["database_write"], 2),
 274                         number_format($a->performance["database_write"], 2),
 275                         number_format($a->performance["network"], 2),
 276                         number_format($a->performance["file"], 2),
 277                         number_format($duration - ($a->performance["database"] + $a->performance["network"] + $a->performance["file"]), 2),
 278                         number_format($duration, 2)),
 279                         LOGGER_DEBUG);
 280         }
 281
 282         $cooldown = Config::get("system", "worker_cooldown", 0);
 283
 284         if ($cooldown > 0) {
 285                 logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
 286                 sleep($cooldown);
 287         }
 288 }
 289
 290 /**
 291  * @brief Checks if the number of database connections has reached a critical limit.
 292  *
 293  * @return bool Are more than 3/4 of the maximum connections used?
 294  */
 295 function poller_max_connections_reached() {
 296
 297         // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 298         $max = Config::get("system", "max_connections");
 299
 300         // Fetch the percentage level where the poller will get active
 301         $maxlevel = Config::get("system", "max_connections_level", 75);
 302
 303         if ($max == 0) {
 304                 // the maximum number of possible user connections can be a system variable
 305                 $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 306                 if (dbm::is_result($r)) {
 307                         $max = $r[0]["Value"];
 308                 }
 309                 // Or it can be granted. This overrides the system variable
 310                 $r = q("SHOW GRANTS");
 311                 if (dbm::is_result($r)) {
 312                         foreach ($r AS $grants) {
 313                                 $grant = array_pop($grants);
 314                                 if (stristr($grant, "GRANT USAGE ON")) {
 315                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 316                                                 $max = $match[1];
 317                                         }
 318                                 }
 319                         }
 320                 }
 321         }
 322
 323         // If $max is set we will use the processlist to determine the current number of connections
 324         // The processlist only shows entries of the current user
 325         if ($max != 0) {
 326                 $r = q("SHOW PROCESSLIST");
 327                 if (!dbm::is_result($r)) {
 328                         return false;
 329                 }
 330                 $used = count($r);
 331
 332                 logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 333
 334                 $level = ($used / $max) * 100;
 335
 336                 if ($level >= $maxlevel) {
 337                         logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 338                         return true;
 339                 }
 340         }
 341
 342         // We will now check for the system values.
 343         // This limit could be reached although the user limits are fine.
 344         $r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 345         if (!dbm::is_result($r)) {
 346                 return false;
 347         }
 348         $max = intval($r[0]["Value"]);
 349         if ($max == 0) {
 350                 return false;
 351         }
 352         $r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 353         if (!dbm::is_result($r)) {
 354                 return false;
 355         }
 356         $used = intval($r[0]["Value"]);
 357         if ($used == 0) {
 358                 return false;
 359         }
 360         logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 361
 362         $level = $used / $max * 100;
 363
 364         if ($level < $maxlevel) {
 365                 return false;
 366         }
 367         logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 368         return true;
 369 }
 370
 371 /**
 372  * @brief fix the queue entry if the worker process died
 373  *
 374  */
 375 function poller_kill_stale_workers() {
 376         $r = q("SELECT `pid`, `executed`, `priority`, `parameter` FROM `workerqueue` WHERE `executed` > '%s'", dbesc(NULL_DATE));
 377
 378         if (!dbm::is_result($r)) {
 379                 // No processing here needed
 380                 return;
 381         }
 382
 383         foreach ($r AS $pid) {
 384                 if (!posix_kill($pid["pid"], 0)) {
 385                         dba::update('workerqueue', array('executed' => NULL_DATE, 'pid' => 0),
 386                                         array('pid' => $pid["pid"]));
 387                 } else {
 388                         // Kill long running processes
 389
 390                         // Check if the priority is in a valid range
 391                         if (!in_array($pid["priority"], array(PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE))) {
 392                                 $pid["priority"] = PRIORITY_MEDIUM;
 393                         }
 394
 395                         // Define the maximum durations
 396                         $max_duration_defaults = array(PRIORITY_CRITICAL => 360, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 360);
 397                         $max_duration = $max_duration_defaults[$pid["priority"]];
 398
 399                         $argv = json_decode($pid["parameter"]);
 400                         $argv[0] = basename($argv[0]);
 401
 402                         // How long is the process already running?
