X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=include%2Fpoller.php;h=5560b3340e6209fc4ab82c97ecd3619bc9840afc;hb=d3cdfa610852f5dbda9bc3e29df6524eb504d068;hp=d971d4f00410a76cb77acac4364516c327052884;hpb=08f276f87b366e5d9c6f92e1dd5edc3da633707e;p=friendica.git

diff --git a/include/poller.php b/include/poller.php
index d971d4f004..5560b3340e 100644
--- a/include/poller.php
+++ b/include/poller.php
@@ -10,10 +10,11 @@ if (!file_exists("boot.php") AND (sizeof($_SERVER["argv"]) != 0)) {
 	chdir($directory);
 }
 
-require_once("boot.php");
+use \Friendica\Core\Config;
 
+require_once("boot.php");
 
-function poller_run(&$argv, &$argc){
+function poller_run($argv, $argc){
 	global $a, $db;
 
 	if(is_null($a)) {
@@ -21,288 +22,660 @@ function poller_run(&$argv, &$argc){
 	}
 
 	if(is_null($db)) {
-	    @include(".htconfig.php");
-    	require_once("include/dba.php");
-	    $db = new dba($db_host, $db_user, $db_pass, $db_data);
-    	unset($db_host, $db_user, $db_pass, $db_data);
-  	};
-
-
-	require_once('include/session.php');
-	require_once('include/datetime.php');
-	require_once('library/simplepie/simplepie.inc');
-	require_once('include/items.php');
-	require_once('include/Contact.php');
-	require_once('include/email.php');
-	require_once('include/socgraph.php');
-	require_once('include/pidfile.php');
-
-	load_config('config');
-	load_config('system');
-
-	$maxsysload = intval(get_config('system','maxloadavg'));
-	if($maxsysload < 1)
-		$maxsysload = 50;
-	if(function_exists('sys_getloadavg')) {
-		$load = sys_getloadavg();
-		if(intval($load[0]) > $maxsysload) {
-			logger('system: load ' . $load[0] . ' too high. Poller deferred to next scheduled run.');
-			return;
-		}
+		@include(".htconfig.php");
+		require_once("include/dba.php");
+		$db = new dba($db_host, $db_user, $db_pass, $db_data);
+		unset($db_host, $db_user, $db_pass, $db_data);
+	};
+
+	Config::load();
+
+	// Quit when in maintenance
+	if (Config::get('system', 'maintenance', true)) {
+		return;
 	}
 
-	$lockpath = get_lockpath();
-	if ($lockpath != '') {
-		$pidfile = new pidfile($lockpath, 'poller');
-		if($pidfile->is_already_running()) {
-			logger("poller: Already running");
-			if ($pidfile->running_time() > 9*60) {
-                                $pidfile->kill();
-                                logger("poller: killed stale process");
-                                // Calling a new instance
-                                proc_run('php','include/poller.php');
-                        }
-			exit;
-		}
+	$a->set_baseurl(Config::get('system', 'url'));
+
+	load_hooks();
+
+	$a->start_process();
+
+	if (poller_max_connections_reached()) {
+		return;
 	}
 
+	if ($a->maxload_reached()) {
+		return;
+	}
 
+	if(($argc <= 1) OR ($argv[1] != "no_cron")) {
+		poller_run_cron();
+	}
 
-	$a->set_baseurl(get_config('system','url'));
+	if ($a->max_processes_reached()) {
+		return;
+	}
 
-	load_hooks();
+	// Checking the number of workers
+	if (poller_too_much_workers()) {
+		poller_kill_stale_workers();
+		return;
+	}
 
-	logger('poller: start');
+	$starttime = time();
 
-	// run queue delivery process in the background
+	while ($r = poller_worker_process()) {
 
-	proc_run('php',"include/queue.php");
+		// Count active workers and compare them with a maximum value that depends on the load
+		if (poller_too_much_workers()) {
+			return;
+		}
 
