X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=include%2Fpoller.php;h=5560b3340e6209fc4ab82c97ecd3619bc9840afc;hb=d3cdfa610852f5dbda9bc3e29df6524eb504d068;hp=c681bfb3898448300578643ba2ad7ff14938bbb6;hpb=7e83ba090f7ff3889aec8a2e8f2b578210a66dc8;p=friendica.git

diff --git a/include/poller.php b/include/poller.php
index c681bfb389..5560b3340e 100644
--- a/include/poller.php
+++ b/include/poller.php
@@ -10,9 +10,11 @@ if (!file_exists("boot.php") AND (sizeof($_SERVER["argv"]) != 0)) {
 	chdir($directory);
 }
 
+use \Friendica\Core\Config;
+
 require_once("boot.php");
 
-function poller_run(&$argv, &$argc){
+function poller_run($argv, $argc){
 	global $a, $db;
 
 	if(is_null($a)) {
@@ -26,119 +28,398 @@ function poller_run(&$argv, &$argc){
 		unset($db_host, $db_user, $db_pass, $db_data);
 	};
 
-	$load = current_load();
-	if($load) {
-		$maxsysload = intval(get_config('system','maxloadavg'));
-		if($maxsysload < 1)
-			$maxsysload = 50;
+	Config::load();
 
-		if(intval($load) > $maxsysload) {
-			logger('system: load ' . $load . ' too high. poller deferred to next scheduled run.');
-			return;
-		}
+	// Quit when in maintenance
+	if (Config::get('system', 'maintenance', true)) {
+		return;
 	}
 
-	// Checking the number of workers
-	if (poller_too_much_workers(1))
-		return;
+	$a->set_baseurl(Config::get('system', 'url'));
 
-	if(($argc <= 1) OR ($argv[1] != "no_cron")) {
-		// Run the cron job that calls all other jobs
-		proc_run("php","include/cron.php");
+	load_hooks();
 
-		// Run the cronhooks job separately from cron for being able to use a different timing
-		proc_run("php","include/cronhooks.php");
+	$a->start_process();
 
-		// Cleaning dead processes
-		$r = q("SELECT DISTINCT(`pid`) FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
-		foreach($r AS $pid)
-			if (!posix_kill($pid["pid"], 0))
-				q("UPDATE `workerqueue` SET `executed` = '0000-00-00 00:00:00', `pid` = 0 WHERE `pid` = %d",
-					intval($pid["pid"]));
-			else {
-				/// @TODO Kill long running processes
-				/// But: Update processes (like the database update) mustn't be killed
-			}
+	if (poller_max_connections_reached()) {
+		return;
+	}
+
+	if ($a->maxload_reached()) {
+		return;
+	}
 
-	} else
-		// Sleep four seconds before checking for running processes again to avoid having too many workers
-		sleep(4);
+	if(($argc <= 1) OR ($argv[1] != "no_cron")) {
+		poller_run_cron();
+	}
 
-	// Checking number of workers
-	if (poller_too_much_workers(2))
+	if ($a->max_processes_reached()) {
 		return;
+	}
+
+	// Checking the number of workers
+	if (poller_too_much_workers()) {
+		poller_kill_stale_workers();
+		return;
+	}
 
 	$starttime = time();
 
-	while ($r = q("SELECT * FROM `workerqueue` WHERE `executed` = '0000-00-00 00:00:00' ORDER BY `created` LIMIT 1")) {
+	while ($r = poller_worker_process()) {
 
 		// Count active workers and compare them with a maximum value that depends on the load
-		if (poller_too_much_workers(3))
+		if (poller_too_much_workers()) {
 			return;
+		}
 
-		q("UPDATE `workerqueue` SET `executed` = '%s', `pid` = %d WHERE `id` = %d AND `executed` = '0000-00-00 00:00:00'",
-			dbesc(datetime_convert()),
-			intval(getmypid()),
-			intval($r[0]["id"]));
-
-		// Assure that there are no tasks executed twice
-		$id = q("SELECT `id` FROM `workerqueue` WHERE `id` = %d AND `pid` = %d",
-			intval($r[0]["id"]),
-			intval(getmypid()));
-		if (!$id) {
-			logger("Queue item ".$r[0]["id"]." was executed multiple times - skip this execution", LOGGER_DEBUG);
-			continue;
+		if (!poller_execute($r[0])) {
+			return;
 		}
 
-		$argv = json_decode($r[0]["parameter"]);
+		// Quit the poller once every hour
+		if (time() > ($starttime + 3600))
+			return;
+	}
+
+}
+
+/**
+ * @brief Execute a worker entry
+ *
+ * @param array $queue Workerqueue entry
+ *
+ * @return boolean "true" if further processing should be stopped
+ */
+function poller_execute($queue) {
+
+	$a = get_app();
+
+	$mypid = getmypid();
+
+	// Quit when in maintenance
+	if (Config::get('system', 'maintenance', true)) {
+		return false;
+	}
+
+	// Constantly check the number of parallel database processes
+	if ($a->max_processes_reached()) {
+		return false;
+	}
 
-		$argc = count($argv);
+	// Constantly check the number of available database connections to let the frontend be accessible at any time
+	if (poller_max_connections_reached()) {
+		return false;
+	}
 
-		// Check for existance and validity of the include file
-		$include = $argv[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;
+	}
 