 403                         $duration = (time() - strtotime($pid["executed"])) / 60;
 404                         if ($duration > $max_duration) {
 405                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
 406                                 posix_kill($pid["pid"], SIGTERM);
 407
 408                                 // We killed the stale process.
 409                                 // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 410                                 // Additionally we are lowering the priority.
 411                                 dba::update('workerqueue',
 412                                                 array('executed' => NULL_DATE, 'created' => datetime_convert(), 'priority' => PRIORITY_NEGLIGIBLE, 'pid' => 0),
 413                                                 array('pid' => $pid["pid"]));
 414                         } else {
 415                                 logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
 416                         }
 417                 }
 418         }
 419 }
 420
 421 /**
 422  * @brief Checks if the number of active workers exceeds the given limits
 423  *
 424  * @return bool Are there too much workers running?
 425  */
 426 function poller_too_much_workers() {
 427         $queues = Config::get("system", "worker_queues", 4);
 428
 429         $maxqueues = $queues;
 430
 431         $active = poller_active_workers();
 432
 433         // Decrease the number of workers at higher load
 434         $load = current_load();
 435         if ($load) {
 436                 $maxsysload = intval(Config::get("system", "maxloadavg", 50));
 437
 438                 $maxworkers = $queues;
 439
 440                 // Some magical mathemathics to reduce the workers
 441                 $exponent = 3;
 442                 $slope = $maxworkers / pow($maxsysload, $exponent);
 443                 $queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 444
 445                 // Create a list of queue entries grouped by their priority
 446                 $listitem = array();
 447
 448                 // Adding all processes with no workerqueue entry
 449                 $processes = dba::p("SELECT COUNT(*) AS `running` FROM `process` WHERE NOT EXISTS (SELECT id FROM `workerqueue` WHERE `workerqueue`.`pid` = `process`.`pid`)");
 450                 if ($process = dba::fetch($processes)) {
 451                         $listitem[0] = "0:".$process["running"];
 452                 }
 453                 dba::close($processes);
 454
 455                 // Now adding all processes with workerqueue entries
 456                 $entries = dba::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` GROUP BY `priority`");
 457                 while ($entry = dba::fetch($entries)) {
 458                         $processes = dba::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE `priority` = ?", $entry["priority"]);
 459                         if ($process = dba::fetch($processes)) {
 460                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 461                         }
 462                         dba::close($processes);
 463                 }
 464                 dba::close($entries);
 465                 $processlist = ' ('.implode(', ', $listitem).')';
 466
 467                 $s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` <= '%s'", dbesc(NULL_DATE));
 468                 $entries = $s[0]["total"];
 469
 470                 if (Config::get("system", "worker_fastlane", false) && ($queues > 0) && ($entries > 0) && ($active >= $queues)) {
 471                         $s = q("SELECT `priority` FROM `workerqueue` WHERE `executed` <= '%s' ORDER BY `priority` LIMIT 1", dbesc(NULL_DATE));
 472                         $top_priority = $s[0]["priority"];
 473
 474                         $s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` > '%s' LIMIT 1",
 475                                 intval($top_priority), dbesc(NULL_DATE));
 476                         $high_running = dbm::is_result($s);
 477
 478                         if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 479                                 logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
 480                                 $queues = $active + 1;
 481                         }
 482                 }
 483
 484                 logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries.$processlist." - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
 485
 486                 // Are there fewer workers running as possible? Then fork a new one.
 487                 if (!Config::get("system", "worker_dont_fork") && ($queues > ($active + 1)) && ($entries > 1)) {
 488                         logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
 489                         $args = array("include/poller.php", "no_cron");
 490                         $a = get_app();
 491                         $a->proc_run($args);
 492                 }
 493         }
 494
 495         return $active >= $queues;
 496 }
 497
 498 /**
 499  * @brief Returns the number of active poller processes
 500  *
 501  * @return integer Number of active poller processes
 502  */
 503 function poller_active_workers() {
 504         $workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
 505
 506         return $workers[0]["processes"];
 507 }
 508
 509 /**
 510  * @brief Check if we should pass some slow processes
 511  *
 512  * When the active processes of the highest priority are using more than 2/3
 513  * of all processes, we let pass slower processes.
