4.2 Optimistic Simulation

Optimistic simulations address the synchronization problem by assuming that lcc violations are not common place and therefore the LP may as well process without regard to the other LPs. If an lcc violation does occur, the optimistic simulation simply repairs the damage done by processing the errant message

Each time an event is processed by an LP, the state of the LP before the event is processed and the event are saved. When an incomming message causes an lcc violation, the LP rolls back processed events to the event with a time stamp smaller than the mesage's time stamp. The LPs state is reset to the state saved by the event then the system begins to process events.

There are a number of variations to this scheme, the best known of them is the Time Warp Operating System, or TWOS. The demonstration below shows the operation of TWOS.


[SECTION 1] [SECTION 1] [SIMULATION PITFALLS] [SECTION 2] [SECTION 1]