package duppy
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Source file duppy.ml
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(***************************************************************************** Duppy, a task scheduler for OCaml. Copyright 2003-2010 Savonet team This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details, fully stated in the COPYING file at the root of the liquidsoap distribution. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************) type fd = Unix.file_descr external poll : Unix.file_descr array -> Unix.file_descr array -> Unix.file_descr array -> float -> Unix.file_descr array * Unix.file_descr array * Unix.file_descr array = "caml_poll" let poll r w e timeout = let r = Array.of_list r in let w = Array.of_list w in let e = Array.of_list e in let r, w, e = poll r w e timeout in (Array.to_list r, Array.to_list w, Array.to_list e) let select, select_fname = match Sys.os_type with | "Unix" -> (poll, "poll") | _ -> (Unix.select, "select") (** [remove f l] is like [List.find f l] but also returns the result of removing * the found element from the original list. *) let remove f l = let rec aux acc = function | [] -> raise Not_found | x :: l -> if f x then (x, List.rev_append acc l) else aux (x :: acc) l in aux [] l (** Events and tasks from the implementation point-of-view: * we have to hide the 'a parameter. *) type e = { r : fd list; w : fd list; x : fd list; t : float } type 'a t = { timestamp : float; prio : 'a; enrich : e -> e; is_ready : e -> (unit -> 'a t list) option; } type 'a scheduler = { out_pipe : Unix.file_descr; in_pipe : Unix.file_descr; compare : 'a -> 'a -> int; select_m : Mutex.t; mutable tasks : 'a t list; tasks_m : Mutex.t; mutable ready : ('a * (unit -> 'a t list)) list; ready_m : Mutex.t; mutable queues : Condition.t list; queues_m : Mutex.t; mutable stop : bool; stop_m : Mutex.t; queue_stopped_c : Condition.t; } let clear_tasks s = Mutex.lock s.tasks_m; s.tasks <- []; Mutex.unlock s.tasks_m let create ?(compare = compare) () = let out_pipe, in_pipe = Unix.pipe () in { out_pipe; in_pipe; compare; select_m = Mutex.create (); tasks = []; tasks_m = Mutex.create (); ready = []; ready_m = Mutex.create (); queues = []; queues_m = Mutex.create (); stop = false; stop_m = Mutex.create (); queue_stopped_c = Condition.create (); } let wake_up s = ignore (Unix.write s.in_pipe (Bytes.of_string "x") 0 1) module Task = struct (** Events and tasks from the user's point-of-view. *) type event = [ `Delay of float | `Write of fd | `Read of fd | `Exception of fd ] type ('a, 'b) task = { priority : 'a; events : 'b list; handler : 'b list -> ('a, 'b) task list; } let time () = Unix.gettimeofday () let rec t_of_task (task : ('a, [< event ]) task) = let t0 = time () in { timestamp = t0; prio = task.priority; enrich = (fun e -> List.fold_left (fun e -> function `Delay s -> { e with t = min e.t (t0 +. s) } | `Read s -> { e with r = s :: e.r } | `Write s -> { e with w = s :: e.w } | `Exception s -> { e with x = s :: e.x }) e task.events); is_ready = (fun e -> let l = List.filter (fun evt -> match (evt :> event) with | `Delay s when time () > t0 +. s -> true | `Read s when List.mem s e.r -> true | `Write s when List.mem s e.w -> true | `Exception s when List.mem s e.x -> true | _ -> false) task.events in if l = [] then None else Some (fun () -> List.map t_of_task (task.handler l))); } let add_t s items = let f item = match item.is_ready { r = []; w = []; x = []; t = 0. } with | Some f -> Mutex.lock s.ready_m; s.ready <- (item.prio, f) :: s.ready; Mutex.unlock s.ready_m | None -> Mutex.lock s.tasks_m; s.tasks <- item :: s.tasks; Mutex.unlock s.tasks_m in List.iter f items; wake_up s let add s t = add_t s [t_of_task t] end open Task let stop s = clear_tasks s; Mutex.lock s.stop_m; s.stop <- true; Mutex.unlock s.stop_m; Mutex.lock s.queues_m; while List.length s.queues > 0 do wake_up s; Mutex.lock s.ready_m; List.iter Condition.signal s.queues; Mutex.unlock s.ready_m; Condition.wait s.queue_stopped_c s.queues_m done; Mutex.unlock s.queues_m