Race condition when records added through resonate lfi/rfi

[dfarr]

When new records are added to the scheduler via resonate.lfi or resonate.rfi we check for the existence of a record by id, and return a handle if one exists. If one does not exist we create a record - leading to a possible race condition.

Solution 1: ingest records in scheduler event loop

The event loop is single threaded, so race conditions can be avoided here. We would need to add information to a queue on the scheduler and await a handle. That handle would then be returned to the caller.

Solution 2: lock on the scheduler

We could a lock to the resonate class that must be obtained before lfis/rfis are added to the scheduler. Because we don't have to lock all concurrent calls, we could lock based on the id.

[Tomperez98]

We resolved this by adding a ForkOrJoin command and creating multiple handles with Subscribe and Notify