[ci skip] Merge pull request #5170 from tianhe1986/develop_session_race_condition
Decreasing the probability of race condition in session lock
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 2556bf0..5e90539 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -310,7 +310,7 @@
if ( ! $this->_memcached->replace($this->_lock_key, time(), 300))
{
return ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND)
- ? $this->_memcached->set($this->_lock_key, time(), 300)
+ ? $this->_memcached->add($this->_lock_key, time(), 300)
: FALSE;
}
}
@@ -326,7 +326,8 @@
continue;
}
- if ( ! $this->_memcached->set($lock_key, time(), 300))
+ $method = ($this->_memcached->getResultCode() === Memcached::RES_NOTFOUND) ? 'add' : 'set';
+ if ( ! $this->_memcached->$method($lock_key, time(), 300))
{
log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
return FALSE;
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
index e220a29..a9e655a 100644
--- a/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -341,7 +341,11 @@
continue;
}
- if ( ! $this->_redis->setex($lock_key, 300, time()))
+ $result = ($ttl === -2)
+ ? $this->_redis->set($lock_key, time(), array('nx', 'ex' => 300))
+ : $this->_redis->setex($lock_key, 300, time());
+
+ if ( ! $result)
{
log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
return FALSE;