let tmp = Bytes.create 1024 (** There should be only one call of #process at a time. * Process waits for tasks to become ready, and moves ready tasks * to the ready queue. *) let process s log = (* Compute the union of all events. *) let e = List.fold_left (fun e t -> t.enrich e) { r = [s.out_pipe]; w = []; x = []; t = infinity } s.tasks in (* Poll for an event. *) let r, w, x = let rec f () = try let timeout = if e.t = infinity then -1. else max 0. (e.t -. time ()) in log (Printf.sprintf "Enter %s at %f, timeout %f (%d/%d/%d)." select_fname (time ()) timeout (List.length e.r) (List.length e.w) (List.length e.x)); let r, w, x = select e.r e.w e.x timeout in log (Printf.sprintf "Left %s at %f (%d/%d/%d)." select_fname (time ()) (List.length r) (List.length w) (List.length x)); (r, w, x) with | Unix.Unix_error (Unix.EINTR, _, _) -> (* [EINTR] means that select was interrupted by * a signal before any of the selected events * occurred and before the timeout interval expired. * We catch it and restart.. *) log (Printf.sprintf "Select interrupted at %f." (time ())); f () | e -> (* Uncaught exception: * 1) Discards all tasks currently in the loop (we do not know which * socket caused an error). * 2) Re-Raise e *) clear_tasks s; raise e in f () in (* Empty the wake_up pipe if needed. *) let () = if List.mem s.out_pipe r then (* For safety, we may absorb more than * one write. This avoids bad situation * when exceesive wake_up may fill up the * pipe's write buffer, causing a wake_up * to become blocking.. *) ignore (Unix.read s.out_pipe tmp 0 1024) in (* Move ready tasks to the ready list. *) let e = { r; w; x; t = 0. } in Mutex.lock s.tasks_m; (* Split [tasks] into [r]eady and still [w]aiting. *) let r, w = List.fold_left (fun (r, w) t -> match t.is_ready e with | Some f -> ((t.prio, f) :: r, w) | None -> (r, t :: w)) ([], []) s.tasks in s.tasks <- w; Mutex.unlock s.tasks_m; Mutex.lock s.ready_m; s.ready <- List.stable_sort (fun (p, _) (p', _) -> s.compare p p') (s.ready @ r); Mutex.unlock s.ready_m (** Code for a queue to process ready tasks. * Returns true a task was found (and hence processed). * * s.ready_m *must* be locked before calling * this function, and is freed *only* * if some task was processed. *) let exec s (priorities : 'a -> bool) = (* This assertion does not work on * win32 because a thread can double-lock * the same mutex.. *) if Sys.os_type <> "Win32" then assert (not (Mutex.try_lock s.ready_m)); try let (_, task), remaining = remove (fun (p, _) -> priorities p) s.ready in s.ready <- remaining; Mutex.unlock s.ready_m; add_t s (task ()); true with Not_found -> false exception Queue_stopped exception Queue_processed (** Main loop for queues. *) let queue ?log ?(priorities = fun _ -> true) s name = let log = match log with Some e -> e | None -> Printf.printf "queue %s: %s\n" name in let c = let c = Condition.create () in Mutex.lock s.queues_m; s.queues <- c :: s.queues; Mutex.unlock s.queues_m; log (Printf.sprintf "Queue #%d starting..." (List.length s.queues)); c in (* Try to process ready tasks, otherwise try to become the master, * or be a slave and wait for the master to get some more ready tasks. *) let run () = Mutex.lock s.stop_m; let stop = s.stop in Mutex.unlock s.stop_m; if stop then raise Queue_stopped; (* Lock the ready tasks until the queue has a task to proceed, * *or* is really ready to restart on its condition, see the * Condition.wait call below for the atomic unlock and wait. *) Mutex.lock s.ready_m; log (Printf.sprintf "There are %d ready tasks." (List.length s.ready)); if exec s priorities then raise Queue_processed; let wake () = let is_ready = Mutex.lock s.ready_m; let is_ready = s.ready <> [] in Mutex.unlock s.ready_m; is_ready in (* Wake up other queues if there are remaining tasks *) if is_ready then begin Mutex.lock s.queues_m; List.iter (fun x -> if x <> c then Condition.signal x) s.queues; Mutex.unlock s.queues_m end in if Mutex.try_lock s.select_m then begin (* Processing finished for me * I can unlock ready_m now.. *) Mutex.unlock s.ready_m; process