Merge branch 'sc/sctp-connect-nowait' into ccase/r13b04_dev

* sc/sctp-connect-nowait:
  Implement a non-blocking SCTP connect

OTP-8414  There are new gen_sctp:connect_init/* functions that initiate an
          SCTP connection without blocking for the result. The result is
          delivered asynchronously as an sctp_assoc_change event. (Thanks
          to Simon Cornish.)

2 files changed, 53 insertions, 23 deletions

diff --git a/lib/kernel/src/gen_sctp.erl b/lib/kernel/src/gen_sctp.erl
index fcd1d1564a..5a31e3976f 100644
--- a/lib/kernel/src/gen_sctp.erl
+++ b/lib/kernel/src/gen_sctp.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 2007-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 2007-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 
@@ -27,7 +27,7 @@
 -include("inet_sctp.hrl").
 
 -export([open/0,open/1,open/2,close/1]).
--export([listen/2,connect/4,connect/5]).
+-export([listen/2,connect/4,connect/5,connect_init/4,connect_init/5]).
 -export([eof/2,abort/2]).
 -export([send/3,send/4,recv/1,recv/2]).
 -export([error_string/1]).
@@ -80,7 +80,26 @@ listen(S, Flag) ->
 connect(S, Addr, Port, Opts) ->
     connect(S, Addr, Port, Opts, infinity).
 
-connect(S, Addr, Port, Opts, Timeout) when is_port(S), is_list(Opts) ->
+connect(S, Addr, Port, Opts, Timeout) ->
+    case do_connect(S, Addr, Port, Opts, Timeout, true) of
+	badarg ->
+	    erlang:error(badarg, [S,Addr,Port,Opts,Timeout]);
+	Result ->
+	    Result
+    end.
+
+connect_init(S, Addr, Port, Opts) ->
+    connect_init(S, Addr, Port, Opts, infinity).
+
+connect_init(S, Addr, Port, Opts, Timeout) ->
+    case do_connect(S, Addr, Port, Opts, Timeout, false) of
+	badarg ->
+	    erlang:error(badarg, [S,Addr,Port,Opts,Timeout]);
+	Result ->
+	    Result
+    end.
+
+do_connect(S, Addr, Port, Opts, Timeout, ConnWait) when is_port(S), is_list(Opts) ->
     case inet_db:lookup_socket(S) of
 	{ok,Mod} ->
 	    case Mod:getserv(Port) of
@@ -89,21 +108,26 @@ connect(S, Addr, Port, Opts, Timeout) when is_port(S), is_list(Opts) ->
 			Timer ->
 			    try Mod:getaddr(Addr, Timer) of
 				{ok,IP} ->
-				    Mod:connect(S, IP, Port, Opts, Timer);
+				    ConnectTimer = if ConnWait == false ->
+							   nowait;
+						      true ->
+							   Timer
+						   end,
+				    Mod:connect(S, IP, Port, Opts, ConnectTimer);
 				Error -> Error
 			    after
 				inet:stop_timer(Timer)
 			    end
 		    catch
 			error:badarg ->
-			    erlang:error(badarg, [S,Addr,Port,Opts,Timeout])
+			    badarg
 		    end;
 		Error -> Error
 	    end;
 	Error -> Error
     end;
-connect(S, Addr, Port, Opts, Timeout) ->
-    erlang:error(badarg, [S,Addr,Port,Opts,Timeout]).
+do_connect(_S, _Addr, _Port, _Opts, _Timeout, _ConnWait) ->
+    badarg.
 
 
 
diff --git a/lib/kernel/src/inet_sctp.erl b/lib/kernel/src/inet_sctp.erl
index 30c0e85dd9..795bf83807 100644
--- a/lib/kernel/src/inet_sctp.erl
+++ b/lib/kernel/src/inet_sctp.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 2007-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 2007-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 %% SCTP protocol contribution by Leonid Timochouk and Serge Aleynikov.
@@ -64,16 +64,22 @@ close(S) ->
 listen(S, Flag) ->
     prim_inet:listen(S, Flag).
 
+%% A non-blocking connect is implemented when the initial call is to
+%% gen_sctp:connect_init which passes the value nowait as the Timer
 connect(S, Addr, Port, Opts, Timer) ->
     case prim_inet:chgopts(S, Opts) of
 	ok ->
 	    case prim_inet:getopt(S, active) of
 		{ok,Active} ->
-		    Timeout = inet:timeout(Timer),
+		    Timeout = if Timer =:= nowait ->
+				      infinity;		%% don't start driver timer in inet_drv
+				 true ->
+				      inet:timeout(Timer)
+			      end,
 		    case prim_inet:connect(S, Addr, Port, Timeout) of
-			ok ->
+			ok when Timer =/= nowait ->
 			    connect_get_assoc(S, Addr, Port, Active, Timer);
-			Err1 -> Err1
+			OkOrErr1 -> OkOrErr1
 		    end;
 		Err2 -> Err2
 	    end;
@@ -89,10 +95,10 @@ connect(S, Addr, Port, Opts, Timer) ->
 %% connect_get_assoc/5 below mistakes it for an invalid response
 %% for a socket in {active,false} or {active,once} modes.
 %%
-%% In {active,true} mode it probably gets right, but it is
-%% a blocking connect that is implemented even for {active,true},
-%% and that may be a shortcoming. A non-blocking connect
-%% would be nice to have.
+%% In {active,true} mode the window of time for the race is smaller,
+%% but it is possible and also it is a blocking connect that is
+%% implemented even for {active,true}, and that may be a
+%% shortcoming.
 
 connect_get_assoc(S, Addr, Port, false, Timer) ->
     case recv(S, inet:timeout(Timer)) of