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Diffstat (limited to 'lib/mnesia/src/mnesia_monitor.erl')
| -rw-r--r-- | lib/mnesia/src/mnesia_monitor.erl | 823 |
1 files changed, 823 insertions, 0 deletions
diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl new file mode 100644 index 0000000000..05ae943e3b --- /dev/null +++ b/lib/mnesia/src/mnesia_monitor.erl @@ -0,0 +1,823 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1996-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +%% +-module(mnesia_monitor). + +-behaviour(gen_server). + +%% Public exports +-export([ + close_dets/1, + close_log/1, + detect_inconcistency/2, + get_env/1, + init/0, + mktab/2, + unsafe_mktab/2, + mnesia_down/2, + needs_protocol_conversion/1, + negotiate_protocol/1, + disconnect/1, + open_dets/2, + unsafe_open_dets/2, + open_log/1, + patch_env/2, + protocol_version/0, + reopen_log/3, + set_env/2, + start/0, + start_proc/4, + terminate_proc/3, + unsafe_close_dets/1, + unsafe_close_log/1, + use_dir/0, + do_check_type/2 + ]). + +%% gen_server callbacks +-export([ + init/1, + handle_call/3, + handle_cast/2, + handle_info/2, + terminate/2, + code_change/3 + ]). + +%% Internal exports +-export([ + call/1, + cast/1, + detect_partitioned_network/2, + has_remote_mnesia_down/1, + negotiate_protocol_impl/2 + ]). + +-import(mnesia_lib, [dbg_out/2, verbose/2, error/2, fatal/2, set/2]). + +-include("mnesia.hrl"). + +-record(state, {supervisor, pending_negotiators = [], + going_down = [], tm_started = false, early_connects = [], + connecting, mq = []}). + +-define(current_protocol_version, {7,6}). + +-define(previous_protocol_version, {7,5}). + +start() -> + gen_server:start_link({local, ?MODULE}, ?MODULE, + [self()], [{timeout, infinity} + %% ,{debug, [trace]} + ]). + +init() -> + call(init). + +mnesia_down(From, Node) -> + cast({mnesia_down, From, Node}). + +mktab(Tab, Args) -> + unsafe_call({mktab, Tab, Args}). +unsafe_mktab(Tab, Args) -> + unsafe_call({unsafe_mktab, Tab, Args}). + +open_dets(Tab, Args) -> + unsafe_call({open_dets, Tab, Args}). +unsafe_open_dets(Tab, Args) -> + unsafe_call({unsafe_open_dets, Tab, Args}). + +close_dets(Tab) -> + unsafe_call({close_dets, Tab}). + +unsafe_close_dets(Name) -> + unsafe_call({unsafe_close_dets, Name}). + +open_log(Args) -> + unsafe_call({open_log, Args}). + +reopen_log(Name, Fname, Head) -> + unsafe_call({reopen_log, Name, Fname, Head}). + +close_log(Name) -> + unsafe_call({close_log, Name}). + +unsafe_close_log(Name) -> + unsafe_call({unsafe_close_log, Name}). + + +disconnect(Node) -> + cast({disconnect, Node}). + +%% Returns GoodNoodes +%% Creates a link to each compatible monitor and +%% protocol_version to agreed version upon success + +negotiate_protocol([]) -> []; +negotiate_protocol(Nodes) -> + call({negotiate_protocol, Nodes}). + +negotiate_protocol_impl(Nodes, Requester) -> + Version = mnesia:system_info(version), + Protocols = acceptable_protocol_versions(), + MonitorPid = whereis(?MODULE), + Msg = {negotiate_protocol, MonitorPid, Version, Protocols}, + {Replies, _BadNodes} = multicall(Nodes, Msg), + Res = check_protocol(Replies, Protocols), + ?MODULE ! {protocol_negotiated,Requester,Res}, + unlink(whereis(?MODULE)), + ok. + +check_protocol([{Node, {accept, Mon, Version, Protocol}} | Tail], Protocols) -> + case lists:member(Protocol, Protocols) of + true -> + case Protocol == protocol_version() of + true -> + set({protocol, Node}, {Protocol, false}); + false -> + set({protocol, Node}, {Protocol, true}) + end, + [node(Mon) | check_protocol(Tail, Protocols)]; + false -> + verbose("Failed to connect with ~p. ~p protocols rejected. " + "expected version = ~p, expected protocol = ~p~n", + [Node, Protocols, Version, Protocol]), + unlink(Mon), % Get rid of unneccessary link + check_protocol(Tail, Protocols) + end; +check_protocol([{Node, {reject, _Mon, Version, Protocol}} | Tail], Protocols) -> + verbose("Failed to connect with ~p. ~p protocols rejected. " + "expected version = ~p, expected protocol = ~p~n", + [Node, Protocols, Version, Protocol]), + check_protocol(Tail, Protocols); +check_protocol([{error, _Reason} | Tail], Protocols) -> + dbg_out("~p connect failed error: ~p~n", [?MODULE, _Reason]), + check_protocol(Tail, Protocols); +check_protocol([{badrpc, _Reason} | Tail], Protocols) -> + dbg_out("~p connect failed badrpc: ~p~n", [?MODULE, _Reason]), + check_protocol(Tail, Protocols); +check_protocol([], [Protocol | _Protocols]) -> + set(protocol_version, Protocol), + []. + +protocol_version() -> + case ?catch_val(protocol_version) of + {'EXIT', _} -> ?current_protocol_version; + Version -> Version + end. + +%% A sorted list of acceptable protocols the +%% preferred protocols are first in the list +acceptable_protocol_versions() -> + [protocol_version(), ?previous_protocol_version]. + +needs_protocol_conversion(Node) -> + case {?catch_val({protocol, Node}), protocol_version()} of + {{'EXIT', _}, _} -> + false; + {{_, Bool}, ?current_protocol_version} -> + Bool; + {{_, Bool}, _} -> + not Bool + end. + +cast(Msg) -> + case whereis(?MODULE) of + undefined -> ignore; + Pid -> gen_server:cast(Pid, Msg) + end. + +unsafe_call(Msg) -> + case whereis(?MODULE) of + undefined -> {error, {node_not_running, node()}}; + Pid -> gen_server:call(Pid, Msg, infinity) + end. + +call(Msg) -> + case whereis(?MODULE) of + undefined -> + {error, {node_not_running, node()}}; + Pid -> + link(Pid), + Res = gen_server:call(Pid, Msg, infinity), + unlink(Pid), + + %% We get an exit signal if server dies + receive + {'EXIT', Pid, _Reason} -> + {error, {node_not_running, node()}} + after 0 -> + Res + end + end. + +multicall(Nodes, Msg) -> + rpc:multicall(Nodes, ?MODULE, call, [Msg]). + +start_proc(Who, Mod, Fun, Args) -> + Args2 = [Who, Mod, Fun, Args], + proc_lib:start_link(mnesia_sp, init_proc, Args2, infinity). + +terminate_proc(Who, R, State) when R /= shutdown, R /= killed -> + fatal("~p crashed: ~p state: ~p~n", [Who, R, State]); + +terminate_proc(Who, Reason, _State) -> + mnesia_lib:verbose("~p terminated: ~p~n", [Who, Reason]), + ok. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%% Callback functions from gen_server + +%%---------------------------------------------------------------------- +%% Func: init/1 +%% Returns: {ok, State} | +%% {ok, State, Timeout} | +%% {stop, Reason} +%%---------------------------------------------------------------------- +init([Parent]) -> + process_flag(trap_exit, true), + ?ets_new_table(mnesia_gvar, [set, public, named_table]), + ?ets_new_table(mnesia_stats, [set, public, named_table]), + set(subscribers, []), + mnesia_lib:verbose("~p starting: ~p~n", [?MODULE, self()]), + Version = mnesia:system_info(version), + set(version, Version), + dbg_out("Version: ~p~n", [Version]), + + case catch process_config_args(env()) of + ok -> + mnesia_lib:set({'$$$_report', current_pos}, 0), + Level = mnesia_lib:val(debug), + mnesia_lib:verbose("Mnesia debug level set to ~p\n", [Level]), + set(mnesia_status, starting), %% set start status + set({current, db_nodes}, [node()]), + set(use_dir, use_dir()), + mnesia_lib:create_counter(trans_aborts), + mnesia_lib:create_counter(trans_commits), + mnesia_lib:create_counter(trans_log_writes), + Left = get_env(dump_log_write_threshold), + mnesia_lib:set_counter(trans_log_writes_left, Left), + mnesia_lib:create_counter(trans_log_writes_prev), + mnesia_lib:create_counter(trans_restarts), + mnesia_lib:create_counter(trans_failures), + set(checkpoints, []), + set(pending_checkpoints, []), + set(pending_checkpoint_pids, []), + + {ok, #state{supervisor = Parent}}; + {'EXIT', Reason} -> + mnesia_lib:report_fatal("Bad configuration: ~p~n", [Reason]), + {stop, {bad_config, Reason}} + end. + +use_dir() -> + case ?catch_val(use_dir) of + {'EXIT', _} -> + case get_env(schema_location) of + disc -> true; + opt_disc -> non_empty_dir(); + ram -> false + end; + Bool -> + Bool + end. + +%% Returns true if the Mnesia directory contains +%% important files +non_empty_dir() -> + mnesia_lib:exists(mnesia_bup:fallback_bup()) or + mnesia_lib:exists(mnesia_lib:tab2dmp(schema)) or + mnesia_lib:exists(mnesia_lib:tab2dat(schema)). + +%%---------------------------------------------------------------------- +%% Func: handle_call/3 +%% Returns: {reply, Reply, State} | +%% {reply, Reply, State, Timeout} | +%% {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, Reply, State} | (terminate/2 is called) +%%---------------------------------------------------------------------- + +handle_call({mktab, Tab, Args}, _From, State) -> + case catch ?ets_new_table(Tab, Args) of + {'EXIT', ExitReason} -> + Msg = "Cannot create ets table", + Reason = {system_limit, Msg, Tab, Args, ExitReason}, + fatal("~p~n", [Reason]), + {noreply, State}; + Reply -> + {reply, Reply, State} + end; + +handle_call({unsafe_mktab, Tab, Args}, _From, State) -> + case catch ?ets_new_table(Tab, Args) of + {'EXIT', ExitReason} -> + {reply, {error, ExitReason}, State}; + Reply -> + {reply, Reply, State} + end; + + +handle_call({open_dets, Tab, Args}, _From, State) -> + case mnesia_lib:dets_sync_open(Tab, Args) of + {ok, Tab} -> + {reply, {ok, Tab}, State}; + + {error, Reason} -> + Msg = "Cannot open dets table", + Error = {error, {Msg, Tab, Args, Reason}}, + fatal("~p~n", [Error]), + {noreply, State} + end; + +handle_call({unsafe_open_dets, Tab, Args}, _From, State) -> + case mnesia_lib:dets_sync_open(Tab, Args) of + {ok, Tab} -> + {reply, {ok, Tab}, State}; + {error, Reason} -> + {reply, {error,Reason}, State} + end; + +handle_call({close_dets, Tab}, _From, State) -> + ok = mnesia_lib:dets_sync_close(Tab), + {reply, ok, State}; + +handle_call({unsafe_close_dets, Tab}, _From, State) -> + mnesia_lib:dets_sync_close(Tab), + {reply, ok, State}; + +handle_call({open_log, Args}, _From, State) -> + Res = disk_log:open([{notify, true}|Args]), + {reply, Res, State}; + +handle_call({reopen_log, Name, Fname, Head}, _From, State) -> + case disk_log:reopen(Name, Fname, Head) of + ok -> + {reply, ok, State}; + + {error, Reason} -> + Msg = "Cannot rename disk_log file", + Error = {error, {Msg, Name, Fname, Head, Reason}}, + fatal("~p~n", [Error]), + {noreply, State} + end; + +handle_call({close_log, Name}, _From, State) -> + case disk_log:close(Name) of + ok -> + {reply, ok, State}; + + {error, Reason} -> + Msg = "Cannot close disk_log file", + Error = {error, {Msg, Name, Reason}}, + fatal("~p~n", [Error]), + {noreply, State} + end; + +handle_call({unsafe_close_log, Name}, _From, State) -> + disk_log:close(Name), + {reply, ok, State}; + +handle_call({negotiate_protocol, Mon, _Version, _Protocols}, _From, State) + when State#state.tm_started == false -> + State2 = State#state{early_connects = [node(Mon) | State#state.early_connects]}, + {reply, {node(), {reject, self(), uninitialized, uninitialized}}, State2}; + +%% From remote monitor.. +handle_call({negotiate_protocol, Mon, Version, Protocols}, From, State) + when node(Mon) /= node() -> + Protocol = protocol_version(), + MyVersion = mnesia:system_info(version), + case lists:member(Protocol, Protocols) of + true -> + accept_protocol(Mon, MyVersion, Protocol, From, State); + false -> + %% in this release we should be able to handle the previous + %% protocol + case hd(Protocols) of + ?previous_protocol_version -> + accept_protocol(Mon, MyVersion, ?previous_protocol_version, From, State); + _ -> + verbose("Connection with ~p rejected. " + "version = ~p, protocols = ~p, " + "expected version = ~p, expected protocol = ~p~n", + [node(Mon), Version, Protocols, MyVersion, Protocol]), + {reply, {node(), {reject, self(), MyVersion, Protocol}}, State} + end + end; + +%% Local request to negotiate with other monitors (nodes). +handle_call({negotiate_protocol, Nodes}, From, State) -> + case mnesia_lib:intersect(State#state.going_down, Nodes) of + [] -> + spawn_link(?MODULE, negotiate_protocol_impl, [Nodes, From]), + {noreply, State#state{connecting={From,Nodes}}}; + _ -> %% Cannot connect now, still processing mnesia down + {reply, busy, State} + end; + +handle_call(init, _From, State) -> + net_kernel:monitor_nodes(true), + EarlyNodes = State#state.early_connects, + State2 = State#state{tm_started = true}, + {reply, EarlyNodes, State2}; + +handle_call(Msg, _From, State) -> + error("~p got unexpected call: ~p~n", [?MODULE, Msg]), + {noreply, State}. + +accept_protocol(Mon, Version, Protocol, From, State) -> + Reply = {node(), {accept, self(), Version, Protocol}}, + Node = node(Mon), + Pending0 = State#state.pending_negotiators, + Pending = lists:keydelete(Node, 1, Pending0), + case lists:member(Node, State#state.going_down) of + true -> + %% Wait for the mnesia_down to be processed, + %% before we reply + P = Pending ++ [{Node, Mon, From, Reply}], + {noreply, State#state{pending_negotiators = P}}; + false -> + %% No need for wait + link(Mon), %% link to remote Monitor + case Protocol == protocol_version() of + true -> + set({protocol, Node}, {Protocol, false}); + false -> + set({protocol, Node}, {Protocol, true}) + end, + {reply, Reply, State#state{pending_negotiators = Pending}} + end. + +%%---------------------------------------------------------------------- +%% Func: handle_cast/2 +%% Returns: {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} (terminate/2 is called) +%%---------------------------------------------------------------------- + +handle_cast({mnesia_down, mnesia_controller, Node}, State) -> + mnesia_tm:mnesia_down(Node), + {noreply, State}; + +handle_cast({mnesia_down, mnesia_tm, {Node, Pending}}, State) -> + mnesia_locker:mnesia_down(Node, Pending), + {noreply, State}; + +handle_cast({mnesia_down, mnesia_locker, Node}, State) -> + Down = {mnesia_down, Node}, + mnesia_lib:report_system_event(Down), + GoingDown = lists:delete(Node, State#state.going_down), + State2 = State#state{going_down = GoingDown}, + Pending = State#state.pending_negotiators, + case lists:keysearch(Node, 