The present disclosure relates to a method for a computer system comprising a plurality of processor cores including a first processor core and a second processor core, wherein a data item is exclusively assigned to the first processor core, of the plurality of processor cores, for executing an atomic primitive by the first processor core. The method includes receiving by the first processor core, from the second processor core, a request for accessing the data item, and in response to determining by the first processor core that the executing of the atomic primitive is not completed by the first processor core, returning a rejection message to the second processor core.