s log; Mutex.unlock s.select_m; wake (); end else begin (* We use s.ready_m mutex here. * Hence, we avoid race conditions * with any other queue being processing * a task that would create a new task: * without this mutex, the new task may not be * notified to this queue if it is going to sleep * in concurrency.. * It also avoid race conditions when restarting * queues since s.ready_m is locked until all * queues have been signaled. *) Condition.wait c s.ready_m; Mutex.unlock s.ready_m end in let rec f () = begin try run () with Queue_processed -> () end; (f [@tailcall]) () in let on_done () = Mutex.lock s.queues_m; s.queues <- List.filter (fun q -> q <> c) s.queues; Condition.signal s.queue_stopped_c; Mutex.unlock s.queues_m in ( try f () with | Queue_stopped -> () | exn -> on_done (); raise exn ); on_done () module Async = struct (* m is used to make sure that * calls to [wake_up] and [stop] * are thread-safe. *) type t = { stop : bool ref; mutable fd : fd option; m : Mutex.t } exception Stopped let add ~priority (scheduler : 'a scheduler) f = (* A pipe to wake up the task *) let out_pipe, in_pipe = Unix.pipe () in let stop = ref false in let tmp = Bytes.create 1024 in let rec task l = if List.exists (( = ) (`Read out_pipe)) l then (* Consume data from the pipe *) ignore (Unix.read out_pipe tmp 0 1024); if !stop then begin begin try (* This interface is purely asynchronous * so we close both sides of the pipe here. *) Unix.close in_pipe; Unix.close out_pipe with _ -> () end; [] end else begin let delay = f () in let event = if delay >= 0. then [`Delay delay] else [] in [{ priority; events = `Read out_pipe :: event; handler = task }] end in let task = { priority; events = [`Read out_pipe]; handler = task } in add scheduler task; { stop; fd = Some in_pipe; m = Mutex.create () } let wake_up t = Mutex.lock t.m; try begin match t.fd with | Some t -> ignore (Unix.write t (Bytes.of_string " ") 0 1) | None -> raise Stopped end; Mutex.unlock t.m with e -> Mutex.unlock t.m; raise e let stop t = Mutex.lock t.m; try begin match t.fd with | Some c -> t.stop := true; ignore (Unix.write c (Bytes.of_string " ") 0 1) | None -> raise Stopped end; t.fd <- None; Mutex.unlock t.m with e -> Mutex.unlock t.m; raise e end module type Transport_t = sig type t type bigarray = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t val sock : t -> Unix.file_descr val read : t -> Bytes.t -> int -> int -> int val write : t -> Bytes.t -> int -> int -> int val ba_write : t -> bigarray -> int -> int -> int end module Unix_transport : Transport_t with type t = Unix.file_descr = struct type t = Unix.file_descr type bigarray = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t let sock s = s let read = Unix.read let write = Unix.write external ba_write : t -> bigarray -> int -> int -> int = "ocaml_duppy_write_ba" end module type Io_t = sig type socket type marker = Length of int | Split of string type bigarray = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t type failure = | Io_error | Unix of Unix.error * string * string | Unknown of exn | Timeout val read : ?recursive:bool -> ?init:string -> ?on_error:(string * failure -> unit) -> ?timeout:float -> priority:'a -> 'a scheduler -> socket -> marker -> (string * string option -> unit) -> unit val write : ?exec:(unit -> unit) -> ?on_error:(failure -> unit) -> ?bigarray:bigarray -> ?offset:int -> ?length:int -> ?string:Bytes.t -> ?timeout:float -> priority:'a -> 'a scheduler -> socket -> unit end module MakeIo (Transport : Transport_t) : Io_t with type socket = Transport.t = struct type socket = Transport.t type marker = Length of int | Split of string type failure = | Io_error | Unix of Unix.error * string * string | Unknown of exn | Timeout exception Io exception Timeout_exc type bigarray = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t let read ?(recursive = false) ?(init = "") ?