3 * StatusNet, the distributed open-source microblogging tool
5 * I/O manager to wrap around socket-reading and polling queue & connection managers.
9 * LICENCE: This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Affero General Public License as published by
11 * the Free Software Foundation, either version 3 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Affero General Public License for more details.
19 * You should have received a copy of the GNU Affero General Public License
20 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 * @category QueueManager
24 * @author Brion Vibber <brion@status.net>
25 * @copyright 2009 StatusNet, Inc.
26 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
27 * @link http://status.net/
30 abstract class IoMaster
34 protected $multiSite = false;
35 protected $managers = array();
36 protected $singletons = array();
38 protected $pollTimeouts = array();
39 protected $lastPoll = array();
42 * @param string $id process ID to use in logging/monitoring
44 public function __construct($id)
47 $this->monitor = new QueueMonitor();
50 public function init($multiSite=null)
52 if ($multiSite !== null) {
53 $this->multiSite = $multiSite;
55 if ($this->multiSite) {
56 $this->sites = $this->findAllSites();
58 $this->sites = array(common_config('site', 'server'));
61 if (empty($this->sites)) {
62 throw new Exception("Empty status_network table, cannot init");
65 foreach ($this->sites as $site) {
66 if ($site != common_config('site', 'server')) {
67 StatusNet::init($site);
69 $this->initManagers();
74 * Initialize IoManagers for the currently configured site
75 * which are appropriate to this instance.
77 * Pass class names into $this->instantiate()
79 abstract function initManagers();
82 * Pull all local sites from status_network table.
83 * @return array of hostnames
85 protected function findAllSites()
88 $sn = new Status_network();
90 while ($sn->fetch()) {
91 $hosts[] = $sn->getServerName();
97 * Instantiate an i/o manager class for the current site.
98 * If a multi-site capable handler is already present,
99 * we don't need to build a new one.
101 * @param string $class
103 protected function instantiate($class)
105 if (isset($this->singletons[$class])) {
106 // Already instantiated a multi-site-capable handler.
107 // Just let it know it should listen to this site too!
108 $this->singletons[$class]->addSite(common_config('site', 'server'));
112 $manager = $this->getManager($class);
114 if ($this->multiSite) {
115 $caps = $manager->multiSite();
116 if ($caps == IoManager::SINGLE_ONLY) {
117 throw new Exception("$class can't run with --all; aborting.");
119 if ($caps == IoManager::INSTANCE_PER_PROCESS) {
120 // Save this guy for later!
121 // We'll only need the one to cover multiple sites.
122 $this->singletons[$class] = $manager;
123 $manager->addSite(common_config('site', 'server'));
127 $this->managers[] = $manager;
130 protected function getManager($class)
132 return call_user_func(array($class, 'get'));
138 * Initialize all io managers, then sit around waiting for input.
139 * Between events or timeouts, pass control back to idle() method
140 * to allow for any additional background processing.
144 $this->logState('init');
148 $timeouts = array_values($this->pollTimeouts);
149 $timeouts[] = 60; // default max timeout
151 // Wait for something on one of our sockets
154 foreach ($this->managers as $manager) {
155 foreach ($manager->getSockets() as $socket) {
156 $sockets[] = $socket;
157 $managers[] = $manager;
159 $timeouts[] = intval($manager->timeout());
162 $timeout = min($timeouts);
167 $this->logState('listening');
168 common_log(LOG_DEBUG, "Waiting up to $timeout seconds for socket data...");
169 $ready = stream_select($read, $write, $except, $timeout, 0);
171 if ($ready === false) {
172 common_log(LOG_ERR, "Error selecting on sockets");
173 } else if ($ready > 0) {
174 foreach ($read as $socket) {
175 $index = array_search($socket, $sockets, true);
176 if ($index !== false) {
177 $this->logState('queue');
178 $managers[$index]->handleInput($socket);
180 common_log(LOG_ERR, "Saw input on a socket we didn't listen to");
186 if ($timeout > 0 && empty($sockets)) {
187 // If we had no listeners, sleep until the pollers' next requested wakeup.
