/**
* Get lock
*
* Acquires an (emulated) lock.
*
* @param string $session_id Session ID
* @return bool
*/
protected function _get_lock($session_id)
{
if (isset($this->_lock_key)) {
return $this->_redis->setTimeout($this->_lock_key, 300);
}
// 30 attempts to obtain a lock, in case another request already has it
$lock_key = $this->_key_prefix . $session_id . ':lock';
$attempt = 0;
do {
if (($ttl = $this->_redis->ttl($lock_key)) > 0) {
sleep(1);
continue;
}
if (!$this->_redis->setex($lock_key, 300, time())) {
log_message('error', 'Session: Error while trying to obtain lock for ' . $this->_key_prefix . $session_id);
return FALSE;
}
$this->_lock_key = $lock_key;
break;
} while (++$attempt < 30);
if ($attempt === 30) {
log_message('error', 'Session: Unable to obtain lock for ' . $this->_key_prefix . $session_id . ' after 30 attempts, aborting.');
return FALSE;
} elseif ($ttl === -1) {
log_message('debug', 'Session: Lock for ' . $this->_key_prefix . $session_id . ' had no TTL, overriding.');
}
$this->_lock = TRUE;
return TRUE;
}
/**
* Get lock
*
* Acquires an (emulated) lock.
*
* @param string $session_id Session ID
* @return bool
*/
protected function _get_lock($session_id)
{
if (isset($this->_lock_key)) {
return $this->_redis->setTimeout($this->_lock_key, 300);
}
// 30 attempts to obtain a lock, in case another request already has it
$lock_key = $this->_key_prefix . $session_id . ':lock';
$attempt = 0;
do {
if (($ttl = $this->_redis->ttl($lock_key)) > 0) {
sleep(1);
continue;
}
if (!$this->_redis->setex($lock_key, 300, time())) {
return FALSE;
}
$this->_lock_key = $lock_key;
break;
} while (++$attempt < 30);
if ($attempt === 30) {
return FALSE;
}
$this->_lock = TRUE;
return TRUE;
}
/**
* Get lock.
*
* Acquires an (emulated) lock.
*
* @param string $session_id Session ID
*
* @return bool
*/
protected function _get_lock($session_id)
{
// PHP 7 reuses the SessionHandler object on regeneration,
// so we need to check here if the lock key is for the
// correct session ID.
if ($this->_lock_key === $this->_key_prefix . $session_id . ':lock') {
return $this->_redis->setTimeout($this->_lock_key, 300);
}
// 30 attempts to obtain a lock, in case another request already has it
$lock_key = $this->_key_prefix . $session_id . ':lock';
$attempt = 0;
do {
if (($ttl = $this->_redis->ttl($lock_key)) > 0) {
sleep(1);
continue;
}
if (!$this->_redis->setex($lock_key, 300, time())) {
log_message('error', 'Session: Error while trying to obtain lock for ' . $this->_key_prefix . $session_id);
return false;
}
$this->_lock_key = $lock_key;
break;
} while (++$attempt < 30);
if ($attempt === 30) {
log_message('error', 'Session: Unable to obtain lock for ' . $this->_key_prefix . $session_id . ' after 30 attempts, aborting.');
return false;
} elseif ($ttl === -1) {
log_message('debug', 'Session: Lock for ' . $this->_key_prefix . $session_id . ' had no TTL, overriding.');
}
$this->_lock = true;
return true;
}
/**
* Write
*
* Writes (create / update) session data
*
* @param string $session_id Session ID
* @param string $session_data Serialized session data
* @return bool
*/
public function write($session_id, $session_data)
{
if (!isset($this->_redis)) {
return $this->_fail();
} elseif ($session_id !== $this->_session_id) {
if (!$this->_release_lock() or !$this->_get_lock($session_id)) {
return $this->_fail();
}
$this->_key_exists = FALSE;
$this->_session_id = $session_id;
}
if (isset($this->_lock_key)) {
$this->_redis->setTimeout($this->_lock_key, 300);
if ($this->_fingerprint !== ($fingerprint = md5($session_data)) or $this->_key_exists === FALSE) {
if ($this->_redis->set($this->_key_prefix . $session_id, $session_data, $this->_config['expiration'])) {
$this->_fingerprint = $fingerprint;
$this->_key_exists = TRUE;
return $this->_success;
}
return $this->_fail();
}
return $this->_redis->setTimeout($this->_key_prefix . $session_id, $this->_config['expiration']) ? $this->_success : $this->_fail();
}
return $this->_fail();
}
/**
* Get lock
*
* Acquires an (emulated) lock.
*
* @param string $session_id Session ID
* @return bool
*/
protected function _get_lock($session_id)
{
if (isset($this->_lock_key)) {
return $this->_redis->setTimeout($this->_lock_key, 5);
}
$lock_key = $this->_key_prefix . $session_id . ':lock';
if (($ttl = $this->_redis->ttl($lock_key)) < 1) {
if (!$this->_redis->setex($lock_key, 5, time())) {
log_message('error', 'Session: Error while trying to obtain lock for ' . $this->_key_prefix . $session_id);
return FALSE;
}
$this->_lock_key = $lock_key;
if ($ttl === -1) {
log_message('debug', 'Session: Lock for ' . $this->_key_prefix . $session_id . ' had no TTL, overriding.');
}
$this->_lock = TRUE;
return TRUE;
}
// Another process has the lock, we'll try to wait for it to free itself ...
$attempt = 0;
while ($attempt++ < 5) {
usleep($ttl * 1000000 - 20000);
if (($ttl = $this->_redis->ttl($lock_key)) > 0) {
continue;
}
if (!$this->_redis->setex($lock_key, 5, time())) {
log_message('error', 'Session: Error while trying to obtain lock for ' . $this->_key_prefix . $session_id);
return FALSE;
}
$this->_lock_key = $lock_key;
break;
}
if ($attempt === 5) {
log_message('error', 'Session: Unable to obtain lock for ' . $this->_key_prefix . $session_id . ' after 5 attempts, aborting.');
return FALSE;
}
$this->_lock = TRUE;
return TRUE;
}
/**
* Set the socket I/O timeout value in seconds plus microseconds.
*
* @param integer $seconds Timeout value in seconds.
* @param integer $microseconds Additional value in microseconds.
*
* @access public
* @since 1.5.0
*/
function setTimeout($seconds, $microseconds = 0)
{
return $this->_socket->setTimeout($seconds, $microseconds);
}
