The ROme OpTimistic Simulator (ROOT-Sim)

The ROme OpTimistic Simulator is an x86 Open Source, parallel/distributed simulation platform developed using C/POSIX technology, which is based on a simulation kernel layer that ultimately relies on MPI for data exchange across different (distributed) kernel instances. The platform transparently supports all the mechanisms associated with parallelization (e.g., mapping of simulation objects on different kernel instances) and optimistic synchronization (e.g., state recoverability). The programming model supported by ROOT-Sim allows the simulation-model developer to use a simple application-callback function named ProcessEvent() as the event handler, whose parameters determine which simulation object is currently taking control for processing its next event, and where the state of this object is located in memory. In ROOT-Sim, a simulation object is a data structure, whose state can be scattered on dynamically allocated memory chunks, hence the memory address passed to the callback locates a top level data structure implementing the object state-layout.