package devkit

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Development kit - general purpose library

Install

Dune Dependency

github.com Readme Edit opam file Versions (8)

Authors

A

Ahrefs <github@ahrefs.com>

Maintainers

I

igor@ahrefs.com

Sources

devkit-1.20210517.tbz

md5=00995ebead339d6ec1ba7859c3fc3a58

sha256=5ad39c7fa1a966a2f0a7f6dbb7e82c787439c73482f5f44b3c9fb54b040d36eb

sha512=8dd3f7d4aaabae9aa9ede13edee2b22214c0d2e2780bb08b2ca8ed588d74fc6d9b1908bb31dfee49c949c7cc425fb98897b8e0f11280070ebd99b965908ea133

doc/devkit.core/Devkit_core/Lwt_mark/index.html

Module `Devkit_core.Lwt_mark`Source

This module uses Lwt thread storage to give threads "marks", which store thread id (some unique int, autogenerated), name (given by user, see name and ignore_result), parent thread name, and few (currently 10, may be changed) last log messages that was output from this thread using Log module.

Thread mark is removed when the thread terminates.

summary () is the way to inspect current marks.

Marking must be initialized (init ()) to work with marks. When marking is not initialized, most of functions behave as no-op, this is implemented by checking internal_flag : bool ref, so it's cheap. There is no way to disable marking.

There are no "links from current thread mark to parent thread mark" ( = no "call stack"), as it may grow infinitely in a perfectly working code that uses constant memory otherwise.

Most of strings (names, logs) are lazy (internally), as their evaluation is needed only when one inspects current threads state. Functions that take strings wrap them with Lazy.from_val.

Sourceval init : unit -> unit

Enables thread marking. Use before calling other functions of this module.

Sourceval is_enabled : unit -> bool

Sourceval name : string -> (unit -> 'a Lwt.t) -> 'a Lwt.t

name n cont creates new lwt thread cont () marked with name n. Usage:

let myfunc () = Lwt_mark.name "myfunc" @@ fun () -> <the_body>

Source

val status : 
  string Lazy.t ->
  ?dump:('a -> string) ->
  (unit -> 'a Lwt.t) ->
  'a Lwt.t

status lazy_name ?dump cont

Usage:

lwt was_read = Lwt_mark.status (lazy (sprintf "reading %i bytes" to_read)) ~dump:string_of_int @@ fun () -> Lwt_unix.read fd buf ofs to_read in

Start/exit of thread cont () will be logged to parent thread's last logs.

lazy_name must be able to be evaluated into a meaningful thread name when it is forced, no matter when (before thread startup, during thread execution, after thread exit).

Use ?dump argument when you need to log return value of the thread.

Internally status works like name, but statuses are groupped and displayed by summary in the section of thread that created them.

Sourceval status_s : string -> ?dump:('a -> string) -> (unit -> 'a Lwt.t) -> 'a Lwt.t

Sourceval async : ?log:Log.logger -> string -> (unit -> unit Lwt.t) -> unit

async ?log name run_thread works like name + Lwt.async run_thread, but thread is marked as "background" (just for display purposes). Pass ~log to log thread failure with devkit logger (level = warn).

Sourceval log : string -> unit

Adds line to current thread's last logs. When marking is enabled, but current thread is not marked/named, line is added to special "<top>" thread logs.

Sourceval log_l : string Lazy.t -> unit

Sourceval log_f : ('a, unit, string, unit) format4 -> 'a

Sourceval summary : unit -> string

Human-readable marks summary: current running threads, their last logs and statuses.