-	// run diaspora photo queue process in the background
+		if (!poller_execute($r[0])) {
+			return;
+		}
 
-	proc_run('php',"include/dsprphotoq.php");
+		// Quit the poller once every hour
+		if (time() > ($starttime + 3600))
+			return;
+	}
 
-	// expire any expired accounts
+}
 
-	q("UPDATE user SET `account_expired` = 1 where `account_expired` = 0
-		AND `account_expires_on` != '0000-00-00 00:00:00'
-		AND `account_expires_on` < UTC_TIMESTAMP() ");
+/**
+ * @brief Execute a worker entry
+ *
+ * @param array $queue Workerqueue entry
+ *
+ * @return boolean "true" if further processing should be stopped
+ */
+function poller_execute($queue) {
 
-	// delete user and contact records for recently removed accounts
+	$a = get_app();
 
-	$r = q("SELECT * FROM `user` WHERE `account_removed` = 1 AND `account_expires_on` < UTC_TIMESTAMP() - INTERVAL 3 DAY");
-	if ($r) {
-		foreach($r as $user) {
-			q("DELETE FROM `contact` WHERE `uid` = %d", intval($user['uid']));
-			q("DELETE FROM `user` WHERE `uid` = %d", intval($user['uid']));
-		}
+	$mypid = getmypid();
+
+	// Quit when in maintenance
+	if (Config::get('system', 'maintenance', true)) {
+		return false;
+	}
+
+	// Constantly check the number of parallel database processes
+	if ($a->max_processes_reached()) {
+		return false;
+	}
+
+	// Constantly check the number of available database connections to let the frontend be accessible at any time
+	if (poller_max_connections_reached()) {
+		return false;
 	}
 
-	$abandon_days = intval(get_config('system','account_abandon_days'));
-	if($abandon_days < 1)
-		$abandon_days = 0;
+	$upd = q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `pid` = 0",
+		dbesc(datetime_convert()),
+		intval($mypid),
+		intval($queue["id"]));
+
+	if (!$upd) {
+		logger("Couldn't update queue entry ".$queue["id"]." - skip this execution", LOGGER_DEBUG);
+		q("COMMIT");
+		return true;
+	}
 
-	// Check OStatus conversations
-	// Check only conversations with mentions (for a longer time)
-	check_conversations(true);
+	// Assure that there are no tasks executed twice
+	$id = q("SELECT `pid`, `executed` FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
+	if (!$id) {
+		logger("Queue item ".$queue["id"]." vanished - skip this execution", LOGGER_DEBUG);
+		q("COMMIT");
+		return true;
+	} elseif ((strtotime($id[0]["executed"]) <= 0) OR ($id[0]["pid"] == 0)) {
+		logger("Entry for queue item ".$queue["id"]." wasn't stored - skip this execution", LOGGER_DEBUG);
+		q("COMMIT");
+		return true;
+	} elseif ($id[0]["pid"] != $mypid) {
+		logger("Queue item ".$queue["id"]." is to be executed by process ".$id[0]["pid"]." and not by me (".$mypid.") - skip this execution", LOGGER_DEBUG);
+		q("COMMIT");
+		return true;
+	}
+	q("COMMIT");
 
-	// Check every conversation
-	check_conversations(false);
+	$argv = json_decode($queue["parameter"]);
 
-	// To-Do: Regenerate usage statistics
-	// q("ANALYZE TABLE `item`");
+	// Check for existance and validity of the include file
+	$include = $argv[0];
 
-	// once daily run birthday_updates and then expire in background
+	if (!validate_include($include)) {
+		logger("Include file ".$argv[0]." is not valid!");
+		q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
+		return true;
+	}
 
-	$d1 = get_config('system','last_expire_day');
-	$d2 = intval(datetime_convert('UTC','UTC','now','d'));
+	require_once($include);
 
-	if($d2 != intval($d1)) {
+	$funcname = str_replace(".php", "", basename($argv[0]))."_run";
 