-		if (!validate_include($include)) {
-			logger("Include file ".$argv[0]." is not valid!");
-			q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
-			continue;
+	// 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");
+
+	$argv = json_decode($queue["parameter"]);
+
+	// Check for existance and validity of the include file
+	$include = $argv[0];
+
+	if (!validate_include($include)) {
+		logger("Include file ".$argv[0]." is not valid!");
+		q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
+		return true;
+	}
+
+	require_once($include);
+
+	$funcname = str_replace(".php", "", basename($argv[0]))."_run";
+
+	if (function_exists($funcname)) {
+
+		poller_exec_function($queue, $funcname, $argv);
+
+		q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($queue["id"]));
+	} else {
+		logger("Function ".$funcname." does not exist");
+	}
+
+	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();
+	}
+
+	// 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);
+
+	$funcname($argv, $argc);
+
+	$a->process_id = $old_process_id;
+
+	$duration = number_format(microtime(true) - $stamp, 3);
+
+	if ($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($duration/60, 3).")", LOGGER_DEBUG);
+	}
+
+	logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - done in ".$duration." seconds.");
+
+	// Write down the performance values into the log
+	if (Config::get("system", "profiler")) {
+		$duration = microtime(true)-$a->performance["start"];
+
+		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 = '';
 		}
 
-		require_once($include);
+		logger("ID ".$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);
+	}
+
+	$cooldown = Config::get("system", "worker_cooldown", 0);
+
+	if ($cooldown > 0) {
+		logger("Process ".$mypid." - Prio ".$queue["priority"]." - ID ".$queue["id"].": ".$funcname." - in cooldown for ".$cooldown." seconds");
+		sleep($cooldown);
+	}
+}
 
-		$funcname=str_replace(".php", "", basename($argv[0]))."_run";
+/**
+ * @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 (function_exists($funcname)) {
-			logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." ".$r[0]["parameter"]);
-			$funcname($argv, $argc);
+	// 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;
 
-			logger("Process ".getmypid()." - ID ".$r[0]["id"].": ".$funcname." - done");
+		$used = count($r);
 
-			q("DELETE FROM `workerqueue` WHERE `id` = %d", intval($r[0]["id"]));
-		} else
-			logger("Function ".$funcname." does not exist");
+		logger("Connection usage (user values): ".$used."/".$max, LOGGER_DEBUG);
 
-		// Quit the poller once every hour
-		if (time() > ($starttime + 3600))
-			return;
+		$level = ($used / $max) * 100;
+
+		if ($level >= $maxlevel) {
+			logger("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
+			return true;
+		}
 	}
 
+	// 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;
+
+	$r = q("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
+	if (!$r)
+		return false;
+
+	$used = intval($r[0]["Value"]);
+	if ($used == 0)
+		return false;
+
+	logger("Connection usage (system values): ".$used."/".$max, LOGGER_DEBUG);
+
+	$level = $used / $max * 100;
+
+	if ($level < $maxlevel)
+		return false;
+
+	logger("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
+	return true;
 }
 
-function poller_too_much_workers($stage) {
+/**
+ * @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));
 
-	$queues = get_config("system", "worker_queues");
+	if (!dbm::is_result($r)) {
+		// No processing here needed
+		return;
+	}
 
-	if ($queues == 0)
-		$queues = 4;
+	foreach ($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;
 
 	$active = poller_active_workers();
 
 	// Decrease the number of workers at higher load
 	$load = current_load();
 	if($load) {
-		$maxsysload = intval(get_config('system','maxloadavg'));
-		if($maxsysload < 1)
-			$maxsysload = 50;
+		$maxsysload = intval(Config::get("system", "maxloadavg", 50));
 
 		$maxworkers = $queues;
 
@@ -147,21 +428,254 @@ function poller_too_much_workers($stage) {
 		$slope = $maxworkers / pow($maxsysload, $exponent);
 		$queues = ceil($slope * pow(max(0, $maxsysload - $load), $exponent));
 
-		logger("Current load stage ".$stage.": ".$load." - maximum: ".$maxsysload." - current queues: ".$active." - maximum: ".$queues, LOGGER_DEBUG);
+		$s = q("SELECT COUNT(*) AS `total` FROM `workerqueue` WHERE `executed` <= '%s'", dbesc(NULL_DATE));
+		$entries = $s[0]["total"];
+
+		if (Config::get("system", "worker_fastlane", false) AND ($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"];
 
+			$s = q("SELECT `id` FROM `workerqueue` WHERE `priority` <= %d AND `executed` > '%s' LIMIT 1",
+				intval($top_priority), dbesc(NULL_DATE));
+			$high_running = dbm::is_result($s);
+
+			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;
+			}
+		}
+
+		// 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("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 `workers` FROM `workerqueue` WHERE `executed` != '0000-00-00 00:00:00'");
+	$workers = q("SELECT COUNT(*) AS `processes` FROM `process` WHERE `command` = 'poller.php'");
+
+	return($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"];
 
-	return($workers[0]["workers"]);
+	// Should not happen
+	if (count($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());
+
+		// 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();
+
+			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();
+	}
+}
+
+/**
+ * @brief Removes long running worker processes
+ */
+function clear_worker_processes() {
+	$timeout = Config::get("system", "frontend_worker_timeout", 10);
+
+	/// @todo We should clean up the corresponding workerqueue entries as well
+	q("DELETE FROM `process` WHERE `created` < '%s' AND `command` = 'worker.php'",
+		dbesc(datetime_convert('UTC','UTC',"now - ".$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();
 }
 ?>