summaryrefslogtreecommitdiff
path: root/lib/daemon.php
blob: 4c2491e97bca284cb6234820b0749f4e61241517 (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
<?php
/**
 * StatusNet - the distributed open-source microblogging tool
 * Copyright (C) 2008, 2009, StatusNet, Inc.
 *
 * 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/>.
 */

if (!defined('STATUSNET') && !defined('LACONICA')) {
    exit(1);
}

class Daemon
{
    var $daemonize = true;
    var $_id = 'generic';

    function __construct($daemonize = true)
    {
        $this->daemonize = $daemonize;
    }

    function name()
    {
        return null;
    }

    function get_id()
    {
        return $this->_id;
    }

    function set_id($id)
    {
        $this->_id = $id;
    }

    function background()
    {
        $pid = pcntl_fork();
        if ($pid < 0) { // error
            common_log(LOG_ERR, "Could not fork.");
            return false;
        } else if ($pid > 0) { // parent
            common_log(LOG_INFO, "Successfully forked.");
            exit(0);
        } else { // child
            return true;
        }
    }

    function alreadyRunning()
    {
        $pidfilename = $this->pidFilename();

        if (!$pidfilename) {
            return false;
        }

        if (!file_exists($pidfilename)) {
            return false;
        }
        $contents = file_get_contents($pidfilename);
        if (posix_kill(trim($contents), 0)) {
            return true;
        } else {
            return false;
        }
    }

    function writePidFile()
    {
        $pidfilename = $this->pidFilename();

        if (!$pidfilename) {
            return false;
        }

        return file_put_contents($pidfilename, posix_getpid() . "\n");
    }

    function clearPidFile()
    {
        $pidfilename = $this->pidFilename();
        if (!$pidfilename) {
            return false;
        }
        return unlink($pidfilename);
    }

    function pidFilename()
    {
        $piddir = common_config('daemon', 'piddir');
        if (!$piddir) {
            return null;
        }
        $name = $this->name();
        if (!$name) {
            return null;
        }
        return $piddir . '/' . $name . '.pid';
    }

    function changeUser()
    {
        $username = common_config('daemon', 'user');

        if ($username) {
            $user_info = posix_getpwnam($username);
            if (!$user_info) {
                common_log(LOG_WARNING,
                           'Ignoring unknown user for daemon: ' . $username);
            } else {
                common_log(LOG_INFO, "Setting user to " . $username);
                posix_setuid($user_info['uid']);
            }
        }

        $groupname = common_config('daemon', 'group');

        if ($groupname) {
            $group_info = posix_getgrnam($groupname);
            if (!$group_info) {
                common_log(LOG_WARNING,
                           'Ignoring unknown group for daemon: ' . $groupname);
            } else {
                common_log(LOG_INFO, "Setting group to " . $groupname);
                posix_setgid($group_info['gid']);
            }
        }
    }

    function runOnce()
    {
        if ($this->alreadyRunning()) {
            common_log(LOG_INFO, $this->name() . ' already running. Exiting.');
            exit(0);
        }

        if ($this->daemonize) {
            common_log(LOG_INFO, 'Backgrounding daemon "'.$this->name().'"');
            $this->background();
        }

        $this->writePidFile();
        $this->changeUser();
        $this->run();
        $this->clearPidFile();
    }

    function run()
    {
        return true;
    }
}