X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=001%2Fsrc%2Flife_cell.erl;h=4ee07acdd3b09b70fd667726b55eda7f1052e361;hb=HEAD;hp=2ebdf7bf353b09d909bab07959ee10a213f66874;hpb=b699b8a46efcf2df395bb19dc1027726ce08a9cb;p=cellular-automata.git diff --git a/001/src/life_cell.erl b/001/src/life_cell.erl deleted file mode 100644 index 2ebdf7b..0000000 --- a/001/src/life_cell.erl +++ /dev/null @@ -1,168 +0,0 @@ --module(life_cell). --behaviour(gen_server). - - -%% API --export([start_link/1]). - -%% Callbacks --export([init/1 - ,handle_call/3 - ,handle_cast/2 - ,handle_info/2 - ,terminate/2 - ,code_change/3 - ]). - - --record(state, {cell_id :: integer() - ,name :: string() - ,cell_state :: 0 | 1 - ,neighbors :: list(atom()) - ,live_neighbors :: integer() - ,num_neighbors :: integer() - ,replies_pending :: integer() - ,gen_id :: integer() - ,early_msgs :: list() - }). - - -%% ============================================================================ -%% API -%% ============================================================================ - -start_link({_, Name, _}=Datum) -> - ServerName = {local, Name}, - Args = [Datum], - Opts = [], - gen_server:start_link(ServerName, ?MODULE, Args, Opts). - - -%% ============================================================================ -%% Callbacks -%% ============================================================================ - -init([{CellID, Name, NeighborNames}]) -> - State = #state{cell_id = CellID - ,name = Name - ,cell_state = crypto:rand_uniform(0, 2) - ,neighbors = NeighborNames - ,num_neighbors = length(NeighborNames) - ,live_neighbors = 0 - ,replies_pending = 0 - ,early_msgs = [] - }, - {ok, State}. - - -terminate(_Reason, State) -> - {ok, State}. - - -code_change(_Old, State, _Other) -> - {ok, State}. - - -handle_call(_Msg, _From, State) -> - {reply, ok, State}. - - -handle_cast({next_gen, GenID}, - #state{name=Name - ,cell_state=CellState - ,neighbors=Neighbors - ,num_neighbors=NumNeighbors - ,early_msgs=EarlyMsgs - }=State) -> - - ok = cast_all(Neighbors, {state_broadcast, GenID, CellState}), - - % Put stashed messages back in the mailbox, - % now that we're ready to handle them - ok = cast_to(Name, EarlyMsgs), - - NewState = State#state{replies_pending=NumNeighbors - ,gen_id=GenID - ,early_msgs=[] - }, - - {noreply, NewState}; - - -%% If we receive 'state_broadcast' before we receive 'next_gen', -%% stash it until we do. -%% -%% Took me a while to realize this, but sometimes it is possible. The more -%% there're cells, the more likely this is to happen. -%% -handle_cast({state_broadcast, ReceivedGenID, _NeighborState}=Msg, - #state{gen_id=GenID - ,early_msgs=EarlyMsgs - }=State) when GenID =/= ReceivedGenID -> - - {noreply, State#state{early_msgs=[Msg|EarlyMsgs]}}; - - -%% Now that we can be sure that this request is for the current generation, we -%% can handle it -handle_cast({state_broadcast, GenID, NeighborState}, - #state{cell_id=CellID - ,gen_id=GenID - ,replies_pending=Pending - ,cell_state=CellState - ,live_neighbors=LiveNeighbors - }=State) -> - - NewPending = Pending - 1, - NewLiveNeighbors = LiveNeighbors + NeighborState, - - NewState = State#state{replies_pending=NewPending - ,live_neighbors=NewLiveNeighbors - }, - - case NewPending of - 0 -> - NewCellState = new_state(CellState, NewLiveNeighbors), - ok = life_time:report_state(CellID, GenID, NewCellState), - - {noreply, NewState#state{live_neighbors=0 - ,cell_state=NewCellState - } - }; - - _N -> - {noreply, NewState} - end; - - -handle_cast(_Msg, State) -> - {noreply, State}. - - -handle_info(_Msg, State) -> - {noreply, State}. - - -%% ============================================================================ -%% Internal -%% ============================================================================ - -% Cast different messages to a single destination -cast_to(_, []) -> ok; -cast_to(Server, [Msg | Msgs]) -> - ok = gen_server:cast(Server, Msg), - cast_to(Server, Msgs). - - -% Cast the same message to multiple destinations -cast_all([], _) -> ok; -cast_all([Server | Servers], Msg) -> - ok = gen_server:cast(Server, Msg), - cast_all(Servers, Msg). - - -new_state(1, LiveNeighbors) when LiveNeighbors < 2 -> 0; -new_state(1, LiveNeighbors) when LiveNeighbors < 4 -> 1; -new_state(1, LiveNeighbors) when LiveNeighbors > 3 -> 0; -new_state(0, LiveNeighbors) when LiveNeighbors =:= 3 -> 1; -new_state(State, _LiveNeighbors) -> State.