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%%% Manager is a process that reads commands from a telnet-like
%%% socket, primarily to add mungers to the Registry under control of
%%% a test (though it could be more generally anything).
-module(manager).
-export([start/1,accept_loop/1,recv_loop/1]).
-import(gen_tcp, [listen/2, accept/1, recv/2, send/2]).
-import(string, [cspan/2, substr/3]).
start(Port) ->
{ok, LSock} = listen(Port, [{packet,line},
{active,false},{reuseaddr,true}]),
Pid = spawn(?MODULE, accept_loop, [LSock]),
ok = gen_tcp:controlling_process(LSock, Pid).
accept_loop(LSock) ->
{ok, Sock} = accept(LSock),
spawn(?MODULE, recv_loop, [Sock]),
accept_loop(LSock).
recv_loop(Sock) ->
case recv(Sock, 0) of
{ok, Msg} ->
%%
%% Take the input, strip off CRLF, slap on a dot so as to
%% make it nice for Erlang parser.
%%
ValidInput = lists:append(substr(Msg, 1, cspan(Msg, "\r\n")),
"."),
{ok,Tokens,_} = erl_scan:string(ValidInput),
{ok, Result} = erl_parse:parse_term(Tokens),
case Result of
{Path, shutdown} ->
%%
%% TODO: I think maybe instead of this, the path_mgr should be told
%% to do the actual socket closing. Then we wouldn't even need
%% the registry to know about the sockets at all.
%%
{ok, {_,_,PathSock,PathFwdSock,_}} = registry:lookup(Path),
gen_tcp:close(PathSock),
gen_tcp:close(PathFwdSock);
shutdown ->
send(Sock, "ok\r\n"),
halt(); % first try is rather crude
list ->
lists:foreach(fun ({Id,Path,_,_,_}) ->
{From,To} = Path,
send(Sock, integer_to_list(Id)),
send(Sock, " {"),
send(Sock, integer_to_list(From)),
send(Sock, ","),
send(Sock, integer_to_list(To)),
send(Sock, "}\r\n")
end, registry:all());
{Path, Command} ->
{ok, {_,_,_,_,Process}} = registry:lookup(Path),
path_mgr:update(Process, Path, Command);
Command ->
%%
%% Each half of a bidirectional path gets
%% registered to the same path_mgr process. So we
%% end up with duplicates if we just look at the list
%% of Pids.
%%
All = registry:all(),
AllPids = lists:map(fun (X) -> element(5, X) end, All),
DistinctPids = lists:usort(AllPids),
lists:foreach(fun (P) -> P ! {munger,Command} end,
DistinctPids)
end,
send(Sock, "ok\r\n"),
recv_loop(Sock);
{error,closed} ->
ok
end.
%%% {{from,to},shutdown} -> look up the sockets, and close them
%%%
|
