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Diffstat (limited to 'deps/goldrush/src/gr_manager.erl')
| -rw-r--r-- | deps/goldrush/src/gr_manager.erl | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/deps/goldrush/src/gr_manager.erl b/deps/goldrush/src/gr_manager.erl new file mode 100644 index 0000000..ce6c55c --- /dev/null +++ b/deps/goldrush/src/gr_manager.erl @@ -0,0 +1,185 @@ +%% Copyright (c) 2013, Pedram Nimreezi <deadzen@deadzen.com> +%% +%% Permission to use, copy, modify, and/or distribute this software for any +%% purpose with or without fee is hereby granted, provided that the above +%% copyright notice and this permission notice appear in all copies. +%% +%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + + +%% @doc Process table manager for goldrush. +%% +%% Manager responsible for the processes, which serve as heir of the +%% {@link gr_counter:start_link/0. <em>Counter</em>} and +%% {@link gr_param:start_link/0. <em>Param</em>} ets table processes. +%% This process creates the table and initial data then assigns itself +%% to inherit the ets table if any process responsible for it is killed. +%% It then waits to give it back while that process is recreated by its +%% supervisor. +-module(gr_manager). +-behaviour(gen_server). + +%% API +-export([start_link/3, wait_for_pid/1]). + +%% gen_server callbacks +-export([init/1, + handle_call/3, + handle_cast/2, + handle_info/2, + terminate/2, + code_change/3]). + +-define(SERVER, ?MODULE). + +-record(state, {table_id :: ets:tab(), managee :: atom()}). + +%%%=================================================================== +%%% API +%%%=================================================================== + +%% Setup the initial data for the ets table +-spec setup(atom() | pid(), term()) -> ok. +setup(Name, Data) -> + gen_server:cast(Name, {setup, Data}). + +%%-------------------------------------------------------------------- +%% @doc +%% Starts the server +%% +%% @spec start_link(Name, Managee, Data) -> {ok, Pid} | ignore | +%% {error, Error} +%% @end +%%-------------------------------------------------------------------- +start_link(Name, Managee, Data) -> + gen_server:start_link({local, Name}, ?MODULE, [Managee, Data], []). + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Initializes the server +%% +%% @spec init(Args) -> {ok, State} | +%% {ok, State, Timeout} | +%% ignore | +%% {stop, Reason} +%% @end +%%-------------------------------------------------------------------- +init([Managee, Data]) -> + process_flag(trap_exit, true), + setup(self(), Data), + {ok, #state{managee=Managee}}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling call messages +%% +%% @spec handle_call(Request, From, State) -> +%% {reply, Reply, State} | +%% {reply, Reply, State, Timeout} | +%% {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, Reply, State} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_call(_Request, _From, State) -> + Reply = {error, unhandled_message}, + {reply, Reply, State}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling cast messages +%% +%% @spec handle_cast(Msg, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_cast({setup, Data}, State = #state{managee=Managee}) -> + ManageePid = whereis(Managee), + link(ManageePid), + TableId = ets:new(?MODULE, [set, private]), + ets:insert(TableId, Data), + ets:setopts(TableId, {heir, self(), Data}), + ets:give_away(TableId, ManageePid, Data), + {noreply, State#state{table_id=TableId}}; +handle_cast(_Msg, State) -> + {noreply, State}. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Handling all non call/cast messages +%% +%% @spec handle_info(Info, State) -> {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} +%% @end +%%-------------------------------------------------------------------- +handle_info({'EXIT', _Pid, _Reason}, State) -> + {noreply, State}; +handle_info({'ETS-TRANSFER', TableId, _Pid, Data}, State = #state{managee=Managee}) -> + ManageePid = wait_for_pid(Managee), + link(ManageePid), + ets:give_away(TableId, ManageePid, Data), + {noreply, State#state{table_id=TableId}}. + +%% @doc Wait for a registered process to be associated to a process identifier. +%% @spec wait_for_pid(Managee) -> ManageePid +-spec wait_for_pid(atom()) -> pid(). +wait_for_pid(Managee) when is_pid(Managee) -> + Managee; +wait_for_pid(Managee) when is_atom(Managee), Managee =/= undefined -> + case whereis(Managee) of + undefined -> + timer:sleep(1), + wait_for_pid(Managee); + ManageePid -> ManageePid + end. + + + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% This function is called by a gen_server when it is about to +%% terminate. It should be the opposite of Module:init/1 and do any +%% necessary cleaning up. When it returns, the gen_server terminates +%% with Reason. The return value is ignored. +%% +%% @spec terminate(Reason, State) -> void() +%% @end +%%-------------------------------------------------------------------- +terminate(_Reason, _State) -> + ok. + +%%-------------------------------------------------------------------- +%% @private +%% @doc +%% Convert process state when code is changed +%% +%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} +%% @end +%%-------------------------------------------------------------------- +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%%%=================================================================== +%%% Internal functions +%%%=================================================================== + + + |