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Diffstat (limited to 'lib/parallelizingdaemon.php')
| -rw-r--r-- | lib/parallelizingdaemon.php | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/lib/parallelizingdaemon.php b/lib/parallelizingdaemon.php new file mode 100644 index 000000000..517115de0 --- /dev/null +++ b/lib/parallelizingdaemon.php @@ -0,0 +1,229 @@ +<?php +/** + * StatusNet, the distributed open-source microblogging tool + * + * Base class for making daemons that can do several tasks in parallel. + * + * PHP version 5 + * + * LICENCE: This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * @category Daemon + * @package StatusNet + * @author Zach Copley <zach@status.net> + * @author Evan Prodromou <evan@status.net> + * @copyright 2009 StatusNet, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://status.net/ + */ + +if (!defined('STATUSNET') && !defined('LACONICA')) { + exit(1); +} + +declare(ticks = 1); + +/** + * Daemon able to spawn multiple child processes to do work in parallel + * + * @category Daemon + * @package StatusNet + * @author Zach Copley <zach@status.net> + * @author Evan Prodromou <evan@status.net> + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://status.net/ + */ + +class ParallelizingDaemon extends Daemon +{ + private $_children = array(); + private $_interval = 0; // seconds + private $_max_children = 0; // maximum number of children + private $_debug = false; + + /** + * Constructor + * + * @param string $id the name/id of this daemon + * @param int $interval sleep this long before doing everything again + * @param int $max_children maximum number of child processes at a time + * @param boolean $debug debug output flag + * + * @return void + * + **/ + + function __construct($id = null, $interval = 60, $max_children = 2, + $debug = null) + { + parent::__construct(true); // daemonize + + $this->_interval = $interval; + $this->_max_children = $max_children; + $this->_debug = $debug; + + if (isset($id)) { + $this->set_id($id); + } + } + + /** + * Run the daemon + * + * @return void + */ + + function run() + { + if (isset($this->_debug)) { + echo $this->name() . " - Debugging output enabled.\n"; + } + + do { + + $objects = $this->getObjects(); + + foreach ($objects as $o) { + + // Fork a child for each object + + $pid = pcntl_fork(); + + if ($pid == -1) { + die ($this->name() . ' - Couldn\'t fork!'); + } + + if ($pid) { + + // Parent + + if (isset($this->_debug)) { + echo $this->name() . + " - Forked new child - pid $pid.\n"; + + } + + $this->_children[] = $pid; + + } else { + + // Child + + // Do something with each object + + $this->childTask($o); + + exit(); + } + + // Remove child from ps list as it finishes + + while (($c = pcntl_wait($status, WNOHANG OR WUNTRACED)) > 0) { + + if (isset($this->_debug)) { + echo $this->name() . " - Child $c finished.\n"; + } + + $this->removePs($this->_children, $c); + } + + // Wait! We have too many damn kids. + + if (sizeof($this->_children) >= $this->_max_children) { + + if (isset($this->_debug)) { + echo $this->name() . " - Too many children. Waiting...\n"; + } + + if (($c = pcntl_wait($status, WUNTRACED)) > 0) { + + if (isset($this->_debug)) { + echo $this->name() . + " - Finished waiting for child $c.\n"; + } + + $this->removePs($this->_children, $c); + } + } + } + + // Remove all children from the process list before restarting + while (($c = pcntl_wait($status, WUNTRACED)) > 0) { + + if (isset($this->_debug)) { + echo $this->name() . " - Child $c finished.\n"; + } + + $this->removePs($this->_children, $c); + } + + // Rest for a bit + + if (isset($this->_debug)) { + echo $this->name() . ' - Waiting ' . $this->_interval . + " secs before running again.\n"; + } + + if ($this->_interval > 0) { + sleep($this->_interval); + } + + } while (true); + } + + /** + * Remove a child process from the list of children + * + * @param array &$plist array of processes + * @param int $ps process id + * + * @return void + */ + + function removePs(&$plist, $ps) + { + for ($i = 0; $i < sizeof($plist); $i++) { + if ($plist[$i] == $ps) { + unset($plist[$i]); + $plist = array_values($plist); + break; + } + } + } + + /** + * Get a list of objects to work on in parallel + * + * @return array An array of objects to work on + */ + + function getObjects() + { + die('Implement ParallelizingDaemon::getObjects().'); + } + + /** + * Do something with each object in parallel + * + * @param mixed $object data to work on + * + * @return void + */ + + function childTask($object) + { + die("Implement ParallelizingDaemon::childTask($object)."); + } + +}
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