59 lines
2.1 KiB
OCaml
59 lines
2.1 KiB
OCaml
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(**************************************************************************)
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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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open Error_monad
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let create_inner
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lock_command
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?(close_on_exec=true)
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?(unlink_on_exit=false) fn =
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protect begin fun () ->
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Lwt_unix.openfile fn Unix.[O_CREAT ; O_WRONLY; O_TRUNC] 0o644 >>= fun fd ->
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if close_on_exec then Lwt_unix.set_close_on_exec fd ;
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Lwt_unix.lockf fd lock_command 0 >>= fun () ->
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if unlink_on_exit then
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Lwt_main.at_exit (fun () -> Lwt_unix.unlink fn) ;
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let pid_str = string_of_int @@ Unix.getpid () in
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Lwt_unix.write_string fd pid_str 0 (String.length pid_str) >>= fun _ ->
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return ()
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end
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let create = create_inner Unix.F_TLOCK
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let blocking_create
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?timeout
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?(close_on_exec=true)
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?(unlink_on_exit=false) fn =
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let create () =
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create_inner Unix.F_LOCK ~close_on_exec ~unlink_on_exit fn in
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match timeout with
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| None -> create ()
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| Some duration -> Lwt_utils.with_timeout duration (fun _ -> create ())
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let is_locked fn =
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if not @@ Sys.file_exists fn then return false else
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protect begin fun () ->
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Lwt_unix.openfile fn [Unix.O_RDONLY] 0o644 >>= fun fd ->
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Lwt.finalize (fun () ->
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Lwt.try_bind
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(fun () -> Lwt_unix.(lockf fd F_TEST 0))
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(fun () -> return false)
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(fun _ -> return true))
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(fun () -> Lwt_unix.close fd)
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end
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let get_pid fn =
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let open Lwt_io in
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Lwt_utils.protect begin fun () ->
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with_file ~mode:Input fn begin fun ic ->
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read ic >>= fun content ->
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return (int_of_string content)
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end
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end
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