-		update_contact_birthdays();
+	if (function_exists($funcname)) {
 
-		update_suggestions();
+		poller_exec_function($queue, $funcname, $argv);
 
-		set_config('system','last_expire_day',$d2);
-		proc_run('php','include/expire.php');
+		q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
+	} else {
+		logger("Function ".$funcname." does not exist");
 	}
 
-	$last = get_config('system','cache_last_cleared');
+	return true;
+}
+
+/**
+ * @brief Execute a function from the queue
+ *
+ * @param array $queue Workerqueue entry
+ * @param string $funcname name of the function
+ * @param array $argv Array of values to be passed to the function
+ */
+function poller_exec_function($queue, $funcname, $argv) {
+
+	$a = get_app();
+
+	$mypid = getmypid();
+
+	$argc = count($argv);
+
+	logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." ".$queue["parameter"]);
+
+	$stamp = (float)microtime(true);
+
+	// We use the callstack here to analyze the performance of executed worker entries.
+	// For this reason the variables have to be initialized.
+	if (Config::get("system", "profiler")) {
+		$a->performance["start"] = microtime(true);
+		$a->performance["database"] = 0;
+		$a->performance["database_write"] = 0;
+		$a->performance["network"] = 0;
+		$a->performance["file"] = 0;
+		$a->performance["rendering"] = 0;
+		$a->performance["parser"] = 0;
+		$a->performance["marktime"] = 0;
+		$a->performance["markstart"] = microtime(true);
+		$a->callstack = array();
+	}
 
- 	if($last) {
-		$next = $last + (3600); // Once per hour
-		$clear_cache = ($next <= time());
-        } else
-		$clear_cache = true;
+	// For better logging create a new process id for every worker call
+	// But preserve the old one for the worker
+	$old_process_id = $a->process_id;
+	$a->process_id = uniqid("wrk", true);
 
-	if ($clear_cache) {
-		// clear old cache
-		Cache::clear();
+	$funcname($argv, $argc);
 
-		// clear old item cache files
-		clear_cache();
+	$a->process_id = $old_process_id;
 
-		// clear cache for photos
-		clear_cache($a->get_basepath(), $a->get_basepath()."/photo");
+	$duration = number_format(microtime(true) - $stamp, 3);
 
-		// clear smarty cache
-		clear_cache($a->get_basepath()."/view/smarty3/compiled", $a->get_basepath()."/view/smarty3/compiled");
+	if ($duration > 3600) {
+		logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 1 hour (".round($duration/60, 3).")", LOGGER_DEBUG);
+	} elseif ($duration > 600) {
+		logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 10 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+	} elseif ($duration > 300) {
+		logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 5 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+	} elseif ($duration > 120) {
+		logger("Prio ".$queue["priority"].": ".$queue["parameter"]." - longer than 2 minutes (".round($duration/60, 3).")", LOGGER_DEBUG);
+	}
 
-		// clear cache for image proxy
-		if (!get_config("system", "proxy_disabled")) {
-			clear_cache($a->get_basepath(), $a->get_basepath()."/proxy");
+	logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds.");
 
-			$cachetime = get_config('system','proxy_cache_time');
-			if (!$cachetime) $cachetime = PROXY_DEFAULT_TIME;
+	// Write down the performance values into the log
+	if (Config::get("system", "profiler")) {
+		$duration = microtime(true)-$a->performance["start"];
 