(on_error = fun _ -> ()) ?timeout ~priority (scheduler : 'a scheduler) socket marker exec = let length = 1024 in let b = Buffer.create length in let buf = Bytes.make length ' ' in Buffer.add_string b init; let unix_socket = Transport.sock socket in let events, check_timeout = match timeout with | None -> ([`Read unix_socket], fun _ -> false) | Some f -> ([`Read unix_socket; `Delay f], List.mem (`Delay f)) in let rec f l = if check_timeout l then raise Timeout_exc; if List.mem (`Read unix_socket) l then begin let input = Transport.read socket buf 0 length in if input <= 0 then raise Io; Buffer.add_subbytes b buf 0 input end; let ret = match marker with | Split r -> let rex = Pcre.regexp r in let acc = Buffer.contents b in let ret = Pcre.full_split ~max:2 ~rex acc in let rec p l = match l with | Pcre.Text x :: Pcre.Delim _ :: l -> let f b x = match x with | Pcre.Text s | Pcre.Delim s -> Buffer.add_string b s | _ -> () in if recursive then begin Buffer.reset b; List.iter (f b) l; Some (x, None) end else begin let b = Buffer.create 10 in List.iter (f b) l; Some (x, Some (Buffer.contents b)) end | _ :: l' -> p l' | [] -> None in p ret | Length n when n <= Buffer.length b -> let s = Buffer.sub b 0 n in let rem = Buffer.sub b n (Buffer.length b - n) in if recursive then begin Buffer.reset b; Buffer.add_string b rem; Some (s, None) end else Some (s, Some rem) | _ -> None in (* Catch all exceptions.. *) let f x = try f x with | Io -> on_error (Buffer.contents b, Io_error); [] | Timeout_exc -> on_error (Buffer.contents b, Timeout); [] | Unix.Unix_error (x, y, z) -> on_error (Buffer.contents b, Unix (x, y, z)); [] | e -> on_error (Buffer.contents b, Unknown e); [] in match ret with | Some x -> ( match x with | s, Some _ when recursive -> exec (s, None); [{ priority; events; handler = f }] | _ -> exec x; [] ) | None -> [{ priority; events; handler = f }] in (* Catch all exceptions.. *) let f x = try f x with | Io -> on_error (Buffer.contents b, Io_error); [] | Timeout_exc -> on_error (Buffer.contents b, Timeout); [] | Unix.Unix_error (x, y, z) -> on_error (Buffer.contents b, Unix (x, y, z)); [] | e -> on_error (Buffer.contents b, Unknown e); [] in (* First one is without read, * in case init contains the wanted match. * Unless the user sets timeout to 0., this * should not interfer with user-defined timeout.. *) let task = { priority; events = [`Delay 0.; `Read unix_socket]; handler = f } in add scheduler task let write ?(exec = fun () -> ()) ?(on_error = fun _ -> ()) ?bigarray ?(offset = 0) ?length ?string ?timeout ~priority (scheduler : 'a scheduler) socket = let length, write = match (string, bigarray) with | Some s, _ -> let length = match length with Some length -> length | None -> Bytes.length s in (length, Transport.write socket s) | None, Some b -> let length = match length with | Some length -> length | None -> Bigarray.Array1.dim b in (length, Transport.ba_write socket b) | _ -> (0, fun _ _ -> 0) in let unix_socket = Transport.sock (socket : Transport.t) in let exec () = if Sys.os_type = "Win32" then Unix.clear_nonblock unix_socket; exec () in let events, check_timeout = match timeout with | None -> ([`Write unix_socket], fun _ -> false) | Some f -> ([`Write unix_socket; `Delay f], List.mem (`Delay f)) in let rec f pos l = try if check_timeout l then raise Timeout_exc; assert (List.exists (( = ) (`Write unix_socket)) l); let len = length - pos in let n = write pos len in if n <= 0 then ( on_error Io_error; [] ) else if n < len then [{ priority; events = [`Write unix_socket]; handler = f (pos + n) }] else ( exec (); [] ) with | Unix.Unix_error (Unix.EWOULDBLOCK, _, _) when Sys.os_type = "Win32" -> [{ priority; events = [`Write unix_socket]; handler = f pos }] | Timeout_exc -> on_error Timeout; [] | Unix.Unix_error (x, y, z) -> on_error (Unix (x, y, z)); [] | e -> on_error (Unknown e); [] in let task = { priority; events; handler = f offset } in if length > 0 then (* Win32 is particularly bad with writting on sockets. It is nearly impossible * to write proper non-blocking code. send will block on blocking sockets if * there isn't enough data available instead of returning a partial buffer * and WSAEventSelect will not return if the socket still has available