188 common_log(LOG_DEBUG, "Sleeping $timeout seconds until next poll cycle...");
189 $this->logState('sleep');
193 $this->logState('poll');
196 $this->logState('idle');
199 $memoryLimit = $this->softMemoryLimit();
200 if ($memoryLimit > 0) {
201 $usage = memory_get_usage();
202 if ($usage > $memoryLimit) {
203 common_log(LOG_INFO, "Queue thread hit soft memory limit ($usage > $memoryLimit); gracefully restarting.");
205 } else if (common_config('queue', 'debug_memory')) {
206 common_log(LOG_DEBUG, "Memory usage $usage");
211 $this->logState('shutdown');
216 * Return fully-parsed soft memory limit in bytes.
217 * @return intval 0 or -1 if not set
219 function softMemoryLimit()
221 $softLimit = trim(common_config('queue', 'softlimit'));
222 if (substr($softLimit, -1) == '%') {
223 $limit = $this->parseMemoryLimit(ini_get('memory_limit'));
225 return intval(substr($softLimit, 0, -1) * $limit / 100);
230 return $this->parseMemoryLimit($softLimit);
236 * Interpret PHP shorthand for memory_limit and friends.
237 * Why don't they just expose the actual numeric value? :P
241 public function parseMemoryLimit($mem)
243 // http://www.php.net/manual/en/faq.using.php#faq.using.shorthandbytes
244 $mem = strtolower(trim($mem));
245 $size = array('k' => 1024,
247 'g' => 1024*1024*1024);
250 } else if (is_numeric($mem)) {
253 $mult = substr($mem, -1);
254 if (isset($size[$mult])) {
255 return substr($mem, 0, -1) * $size[$mult];
264 foreach ($this->managers as $index => $manager) {
265 $manager->start($this);
266 // @fixme error check
267 if ($manager->pollInterval()) {
268 // We'll want to check for input on the first pass
269 $this->pollTimeouts[$index] = 0;
270 $this->lastPoll[$index] = 0;
277 foreach ($this->managers as $manager) {
279 // @fixme error check
284 * Called during the idle portion of the runloop to see which handlers
288 foreach ($this->managers as $index => $manager) {
289 $interval = $manager->pollInterval();
290 if ($interval <= 0) {
291 // Not a polling manager.
295 if (isset($this->pollTimeouts[$index])) {
296 $timeout = $this->pollTimeouts[$index];
297 if (time() - $this->lastPoll[$index] < $timeout) {
298 // Not time to poll yet.
304 $hit = $manager->poll();
306 $this->lastPoll[$index] = time();
308 // Do the next poll quickly, there may be more input!
309 $this->pollTimeouts[$index] = 0;
311 // Empty queue. Exponential backoff up to the maximum poll interval.
313 $timeout = min($timeout * 2, $interval);
317 $this->pollTimeouts[$index] = $timeout;
323 * Called after each handled item or empty polling cycle.
324 * This is a good time to e.g. service your XMPP connection.
328 foreach ($this->managers as $manager) {
334 * Send thread state update to the monitoring server, if configured.
336 * @param string $state ('init', 'queue', 'shutdown' etc)
337 * @param string $substate (optional, eg queue name 'omb' 'sms' etc)
339 protected function logState($state, $substate='')
341 $this->monitor->logState($this->id, $state, $substate);
346 * Thread ID will be implicit; other owners can be listed as well
347 * for per-queue and per-site records.
349 * @param string $key counter name
350 * @param array $owners list of owner keys like 'queue:jabber' or 'site:stat01'
352 public function stats($key, $owners=array())
354 $owners[] = "thread:" . $this->id;
355 $this->monitor->stats($key, $owners);