-			q('DELETE FROM `photo` WHERE `uid` = 0 AND `resource-id` LIKE "pic:%%" AND `created` < NOW() - INTERVAL %d SECOND', $cachetime);
+		if (Config::get("rendertime", "callstack")) {
+			if (isset($a->callstack["database"])) {
+				$o = "\nDatabase Read:\n";
+				foreach ($a->callstack["database"] AS $func => $time) {
+					$time = round($time, 3);
+					if ($time > 0)
+						$o .= $func.": ".$time."\n";
+				}
+			}
+			if (isset($a->callstack["database_write"])) {
+				$o .= "\nDatabase Write:\n";
+				foreach ($a->callstack["database_write"] AS $func => $time) {
+					$time = round($time, 3);
+					if ($time > 0)
+						$o .= $func.": ".$time."\n";
+				}
+			}
+			if (isset($a->callstack["network"])) {
+				$o .= "\nNetwork:\n";
+				foreach ($a->callstack["network"] AS $func => $time) {
+					$time = round($time, 3);
+					if ($time > 0)
+						$o .= $func.": ".$time."\n";
+				}
+			}
+		} else {
+			$o = '';
 		}
 
-		set_config('system','cache_last_cleared', time());
+		logger("ID ".$queue["id"].": ".$funcname.": ".sprintf("DB: %s/%s, Net: %s, I/O: %s, Other: %s, Total: %s".$o,
+			number_format($a->performance["database"] - $a->performance["database_write"], 2),
+			number_format($a->performance["database_write"], 2),
+			number_format($a->performance["network"], 2),
+			number_format($a->performance["file"], 2),
+			number_format($duration - ($a->performance["database"] + $a->performance["network"] + $a->performance["file"]), 2),
+			number_format($duration, 2)),
+			LOGGER_DEBUG);
 	}
 
-	$manual_id  = 0;
-	$generation = 0;
-	$force      = false;
-	$restart    = false;
+	$cooldown = Config::get("system", "worker_cooldown", 0);
 
-	if(($argc > 1) && ($argv[1] == 'force'))
-		$force = true;
+	if ($cooldown > 0) {
+		logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
+		sleep($cooldown);
+	}
+}
 
-	if(($argc > 1) && ($argv[1] == 'restart')) {
-		$restart = true;
-		$generation = intval($argv[2]);
-		if(! $generation)
-			killme();
+/**
+ * @brief Checks if the number of database connections has reached a critical limit.
+ *
+ * @return bool Are more than 3/4 of the maximum connections used?
+ */
+function poller_max_connections_reached() {
+
+	// Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
+	$max = Config::get("system", "max_connections");
+
+	// Fetch the percentage level where the poller will get active
+	$maxlevel = Config::get("system", "max_connections_level", 75);
+
+	if ($max == 0) {
+		// the maximum number of possible user connections can be a system variable
+		$r = q("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
+		if ($r)
+			$max = $r[0]["Value"];
+
+		// Or it can be granted. This overrides the system variable
+		$r = q("SHOW GRANTS");
+		if ($r)
+			foreach ($r AS $grants) {
+				$grant = array_pop($grants);
+				if (stristr($grant, "GRANT USAGE ON"))
+					if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match))
+						$max = $match[1];
+			}
 	}
 
-	if(($argc > 1) && intval($argv[1])) {
-		$manual_id = intval($argv[1]);
-		$force     = true;
+	// If $max is set we will use the processlist to determine the current number of connections
+	// The processlist only shows entries of the current user
+	if ($max != 0) {
+		$r = q("SHOW PROCESSLIST");
+		if (!dbm::is_result($r))
+			return false;
+
+		$used = count($r);
+
+		logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
+
+		$level = ($used / $max) * 100;
+
+		if ($level >= $maxlevel) {
+			logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
+			return true;
+		}
 	}
 
-	$interval = intval(get_config('system','poll_interval'));
-	if(! $interval)
-		$interval = ((get_config('system','delivery_interval') === false) ? 3 : intval(get_config('system','delivery_interval')));
+	// We will now check for the system values.
+	// This limit could be reached although the user limits are fine.
+	$r = q("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
+	if (!$r)
+		return false;
+
+	$max = intval($r[0]["Value"]);
+	if ($max == 0)
+		return false;
 
-	$sql_extra = (($manual_id) ? " AND `id` = $manual_id " : "");
+	$r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
+	if (!$r)
+		return false;
 
-	reload_plugins();
+	$used = intval($r[0]["Value"]);
+	if ($used == 0)
+		return false;
 
