Logical clock algorithms

a simple algorithm used to determine the order of events in a distributed computer system

algorithm for partial ordering of events and detecting causality in distributed systems

mechanism for capturing chronological and causal relationships

In computer science, the happened-before relation (denoted: \to \;) is a relation between the result of two events, such that if one event should happen before another event, the result must reflect that, even if those events are in reality executed out of order (usually to optimize program flow). This involves ordering events based on the potential causal relationship of pairs of events in a concurrent system, especially asynchronous distributed systems. It was formulated by Leslie Lamport.