我试图理解以下错误:
4> c(sv).
{ok,sv}
5> B=sv:start().
<0.93.0>
6> =ERROR REPORT==== 14-Jul-2020::21:44:13.256000 ===
Error in process <0.93.0> with exit value:
{undef,[{common,createProcess,
[{monitor,monitor,
{monstate,undefined,undefined,undefined,true,
undefined,false}}],
[]},
{sv,server,1,[{file,"sv.erl"},{line,14}]}]}
我有一个sv
模块,它从模块实例化一个进程monitor
,然后从模块实例化一个进程worker
。实例化通过调用common
模块进行。两者都sv
使用monitor
模块中定义的记录.hrl
。
sv.erl -> monitor.erl -> worker.erl
| |
common.erl
records.hrl
common.erl
%%% common functionality module
-module(common).
-export([createProcess/1]).
-import(worker,[worker/1]).
-import(monitor,[monitor/1]).
-include("records.hrl").
createProcess({M,F,A})->
Pid=spawn(M,F,[A]),
Ref=erlang:monitor(process,Pid),
{Pid,Ref}.
记录.hrl
-record(monstate,{
queue,
qc,
wpid,
free=true,
wref,
init=false
}).
-record(sstate,{
init=false,
mpid=null,
mref=null
}).
sv.erl
-module(sv).
-import(common,[createProcess/1]).
-include("records.hrl").
-export([start/0,server/1]).
start()->
spawn(?MODULE,server,[#sstate{init=false}]).
server(State=#sstate{init=I})when I=:=false ->
{MPid,MRef}=createProcess({monitor,monitor,#monstate{init=false}}),
server(State#sstate{init=true,mpid=MPid,mref=MRef});
server(State=#sstate{mpid=MPid,mref=MRef})->
receive
{From,state}->From ! State,
server(State);
{From,Message}-> MPid ! {request,{From,Message}},
server(State);
{'DOWN',MRef,process,MPid,_}-> {NewMPid,NewMRef}=createProcess({?MODULE,monitor,#monstate{init=false}}),
server(State#sstate{mpid=NewMPid,mref=NewMRef});
_ ->exit(invalid_message)
end.
监视器.erl
%%% servers as both a gen_server that can be queried and a supervisor for its worker process
-module(monitor).
-export([monitor/1]).
-import(common,[createProcess/1]).
-include("records.hrl").
-define(QUEUE_SIZE,5).
tryEnqueue(Message,MState=#monstate{queue=Q,qc=C}) when C<?QUEUE_SIZE->
NewQueue=queue:in(Message,Q),
{queued,MState#monstate{qc=C+1,queue=NewQueue}};
tryEnqueue(_,MState)->{queue_full,MState}.
monitor(MState=#monstate{wpid=_,wref=_,init=I}) when I=:= false ->
{WorkerPid,WorkerRef}=createProcess({worker,worker,self()}),
monitor(MState#monstate{wpid=WorkerPid,wref=WorkerRef,init=true,qc=0,queue=queue:new()});
monitor(MState=#monstate{wpid=W,free=Free,wref=Ref,queue=Q,qc=C})->
receive
{request,{From ,Message}} -> case Free of
true -> W ! {From,Message},
monitor(MState#monstate{free=false});
false ->
St=case tryEnqueue({From,Message},MState) of
{queue_full,S} -> From ! {queue_full,Message},S;
{queued,S} -> S
end,
monitor(St)
end;
{worker,{finished,_}}-> case queue:out(Q) of
{{_,Element},Rest} -> W ! Element,
monitor(MState#monstate{free=false,queue=Rest,qc=C-1});
{empty,Rest} -> monitor(MState#monstate{free=true,queue=Rest})
end;
{'DOWN',Ref,process,_,_}->
{NewWorkerPid,NewWorkerRef}=createProcess({?MODULE,worker,self()}),
monitor(MState#monstate{wpid=NewWorkerPid,wref=NewWorkerRef,free=true});
_->exit(invalid_message)
end.
所以我不知道如何解释错误:
- 有一个对
common
模块的调用,它有一个MFA
:[{monitor,monitor,{monstate,undefined,undefined,.....}]
。里面的内容{ }
看起来不错,但我没有得到包含的内容[ ]
。
PS我的common
模块从两个模块产生进程,sv
这些monitor
模块也导入了这些模块,并且它们的相关记录也包括在内。我不明白这个问题。