diff options
| -rw-r--r-- | erts/emulator/test/process_SUITE.erl | 84 |
1 files changed, 64 insertions, 20 deletions
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl index 0cb0d6c1e2..cef1b79035 100644 --- a/erts/emulator/test/process_SUITE.erl +++ b/erts/emulator/test/process_SUITE.erl @@ -1089,42 +1089,86 @@ process_info_status_handled_signal(Config) when is_list(Config) -> %% OTP-15709 %% Provoke a bug where process_info(reductions) returned wrong result %% because REDS_IN (def_arg_reg[5]) is read when the process in not running. +%% +%% And a bug where process_info(reductions) on a process which was releasing its +%% main lock during execution could result in negative reduction diffs. process_info_reductions(Config) when is_list(Config) -> - pi_reductions_tester(spawn_link(fun() -> pi_reductions_spinnloop() end)), - pi_reductions_tester(spawn_link(fun() -> pi_reductions_recvloop() end)), + {S1, S2} = case erlang:system_info(schedulers) of + 1 -> {1,1}; + _ -> {1,2} + end, + io:format("Run on schedulers ~p and ~p\n", [S1,S2]), + Boss = self(), + Doer = spawn_opt(fun () -> + pi_reductions_tester(true, 10, fun pi_reductions_spinnloop/0, S2), + pi_reductions_tester(true, 10, fun pi_reductions_recvloop/0, S2), + pi_reductions_tester(false, 100, fun pi_reductions_main_unlocker/0, S2), + Boss ! {self(), done} + end, + [link, {scheduler, S1}]), + + {Doer, done} = receive M -> M end, ok. -pi_reductions_tester(Pid) -> - {_, DiffList} = - lists:foldl(fun(_, {Prev, Acc}) -> - %% Add another item that force sending the request - %% as a signal, like 'current_function'. - PI = process_info(Pid, [reductions, current_function]), - [{reductions,Reds}, {current_function,_}] = PI, - Diff = Reds - Prev, - {Diff, true} = {Diff, (Diff >= 0)}, - {Diff, true} = {Diff, (Diff =< 1000*1000)}, - {Reds, [Diff | Acc]} - end, - {0, []}, - lists:seq(1,10)), +pi_reductions_tester(ForceSignal, MaxCalls, Fun, S2) -> + Pid = spawn_opt(Fun, [link, {scheduler,S2}]), + Extra = case ForceSignal of + true -> + %% Add another item that force sending the request + %% as a signal, like 'current_function'. + [current_function]; + false -> + [] + end, + LoopFun = fun Me(Calls, Prev, Acc0) -> + PI = process_info(Pid, [reductions | Extra]), + [{reductions,Reds} | _] = PI, + Diff = Reds - Prev, + %% Verify we get sane non-negative reduction diffs + {Diff, true} = {Diff, (Diff >= 0)}, + {Diff, true} = {Diff, (Diff =< 1000*1000)}, + Acc1 = [Diff | Acc0], + case Calls >= MaxCalls of + true -> Acc1; + false -> Me(Calls+1, Reds, Acc1) + end + end, + DiffList = LoopFun(0, 0, []), unlink(Pid), exit(Pid,kill), - io:format("Reduction diffs: ~p\n", [DiffList]), + io:format("Reduction diffs: ~p\n", [lists:reverse(DiffList)]), ok. pi_reductions_spinnloop() -> %% 6 args to make use of def_arg_reg[5] which is also used as REDS_IN - pi_reductions_spinnloop(1, atom, "hej", self(), make_ref(), 3.14). + pi_reductions_spinnloop(999*1000, atom, "hej", self(), make_ref(), 3.14). -pi_reductions_spinnloop(A,B,C,D,E,F) -> - pi_reductions_spinnloop(B,C,D,E,F,A). +pi_reductions_spinnloop(N,A,B,C,D,E) when N > 0 -> + pi_reductions_spinnloop(N-1,B,C,D,E,A); +pi_reductions_spinnloop(0,_,_,_,_,_) -> + %% Stop to limit max number of reductions consumed + pi_reductions_recvloop(). pi_reductions_recvloop() -> receive "a free lunch" -> false end. +pi_reductions_main_unlocker() -> + Other = spawn_link(fun() -> receive die -> ok end end), + pi_reductions_main_unlocker_loop(Other). + +pi_reductions_main_unlocker_loop(Other) -> + %% Assumption: register(OtherPid, Name) will unlock main lock of calling + %% process during execution. + register(pi_reductions_main_unlocker, Other), + unregister(pi_reductions_main_unlocker), + + %% Yield in order to increase probability of process_info sometimes probing + %% this process when it's not RUNNING. + erlang:yield(), + pi_reductions_main_unlocker_loop(Other). + %% Tests erlang:bump_reductions/1. bump_reductions(Config) when is_list(Config) -> |