Cassandra has a deterministic testing framework in this vein that will support Loom before too long. Loom is more of an efficiency enhancement, however, permitt

Cassandra has a deterministic testing framework in this vein that will support Loom before too long. Loom is more of an efficiency enhancement, however, permitting you to run a simulation with a single operating system thread, avoiding the overhead of managing which thread the OS is permitted to run. The framework already intercepts all of these operations and ensures they are executed deterministically.