gen_server

shijiang1130

1. -module(otp).
   
2. -behaviour(gen_server).
   
3. -define(SERVER, ?MODULE).
   
4. -define(TABLE_ID,?MODULE).
   
5. 
   
6. %% ------------------------------------------------------------------
   
7. %% API Function Exports
   
8. %% ------------------------------------------------------------------
   
9. 
   
10. -export([start_link/0]).
    
11. 
    
12. %% ------------------------------------------------------------------
    
13. %% gen_server Function Exports
    
14. %% ------------------------------------------------------------------
    
15. 
    
16. -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
    
17.          terminate/2, code_change/3]).
    
18. 
    
19. %% ------------------------------------------------------------------
    
20. %% API Function Definitions
    
21. %% ------------------------------------------------------------------
    
22. 
    
23. start_link() ->
    
24.     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
    
25. 
    
26. %% ------------------------------------------------------------------
    
27. %% gen_server Function Definitions
    
28. %% ------------------------------------------------------------------
    
29. 
    
30. init(Args) ->
    
31.     process_flag(trap_exit,true),
    
32.     ets:new(?TABLE_ID,[public,duplicate_bag,named_table]),
    
33.     {ok, Args}.
    
34. 
    
35. handle_call(_Request, _From, State) ->
    
36.     {reply, ok, State}.
    
37. 
    
38. handle_cast(_Msg, State) ->
    
39.     io:format("cast"),
    
40.     Pid=spawn(fun()->os:cmd("ping -n 3 127.0.0.1") end),
    
41.     ets:insert(?TABLE_ID,{pid,Pid}),
    
42.     erlang:monitor(process,Pid),
    
43.     {noreply, State}.
    
44. 
    
45. handle_info(_Info, State) ->
    
46.     io:format("~p~n",[_Info]),
    
47.     {noreply, State}.
    
48. 
    
49. terminate(_Reason, _State) ->
    
50.     ok.
    
51. 
    
52. code_change(_OldVsn, State, _Extra) ->
    
53.     {ok, State}.
    
54. 
    
55. %% ------------------------------------------------------------------
    
56. %% Internal Function Definitions
    
57. %% ------------------------------------------------------------------
    

复制代码

shijiang1130

handle_info 会捕捉到

1. Pid=spawn(fun()->os:cmd("ping -n 3 127.0.0.1") end)

复制代码

的退出信息。

shijiang1130

这样就可以弄一个进程池了