-	$d = datetime_convert();
+	logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
 
-	if(! $restart)
-		proc_run('php','include/cronhooks.php');
+	$level = $used / $max * 100;
 
-	// Only poll from those with suitable relationships,
-	// and which have a polling address and ignore Diaspora since
-	// we are unable to match those posts with a Diaspora GUID and prevent duplicates.
+	if ($level < $maxlevel)
+		return false;
 
-	$abandon_sql = (($abandon_days)
-		? sprintf(" AND `user`.`login_date` > UTC_TIMESTAMP() - INTERVAL %d DAY ", intval($abandon_days))
-		: ''
-	);
+	logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
+	return true;
+}
 
-	$contacts = q("SELECT `contact`.`id` FROM `contact` INNER JOIN `user` ON `user`.`uid` = `contact`.`uid`
-		WHERE `rel` IN (%d, %d) AND `poll` != '' AND `network` IN ('%s', '%s', '%s', '%s', '%s', '%s')
-		$sql_extra
-		AND NOT `self` AND NOT `contact`.`blocked` AND NOT `contact`.`readonly` AND NOT `contact`.`archive`
-		AND NOT `user`.`account_expired` AND NOT `user`.`account_removed` $abandon_sql ORDER BY RAND()",
-		intval(CONTACT_IS_SHARING),
-		intval(CONTACT_IS_FRIEND),
-		dbesc(NETWORK_DFRN),
-		dbesc(NETWORK_ZOT),
-		dbesc(NETWORK_OSTATUS),
-		dbesc(NETWORK_FEED),
-		dbesc(NETWORK_MAIL),
-		dbesc(NETWORK_MAIL2)
-	);
+/**
+ * @brief fix the queue entry if the worker process died
+ *
+ */
+function poller_kill_stale_workers() {
+	$r = q("SELECT `pid`, `executed`, `priority`, `parameter` FROM `workerqueue` WHERE `executed` > '%s'", dbesc(NULL_DATE));
 
-	if(! count($contacts)) {
+	if (!dbm::is_result($r)) {
+		// No processing here needed
 		return;
 	}
 
-	foreach($contacts as $c) {
+	foreach ($r AS $pid) {
+		if (!posix_kill($pid["pid"], 0)) {
+			q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = 0 WHERE `pid` = %d",
+				dbesc(NULL_DATE), intval($pid["pid"]));
+		} else {
+			// Kill long running processes
+
+			// Check if the priority is in a valid range
+			if (!in_array($pid["priority"], array(PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE)))
+				$pid["priority"] = PRIORITY_MEDIUM;
+
+			// Define the maximum durations
+			$max_duration_defaults = array(PRIORITY_CRITICAL => 360, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 360);
+			$max_duration = $max_duration_defaults[$pid["priority"]];
+
+			$argv = json_decode($pid["parameter"]);
+			$argv[0] = basename($argv[0]);
+
+			// How long is the process already running?
+			$duration = (time() - strtotime($pid["executed"])) / 60;
+			if ($duration > $max_duration) {
+				logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") took more than ".$max_duration." minutes. It will be killed now.");
+				posix_kill($pid["pid"], SIGTERM);
+
+				// We killed the stale process.
+				// To avoid a blocking situation we reschedule the process at the beginning of the queue.
+				// Additionally we are lowering the priority.
+				q("UPDATE `workerqueue` SET `executed` = '%s', `created` = '%s',
+							`priority` = %d, `pid` = 0 WHERE `pid` = %d",
+					dbesc(NULL_DATE),
+					dbesc(datetime_convert()),
+					intval(PRIORITY_NEGLIGIBLE),
+					intval($pid["pid"]));
+			} else {
+				logger("Worker process ".$pid["pid"]." (".implode(" ", $argv).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", LOGGER_DEBUG);
+			}
+		}
+	}
+}
+
+/**
+ * @brief Checks if the number of active workers exceeds the given limits
+ *
+ * @return bool Are there too much workers running?
+ */
+function poller_too_much_workers() {
+	$queues = Config::get("system", "worker_queues", 4);
+
+	$maxqueues = $queues;
 
