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erlang学习：用OTP构建系统3，应用程序服务器

article 2024/9/25 5:34:01

按照书上搭建两个服务器，一个是质数服务器，一个是面积服务器

今天先按照书上的将这两个服务器的代码编写好，为后面监控树的学习做准备
质数服务器代码

-module(prime_server).
-behaviour(gen_server).
 
-export([new_prime/1, start_link/0]).
-export([init/1,handle_call/3,handle_cast/2,handle_info/2,terminate/2,code_change/3]).
 
start_link() ->
  gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
new_prime(N) ->
  gen_server:call(?MODULE, {prime, N}, 20000).
 
init([]) ->
  process_flag(trap_exit, true),
  io:format("~p starting~n", [?MODULE]),
  {ok, 0}.
 
handle_call({prime, K}, _From, N) ->
  {reply, make_new_prime(K), N + 1}.
 
handle_cast(_Msg, N) ->
  {noreply, N}.
 
handle_info(_Info, N) ->
  {noreply, N}.
 
terminate(_Reason, _N) ->
  io:format("~p stopping~n", [?MODULE]),
  ok.
 
code_change(_OldVsn, N, _Extra) ->
  {ok, N}.
 
make_new_prime(K) ->
  if
    K > 100 ->
      alarm_handler:set_alarm(tooHot),
      N = lib_primes:make_prime(K),
      alarm_handler:clear_alarm(tooHot),
      N;
    true ->
      lib_primes:make_prime(K)
  end.

面积服务器代码


-module(area_server).
-behaviour(gen_server).
 
-export([area/1, start_link/0]).
 
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
start_link() ->
  gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
area(Thing) ->
  gen_server:call(?MODULE, {area, Thing}).
 
init([]) ->
  process_flag(trap_exit, true),
  io:format("~p starting~n", [?MODULE]),
  {ok, 0}.
 
handle_call({area, Thing}, _From, N) ->
  {reply, compute_area(Thing), N + 1}.
 
handle_cast(_Msg, N) ->
  {noreply, N}.
 
handle_info(_Info, N) ->
  {noreply, N}.
 
terminate(_Reason, _N) ->
  io:format("~p stopping~n", [?MODULE]),
  ok.
 
code_change(_OldVsn, N, _Extra) -> {ok, N}.
 
compute_area({square, X}) ->
  X * X;
compute_area({rectongle, X, Y}) ->
  X * Y.