Erlang消息传递-tut15.erl

作 w3cschool erlang 的练习

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-module(tut15).

-export([start/0, ping/2, pong/0]).

%% Erlang 消息传递
%% Erlang 进程之间的消息可以是任何简单的 Erlang 项. 比如说, 可以是列表、元组、整数、原子、进程标识等等
%% recevie 关键字的语法: 请注意, 在 end 前的最后一个 actions 并没有 ";"
%%     receive
%%         pattern1 ->
%%             actions1;
%%         pattern2 ->
%%             actions2;
%%         ...
%%         patternN ->
%%             actionsN
%%     end.

ping(0, Pong_PID) ->
    Pong_PID ! finished,
    io:format("ping finished~n", []);
ping(N, Pong_PID) ->
    Pong_PID ! {ping, self()},
    receive
        pong ->
            io:format("Ping received pong~n", [])
    end,
    ping(N - 1, Pong_PID).


pong() ->
    receive
        finished ->
            io:format("Pong finished~n", []);
        {ping, Ping_PID} ->
            io:format("Pong received ping~n", []),
            Ping_PID ! pong,
            pong()
    end.


start() ->
    Pong_PID = spawn(tut15, pong, []),
    spawn(tut15, ping, [3, Pong_PID]).

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