summaryrefslogtreecommitdiff
path: root/lib/iomaster.php
blob: 1f6c31ee7e3a326ceda67b127c9890b7cba4277c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
<?php
/**
 * StatusNet, the distributed open-source microblogging tool
 *
 * I/O manager to wrap around socket-reading and polling queue & connection managers.
 *
 * 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  QueueManager
 * @package   StatusNet
 * @author    Brion Vibber <brion@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/
 */

abstract class IoMaster
{
    public $id;

    protected $multiSite = false;
    protected $managers = array();
    protected $singletons = array();

    protected $pollTimeouts = array();
    protected $lastPoll = array();

    public $shutdown = false; // Did we do a graceful shutdown?
    public $respawn = true; // Should we respawn after shutdown?

    /**
     * @param string $id process ID to use in logging/monitoring
     */
    public function __construct($id)
    {
        $this->id = $id;
        $this->monitor = new QueueMonitor();
    }

    public function init($multiSite=null)
    {
        if ($multiSite !== null) {
            $this->multiSite = $multiSite;
        }
        if ($this->multiSite) {
            $this->sites = $this->findAllSites();
        } else {
            $this->sites = array(common_config('site', 'server'));
        }

        if (empty($this->sites)) {
            throw new Exception("Empty status_network table, cannot init");
        }

        foreach ($this->sites as $site) {
            if ($site != common_config('site', 'server')) {
                StatusNet::init($site);
            }
            $this->initManagers();
        }
    }

    /**
     * Initialize IoManagers for the currently configured site
     * which are appropriate to this instance.
     *
     * Pass class names into $this->instantiate()
     */
    abstract function initManagers();

    /**
     * Pull all local sites from status_network table.
     * @return array of hostnames
     */
    protected function findAllSites()
    {
        $hosts = array();
        $sn = new Status_network();
        $sn->find();
        while ($sn->fetch()) {
            $hosts[] = $sn->getServerName();
        }
        return $hosts;
    }

    /**
     * Instantiate an i/o manager class for the current site.
     * If a multi-site capable handler is already present,
     * we don't need to build a new one.
     *
     * @param string $class
     */
    protected function instantiate($class)
    {
        if (is_string($class) && isset($this->singletons[$class])) {
            // Already instantiated a multi-site-capable handler.
            // Just let it know it should listen to this site too!
            $this->singletons[$class]->addSite(common_config('site', 'server'));
            return;
        }

        $manager = $this->getManager($class);

        if ($this->multiSite) {
            $caps = $manager->multiSite();
            if ($caps == IoManager::SINGLE_ONLY) {
                throw new Exception("$class can't run with --all; aborting.");
            }
            if ($caps == IoManager::INSTANCE_PER_PROCESS) {
                // Save this guy for later!
                // We'll only need the one to cover multiple sites.
                $this->singletons[$class] = $manager;
                $manager->addSite(common_config('site', 'server'));
            }
        }

        $this->managers[] = $manager;
    }
    
    protected function getManager($class)
    {
        if(is_object($class)){
            return $class;
        } else {
            return call_user_func(array($class, 'get'));
        }
    }

    /**
     * Basic run loop...
     *
     * Initialize all io managers, then sit around waiting for input.
     * Between events or timeouts, pass control back to idle() method
     * to allow for any additional background processing.
     */
    function service()
    {
        $this->logState('init');
        $this->start();

        while (!$this->shutdown) {
            $timeouts = array_values($this->pollTimeouts);
            $timeouts[] = 60; // default max timeout

            // Wait for something on one of our sockets
            $sockets = array();
            $managers = array();
            foreach ($this->managers as $manager) {
                foreach ($manager->getSockets() as $socket) {
                    $sockets[] = $socket;
                    $managers[] = $manager;
                }
                $timeouts[] = intval($manager->timeout());
            }

            $timeout = min($timeouts);
            if ($sockets) {
                $read = $sockets;
                $write = array();
                $except = array();
                $this->logState('listening');
                common_log(LOG_DEBUG, "Waiting up to $timeout seconds for socket data...");
                $ready = stream_select($read, $write, $except, $timeout, 0);

                if ($ready === false) {
                    common_log(LOG_ERR, "Error selecting on sockets");
                } else if ($ready > 0) {
                    foreach ($read as $socket) {
                        $index = array_search($socket, $sockets, true);
                        if ($index !== false) {
                            $this->logState('queue');
                            $managers[$index]->handleInput($socket);
                        } else {
                            common_log(LOG_ERR, "Saw input on a socket we didn't listen to");
                        }
                    }
                }
            }

            if ($timeout > 0 && empty($sockets)) {
                // If we had no listeners, sleep until the pollers' next requested wakeup.
                common_log(LOG_DEBUG, "Sleeping $timeout seconds until next poll cycle...");
                $this->logState('sleep');
                sleep($timeout);
            }

            $this->logState('poll');
            $this->poll();

