diff --git a/pvAccessApp/remote/channelSearchManager.h b/pvAccessApp/remote/channelSearchManager.h
index b09571c..c18ca62 100644
--- a/pvAccessApp/remote/channelSearchManager.h
+++ b/pvAccessApp/remote/channelSearchManager.h
@@ -262,7 +262,7 @@ public:
 	 */
 	virtual void unsetListOwnership() = 0;
 	/**
-	 * Adds this search instance into the provided list and sets it as the owner of this search instance.
+	 * Adds this search instance into the provided list and set it as the owner of this search instance.
 	 *
 	 * @param newOwner a list to which this search instance is added.
 	 * @param ownerMutex mutex belonging to the newOwner list. The mutex will be locked beofe any modification
@@ -442,10 +442,18 @@ private:
      * Mutex for request pending channel list.
      */
     Mutex _requestPendingChannelsMutex;
+    /**
+     * Mutex for request pending channel list.
+     */
+    Mutex _responsePendingChannelsMutex;
     /**
      * General mutex.
      */
     Mutex _mutex;
+    /**
+     * Volatile varialbe mutex.
+     */
+    Mutex _volMutex;
 	/**
 	 * Max search tries per frame.
 	 */
@@ -587,6 +595,14 @@ private:
      * General mutex.
      */
     Mutex _mutex;
+    /**
+     * Channel mutex.
+     */
+    Mutex _channelMutex;
+    /**
+     * Volatile variable mutex.
+     */
+    Mutex _volMutex;
     /**
      * Mock transport send control
      */