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open Lwt
open Xs_protocol
let ( |> ) a b = b a
let ( ++ ) f g x = f (g x)
let debug fmt = Logging.debug "xs_server" fmt
let error fmt = Logging.error "xs_server" fmt
let store =
let store = Store.create () in
List.iter
(fun path ->
let p = Store.Path.create path (Store.Path.getdomainpath 0) in
if not (Store.exists store p)
then Store.mkdir store 0 (Perms.of_domain 0) p
) [ "/local"; "/local/domain"; "/tool"; "/tool/xenstored"; "/tool/xenstored/quota"; "/tool/xenstored/connection"; "/tool/xenstored/log"; "/tool/xenstored/memory" ];
store
module type TRANSPORT = sig
type 'a t = 'a Lwt.t
val return: 'a -> 'a Lwt.t
val ( >>= ): 'a t -> ('a -> 'b Lwt.t) -> 'b Lwt.t
type server
val listen: unit -> server Lwt.t
type channel
val read: channel -> bytes -> int -> int -> int Lwt.t
val write: channel -> bytes -> int -> int -> unit Lwt.t
val destroy: channel -> unit Lwt.t
val address_of: channel -> Xs_protocol.address Lwt.t
val namespace_of: channel -> (module Namespace.IO) option
val accept_forever: server -> (channel -> unit Lwt.t) -> 'a Lwt.t
end
module Server = functor(T: TRANSPORT) -> struct
module PS = PacketStream(T)
let handle_connection t =
T.address_of t
>>= fun address ->
let interface = T.namespace_of t in
let c = Connection.create address interface in
let channel = PS.make t in
let m = Lwt_mutex.create () in
let take_watch_events () =
let q = List.rev (Queue.fold (fun acc x -> x :: acc) [] c.Connection.watch_events) in
Queue.clear c.Connection.watch_events;
q in
let flush_watch_events q =
Lwt_list.iter_s
(fun (path, token) ->
PS.send channel (Xs_protocol.(Response.(print (Watchevent(path, token)) 0l 0l)))
) q in
let (background_watch_event_flusher: unit Lwt.t) =
let rec forever () =
Lwt_mutex.with_lock m
(fun () ->
let rec loop () =
if Queue.length c.Connection.watch_events = 0 then begin
Lwt_condition.wait ~mutex:m c.Connection.cvar
>>= fun () ->
loop ()
end else return () in
loop ()
>>= fun () ->
flush_watch_events (take_watch_events ())
)
>>= fun () ->
forever () in
forever () in
Lwt.catch (fun () ->
let rec forever () =
( PS.recv channel
>>= function
| Ok x -> return x
| Exception e -> Lwt.fail e )
>>= fun request ->
let events = take_watch_events () in
let reply = Call.reply store c request in
Lwt_mutex.with_lock m
(fun () ->
flush_watch_events events
>>= fun () ->
PS.send channel reply
)
>>= fun () ->
forever () in
forever ()
>>= fun () ->
T.destroy t
) (fun _ ->
Lwt.cancel background_watch_event_flusher;
Connection.destroy address;
T.destroy t)
let serve_forever () =
Parser.allow_oversize_packets := false;
T.listen ()
>>= fun server ->
T.accept_forever server handle_connection
end