startTrains() ->
TotalDist = 100,
Trains = [trainA,trainB ],
PID = spawn(fun() ->
train(1,length(Trains)) end),
[ PID ! {self(),TrainData,TotalDist} || TrainData <- Trains],
receive
{_From, Mesg} ->
error_logger:info_msg("~n Mesg ~p ~n",[Mesg])
after 10500 ->
refresh
end.
所以,我创建了两个名为trainA、trainB的进程。我想将这些进程增加 5,直到达到 100。我做了不同的进程,使每个火车(进程)并行增加其位置。但我很惊讶地按顺序获得输出,即进程 trainA 结束,然后进程 trainB 开始。但我想同时增加自己。 我想运行这样的进程
trainA 10 trainB 0
trainA 15 trainB 5
....
trainA 100 trainB 100
但我越来越
trainA 0
....
trainA 90
trainA 95
trainA 100
trainA ends
trainB 0
trainB 5
trainB 10
.....
trainB 100
如何让进程并行/同时运行?希望你能收到我的问题。请帮助我。
您仅生成一个由函数
train/2
初始化的进程。您提供的代码不完整,所以我只能猜测,但我认为您的代码是错误的,因为您只有一个火车流程。寻找灵感:
-module(trains).
-export([startTrains/0]).
startTrains() ->
TotalDist = 100,
Names = [trainA,trainB ],
Self = self(),
Trains = [spawn_link(fun() ->
train(Name, Self) end) || Name <- Names],
[ Train ! {start, Self, 0, TotalDist} || Train <- Trains],
ok = collectResults(Names).
collectResults([]) -> ok;
collectResults(Trains) ->
receive
{stop, Name, Pos, Length} ->
io:format("~p stops at ~p (~p)~n", [Name, Pos, Length]),
collectResults(Trains -- [Name]);
Msg ->
io:format("Supervisor received unexpected message ~p~n", [Msg]),
collectResults(Trains)
after 10500 -> timeout
end.
train(Name, Sup) ->
receive
{start, Sup, Pos, Length} -> run_train(Name, Sup, Pos, Length);
Msg ->
io:format("~p received unexpected message ~p~n", [Name, Msg]),
train(Name, Sup)
end.
run_train(Name, Sup, Pos, Length)
when Pos < Length ->
receive after 500 ->
NewPos = Pos + 5,
io:format("~p ~p~n", [Name, Pos]),
run_train(Name, Sup, NewPos, Length)
end;
run_train(Name, Sup, Pos, Length) ->
Sup ! {stop, Name, Pos, Length}.
但是如果我认真思考的话,我应该考虑
gen_fsm
和OTP原则。但在你当前的阶段,继续使用 erlang 原语,以获得更好的感觉。