space. * Thus, setting the socket to non-blocking and writting as much as we can. *) if Sys.os_type = "Win32" then begin Unix.set_nonblock unix_socket; List.iter (add scheduler) (f offset [`Write unix_socket]) end else add scheduler task else exec () end module Io : Io_t with type socket = Unix.file_descr = MakeIo (Unix_transport) (** A monad for implicit continuations or responses *) module Monad = struct type ('a, 'b) handler = { return : 'a -> unit; raise : 'b -> unit } type ('a, 'b) t = ('a, 'b) handler -> unit let return x h = h.return x let raise x h = h.raise x let bind f g h = let ret x = let process = g x in process h in f { return = ret; raise = h.raise } let ( >>= ) = bind let run ~return:ret ~raise f = f { return = ret; raise } let catch f g h = let raise x = let process = g x in process h in f { return = h.return; raise } let ( =<< ) x y = catch y x let rec fold_left f a = function | [] -> a | b :: l -> fold_left f (bind a (fun a -> f a b)) l let fold_left f a l = fold_left f (return a) l let iter f l = fold_left (fun () b -> f b) () l module Mutex_o = Mutex module Mutex = struct module type Mutex_control = sig type priority val scheduler : priority scheduler val priority : priority end module type Mutex_t = sig (** Type for a mutex. *) type mutex module Control : Mutex_control (** [create ()] creates a mutex. Implementation-wise, * a duppy task is created that will be used to select a * waiting computation, lock the mutex on it and resume it. * Thus, [priority] and [s] represents, resp., the priority * and scheduler used when running calling process' computation. *) val create : unit -> mutex (** A computation that locks a mutex * and returns [unit] afterwards. Computation * will be blocked until the mutex is sucessfuly locked. *) val lock : mutex -> (unit, 'a) t (** A computation that tries to lock a mutex. * Returns immediatly [true] if the mutex was sucesfully locked * or [false] otherwise. *) val try_lock : mutex -> (bool, 'a) t (** A computation that unlocks a mutex. * Should return immediatly. *) val unlock : mutex -> (unit, 'a) t end module Factory (Control : Mutex_control) = struct (* A mutex is either locked or not * and has a list of tasks waiting to get * it. *) type mutex = { mutable locked : bool; mutable tasks : (unit -> unit) list; } module Control = Control let tmp = Bytes.create 1024 let x, y = Unix.pipe () let stop = ref false let wake_up () = ignore (Unix.write y (Bytes.of_string " ") 0 1) let ctl_m = Mutex_o.create () let finalise _ = stop := true; wake_up () let mutexes = Queue.create () let () = Gc.finalise finalise mutexes let register () = let m = { locked = false; tasks = [] } in Queue.push m mutexes; m let cleanup m = Mutex_o.lock ctl_m; let q = Queue.create () in Queue.iter (fun m' -> if m <> m' then Queue.push m q) mutexes; Queue.clear mutexes; Queue.transfer q mutexes; Mutex_o.unlock ctl_m let task f = { Task.priority = Control.priority; events = [`Delay 0.]; handler = (fun _ -> f (); []); } (* This should only be called when [ctl_m] is locked. *) let process_mutex tasks m = if not m.locked then ( (* I don't think shuffling tasks * matters here.. *) match m.tasks with | x :: l -> m.tasks <- l; m.locked <- true; task x :: tasks | _ -> tasks ) else tasks let rec handler _ = Mutex_o.lock ctl_m; if not !stop then begin let tasks = Queue.fold process_mutex [] mutexes in Mutex_o.unlock ctl_m; ignore (Unix.read x tmp 0 1024); { Task.priority = Control.priority; events = [`Read x]; handler } :: tasks end else begin Mutex_o.unlock ctl_m; try Unix.close x; Unix.close y; [] with _ -> [] end let () = Task.add Control.scheduler { Task.priority = Control.priority; events = [`Read x]; handler } let create () = Mutex_o.lock ctl_m; let ret = register () in Mutex_o.unlock ctl_m; Gc.finalise cleanup ret; ret let lock m h' = Mutex_o.lock ctl_m; if not m.locked then begin m.locked <- true; Mutex_o.unlock ctl_m; h'.return () end else begin m.tasks <- h'.return :: m.tasks; Mutex_o.unlock ctl_m end let try_lock m h' = Mutex_o.lock ctl_m; if not m.locked then begin