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-module(rexi_server).
-behaviour(gen_server).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2,
code_change/3]).
-export([start_link/0, init_p/2]).
-include_lib("eunit/include/eunit.hrl").
-record(st, {
workers = []
}).
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
init([]) ->
{ok, #st{}}.
handle_call(_Request, _From, St) ->
{reply, ignored, St}.
handle_cast({doit, From, MFA}, #st{workers=Workers} = St) ->
{LocalPid, Ref} = spawn_monitor(?MODULE, init_p, [From, MFA]),
{noreply, St#st{workers = add_worker({LocalPid, Ref, From}, Workers)}};
handle_cast({kill, Ref}, #st{workers=Workers} = St) ->
case find_worker(Ref, Workers) of
{Pid, Ref, _} ->
exit(Pid, kill);
false -> ok end,
{noreply, St#st{workers = remove_worker(Ref, Workers)}}.
handle_info({'DOWN', Ref, process, _, normal}, #st{workers=Workers} = St) ->
{noreply, St#st{workers = remove_worker(Ref, Workers)}};
handle_info({'DOWN', Ref, process, Pid, Reason}, #st{workers=Workers} = St) ->
case find_worker(Ref, Workers) of
{Pid, Ref, From} ->
notify_caller(From, Reason);
false -> ok end,
{noreply, St#st{workers = remove_worker(Ref, Workers)}};
handle_info(_Info, St) ->
{noreply, St}.
terminate(_Reason, St) ->
[exit(Pid,kill) || {Pid, _, _} <- St#st.workers],
ok.
code_change(_OldVsn, St, _Extra) ->
{ok, St}.
%% @doc initializes a process started by rexi_server.
-spec init_p({pid(),reference()}, mfa()) -> any().
init_p(From, {M,F,A}) ->
put(rexi_from, From),
try apply(M, F, A) catch _:Reason -> exit(Reason) end.
%% internal
add_worker(Worker, List) ->
[Worker | List].
remove_worker(Ref, List) ->
lists:keydelete(Ref, 2, List).
find_worker(Ref, List) ->
lists:keyfind(Ref, 2, List).
notify_caller({Caller, Ref}, Reason) ->
Caller ! {Ref, {rexi_EXIT, Reason}}.
|
