From efa34c63e8a62dab87918c7854e51291bd8fabeb Mon Sep 17 00:00:00 2001 From: Zheng Li Date: Fri, 24 Mar 2017 17:02:08 +0000 Subject: [PATCH 06/30] oxenstored: use hash table to store socket connections Currently we use list to store socket connections. This is fine for smaller number of connections. But when we scale up, traveling through a list of hundreds or thousands of connections just to find a single one of them is very low efficient. This patch replaces the list with a (Unix.file_descr -> Connection.t) hash table. Reported-by: Juergen Gross Signed-off-by: Zheng Li Reviewed-by: David Scott --- tools/ocaml/xenstored/connections.ml | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/tools/ocaml/xenstored/connections.ml b/tools/ocaml/xenstored/connections.ml index f4550f9..3e6a48b 100644 --- a/tools/ocaml/xenstored/connections.ml +++ b/tools/ocaml/xenstored/connections.ml @@ -18,17 +18,17 @@ let debug fmt = Logging.debug "connections" fmt type t = { - mutable anonymous: Connection.t list; + anonymous: (Unix.file_descr, Connection.t) Hashtbl.t; domains: (int, Connection.t) Hashtbl.t; mutable watches: (string, Connection.watch list) Trie.t; } -let create () = { anonymous = []; domains = Hashtbl.create 8; watches = Trie.create () } +let create () = { anonymous = Hashtbl.create 37; domains = Hashtbl.create 37; watches = Trie.create () } let add_anonymous cons fd can_write = let xbcon = Xenbus.Xb.open_fd fd in let con = Connection.create xbcon None in - cons.anonymous <- con :: cons.anonymous + Hashtbl.add cons.anonymous (Xenbus.Xb.get_fd xbcon) con let add_domain cons dom = let xbcon = Xenbus.Xb.open_mmap (Domain.get_interface dom) (fun () -> Domain.notify dom) in @@ -36,14 +36,14 @@ let add_domain cons dom = Hashtbl.add cons.domains (Domain.get_id dom) con let select cons = - let inset = List.map (fun c -> Connection.get_fd c) cons.anonymous - and outset = List.fold_left (fun l c -> if Connection.has_output c - then Connection.get_fd c :: l - else l) [] cons.anonymous in - inset, outset + Hashtbl.fold + (fun _ con (ins, outs) -> + let fd = Connection.get_fd con in + (fd :: ins, if Connection.has_output con then fd :: outs else outs)) + cons.anonymous ([], []) -let find cons fd = - List.find (fun c -> Connection.get_fd c = fd) cons.anonymous +let find cons = + Hashtbl.find cons.anonymous let find_domain cons id = Hashtbl.find cons.domains id @@ -55,7 +55,7 @@ let del_watches_of_con con watches = let del_anonymous cons con = try - cons.anonymous <- Utils.list_remove con cons.anonymous; + Hashtbl.remove cons.anonymous (Connection.get_fd con); cons.watches <- Trie.map (del_watches_of_con con) cons.watches; Connection.close con with exn -> @@ -74,7 +74,7 @@ let iter_domains cons fct = Hashtbl.iter (fun k c -> fct c) cons.domains let iter_anonymous cons fct = - List.iter (fun c -> fct c) (List.rev cons.anonymous) + Hashtbl.iter (fun _ c -> fct c) cons.anonymous let iter cons fct = iter_domains cons fct; iter_anonymous cons fct @@ -163,10 +163,10 @@ let stats cons = nb_ops_dom := !nb_ops_dom + con_ops; nb_watchs_dom := !nb_watchs_dom + con_watchs; ); - (List.length cons.anonymous, !nb_ops_anon, !nb_watchs_anon, + (Hashtbl.length cons.anonymous, !nb_ops_anon, !nb_watchs_anon, Hashtbl.length cons.domains, !nb_ops_dom, !nb_watchs_dom) let debug cons = - let anonymous = List.map Connection.debug cons.anonymous in + let anonymous = Hashtbl.fold (fun _ con accu -> Connection.debug con :: accu) cons.anonymous [] in let domains = Hashtbl.fold (fun _ con accu -> Connection.debug con :: accu) cons.domains [] in String.concat "" (domains @ anonymous) -- 2.1.4