mirror of https://github.com/friendica/friendica
84 lines
1.9 KiB
PHP
84 lines
1.9 KiB
PHP
<?php
|
|
|
|
namespace Friendica\Util\Lock;
|
|
|
|
use dba;
|
|
use Friendica\Database\DBM;
|
|
|
|
/**
|
|
* Locking driver that stores the locks in the database
|
|
*/
|
|
class DatabaseLockDriver implements ILockDriver
|
|
{
|
|
/**
|
|
* @brief Sets a lock for a given name
|
|
*
|
|
* @param string $key The Name of the lock
|
|
* @param integer $timeout Seconds until we give up
|
|
*
|
|
* @return boolean Was the lock successful?
|
|
*/
|
|
public function acquireLock($key, $timeout = 120)
|
|
{
|
|
$got_lock = false;
|
|
$start = time();
|
|
|
|
do {
|
|
dba::lock('locks');
|
|
$lock = dba::selectFirst('locks', ['locked', 'pid'], ['name' => $key]);
|
|
|
|
if (DBM::is_result($lock)) {
|
|
if ($lock['locked']) {
|
|
// When the process id isn't used anymore, we can safely claim the lock for us.
|
|
if (!posix_kill($lock['pid'], 0)) {
|
|
$lock['locked'] = false;
|
|
}
|
|
// We want to lock something that was already locked by us? So we got the lock.
|
|
if ($lock['pid'] == getmypid()) {
|
|
$got_lock = true;
|
|
}
|
|
}
|
|
if (!$lock['locked']) {
|
|
dba::update('locks', ['locked' => true, 'pid' => getmypid()], ['name' => $key]);
|
|
$got_lock = true;
|
|
}
|
|
} elseif (!DBM::is_result($lock)) {
|
|
dba::insert('locks', ['name' => $key, 'locked' => true, 'pid' => getmypid()]);
|
|
$got_lock = true;
|
|
}
|
|
|
|
dba::unlock();
|
|
|
|
if (!$got_lock && ($timeout > 0)) {
|
|
usleep(rand(100000, 2000000));
|
|
}
|
|
} while (!$got_lock && ((time() - $start) < $timeout));
|
|
|
|
return $got_lock;
|
|
}
|
|
|
|
/**
|
|
* @brief Removes a lock if it was set by us
|
|
*
|
|
* @param string $key Name of the lock
|
|
*
|
|
* @return mixed
|
|
*/
|
|
public function releaseLock($key)
|
|
{
|
|
dba::update('locks', ['locked' => false, 'pid' => 0], ['name' => $key, 'pid' => getmypid()]);
|
|
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* @brief Removes all lock that were set by us
|
|
*
|
|
* @return void
|
|
*/
|
|
public function releaseAll()
|
|
{
|
|
dba::update('locks', ['locked' => false, 'pid' => 0], ['pid' => getmypid()]);
|
|
}
|
|
}
|