diff options
Diffstat (limited to 'lib/kernel')
| -rw-r--r-- | lib/kernel/src/heart.erl | 97 |
1 files changed, 78 insertions, 19 deletions
diff --git a/lib/kernel/src/heart.erl b/lib/kernel/src/heart.erl index 97f384b1d8..ad3bbf2f7a 100644 --- a/lib/kernel/src/heart.erl +++ b/lib/kernel/src/heart.erl @@ -34,7 +34,10 @@ %%% %%% It recognizes the flag '-heart' %%%-------------------------------------------------------------------- --export([start/0, init/2, set_cmd/1, clear_cmd/0, get_cmd/0, cycle/0]). +-export([start/0, init/2, + set_cmd/1, clear_cmd/0, get_cmd/0, + set_callback/2, clear_callback/0, get_callback/0, + cycle/0]). -define(START_ACK, 1). -define(HEART_BEAT, 2). @@ -50,7 +53,8 @@ -define(HEART_PORT_NAME, heart_port). -record(state,{port :: port(), - cmd :: [] | binary()}). + cmd :: [] | binary(), + callback :: 'undefined' | {module(), function()}}). %%--------------------------------------------------------------------- @@ -84,7 +88,7 @@ wait_for_init_ack(From) -> init(Starter, Parent) -> process_flag(trap_exit, true), process_flag(priority, max), - register(heart, self()), + register(?MODULE, self()), case catch start_portprogram() of {ok, Port} -> Starter ! {ok, self()}, @@ -99,20 +103,41 @@ init(Starter, Parent) -> Cmd :: string(). set_cmd(Cmd) -> - heart ! {self(), set_cmd, Cmd}, + ?MODULE ! {self(), set_cmd, Cmd}, wait(). -spec get_cmd() -> {ok, Cmd} when Cmd :: string(). get_cmd() -> - heart ! {self(), get_cmd}, + ?MODULE ! {self(), get_cmd}, wait(). -spec clear_cmd() -> ok. clear_cmd() -> - heart ! {self(), clear_cmd}, + ?MODULE ! {self(), clear_cmd}, + wait(). + +-spec set_callback(Module,Function) -> 'ok' | {'error', {'bad_callback', {Module, Function}}} when + Module :: module(), + Function :: function(). + +set_callback(Module, Function) -> + ?MODULE ! {self(), set_callback, {Module,Function}}, + wait(). + +-spec get_callback() -> {'ok', Callback} | 'none' when + Callback :: {module(), function()}. + +get_callback() -> + ?MODULE ! {self(), get_callback}, + wait(). + +-spec clear_callback() -> ok. + +clear_callback() -> + ?MODULE ! {self(), clear_callback}, wait(). @@ -120,12 +145,12 @@ clear_cmd() -> -spec cycle() -> 'ok' | {'error', term()}. cycle() -> - heart ! {self(), cycle}, + ?MODULE ! {self(), cycle}, wait(). wait() -> receive - {heart, Res} -> + {?MODULE, Res} -> Res end. @@ -186,7 +211,7 @@ wait_ack(Port) -> end. loop(Parent, #state{port=Port}=S) -> - _ = send_heart_beat(Port), + _ = send_heart_beat(S), receive {From, set_cmd, NewCmd0} -> Enc = file:native_name_encoding(), @@ -194,20 +219,39 @@ loop(Parent, #state{port=Port}=S) -> NewCmd when is_binary(NewCmd), byte_size(NewCmd) < 2047 -> _ = send_heart_cmd(Port, NewCmd), _ = wait_ack(Port), - From ! {heart, ok}, + From ! {?MODULE, ok}, loop(Parent, S#state{cmd=NewCmd}); _ -> - From ! {heart, {error, {bad_cmd, NewCmd0}}}, + From ! {?MODULE, {error, {bad_cmd, NewCmd0}}}, loop(Parent, S) end; {From, clear_cmd} -> - From ! {heart, ok}, + From ! {?MODULE, ok}, _ = send_heart_cmd(Port, []), _ = wait_ack(Port), loop(Parent, S#state{cmd = []}); {From, get_cmd} -> - From ! {heart, get_heart_cmd(Port)}, + From ! {?MODULE, get_heart_cmd(Port)}, loop(Parent, S); + {From, set_callback, Callback} -> + case Callback of + {M,F} when is_atom(M), is_atom(F) -> + From ! {?MODULE, ok}, + loop(Parent, S#state{callback=Callback}); + _ -> + From ! {?MODULE, {error, {bad_callback, Callback}}}, + loop(Parent, S) + end; + {From, get_callback} -> + Res = case S#state.callback of + undefined -> none; + Cb -> {ok, Cb} + end, + From ! {?MODULE, Res}, + loop(Parent, S); + {From, clear_callback} -> + From ! {?MODULE, ok}, + loop(Parent, S#state{callback=undefined}); {From, cycle} -> %% Calls back to loop do_cycle_port_program(From, Parent, S); @@ -219,7 +263,7 @@ loop(Parent, #state{port=Port}=S) -> {'EXIT', Port, badsig} -> % we can ignore badsig-messages! loop(Parent, S); {'EXIT', Port, _Reason} -> - exit({port_terminated, {heart, loop, [Parent, S]}}); + exit({port_terminated, {?MODULE, loop, [Parent, S]}}); _ -> loop(Parent, S) after @@ -244,7 +288,7 @@ do_cycle_port_program(Caller, Parent, #state{port=Port} = S) -> receive {'EXIT', Port, _Reason} -> _ = send_heart_cmd(NewPort, S#state.cmd), - Caller ! {heart, ok}, + Caller ! {?MODULE, ok}, loop(Parent, S#state{port=NewPort}) after ?CYCLE_TIMEOUT -> @@ -252,20 +296,22 @@ do_cycle_port_program(Caller, Parent, #state{port=Port} = S) -> %% well, the old one has to be sick not to respond %% so we'll settle for the new one... _ = send_heart_cmd(NewPort, S#state.cmd), - Caller ! {heart, {error, stop_error}}, + Caller ! {?MODULE, {error, stop_error}}, loop(Parent, S#state{port=NewPort}) end; no_heart -> - Caller ! {heart, {error, no_heart}}, + Caller ! {?MODULE, {error, no_heart}}, loop(Parent, S); error -> - Caller ! {heart, {error, start_error}}, + Caller ! {?MODULE, {error, start_error}}, loop(Parent, S) end. %% "Beates" the heart once. -send_heart_beat(Port) -> Port ! {self(), {command, [?HEART_BEAT]}}. +send_heart_beat(#state{port=Port, callback=Cb}) -> + ok = check_callback(Cb), + Port ! {self(), {command, [?HEART_BEAT]}}. %% Set a new HEART_COMMAND. send_heart_cmd(Port, []) -> @@ -280,6 +326,19 @@ get_heart_cmd(Port) -> {ok, Cmd} end. +%% validate system by performing a check before the heartbeat +%% return 'ok' if everything is alright. +%% Terminate if with reason if something is a miss. +%% It is fine to timeout in the callback, in fact that is the intention +%% if something goes wront -> no heartbeat. + +check_callback(Callback) -> + case Callback of + undefined -> ok; + {M,F} -> + erlang:apply(M,F,[]) + end. + %% Sends shutdown command to the port. send_shutdown(Port) -> Port ! {self(), {command, [?SHUT_DOWN]}}. |