rabbitmq erlang 源代码读 三 core process启动 gen_server
fromhttp://blog.chinaunix.net/u3/103972/showart.php?id=2130456这里格式较好
我原来的博客zdx3578.cublog.cn
看erlang自己的源代码proc_lib.erl
proc_info(Pid,Item)whennode(Pid)=:=node()->
process_info(Pid,Item);
proc_info(Pid,Item)->
caselists:member(node(Pid),nodes())of
true->
check(rpc:call(node(Pid),erlang,process_info,[Pid,Item]));
_->
hidden
end.
erlang把底层远程调用都隐藏了，这就是“显意编程”（intentionalprogramming）吧http://erlang-china.org/uploads/2007/09/joes-thesis.zip的4.5
gen_server.erl源代码看看
gen_server.erl%%从粗体看下去再从斜体看上来
start(Mod,Args,Options)->
gen:start(?MODULE,nolink,Mod,Args,Options).
start_link(Mod,Args,Options)->
gen:start(?MODULE,link,Mod,Args,Options).
gen.erl
start(GenMod,LinkP,Mod,Args,Options)->
do_spawn(GenMod,LinkP,Mod,Args,Options).
do_spawn(GenMod,_,Mod,Args,Options)->
Time=timeout(Options),
proc_lib:start(?MODULE,init_it,[GenMod,self(),self,Mod,Args,Options],Time,spawn_opts(Options)).%%MFA
proc_lib.erl
-specstart(atom(),atom(),[term()],timeout(),[spawn_option()])->term().
start(M,F,A,Timeout,SpawnOpts)whenis_atom(M),is_atom(F),is_list(A)->
Pid=?MODULE:spawn_opt(M,F,A,SpawnOpts),
sync_wait(Pid,Timeout).
spawn_opt(M,F,A,Opts)whenis_atom(M),is_atom(F),is_list(A)->
Parent=get_my_name(),
Ancestors=get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(?MODULE,init_p,[Parent,Ancestors,M,F,A],Opts).
-specinit_p(pid(),[pid()],atom(),atom(),[term()])->term().
init_p(Parent,Ancestors,M,F,A)whenis_atom(M),is_atom(F),is_list(A)->
put('$ancestors',[Parent|Ancestors]),
put('$initial_call',trans_init(M,F,A)),
init_p_do_apply(M,F,A).
init_p_do_apply(M,F,A)->
try
apply(M,F,A)
catch
Class:Reason->
exit_p(Class,Reason)
end.
gen.erl的如下语句
proc_lib:start(?MODULE,init_it,[GenMod,self(),self,Mod,Args,Options],Time,spawn_opts(Options)).%%MFA就执行gen.erl的init_it
init_it(GenMod,Starter,Parent,Mod,Args,Options)->%%FA
init_it2(GenMod,Starter,Parent,self(),Mod,Args,Options).
init_it2(GenMod,Starter,Parent,Name,Mod,Args,Options)->
GenMod:init_it(Starter,Parent,Name,Mod,Args,Options).%%AGenMod就是gen_server，执行gen_server的init
gen_server.erl
init_it(Starter,self,Name,Mod,Args,Options)->
init_it(Starter,self(),Name,Mod,Args,Options);
init_it(Starter,Parent,Name0,Mod,Args,Options)->
Name=name(Name0),
Debug=debug_options(Name,Options),
casecatchMod:init(Args)of%%gen_server在调用Mod模块的init
{ok,State}->
proc_lib:init_ack(Starter,{ok,self()}),
loop(Parent,Name,State,Mod,infinity,Debug);%%开始循环
{ok,State,Timeout}->
proc_lib:init_ack(Starter,{ok,self()}),
loop(Parent,Name,State,Mod,Timeout,Debug);
。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。
end.
%%%TheMAINloop.
%%%---------------------------------------------------
loop(Parent,Name,State,Mod,hibernate,Debug)->
proc_lib:hibernate(?MODULE,wake_hib,[Parent,Name,State,Mod,Debug]);
loop(Parent,Name,State,Mod,Time,Debug)->
Msg=receive
Input->
Input
afterTime->
timeout
end,
decode_msg(Msg,Parent,Name,State,Mod,Time,Debug,false).
decode_msg(Msg,Parent,Name,State,Mod,Time,Debug,Hib)->
caseMsgof
{system,From,Req}->
sys:handle_system_msg(Req,From,Parent,?MODULE,Debug,
[Name,State,Mod,Time],Hib);
{'EXIT',Parent,Reason}->
terminate(Reason,Name,Msg,Mod,State,Debug);
_MsgwhenDebug=:=[]->
handle_msg(Msg,Parent,Name,State,Mod);
_Msg->
Debug1=sys:handle_debug(Debug,{?MODULE,print_event},
Name,{in,Msg}),
handle_msg(Msg,Parent,Name,State,Mod,Debug1)
end.
