我有一个接收websocket连接的ws_handler。
此过程等待以<<"h
开始登录的输入。
然后保存默认的Websocket状态,一个Player进程ID(通过对当前PID的引用产生),以及一个发件箱消息,`&lt;&lt;&lt;&lt;&lt;&lt;&#&gt;&lt;&lt;&lt;&lt;&lt;&#&gt;&gt;&#34;&gt;&gt;&gt;
websocket_handle({text, <<"h", Name/binary>>}, State) ->
{ok, PID} = player:go(self(), <<"profiledata", Name/binary>>),
erlang:start_timer(1000, self(), <<"Hello!">>),
{reply, {text, <<"You joined, ", Name/binary>>}, {State, PID, <<"turn1">>}};
我想控制来自这个单独的播放器进程的数据流,然后让我的websocket处理程序检索消息并通过Outbox
元素将它们传递给它的客户端。
所以我将其添加到手动触发消息:
websocket_handle({text, <<"myscreen">>}, S = {_, P, _}) ->
gen_server:call(P, myscreen),
{ok, S};
并在player.erl中,
handle_call(myscreen, _, {WS, Profile, Cab}) ->
gen_server:cast(WS, myscreenupdate),
{reply, ok, {WS, Profile, Cab}};
回到ws_handler我希望这个被调用:
websocket_info(myscreenupdate, State = {St,P, _}) ->
{reply, {text, <<"My screen update">>}, {St, P, <<"turn2">>}};
但浏览器中的websocket输出会连续打印turn1
,而不是turn2
。
我在gen_server:call
中尝试了player.erl
,我发现了超时崩溃。我认为这是因为{reply
中websocket_handle
的{{1}}元组应该回复websocket ..但如果这是真的,那么我期待数据到更新:
ws_handler
所以我不确定这里发生了什么。
如何从Player进程更新状态,然后让我的websocket处理程序检索该状态并将其发送到其连接?
websocket_info(myscreenupdate, State = {St,P, _}) ->
{reply, {text, <<"My screen update">>}, {St, P, <<"turn2">>}};
player.erl:
ws_handler.erl:
-module(ws_handler).
-export([init/2]).
-export([websocket_init/1]).
-export([websocket_handle/2]).
-export([websocket_info/2]).
init(Req, Opts) ->
{cowboy_websocket, Req, Opts}.
websocket_init(State) ->
{ok, State}.
websocket_handle({text, <<"h", Name/binary>>}, State) ->
{ok, PID} = player:go(self(), <<"profiledata", Name/binary>>),
erlang:start_timer(1000, self(), <<"Hello!">>),
{reply, {text, <<"You joined, ", Name/binary>>}, {State, PID, <<"turn1">>}};
websocket_handle({text, <<"myscreen">>}, S = {_, P, _}) ->
gen_server:call(P, myscreen),
{ok, S};
websocket_handle({text, <<"auth", Auth/binary>>}, S = {_St, P, _}) ->
case s:s(P, Auth) of
{ok, Valid} -> {reply, {text, << "Authorized">>}, S};
_ -> {reply, {text, <<"Error">>}, S}
end;
websocket_handle({text, Msg}, S = {_St, P, Outbox}) ->
{reply, {text, Outbox}, S};
websocket_handle(_Data, State) ->
{ok, State}.
websocket_info(myscreenupdate, State = {St,P, _}) ->
{reply, {text, <<"My screen update">>}, {St, P, <<"turn2">>}};
websocket_info({timeout, _Ref, _Ignored}, State = {_, P, Outbox}) ->
erlang:start_timer(1000, self(), <<"This is ignored">>),
Msg = Outbox,
{reply, {text, Msg}, State};
websocket_info(_Info, State) ->
{ok, State}.
答案 0 :(得分:1)
问题是牛仔的websocket_info/2
处理程序只会通过使用erlang内置消息运算符!
(或等效地,erlang:send/{2,3}
函数)接收发送到websocket进程的消息
所以你应该这样做:
WS ! myscreenupdate
而不是
gen_server:cast(WS, myscreenupdate)
当您使用gen_server:cast
时,牛仔消息循环可能会丢弃该消息,因为它不是可识别的消息。当你使用gen_server:call
时,你会陷入僵局。