Added pre-emptive session renewal to avoid "random" submission errors

[lhc/web/wiklou.git] / includes / objectcache / ObjectCacheSessionHandler.php

diff --git a/includes/objectcache/ObjectCacheSessionHandler.php b/includes/objectcache/ObjectCacheSessionHandler.php
index 789f1e3..ae3850f 100644 (file)
--- a/includes/objectcache/ObjectCacheSessionHandler.php
+++ b/includes/objectcache/ObjectCacheSessionHandler.php
@@ -31,6 +31,8 @@ class ObjectCacheSessionHandler {
        /** @var array Map of (session ID => SHA-1 of the data) */
        protected static $hashCache = array();
 
+       const TTL_REFRESH_WINDOW = 600; // refresh if expiring in 10 minutes
+
        /**
         * Install a session handler for the current web request
         */
@@ -157,10 +159,24 @@ class ObjectCacheSessionHandler {
        }
 
        /**
-        * Shutdown function. See the comment inside ObjectCacheSessionHandler::install
-        * for rationale.
+        * Shutdown function.
+        * See the comment inside ObjectCacheSessionHandler::install for rationale.
         */
        static function handleShutdown() {
+               global $wgObjectCacheSessionExpiry;
+
+               $now = microtime( true );
+               // Session are only written in object stores when $_SESSION changes,
+               // which also renews the TTL ($wgObjectCacheSessionExpiry). If a user
+               // is active but not causing session data changes, it may suddenly
+               // as they view a form, blocking the first submission.
+               // Make a dummy change every so often to avoid this.
+               if ( !isset( $_SESSION['wsExpiresUnix'] )
+                       || ( $now + self::TTL_REFRESH_WINDOW ) > isset( $_SESSION['wsExpiresUnix'] )
+               ) {
+                       $_SESSION['wsExpiresUnix'] = $now + $wgObjectCacheSessionExpiry;
+               }
+
                session_write_close();
        }
 }