-		$res = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
-			intval($c['id'])
-		);
+	$active = poller_active_workers();
 
-		if((! $res) || (! count($res)))
-			continue;
+	// Decrease the number of workers at higher load
+	$load = current_load();
+	if($load) {
+		$maxsysload = intval(Config::get("system", "maxloadavg", 50));
 
-		foreach($res as $contact) {
+		$maxworkers = $queues;
 
-			$xml = false;
+		// Some magical mathemathics to reduce the workers
+		$exponent = 3;
+		$slope = $maxworkers / pow($maxsysload, $exponent);
+		$queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 
-			if($manual_id)
-				$contact['last-update'] = '0000-00-00 00:00:00';
+		$s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` <= '%s'", dbesc(NULL_DATE));
+		$entries = $s[0]["total"];
 
-			if(in_array($contact['network'], array(NETWORK_DFRN, NETWORK_ZOT, NETWORK_OSTATUS)))
-				$contact['priority'] = 2;
+		if (Config::get("system", "worker_fastlane", false) AND ($queues > 0) AND ($entries > 0) AND ($active >= $queues)) {
+			$s = q("SELECT `priority` FROM `workerqueue` WHERE `executed` <= '%s' ORDER BY `priority` LIMIT 1", dbesc(NULL_DATE));
+			$top_priority = $s[0]["priority"];
 
-			if($contact['subhub'] AND in_array($contact['network'], array(NETWORK_DFRN, NETWORK_ZOT, NETWORK_OSTATUS))) {
-				// We should be getting everything via a hub. But just to be sure, let's check once a day.
-				// (You can make this more or less frequent if desired by setting 'pushpoll_frequency' appropriately)
-				// This also lets us update our subscription to the hub, and add or replace hubs in case it
-				// changed. We will only update hubs once a day, regardless of 'pushpoll_frequency'.
+			$s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` > '%s' LIMIT 1",
+				intval($top_priority), dbesc(NULL_DATE));
+			$high_running = dbm::is_result($s);
 
-				$poll_interval = get_config('system','pushpoll_frequency');
-				$contact['priority'] = (($poll_interval !== false) ? intval($poll_interval) : 3);
+			if (!$high_running AND ($top_priority > PRIORITY_UNDEFINED) AND ($top_priority < PRIORITY_NEGLIGIBLE)) {
+				logger("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", LOGGER_DEBUG);
+				$queues = $active + 1;
 			}
+		}
 
-			if($contact['priority'] AND !$force) {
-
-				$update     = false;
-
-				$t = $contact['last-update'];
-
-				/**
-				 * Based on $contact['priority'], should we poll this site now? Or later?
-				 */
-
-				switch ($contact['priority']) {
-					case 5:
-						if(datetime_convert('UTC','UTC', 'now') > datetime_convert('UTC','UTC', $t . " + 1 month"))
-							$update = true;
-						break;
-					case 4:
-						if(datetime_convert('UTC','UTC', 'now') > datetime_convert('UTC','UTC', $t . " + 1 week"))
-							$update = true;
-						break;
-					case 3:
-						if(datetime_convert('UTC','UTC', 'now') > datetime_convert('UTC','UTC', $t . " + 1 day"))
-							$update = true;
-						break;
-					case 2:
-						if(datetime_convert('UTC','UTC', 'now') > datetime_convert('UTC','UTC', $t . " + 12 hour"))
-							$update = true;
-						break;
-					case 1:
-					default:
-						if(datetime_convert('UTC','UTC', 'now') > datetime_convert('UTC','UTC', $t . " + 1 hour"))
-							$update = true;
-						break;
-				}
-				if(!$update)
-					continue;
+		// Create a list of queue entries grouped by their priority
+		$running = array(PRIORITY_CRITICAL => 0,
+				PRIORITY_HIGH => 0,
+				PRIORITY_MEDIUM => 0,
+				PRIORITY_LOW => 0,
+				PRIORITY_NEGLIGIBLE => 0);
+
+		$r = q("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` GROUP BY `priority`");
+		if (dbm::is_result($r))
+			foreach ($r AS $process)
+				$running[$process["priority"]] = $process["running"];
+
+		$processlist = "";
+		$r = q("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` GROUP BY `priority`");
+		if (dbm::is_result($r))
+			foreach ($r as $entry) {
+				if ($processlist != "")
+					$processlist .= ", ";
+				$processlist .= $entry["priority"].":".$running[$entry["priority"]]."/".$entry["entries"];
 			}
 
