Abstract: Embodiments of the present disclosure support a simulation of a plurality of processor core models. The processor core models are executed in parallel within a sliding time window of a defined size. Each processor core model is executed in a different corresponding thread and advances a local core time within the sliding time window. The sliding time window advances by updating a start time of the sliding time window based on the local core time of each processor core model. One or more hardware models and a simulation kernel are executed in a separate thread having a simulation time and simulation events. The start time of the sliding time window is updated based further on an event time of a next event of the simulation events scheduled in the separate thread.

Abstract: Embodiments of the present disclosure support a simulation of a plurality of processor core models. The processor core models are executed in parallel within a sliding time window of a defined size. Each processor core model is executed in a different corresponding thread and advances a local core time within the sliding time window. The sliding time window advances by updating a start time of the sliding time window based on the local core time of each processor core model. One or more hardware models and a simulation kernel are executed in a separate thread having a simulation time and simulation events. The start time of the sliding time window is updated based further on an event time of a next event of the simulation events scheduled in the separate thread.

Abstract: Software verification using two-state invariants is described. In an embodiment a verifier represents an annotated program to be verified as a plurality of atomic transitions between global program states, each state comprising a plurality of objects. For example, the verifier accesses the annotations which specify a two-state invariant for each object. A two-state invariant is a predicate that relates a global program state before a state transition to the state after that state transition. In an example some of the two-state invariants are cross-object in that they refer to other objects. For example, a verification system checks that only the two-state invariants of the objects which changed in each transition are preserved; this modularity enables the verifier to work for large code bases and concurrent software. In an example the modularity is possible since the two-state invariants meet an admissibility requirement which is independent of the functionality of the program.

Abstract: One or more resolution processes run concurrently with the synchronization process of each replica, in response to detection of one or more synchronization conflicts. Each resolution process works to resolve the conflict for a data object while the synchronization process continues to process other synchronization updates. After a conflict resolution has been determined, the conflict resolution is tested against current conditions of the local replica. If the conflict resolution is not stale, it is applied to the local replica and passed back to the synchronization process for propagation to remote replicas. Otherwise, if the conflict resolution is stale, it is discarded.

Abstract: One or more resolution processes run concurrently with the synchronization process of each replica, in response to detection of one or more synchronization conflicts. Each resolution process works to resolve the conflict for a data object while the synchronization process continues to process other synchronization updates. After a conflict resolution has been determined, the conflict resolution is tested against current conditions of the local replica. If the conflict resolution is not stale, it is applied to the local replica and passed back to the synchronization process for propagation to remote replicas. Otherwise, if the conflict resolution is stale, it is discarded.