infer_clone/infer/src/backend/ProcLocker.mli

(*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *)

open! IStd

exception UnlockNotLocked of Procname.t

val setup : unit -> unit
(** This should be called once before trying to lock Anything. *)

val try_lock : Procname.t -> bool
(** true = the lock belongs to the calling process. false = the lock belongs to a different worker *)

val unlock : Procname.t -> unit
(** This will work as a cleanup function because after calling unlock all the workers that need an
    unlocked Proc should find it's summary already Cached. Throws if the lock had not been taken. *)

val clean : unit -> unit
(** This should be called when locks will no longer be used to remove any files or state that's not
    necessary. *)

val is_locked : Procname.t -> bool
[scheduler] [restart] Implement the ProcLocker Summary: The ProcLocker uses files as locks and relies on the guarantees of the `Unix.open_file` function when using `O_CREAT` and `O_EXCL` simultaneously. - `setup`: creates a directory for the lock files inside `infe-out` and deletes its content if it already existed. - `clean`: does nothing for now. Any file locks that may have been left unlocked are removed by the `setup` in the next run. This way the user can see what locks were taken if the program crashes. - `lock_exn`: try to lock the `Procname` and if it can't releases all the locks that is currently holding. - `unlock`: removes the corresponding file. Reviewed By: ngorogiannis Differential Revision: D19639402 fbshipit-source-id: e02f277ff 5 years ago			`(*`
			`* Copyright (c) Facebook, Inc. and its affiliates.`
			`*`
			`* This source code is licensed under the MIT license found in the`
			`* LICENSE file in the root directory of this source tree.`
			`*)`

			`open! IStd`

			`exception UnlockNotLocked of Procname.t`

			`val setup : unit -> unit`
			`(** This should be called once before trying to lock Anything. *)`

			`val try_lock : Procname.t -> bool`
			`(** true = the lock belongs to the calling process. false = the lock belongs to a different worker *)`

			`val unlock : Procname.t -> unit`
			`(** This will work as a cleanup function because after calling unlock all the workers that need an`
			`unlocked Proc should find it's summary already Cached. Throws if the lock had not been taken. *)`

			`val clean : unit -> unit`
			`(** This should be called when locks will no longer be used to remove any files or state that's not`
			`necessary. *)`
[scheduler][restart] Reduce live-locking by using data produced on failure Summary: When a worker fails because it can't a get the lock of a `Procname` it will include it in the exception that it throws so the `RestartScheduler` can record it as a dependency. Then when scheduling a new work item from `RestartScheduler.next` it will check if this dependency is already met, if it isn't it will not schedule the `Procname` yet. Reviewed By: ngorogiannis Differential Revision: D19820331 fbshipit-source-id: b48cacc9a 5 years ago
			`val is_locked : Procname.t -> bool`