public static function lock()
{
self::$lock_file = self::$lock_dir . self::$lid . '.lock';
self::$lock_data_file = self::$lock_dir . self::$lid . '.dat';
self::$log_file = self::$lock_dir . self::$lid . '.log';
self::$pid = getmypid();
self::$start = microtime(true);
if (file_exists(self::$lock_data_file)) {
self::$data = unserialize(file_get_contents(self::$lock_data_file));
}
if (file_exists(self::$lock_file)) {
$contents = file_get_contents(self::$lock_file);
list(self::$last_pid, $old_timestamp) = explode(PHP_EOL, $contents);
if ($old_timestamp + self::$timeout * 60 < time()) {
self::$lock_aquired = true;
self::log('a previous process timed out:' . self::$last_pid);
self::log('lock aquired. starting');
} else {
self::$lock_aquired = false;
self::log('exiting. overlapped with ' . self::$last_pid);
}
} else {
self::$lock_aquired = true;
self::log('lock aquired. starting');
}
if (self::$lock_aquired) {
$h = fopen(self::$lock_file, 'w');
fwrite($h, self::$pid . PHP_EOL . time());
}
return self::$lock_aquired;
}
