type ('state, 'job_tag) t
Every Key.t
in the table has an associated state
, which each job running on that
key gets access to. Jobs maybe have an associated job_tag
which is provided
purely to assist debugging, as the tag is included in the sexp serialization of
t
.
include sig ... end
val sexp_of_t : ('state ‑> Base.Sexp.t) ‑> ('job_tag ‑> Base.Sexp.t) ‑> ('state, 'job_tag) t ‑> Base.Sexp.t
val create : unit ‑> (_, _) t
val enqueue : ('state, 'job_tag) t ‑> key:Key.t ‑> ?tag:'job_tag ‑> ('state option ‑> 'b Async.Deferred.t) ‑> 'b Async.Deferred.t
enqueue t ~key f
enqueues f
for key
. f
will be called with the state of
key
when invoked.
Invariant 1: it is guaranteed that f
will not be called immediately.
Invariant 2: if f
raises, then the exception will be raised to the monitor in
effect when enqueue
was called. Subsequent jobs for key
will proceed.
Invariant 3: to avoid race, there are no deferred operations between finding the
state and calling f
with the state found. Otherwise, the user would need to
consider the race that the state passed to f
might have been changed by
set_state
.
set_state t key state_opt
sets the state for key
immediately. The state will be
kept internally until set to None
num_unfinished_jobs t key
returns the number of jobs for key
including including
pending and running.
Fold over keys with states or pending/running jobs. It's safe to mutate (enqueue
or set_state
) when folding
val prior_jobs_done : (_, _) t ‑> unit Async.Deferred.t
The result is determined when all jobs enqueued before this are finished. The
implementation adds a new job to every key currently with at least one running job
attached, so it will affect num_unfinished_jobs