--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/WWW_Find/scgi_server.ML Fri Nov 20 18:36:44 2009 +1100
@@ -0,0 +1,125 @@
+(* Title: scgi_echo.ML
+ Author: Timothy Bourke, NICTA
+
+Simple SCGI server.
+*)
+
+signature SCGI_SERVER =
+sig
+ val max_threads : int Unsynchronized.ref
+ type handler = ScgiReq.t * Word8Vector.vector * (string -> unit) -> unit
+ val register : (string * Mime.t option * handler) -> unit
+ val server : string -> int -> unit
+ val server' : int -> string -> int -> unit (* keeps trying for port *)
+end;
+
+structure ScgiServer : SCGI_SERVER =
+struct
+val max_threads = Unsynchronized.ref 5;
+
+type handler = ScgiReq.t * Word8Vector.vector * (string -> unit) -> unit;
+
+local
+val servers = Unsynchronized.ref (Symtab.empty : (Mime.t option * handler) Symtab.table);
+in
+fun register (name, mime, f) =
+ Unsynchronized.change servers (Symtab.update_new (name, (mime, f)));
+fun lookup name = Symtab.lookup (!servers) name;
+
+fun dump_handlers () = (
+ tracing(" with handlers:");
+ app (fn (x, _) => tracing (" - " ^ x)) (Symtab.dest (!servers)))
+end;
+
+fun server server_prefix port =
+ let
+ val passive_sock = SocketUtil.init_server_socket (SOME "localhost") port;
+
+ val thread_wait = ConditionVar.conditionVar ();
+ val thread_wait_mutex = Mutex.mutex ();
+
+ local
+ val threads = Unsynchronized.ref ([] : Thread.thread list);
+ fun purge () = Unsynchronized.change threads (filter Thread.isActive);
+ in
+ fun add_thread th = Unsynchronized.change threads (cons th);
+
+ fun launch_thread threadf =
+ (purge ();
+ if length (!threads) < (!max_threads) then ()
+ else (tracing ("Waiting for a free thread...");
+ ConditionVar.wait (thread_wait, thread_wait_mutex));
+ add_thread
+ (Thread.fork
+ (fn () => exception_trace threadf,
+ [Thread.EnableBroadcastInterrupt true,
+ Thread.InterruptState
+ Thread.InterruptAsynchOnce])))
+ end;
+
+ fun loop () =
+ let
+ val (sock, _)= Socket.accept passive_sock;
+
+ val (sin, sout) = SocketUtil.make_streams sock;
+
+ fun send msg = BinIO.output (sout, Byte.stringToBytes msg);
+ fun send_log msg = (tracing msg; send msg);
+
+ fun get_content (st, 0) = Word8Vector.fromList []
+ | get_content x = BinIO.inputN x;
+
+ fun do_req () =
+ let
+ val (req as ScgiReq.Req {path_info, request_method, ...},
+ content_is) =
+ ScgiReq.parse sin
+ handle ScgiReq.InvalidReq s =>
+ (send
+ (HttpUtil.reply_header (HttpStatus.bad_request, NONE, []));
+ raise Fail ("Invalid request: " ^ s));
+ val () = tracing ("request: " ^ path_info);
+ in
+ (case lookup (unprefix server_prefix path_info) of
+ NONE => send (HttpUtil.reply_header (HttpStatus.not_found, NONE, []))
+ | SOME (NONE, f) => f (req, get_content content_is, send)
+ | SOME (t, f) =>
+ (send (HttpUtil.reply_header (HttpStatus.ok, t, []));
+ if request_method = ScgiReq.Head then ()
+ else f (req, get_content content_is, send)))
+ end;
+
+ fun thread_req () =
+ (do_req () handle e => (warning (exnMessage e));
+ BinIO.closeOut sout handle e => warning (exnMessage e);
+ BinIO.closeIn sin handle e => warning (exnMessage e);
+ Socket.close sock handle e => warning (exnMessage e);
+ tracing ("request done.");
+ ConditionVar.signal thread_wait);
+ in
+ launch_thread thread_req;
+ loop ()
+ end;
+ in
+ tracing ("SCGI server started.");
+ dump_handlers ();
+ loop ();
+ Socket.close passive_sock
+ end;
+
+local
+val delay = 5;
+in
+fun server' 0 server_prefix port = (warning "Giving up."; exit 1)
+ | server' countdown server_prefix port =
+ server server_prefix port
+ handle OS.SysErr ("bind failed", _) =>
+ (warning ("Could not acquire port "
+ ^ Int.toString port ^ ". Trying again in "
+ ^ Int.toString delay ^ " seconds...");
+ OS.Process.sleep (Time.fromSeconds delay);
+ server' (countdown - 1) server_prefix port);
+end;
+
+end;
+