This module limits the concurrency in jenga.
Note that the various locking functions below should _not_ be called when inside
of the File_access throttle, to avoid deadlocks.
val lock_directory_for_action : dir:Path.t ‑> (unit ‑> 'a Async.Deferred.t) ‑> 'a Async.Deferred.tAt any given time, you can either have any number of functions passed
to lock_directory_for_action or any number of functions passed to
lock_directory_for_listing running, but not both at the same time.
This is presumably because an action running in a directory may create temporary files, so we prefer to avoid retriggering spuriously when we see them coming and going.
val lock_directory_for_listing : dir:Path.t ‑> (unit ‑> 'a Async.Deferred.t) ‑> 'a Async.Deferred.tval lock_targets_for_action : targets:Path.Rel.t list ‑> (unit ‑> 'a Async.Deferred.t) ‑> 'a Async.Deferred.tPrevent overlapping execution of actions on each target.
Note that you can have multiple concurrent actions for a target
even when you have only one Rule.t:
If the value of Action.t Dep.t changes over time, jenga
might decide to start the new Action.t before the old one is finished.
This lock is there to prevent that.
val is_action_running_for_path : Path.Rel.t ‑> bool