Module Async_kernel.Bvar

A Bvar is a synchronization point that allows one to broadcast a value to clients waiting on the broadcast. With a Bvar, one can efficiently notify multiple clients of edge-triggered conditions, repeating as each edge trigger occurs.

Bvar is like an ivar/deferred, except that it is always "empty" and can be repeatedly "filled" (via broadcast).

Another way to view Bvar is as a restriction of Condition that supports only broadcast, not signaling a single waiter. Dropping signal simplifies the implementation significantly.

The 'permissions parameter is used for read/write permissions. Also see Perms.

type ('a, -'permissions) t
val sexp_of_t : ('a -> Ppx_sexp_conv_lib.Sexp.t) -> ('permissions -> Ppx_sexp_conv_lib.Sexp.t) -> ('a, 'permissions) t -> Ppx_sexp_conv_lib.Sexp.t
include Core_kernel.Invariant.S2 with type ('a, 'permissions) t := ('a, 'permissions) t
val invariant : ('a -> unit) -> ('b -> unit) -> ('a, 'permissions) t -> unit
val create : unit -> ('a, Core_kernel.read_write) t
val wait : ('a, [> Core_kernel.read ]) t -> 'a Async_kernel__Types.Deferred.t

wait t becomes determined by the next call to broadcast t a.

val broadcast : ('a, [> Core_kernel.write ]) t -> 'a -> unit
val has_any_waiters : ('a, _) t -> bool

has_any_waiters t returns true iff there has been a call to wait t since the most recent call to broadcast t.