1. An apparatus comprising: a coherence agent, implemented at least in part in hardware, wherein the coherence agent is to: identify a particular action; identify that a particular one of a plurality of state machine tables stored in memory corresponds to the particular action, wherein the plurality of state machine tables comprise machine-readable table structures and describe conditions governing state machine transitions to be made by coherence agents to comply with a particular coherence protocol; read the particular table to identify a particular row corresponding to a current coherence state of a cache line, wherein the particular row comprises a reference to another one of the plurality of state machine tables; access the other state machine table based on the reference to determine a particular coherence state transition from the current coherence state of the cache line; and transition the cache line from the current coherence state to a new coherence state based on the particular coherence state transition; and handle a request from another coherence agent corresponding to a cache managed by the coherence agent based on the new coherence state.