m.locked <- true; Mutex_o.unlock ctl_m; h'.return true end else begin Mutex_o.unlock ctl_m; h'.return false end let unlock m h' = Mutex_o.lock ctl_m; (* Here we allow inter-thread * and double unlock.. Double unlock * is not necessarily a problem and * inter-thread unlock well.. what is * a thread here ?? :-) *) m.locked <- false; let wake = m.tasks <> [] in Mutex_o.unlock ctl_m; if wake then wake_up (); h'.return () end end module Condition = struct module Factory (Mutex : Mutex.Mutex_t) = struct type condition = { condition_m : Mutex_o.t; waiting : (unit -> unit) Queue.t; } module Control = Mutex.Control let create () = { condition_m = Mutex_o.create (); waiting = Queue.create () } (* Mutex.unlock m needs to happen _after_ * the task has been registered. *) let wait c m h = let proc () = Mutex.lock m h in Mutex_o.lock c.condition_m; Queue.push proc c.waiting; Mutex_o.unlock c.condition_m; (* Mutex.unlock does not raise exceptions (for now..) *) let h' = { return = (fun () -> ()); raise = (fun _ -> assert false) } in Mutex.unlock m h' let wake_up h = let handler _ = h (); [] in Task.add Control.scheduler { Task.priority = Control.priority; events = [`Delay 0.]; handler } let signal c h = Mutex_o.lock c.condition_m; let h' = Queue.pop c.waiting in Mutex_o.unlock c.condition_m; wake_up h'; h.return () let broadcast c h = let q = Queue.create () in Mutex_o.lock c.condition_m; Queue.transfer c.waiting q; Mutex_o.unlock c.condition_m; Queue.iter wake_up q; h.return () end end module type Monad_io_t = sig type socket module Io : Io_t with type socket = socket type ('a, 'b) handler = { scheduler : 'a scheduler; socket : Io.socket; mutable data : string; on_error : Io.failure -> 'b; } val exec : ?delay:float -> priority:'a -> ('a, 'b) handler -> ('c, 'b) t -> ('c, 'b) t val delay : priority:'a -> ('a, 'b) handler -> float -> (unit, 'b) t val read : ?timeout:float -> priority:'a -> marker:Io.marker -> ('a, 'b) handler -> (string, 'b) t val read_all : ?timeout:float -> priority:'a -> 'a scheduler -> Io.socket -> (string, string * Io.failure) t val write : ?timeout:float -> priority:'a -> ('a, 'b) handler -> ?offset:int -> ?length:int -> Bytes.t -> (unit, 'b) t val write_bigarray : ?timeout:float -> priority:'a -> ('a, 'b) handler -> Io.bigarray -> (unit, 'b) t end module MakeIo (Io : Io_t) = struct type socket = Io.socket module Io = Io type ('a, 'b) handler = { scheduler : 'a scheduler; socket : Io.socket; mutable data : string; on_error : Io.failure -> 'b; } let exec ?(delay = 0.) ~priority h f h' = let handler _ = begin try f h' with e -> h'.raise (h.on_error (Io.Unknown e)) end; [] in Task.add h.scheduler { Task.priority; events = [`Delay delay]; handler } let delay ~priority h delay = exec ~delay ~priority h (return ()) let read ?timeout ~priority ~marker h h' = let process x = let s = match x with | s, None -> h.data <- ""; s | s, Some s' -> h.data <- s'; s in h'.return s in let init = h.data in h.data <- ""; let on_error (s, x) = h.data <- s; h'.raise (h.on_error x) in Io.read ?timeout ~priority ~init ~recursive:false ~on_error h.scheduler h.socket marker process let read_all ?timeout ~priority s sock = let handler = { scheduler = s; socket = sock; data = ""; on_error = (fun e -> e) } in let buf = Buffer.create 1024 in let rec f () = let data = read ?timeout ~priority ~marker:(Io.Length 1024) handler in let process data = Buffer.add_string buf data; f () in data >>= process in let catch_ret e = Buffer.add_string buf handler.data; match e with | Io.Io_error -> return (Buffer.contents buf) | e -> raise (Buffer.contents buf, e) in catch (f ()) catch_ret let write ?timeout ~priority h ?offset ?length s h' = let on_error x = h'.raise (h.on_error x) in let exec () = h'.return () in Io.write ?timeout ~priority ~on_error ~exec ?offset ?length ~string:s h.scheduler h.socket let write_bigarray ?timeout ~priority h ba h' = let on_error x = h'.raise (h.on_error x) in let exec () = h'.return () in Io.write ?timeout ~priority ~on_error ~exec ~bigarray:ba h.scheduler h.socket end module Io = MakeIo (Io) end