Abstract: Scheme for the distinguishing of reachable objects and non-reachable objects used by an object-based application in a system with volatile memory of limited size. The object-based application operates on n objects whereby Z objects thereof are root objects. The following steps are carried out for each root object: (a) traversing from said root object to any other object that can be reached from said root object; (b) marking all objects that were reached from said root object and storing, while marking, in said volatile memory a description of the path from said root object to the currently visited object; if the marking phase reaches an object and the respective path does not fit into said volatile memory, then this object is not marked but identified as an object which has to be processed later; and continuing the marking phase until all root objects identified as objects which have to be processed later are processed.

Abstract: A method for transactional writing of data into a data space in a persistent memory. The data space has a data space header which signals that the data space is free. A data header is generated when there is a writing transaction in the data space. After successful completion of the transactional writing, the data header signals that the data space is occupied by the written data. The data is written directly to the persistent memory, and in the case the transactional writing is not successfully completed, the data space header is valid for the data space. If the transactional writing is successfully completed, the data header is valid for the written data in the data space. A persistent buffer serves for storing validity information for ensuring the validity of the data header or the data space header as appropriate.