47 lines
1.9 KiB
OCaml
47 lines
1.9 KiB
OCaml
(**************************************************************************)
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(* *)
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(* Copyright (c) 2014 - 2017. *)
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(* Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
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(* *)
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(* All rights reserved. No warranty, explicit or implicit, provided. *)
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(* *)
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(**************************************************************************)
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(** A 'dropbox' with a single element. *)
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type 'a t
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(** Type of dropbox holding a value of type ['a] *)
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val create: unit -> 'a t
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(** Create an empty dropbox. *)
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val put: 'a t -> 'a -> unit
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(** Put an element inside the dropbox. If the dropbox was already
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containing an element, the old element is replaced by the new one.
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The function might return [Closed] if the dropbox has been closed
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with [close]. *)
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val take: 'a t -> 'a Lwt.t
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(** Wait until the dropbox contains an element, then returns the elements.
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The elements is removed from the dropbox. The function might return
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[Closed] if the dropbox is empty and closed. *)
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val take_with_timeout: float -> 'a t -> 'a option Lwt.t
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(** Like [take] except that it returns [None] after [timeout seconds]
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if the dropbox is still empty. *)
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val peek: 'a t -> 'a option
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(** Read the current element of the dropbox without removing it. It
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immediatly returns [None] if the dropbox is empty. *)
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exception Closed
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(** The exception returned when trying to access a 'closed' dropbox. *)
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val close: 'a t -> unit
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(** Close the dropox. It terminates all the waiting reader with the
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exception [Closed]. All further read or write will also immediatly
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fail with [Closed], except if the dropbox is not empty when
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[close] is called. In that can, a single (and last) [take] will
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succeed. *)
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