Erlang注册进程名称-tut16.erl

作 w3cschool erlang 的练习

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-module(tut16).

-export([start/0, ping/1, pong/0]).

%% Erlang 注册进程名称

%% ping 进程必须通过某种途径 获得 pong 进程的进程标识符后 
%% 才能将消息发送给 pong 进程

%% Erlang 提供了 为每个进程提供一个名称绑定的机制, 
%% 这样进程间通信就可以通过进程名来实现, 而不需要知道进程的进程标识符了.
%% 为每个进程注册一个名称需要用到内置函数 register :
%%     register(some_atom, Pid)

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

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

start() ->
    register(pong, spawn(tut16, pong, [])),
    spawn(tut16, ping, [3]).

 

 

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