 514  *
 515  * @param string $highest_priority Returns the currently highest priority
 516  * @return bool We let pass a slower process than $highest_priority
 517  */
 518 function poller_passing_slow(&$highest_priority) {
 519
 520         $highest_priority = 0;
 521
 522         $r = q("SELECT `priority`
 523                 FROM `process`
 524                 INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`");
 525
 526         // No active processes at all? Fine
 527         if (!dbm::is_result($r)) {
 528                 return false;
 529         }
 530         $priorities = array();
 531         foreach ($r AS $line) {
 532                 $priorities[] = $line["priority"];
 533         }
 534         // Should not happen
 535         if (count($priorities) == 0) {
 536                 return false;
 537         }
 538         $highest_priority = min($priorities);
 539
 540         // The highest process is already the slowest one?
 541         // Then we quit
 542         if ($highest_priority == PRIORITY_NEGLIGIBLE) {
 543                 return false;
 544         }
 545         $high = 0;
 546         foreach ($priorities AS $priority) {
 547                 if ($priority == $highest_priority) {
 548                         ++$high;
 549                 }
 550         }
 551         logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
 552         $passing_slow = (($high/count($priorities)) > (2/3));
 553
 554         if ($passing_slow) {
 555                 logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
 556         }
 557         return $passing_slow;
 558 }
 559
 560 /**
 561  * @brief Returns the next worker process
 562  *
 563  * @return string SQL statement
 564  */
 565 function poller_worker_process() {
 566
 567         // Check if we should pass some low priority process
 568         $highest_priority = 0;
 569
 570         if (poller_passing_slow($highest_priority)) {
 571                 dba::lock('workerqueue');
 572
 573                 // Are there waiting processes with a higher priority than the currently highest?
 574                 $r = q("SELECT * FROM `workerqueue`
 575                                 WHERE `executed` <= '%s' AND `priority` < %d
 576                                 ORDER BY `priority`, `created` LIMIT 1",
 577                                 dbesc(NULL_DATE),
 578                                 intval($highest_priority));
 579                 if (dbm::is_result($r)) {
 580                         return $r;
 581                 }
 582                 // Give slower processes some processing time
 583                 $r = q("SELECT * FROM `workerqueue`
 584                                 WHERE `executed` <= '%s' AND `priority` > %d
 585                                 ORDER BY `priority`, `created` LIMIT 1",
 586                                 dbesc(NULL_DATE),
 587                                 intval($highest_priority));
 588
 589                 if (dbm::is_result($r)) {
 590                         return $r;
 591                 }
 592         } else {
 593                 dba::lock('workerqueue');
 594         }
 595
 596         // If there is no result (or we shouldn't pass lower processes) we check without priority limit
 597         if (!dbm::is_result($r)) {
 598                 $r = q("SELECT * FROM `workerqueue` WHERE `executed` <= '%s' ORDER BY `priority`, `created` LIMIT 1", dbesc(NULL_DATE));
 599         }
 600
 601         // We only unlock the tables here, when we got no data
 602         if (!dbm::is_result($r)) {
 603                 dba::unlock();
 604         }
 605
 606         return $r;
 607 }
 608
 609 /**
 610  * @brief Assigns a workerqueue entry to the current process
 611  *
 612  * When we are sure that the table locks are working correctly, we can remove the checks from here
 613  *
 614  * @param array $queue Workerqueue entry
 615  *
 616  * @return boolean "true" if the claiming was successful
 617  */
 618 function poller_claim_process($queue) {
 619         $mypid = getmypid();
 620
 621         $success = dba::update('workerqueue', array('executed' => datetime_convert(), 'pid' => $mypid),
 622                         array('id' => $queue["id"], 'pid' => 0));
 623         dba::unlock();
 624
 625         if (!$success) {
 626                 logger("Couldn't update queue entry ".$queue["id"]." - skip this execution", LOGGER_DEBUG);
 627                 return false;
 628         }
 629
 630         // Assure that there are no tasks executed twice
 631         $id = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