-			logger("Polling ".$contact["network"]." ".$contact["id"]." ".$contact["nick"]." ".$contact["name"]);
+		logger("Load: ".$load."/".$maxsysload." - processes: ".$active."/".$entries." (".$processlist.") - maximum: ".$queues."/".$maxqueues, LOGGER_DEBUG);
+
+		// Are there fewer workers running as possible? Then fork a new one.
+		if (!Config::get("system", "worker_dont_fork") AND ($queues > ($active + 1)) AND ($entries > 1)) {
+			logger("Active workers: ".$active."/".$queues." Fork a new worker.", LOGGER_DEBUG);
+			$args = array("include/poller.php", "no_cron");
+			$a = get_app();
+			$a->proc_run($args);
+		}
+	}
+
+	return($active >= $queues);
+}
+
+/**
+ * @brief Returns the number of active poller processes
+ *
+ * @return integer Number of active poller processes
+ */
+function poller_active_workers() {
+	$workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
+
+	return($workers[0]["processes"]);
+}
+
+/**
+ * @brief Check if we should pass some slow processes
+ *
+ * When the active processes of the highest priority are using more than 2/3
+ * of all processes, we let pass slower processes.
+ *
+ * @param string $highest_priority Returns the currently highest priority
+ * @return bool We let pass a slower process than $highest_priority
+ */
+function poller_passing_slow(&$highest_priority) {
+
+	$highest_priority = 0;
+
+	$r = q("SELECT `priority`
+		FROM `process`
+		INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`");
+
+	// No active processes at all? Fine
+	if (!dbm::is_result($r))
+		return(false);
+
+	$priorities = array();
+	foreach ($r AS $line)
+		$priorities[] = $line["priority"];
+
+	// Should not happen
+	if (count($priorities) == 0)
+		return(false);
+
+	$highest_priority = min($priorities);
+
+	// The highest process is already the slowest one?
+	// Then we quit
+	if ($highest_priority == PRIORITY_NEGLIGIBLE)
+		return(false);
+
+	$high = 0;
+	foreach ($priorities AS $priority)
+		if ($priority == $highest_priority)
+			++$high;
+
+	logger("Highest priority: ".$highest_priority." Total processes: ".count($priorities)." Count high priority processes: ".$high, LOGGER_DEBUG);
+	$passing_slow = (($high/count($priorities)) > (2/3));
+
+	if ($passing_slow)
+		logger("Passing slower processes than priority ".$highest_priority, LOGGER_DEBUG);
+
+	return($passing_slow);
+}
+
+/**
+ * @brief Returns the next worker process
+ *
+ * @return string SQL statement
+ */
+function poller_worker_process() {
+
+	q("START TRANSACTION;");
+
+	// Check if we should pass some low priority process
+	$highest_priority = 0;
+
+	if (poller_passing_slow($highest_priority)) {
+		// Are there waiting processes with a higher priority than the currently highest?
+		$r = q("SELECT * FROM `workerqueue`
+				WHERE `executed` <= '%s' AND `priority` < %d
+				ORDER BY `priority`, `created` LIMIT 1",
+				dbesc(NULL_DATE),
+				intval($highest_priority));
+		if (dbm::is_result($r)) {
+			return $r;
+		}
+		// Give slower processes some processing time
+		$r = q("SELECT * FROM `workerqueue`
+				WHERE `executed` <= '%s' AND `priority` > %d
+				ORDER BY `priority`, `created` LIMIT 1",
+				dbesc(NULL_DATE),
+				intval($highest_priority));
+	}
+
+	// If there is no result (or we shouldn't pass lower processes) we check without priority limit
+	if (($highest_priority == 0) OR !dbm::is_result($r)) {
+		$r = q("SELECT * FROM `workerqueue` WHERE `executed` <= '%s' ORDER BY `priority`, `created` LIMIT 1", dbesc(NULL_DATE));
+	}
+	return $r;
+}
+
+/**
+ * @brief Call the front end worker
+ */
+function call_worker() {
+	if (!Config::get("system", "frontend_worker")) {
+		return;
+	}
+
+	$url = App::get_baseurl()."/worker";
+	fetch_url($url, false, $redirects, 1);
+}
+
+/**
+ * @brief Call the front end worker if there aren't any active
+ */
+function call_worker_if_idle() {
+	if (!Config::get("system", "frontend_worker")) {
+		return;
+	}
+
+	// Do we have "proc_open"? Then we can fork the poller
+	if (function_exists("proc_open")) {
+		// When was the last time that we called the worker?
+		// Less than one minute? Then we quit
+		if ((time() - Config::get("system", "worker_started")) < 60) {
+			return;
+		}
+
+		set_config("system", "worker_started", time());
 
