Raytheon Company

William Wysocki

Gregory Price

Matthew A Taylor

Peter C Jensen

Ryan S Snyder

Techniques are disclosed for interposing on nondeterministic events during multicore virtual machine (VM) execution to capture information that allows for deterministically recreating the nondeterministic events during execution replay of the VM. A method may include reading, by a virtual processor running within a multicore VM instance, an instruction to execute, and, responsive to a determination that the instruction is a nondeterministic instruction, interposing on the nondeterministic instruction execution so as to allow deterministic execution of the nondeterministic instruction during replay execution of the multicore VM instance. Interposing on the nondeterministic instruction execution may include recording a partial barrier event and/or a full barrier event. The nondeterministic instruction may be a read memory access instruction or a write memory access instruction.

Deterministic execution replay for multicore systems

Embodiments of a central emulator, distributed emulator and method for emulation of a system are generally described herein. The central emulator may receive state variables from distributed emulators at various emulation times. As an example, such an emulation time may be related to an emulation event at one of the distributed emulators. The central emulator may determine global snapshots of the system emulation for the emulation times based on the state variables. The global snapshots may be used to control a timing of the system emulation for operations such as rewinding, pausing, forwarding and/or setting to a target time.

Growing community of inventors

Ellicott City, MD, United States of America

William Wysocki