 632         if (!$id) {
 633                 logger("Queue item ".$queue["id"]." vanished - skip this execution", LOGGER_DEBUG);
 634                 return false;
 635         } elseif ((strtotime($id[0]["executed"]) <= 0) || ($id[0]["pid"] == 0)) {
 636                 logger("Entry for queue item ".$queue["id"]." wasn't stored - skip this execution", LOGGER_DEBUG);
 637                 return false;
 638         } elseif ($id[0]["pid"] != $mypid) {
 639                 logger("Queue item ".$queue["id"]." is to be executed by process ".$id[0]["pid"]." and not by me (".$mypid.") - skip this execution", LOGGER_DEBUG);
 640                 return false;
 641         }
 642         return true;
 643 }
 644
 645 /**
 646  * @brief Removes a workerqueue entry from the current process
 647  */
 648 function poller_unclaim_process() {
 649         $mypid = getmypid();
 650
 651         dba::update('workerqueue', array('executed' => NULL_DATE, 'pid' => 0), array('pid' => $mypid));
 652 }
 653
 654 /**
 655  * @brief Call the front end worker
 656  */
 657 function call_worker() {
 658         if (!Config::get("system", "frontend_worker")) {
 659                 return;
 660         }
 661
 662         $url = App::get_baseurl()."/worker";
 663         fetch_url($url, false, $redirects, 1);
 664 }
 665
 666 /**
 667  * @brief Call the front end worker if there aren't any active
 668  */
 669 function call_worker_if_idle() {
 670         if (!Config::get("system", "frontend_worker")) {
 671                 return;
 672         }
 673
 674         // Do we have "proc_open"? Then we can fork the poller
 675         if (function_exists("proc_open")) {
 676                 // When was the last time that we called the worker?
 677                 // Less than one minute? Then we quit
 678                 if ((time() - Config::get("system", "worker_started")) < 60) {
 679                         return;
 680                 }
 681
 682                 set_config("system", "worker_started", time());
 683
 684                 // Do we have enough running workers? Then we quit here.
 685                 if (poller_too_much_workers()) {
 686                         // Cleaning dead processes
 687                         poller_kill_stale_workers();
 688                         get_app()->remove_inactive_processes();
 689
 690                         return;
 691                 }
 692
 693                 poller_run_cron();
 694
 695                 logger('Call poller', LOGGER_DEBUG);
 696
 697                 $args = array("include/poller.php", "no_cron");
 698                 $a = get_app();
 699                 $a->proc_run($args);
 700                 return;
 701         }
 702
 703         // We cannot execute background processes.
 704         // We now run the processes from the frontend.
 705         // This won't work with long running processes.
 706         poller_run_cron();
 707
 708         clear_worker_processes();
 709
 710         $workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'worker.php'");
 711
 712         if ($workers[0]["processes"] == 0) {
 713                 call_worker();
 714         }
 715 }
 716
 717 /**
 718  * @brief Removes long running worker processes
 719  */
 720 function clear_worker_processes() {
 721         $timeout = Config::get("system", "frontend_worker_timeout", 10);
 722
 723         /// @todo We should clean up the corresponding workerqueue entries as well
 724         q("DELETE FROM `process` WHERE `created` < '%s' AND `command` = 'worker.php'",
 725                 dbesc(datetime_convert('UTC','UTC',"now - ".$timeout." minutes")));
 726 }
 727
 728 /**
 729  * @brief Runs the cron processes
 730  */
 731 function poller_run_cron() {
 732         logger('Add cron entries', LOGGER_DEBUG);
 733
 734         // Check for spooled items
 735         proc_run(PRIORITY_HIGH, "include/spool_post.php");
 736
 737         // Run the cron job that calls all other jobs
 738         proc_run(PRIORITY_MEDIUM, "include/cron.php");
 739
 740         // Run the cronhooks job separately from cron for being able to use a different timing
 741         proc_run(PRIORITY_MEDIUM, "include/cronhooks.php");
 742
 743         // Cleaning dead processes
 744         poller_kill_stale_workers();
 745 }
 746
 747 if (array_search(__file__,get_included_files())===0){
 748         poller_run($_SERVER["argv"],$_SERVER["argc"]);
 749
 750         poller_unclaim_process();
 751
 752         get_app()->end_process();
 753
 754         Lock::remove('poller_worker');
 755
 756         killme();
 757 }