-			proc_run('php','include/onepoll.php',$contact['id']);
+		// Do we have enough running workers? Then we quit here.
+		if (poller_too_much_workers()) {
+			// Cleaning dead processes
+			poller_kill_stale_workers();
+			get_app()->remove_inactive_processes();
 
-			if($interval)
-				@time_sleep_until(microtime(true) + (float) $interval);
+			return;
 		}
+
+		poller_run_cron();
+
+		logger('Call poller', LOGGER_DEBUG);
+
+		$args = array("include/poller.php", "no_cron");
+		$a = get_app();
+		$a->proc_run($args);
+		return;
+	}
+
+	// We cannot execute background processes.
+	// We now run the processes from the frontend.
+	// This won't work with long running processes.
+	poller_run_cron();
+
+	clear_worker_processes();
+
+	$workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'worker.php'");
+
+	if ($workers[0]["processes"] == 0) {
+		call_worker();
 	}
+}
 
-	logger('poller: end');
+/**
+ * @brief Removes long running worker processes
+ */
+function clear_worker_processes() {
+	$timeout = Config::get("system", "frontend_worker_timeout", 10);
 
-	return;
+	/// @todo We should clean up the corresponding workerqueue entries as well
+	q("DELETE FROM `process` WHERE `created` < '%s' AND `command` = 'worker.php'",
+		dbesc(datetime_convert('UTC','UTC',"now - ".$timeout." minutes")));
+}
+
+/**
+ * @brief Runs the cron processes
+ */
+function poller_run_cron() {
+	logger('Add cron entries', LOGGER_DEBUG);
+
+	// Check for spooled items
+	proc_run(PRIORITY_HIGH, "include/spool_post.php");
+
+	// Run the cron job that calls all other jobs
+	proc_run(PRIORITY_MEDIUM, "include/cron.php");
+
+	// Run the cronhooks job separately from cron for being able to use a different timing
+	proc_run(PRIORITY_MEDIUM, "include/cronhooks.php");
+
+	// Cleaning dead processes
+	poller_kill_stale_workers();
 }
 
 if (array_search(__file__,get_included_files())===0){
-  poller_run($_SERVER["argv"],$_SERVER["argc"]);
-  killme();
+	poller_run($_SERVER["argv"],$_SERVER["argc"]);
+
+	get_app()->end_process();
+
+	killme();
 }
+?>