diff options
| -rw-r--r-- | erts/emulator/beam/beam_emu.c | 15 | ||||
| -rw-r--r-- | erts/emulator/beam/msg_instrs.tab | 1 | ||||
| -rw-r--r-- | erts/emulator/test/process_SUITE.erl | 42 |
3 files changed, 52 insertions, 6 deletions
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index 4351dda5a7..10d70a96e8 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -3261,20 +3261,23 @@ erts_is_builtin(Eterm Mod, Eterm Name, int arity) /* - * Return the current number of reductions for the given process. + * Return the current number of reductions consumed by the given process. * To get the total number of reductions, p->reds must be added. */ Uint -erts_current_reductions(Process *current, Process *p) +erts_current_reductions(Process *c_p, Process *p) { - if (current != p) { + Sint reds_left; + if (c_p != p || !(erts_atomic32_read_nob(&c_p->state) + & ERTS_PSFLG_RUNNING)) { return 0; - } else if (current->fcalls < 0 && ERTS_PROC_GET_SAVED_CALLS_BUF(current)) { - return current->fcalls + CONTEXT_REDS; + } else if (c_p->fcalls < 0 && ERTS_PROC_GET_SAVED_CALLS_BUF(c_p)) { + reds_left = c_p->fcalls + CONTEXT_REDS; } else { - return REDS_IN(current) - current->fcalls; + reds_left = c_p->fcalls; } + return REDS_IN(c_p) - reds_left; } int diff --git a/erts/emulator/beam/msg_instrs.tab b/erts/emulator/beam/msg_instrs.tab index 9bf3aefaca..a6a0dec451 100644 --- a/erts/emulator/beam/msg_instrs.tab +++ b/erts/emulator/beam/msg_instrs.tab @@ -105,6 +105,7 @@ i_loop_rec(Dest) { $SET_CP_I_ABS(I); c_p->arity = 0; c_p->current = NULL; + c_p->fcalls = FCALLS; FCALLS -= erts_proc_sig_receive_helper(c_p, FCALLS, neg_o_reds, &msgp, &get_out); SWAPIN; diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl index b23f77a0b2..0cb0d6c1e2 100644 --- a/erts/emulator/test/process_SUITE.erl +++ b/erts/emulator/test/process_SUITE.erl @@ -44,6 +44,7 @@ process_info_garbage_collection/1, process_info_smoke_all/1, process_info_status_handled_signal/1, + process_info_reductions/1, bump_reductions/1, low_prio/1, binary_owner/1, yield/1, yield2/1, otp_4725/1, bad_register/1, garbage_collect/1, otp_6237/1, process_info_messages/1, process_flag_badarg/1, process_flag_heap_size/1, @@ -84,6 +85,7 @@ all() -> process_info_garbage_collection, process_info_smoke_all, process_info_status_handled_signal, + process_info_reductions, bump_reductions, low_prio, yield, yield2, otp_4725, bad_register, garbage_collect, process_info_messages, process_flag_badarg, process_flag_heap_size, @@ -1084,6 +1086,46 @@ process_info_status_handled_signal(Config) when is_list(Config) -> false = erlang:is_process_alive(P), ok. +%% 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. +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)), + 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)), + unlink(Pid), + exit(Pid,kill), + io:format("Reduction diffs: ~p\n", [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(A,B,C,D,E,F) -> + pi_reductions_spinnloop(B,C,D,E,F,A). + +pi_reductions_recvloop() -> + receive + "a free lunch" -> false + end. + + %% Tests erlang:bump_reductions/1. bump_reductions(Config) when is_list(Config) -> erlang:garbage_collect(), |