1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
%% The contents of this file are subject to the Mozilla Public License
%% Version 1.1 (the "License"); you may not use this file except in
%% compliance with the License. You may obtain a copy of the License
%% at http://www.mozilla.org/MPL/
%%
%% 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.
%%
%% The Original Code is RabbitMQ.
%%
%% The Initial Developer of the Original Code is VMware, Inc.
%% Copyright (c) 2007-2011 VMware, Inc. All rights reserved.
%%
-module(tcp_acceptor).
-behaviour(gen_server).
-export([start_link/2]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-record(state, {callback, sock, ref}).
%%--------------------------------------------------------------------
start_link(Callback, LSock) ->
gen_server:start_link(?MODULE, {Callback, LSock}, []).
%%--------------------------------------------------------------------
init({Callback, LSock}) ->
gen_server:cast(self(), accept),
{ok, #state{callback=Callback, sock=LSock}}.
handle_call(_Request, _From, State) ->
{noreply, State}.
handle_cast(accept, State) ->
ok = file_handle_cache:obtain(),
accept(State);
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({inet_async, LSock, Ref, {ok, Sock}},
State = #state{callback={M,F,A}, sock=LSock, ref=Ref}) ->
%% patch up the socket so it looks like one we got from
%% gen_tcp:accept/1
{ok, Mod} = inet_db:lookup_socket(LSock),
inet_db:register_socket(Sock, Mod),
try
%% report
{Address, Port} = inet_op(fun () -> inet:sockname(LSock) end),
{PeerAddress, PeerPort} = inet_op(fun () -> inet:peername(Sock) end),
error_logger:info_msg("accepted TCP connection on ~s:~p from ~s:~p~n",
[rabbit_misc:ntoab(Address), Port,
rabbit_misc:ntoab(PeerAddress), PeerPort]),
%% In the event that somebody floods us with connections we can spew
%% the above message at error_logger faster than it can keep up.
%% So error_logger's mailbox grows unbounded until we eat all the
%% memory available and crash. So here's a meaningless synchronous call
%% to the underlying gen_event mechanism - when it returns the mailbox
%% is drained.
gen_event:which_handlers(error_logger),
%% handle
file_handle_cache:transfer(apply(M, F, A ++ [Sock])),
ok = file_handle_cache:obtain()
catch {inet_error, Reason} ->
gen_tcp:close(Sock),
error_logger:error_msg("unable to accept TCP connection: ~p~n",
[Reason])
end,
%% accept more
accept(State);
handle_info({inet_async, LSock, Ref, {error, closed}},
State=#state{sock=LSock, ref=Ref}) ->
%% It would be wrong to attempt to restart the acceptor when we
%% know this will fail.
{stop, normal, State};
handle_info({inet_async, LSock, Ref, {error, Reason}},
State=#state{sock=LSock, ref=Ref}) ->
{Address, Port} = inet_op(fun () -> inet:sockname(LSock) end),
error_logger:error_msg("failed to accept TCP connection on ~s:~p: ~p~n",
[rabbit_misc:ntoab(Address), Port, Reason]),
accept(State);
handle_info(_Info, State) ->
{noreply, State}.
terminate(_Reason, _State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%--------------------------------------------------------------------
inet_op(F) -> rabbit_misc:throw_on_error(inet_error, F).
accept(State = #state{sock=LSock}) ->
case prim_inet:async_accept(LSock, -1) of
{ok, Ref} -> {noreply, State#state{ref=Ref}};
Error -> {stop, {cannot_accept, Error}, State}
end.
|
