Multi-threaded Parallel Discrete Event Simulation (PDES) engine
- This provides an engine for performing simulations of systems on a shared-memory computer using multiple threads. It is therefore suitable only for systems that can record a complete snapshot of their state in the RAM of a practical computer.
- It is for simulating asynchronous systems, that have widely scattered times of events, so advancement of the simulated state using a global clock is inefficient.
- In common with most PDES algorithms, this engine partly enables parallel computation by eliminating an explicit global (shared) event list.
- This engine further enables parallel computation by not attempting to compute and record a single set of state variables at one point in time. It instead computes and records a time history of all the state variables.
- Unlike other PDES algorithms, the engine does not mandate a process-oriented methodology, although it can be used in that manner. Instead, the engine models the system as composed as a set of objects, each of which has a time-varying state.
- This uses an actor model for the simulated objects. The simulated objects interact only by sending signals to each other. Reception of a signal is an event. An event may emit further signals.
- The algorithm of the enforces causality and avoids deadlock by requiring that signals have a propagation delay, and that the event caused by reception of a signal depends only on the type of signal and the state of the receiver at the time the signal was received.
- Computation of the state histories for different objects can proceed at different rates, for objects uncoupled (or only loosely coupled) by signals. If the engine computes a state history too far ahead, it rolls-back work and reschedules computations.
- The engine reduces the memory required to record all the state histories by recording only the changes in the object states. It assumes that the object states will be recorded as collections of immutable objects. Successive states then can reuse (share) references to immutable objects for unchanged parts of the state, to further reduce the memory required.
© Copyright Benedict Adamson 2018,2021-22.
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- Java 11
- Annotations:
- Development environment:
- IntelliJ IDEA
- previously Eclipse IDE
- previously Jenkins Editor
- previously SpotBugs Eclipse plugin
- Software configuration management:
- Building:
- Static analysis and testing: