gen_server:enter_loop

shijiang1130

enter_loop(Module, Options, State)
enter_loop(Module, Options, State, ServerName)
enter_loop(Module, Options, State, Timeout)
enter_loop(Module, Options, State, ServerName, Timeout)

Types:

Module = atom()
Options = [Option]
Option = {debug,Dbgs}
  Dbgs = [Dbg]
   Dbg = trace | log | statistics
    | {log_to_file,FileName} | {install,{Func,FuncState}}
State = term()
ServerName = {local,Name} | {global,GlobalName} | {via,Module,ViaName}
Name = atom()
GlobalName = ViaName = term()
Timeout = int() | infinity
Makes an existing process into a gen_server. Does not return, instead the calling process will enter the gen_server receive loop and become a gen_server process. The process must have been started using one of the start functions in proc_lib, see proc_lib(3). The user is responsible for any initialization of the process, including registering a name for it.

This function is useful when a more complex initialization procedure is needed than the gen_server behaviour provides.

Module, Options and ServerName have the same meanings as when calling gen_server:start[_link]/3,4. However, if ServerName is specified, the process must have been registered accordingly before this function is called.

State and Timeout have the same meanings as in the return value of Module:init/1. Also, the callback module Module does not need to export an init/1 function.

Failure: If the calling process was not started by a proc_lib start function, or if it is not registered according to ServerName.

shijiang1130

没看懂

shijiang1130

1. enter_loop(Mod, Options, State) ->
   
2.     enter_loop(Mod, Options, State, self(), infinity).
   
3. 
   
4. enter_loop(Mod, Options, State, ServerName = {Scope, _})
   
5.   when Scope == local; Scope == global ->
   
6.     enter_loop(Mod, Options, State, ServerName, infinity);
   
7. 
   
8. enter_loop(Mod, Options, State, ServerName = {via, _, _}) ->
   
9.     enter_loop(Mod, Options, State, ServerName, infinity);
   
10. 
    
11. enter_loop(Mod, Options, State, Timeout) ->
    
12.     enter_loop(Mod, Options, State, self(), Timeout).
    
13. 
    
14. enter_loop(Mod, Options, State, ServerName, Timeout) ->
    
15.     Name = get_proc_name(ServerName),
    
16.     Parent = get_parent(),
    
17.     Debug = debug_options(Name, Options),
    
18.     loop(Parent, Name, State, Mod, Timeout, Debug).
    

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shijiang1130

1. %%% ---------------------------------------------------
   
2. %%% Initiate the new process.
   
3. %%% Register the name using the Rfunc function
   
4. %%% Calls the Mod:init/Args function.
   
5. %%% Finally an acknowledge is sent to Parent and the main
   
6. %%% loop is entered.
   
7. %%% ---------------------------------------------------
   
8. init_it(Starter, self, Name, Mod, Args, Options) ->
   
9.     init_it(Starter, self(), Name, Mod, Args, Options);
   
10. init_it(Starter, Parent, Name0, Mod, Args, Options) ->
    
11.     Name = name(Name0),
    
12.     Debug = debug_options(Name, Options),
    
13.     case catch Mod:init(Args) of
    
14.         {ok, State} ->
    
15.             proc_lib:init_ack(Starter, {ok, self()}),             
    
16.             loop(Parent, Name, State, Mod, infinity, Debug);
    
17.         {ok, State, Timeout} ->
    
18.             proc_lib:init_ack(Starter, {ok, self()}),             
    
19.             loop(Parent, Name, State, Mod, Timeout, Debug);
    
20.         {stop, Reason} ->
    
21.             %% For consistency, we must make sure that the
    
22.             %% registered name (if any) is unregistered before
    
23.             %% the parent process is notified about the failure.
    
24.             %% (Otherwise, the parent process could get
    
25.             %% an 'already_started' error if it immediately
    
26.             %% tried starting the process again.)
    
27.             unregister_name(Name0),
    
28.             proc_lib:init_ack(Starter, {error, Reason}),
    
29.             exit(Reason);
    
30.         ignore ->
    
31.             unregister_name(Name0),
    
32.             proc_lib:init_ack(Starter, ignore),
    
33.             exit(normal);
    
34.         {'EXIT', Reason} ->
    
35.             unregister_name(Name0),
    
36.             proc_lib:init_ack(Starter, {error, Reason}),
    
37.             exit(Reason);
    
38.         Else ->
    
39.             Error = {bad_return_value, Else},
    
40.             proc_lib:init_ack(Starter, {error, Error}),
    
41.             exit(Error)
    
42.     end.

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shijiang1130

啊，是这么来的

arserangel

最近没有人在这里发帖子了。。。