            $this->logState('idle');
            $this->idle();

            $this->checkMemory();
        }

        $this->logState('shutdown');
        $this->finish();
    }

    /**
     * Check runtime memory usage, possibly triggering a graceful shutdown
     * and thread respawn if we've crossed the soft limit.
     */
    protected function checkMemory()
    {
        $memoryLimit = $this->softMemoryLimit();
        if ($memoryLimit > 0) {
            $usage = memory_get_usage();
            if ($usage > $memoryLimit) {
                common_log(LOG_INFO, "Queue thread hit soft memory limit ($usage > $memoryLimit); gracefully restarting.");
                $this->requestRestart();
            } else if (common_config('queue', 'debug_memory')) {
                common_log(LOG_DEBUG, "Memory usage $usage");
            }
        }
    }

    /**
     * Return fully-parsed soft memory limit in bytes.
     * @return intval 0 or -1 if not set
     */
    function softMemoryLimit()
    {
        $softLimit = trim(common_config('queue', 'softlimit'));
        if (substr($softLimit, -1) == '%') {
            $limit = $this->parseMemoryLimit(ini_get('memory_limit'));
            if ($limit > 0) {
                return intval(substr($softLimit, 0, -1) * $limit / 100);
            } else {
                return -1;
            }
        } else {
            return $this->parseMemoryLimit($softLimit);
        }
        return $softLimit;
    }

    /**
     * Interpret PHP shorthand for memory_limit and friends.
     * Why don't they just expose the actual numeric value? :P
     * @param string $mem
     * @return int
     */
    public function parseMemoryLimit($mem)
    {
        // http://www.php.net/manual/en/faq.using.php#faq.using.shorthandbytes
        $mem = strtolower(trim($mem));
        $size = array('k' => 1024,
                      'm' => 1024*1024,
                      'g' => 1024*1024*1024);
        if (empty($mem)) {
            return 0;
        } else if (is_numeric($mem)) {
            return intval($mem);
        } else {
            $mult = substr($mem, -1);
            if (isset($size[$mult])) {
                return substr($mem, 0, -1) * $size[$mult];
            } else {
                return intval($mem);
            }
        }
    }

    function start()
    {
        foreach ($this->managers as $index => $manager) {
            $manager->start($this);
            // @fixme error check
            if ($manager->pollInterval()) {
                // We'll want to check for input on the first pass
                $this->pollTimeouts[$index] = 0;
                $this->lastPoll[$index] = 0;
            }
        }
    }

    function finish()
    {
        foreach ($this->managers as $manager) {
            $manager->finish();
            // @fixme error check
        }
    }

    /**
     * Called during the idle portion of the runloop to see which handlers
     */
    function poll()
    {
        foreach ($this->managers as $index => $manager) {
            $interval = $manager->pollInterval();
            if ($interval <= 0) {
                // Not a polling manager.
                continue;
            }

            if (isset($this->pollTimeouts[$index])) {
                $timeout = $this->pollTimeouts[$index];
                if (time() - $this->lastPoll[$index] < $timeout) {
                    // Not time to poll yet.
                    continue;
                }
            } else {
                $timeout = 0;
            }
            $hit = $manager->poll();

            $this->lastPoll[$index] = time();
            if ($hit) {
                // Do the next poll quickly, there may be more input!
                $this->pollTimeouts[$index] = 0;
            } else {
                // Empty queue. Exponential backoff up to the maximum poll interval.
                if ($timeout > 0) {
                    $timeout = min($timeout * 2, $interval);
                } else {
                    $timeout = 1;
                }
                $this->pollTimeouts[$index] = $timeout;
            }
        }
    }

    /**
     * Called after each handled item or empty polling cycle.
     * This is a good time to e.g. service your XMPP connection.
     */
    function idle()
    {
        foreach ($this->managers as $manager) {
            $manager->idle();
        }
    }

    /**
     * Send thread state update to the monitoring server, if configured.
     *
     * @param string $state ('init', 'queue', 'shutdown' etc)
     * @param string $substate (optional, eg queue name 'omb' 'sms' etc)
     */
    protected function logState($state, $substate='')
    {
        $this->monitor->logState($this->id, $state, $substate);
    }

    /**
     * Send thread stats.
     * Thread ID will be implicit; other owners can be listed as well
     * for per-queue and per-site records.
     *
     * @param string $key counter name
     * @param array $owners list of owner keys like 'queue:xmpp' or 'site:stat01'
     */
    public function stats($key, $owners=array())
    {
        $owners[] = "thread:" . $this->id;
        $this->monitor->stats($key, $owners);
    }

    /**
     * For IoManagers to request a graceful shutdown at end of event loop.
     */
    public function requestShutdown()
    {
        $this->shutdown = true;
        $this->respawn = false;
    }

    /**
     * For IoManagers to request a graceful restart at end of event loop.
     */
    public function requestRestart()
    {
        $this->shutdown = true;
        $this->respawn = true;
    }

}