%%%Messagehandlingfunctions
%%%---------------------------------------------------
dispatch({'$gen_cast',Msg},Mod,State)->
Mod:handle_cast(Msg,State);
dispatch(Info,Mod,State)->
Mod:handle_info(Info,State).
handle_msg({'$gen_call',From,Msg},Parent,Name,State,Mod)->
casecatchMod:handle_call(Msg,From,State)of%%回调handle_call
{reply,Reply,NState}->
reply(From,Reply),
loop(Parent,Name,NState,Mod,infinity,[]);%%继续循环
{reply,Reply,NState,Time1}->
reply(From,Reply),
loop(Parent,Name,NState,Mod,Time1,[]);
{noreply,NState}->
loop(Parent,Name,NState,Mod,infinity,[]);
{noreply,NState,Time1}->
loop(Parent,Name,NState,Mod,Time1,[]);
{stop,Reason,Reply,NState}->
{'EXIT',R}=
(catchterminate(Reason,Name,Msg,Mod,NState,[])),
reply(From,Reply),
exit(R);
Other->handle_common_reply(Other,Parent,Name,Msg,Mod,State)
end;
handle_msg(Msg,Parent,Name,State,Mod)->
Reply=(catchdispatch(Msg,Mod,State)),
handle_common_reply(Reply,Parent,Name,Msg,Mod,State).
——————————————————————————————————————————————————————————————
rabbit.erl
start(normal,[])->
{ok,SupPid}=rabbit_sup:start_link(),
rabbit_sup.erl
-define(SERVER,?MODULE).
start_link()->
supervisor:start_link({local,?SERVER},?MODULE,[]).%%注册supervisorname{local,rabbit_sup}
init([])->
{ok,{{one_for_one,10,10},[]}}.
rabbit.erl
{"coreprocesses",
fun()->
ok=start_child(rabbit_log),
ok=rabbit_hooks:start(),
ok=rabbit_binary_generator:
check_empty_content_body_frame_size(),
{ok,MemoryAlarms}=application:get_env(memory_alarms),
ok=rabbit_alarm:start(MemoryAlarms),
ok=rabbit_amqqueue:start(),
ok=start_child(rabbit_router),
ok=start_child(rabbit_node_monitor)
end},
start_child(Mod)->
{ok,_}=supervisor:start_child(rabbit_sup,%%这个名的注册就是在start/2启动时的rabbit_sup:start_link()启动的
{Mod,{Mod,start_link,[]},
transient,100,worker,[Mod]}),
ok.
supervisor.erl:
-behaviour(gen_server).
start_child(Supervisor,ChildSpec)->
call(Supervisor,{start_child,ChildSpec}).
call(Supervisor,Req)->
gen_server:call(Supervisor,Req,infinity).
gen_server.erl
call(Name,Request,Timeout)->
casecatchgen:call(Name,'$gen_call',Request,Timeout)of
{ok,Res}->
Res;
{'EXIT',Reason}->
exit({Reason,{?MODULE,call,[Name,Request,Timeout]}})
end.
gen.erl
call(Pid,Label,Request,Timeout)
whenis_pid(Pid),Timeout=:=infinity;
is_pid(Pid),is_integer(Timeout),Timeout>=0->
do_call(Pid,Label,Request,Timeout);
do_call(Process,Label,Request,Timeout)->
Node=caseProcessof
{_S,N}whenis_atom(N)->
N;
_whenis_pid(Process)->
node(Process)
end,
tryerlang:monitor(process,Process)of
Mref->
catcherlang:send(Process,{Label,{self(),Mref},Request},
[noconnect]),
wait_resp_mon(Node,Mref,Timeout)
catch
error:_->
monitor_node(Node,true),
receive
{nodedown,Node}->
monitor_node(Node,false),
exit({nodedown,Node})
after0->
Tag=make_ref(),
Process!{Label,{self(),Tag},Request},
wait_resp(Node,Tag,Timeout)
end
end.
wait_resp_mon(Node,Mref,Timeout)->
..............
wait_resp(Node,Tag,Timeout)->
..............
gen_server.erl
dispatch({'$gen_cast',Msg},Mod,State)->
Mod:handle_cast(Msg,State);
dispatch(Info,Mod,State)->
Mod:handle_info(Info,State).
handle_msg({'$gen_call',From,Msg},Parent,Name,State,Mod)->
casecatchMod:handle_call(Msg,From,State)of
{reply,Reply,NState}->
reply(From,Reply),
loop(Parent,Name,NState,Mod,infinity,[]);
{reply,Reply,NState,Time1}->
reply(From,Reply),
loop(Parent,Name,NState,Mod,Time1,[]);
{noreply,NState}->
loop(Parent,Name,NState,Mod,infinity,[]);
{noreply,NState,Time1}->
loop(Parent,Name,NState,Mod,Time1,[]);
{stop,Reason,Reply,NState}->
{'EXIT',R}=
(catchterminate(Reason,Name,Msg,Mod,NState,[])),
reply(From,Reply),
exit(R);
Other->handle_common_reply(Other,Parent,Name,Msg,Mod,State)
end;
handle_msg(Msg,Parent,Name,State,Mod)->
Reply=(catchdispatch(Msg,Mod,State)),
handle_common_reply(Reply,Parent,Name,Msg,Mod,State).
handle_common_reply(Reply,Parent,Name,Msg,Mod,State)->
caseReplyof
{noreply,NState}->
loop(Parent,Name,NState,Mod,infinity,[]);
{noreply,NState,Time1}->
loop(Parent,Name,NState,Mod,Time1,[]);
{stop,Reason,NState}->
terminate(Reason,Name,Msg,Mod,NState,[]);
{'EXIT',What}->
terminate(What,Name,Msg,Mod,State,[]);
_->
terminate({bad_return_value,Reply},Name,Msg,Mod,State,[])
end.
supervisor.erl:
handle_call({start_child,ChildSpec},_From,State)->
casecheck_childspec(ChildSpec)of
{ok,Child}->
{Resp,NState}=handle_start_child(Child,State),
{reply,Resp,NState};
What->
{reply,{error,What},State}
end;