1, Pending) of + {value, {Node, Mon, ReplyTo, Reply}} -> + %% Late reply to remote monitor + link(Mon), %% link to remote Monitor + gen_server:reply(ReplyTo, Reply), + P2 = lists:keydelete(Node, 1,Pending), + State3 = State2#state{pending_negotiators = P2}, + process_q(State3); + false -> + %% No pending remote monitors + {noreply, State2} + end; + +handle_cast({disconnect, Node}, State) -> + case rpc:call(Node, erlang, whereis, [?MODULE]) of + {badrpc, _} -> + ignore; + undefined -> + ignore; + RemoteMon when is_pid(RemoteMon) -> + unlink(RemoteMon) + end, + {noreply, State}; + +handle_cast({inconsistent_database, Context, Node}, State) -> + Msg = {inconsistent_database, Context, Node}, + mnesia_lib:report_system_event(Msg), + {noreply, State}; + +handle_cast(Msg, State) -> + error("~p got unexpected cast: ~p~n", [?MODULE, Msg]), + {noreply, State}. + +%%---------------------------------------------------------------------- +%% Func: handle_info/2 +%% Returns: {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} (terminate/2 is called) +%%---------------------------------------------------------------------- + +handle_info({'EXIT', Pid, R}, State) when Pid == State#state.supervisor -> + dbg_out("~p was ~p by supervisor~n",[?MODULE, R]), + {stop, R, State}; + +handle_info({'EXIT', Pid, fatal}, State) when node(Pid) == node() -> + dbg_out("~p got FATAL ERROR from: ~p~n",[?MODULE, Pid]), + exit(State#state.supervisor, shutdown), + {noreply, State}; + +handle_info(Msg = {'EXIT',Pid,_}, State) -> + Node = node(Pid), + if + Node /= node(), State#state.connecting == undefined -> + %% Remotly linked process died, assume that it was a mnesia_monitor + mnesia_recover:mnesia_down(Node), + mnesia_controller:mnesia_down(Node), + {noreply, State#state{going_down = [Node | State#state.going_down]}}; + Node /= node() -> + {noreply, State#state{mq = State#state.mq ++ [{info, Msg}]}}; + true -> + %% We have probably got an exit signal from + %% disk_log or dets + Hint = "Hint: check that the disk still is writable", + fatal("~p got unexpected info: ~p; ~p~n", + [?MODULE, Msg, Hint]) + end; + +handle_info({protocol_negotiated, From,Res}, State) -> + From = element(1,State#state.connecting), + gen_server:reply(From, Res), + process_q(State#state{connecting = undefined}); + +handle_info({nodeup, Node}, State) -> + %% Ok, we are connected to yet another Erlang node + %% Let's check if Mnesia is running there in order + %% to detect if the network has been partitioned + %% due to communication failure. + + HasDown = mnesia_recover:has_mnesia_down(Node), + ImRunning = mnesia_lib:is_running(), + + if + %% If I'm not running the test will be made later. + HasDown == true, ImRunning == yes -> + spawn_link(?MODULE, detect_partitioned_network, [self(), Node]); + true -> + ignore + end, + {noreply, State}; + +handle_info({nodedown, _Node}, State) -> + %% Ignore, we are only caring about nodeup's + {noreply, State}; + +handle_info({disk_log, _Node, Log, Info}, State) -> + case Info of + {truncated, _No} -> + ok; + _ -> + mnesia_lib:important("Warning Log file ~p error reason ~s~n", + [Log, disk_log:format_error(Info)]) + end, + {noreply, State}; + +handle_info(Msg, State) -> + error("~p got unexpected info (~p): ~p~n", [?MODULE, State, Msg]). + +process_q(State = #state{mq=[]}) -> {noreply,State}; +process_q(State = #state{mq=[{info,Msg}|R]}) -> + handle_info(Msg, State#state{mq=R}); +process_q(State = #state{mq=[{cast,Msg}|R]}) -> + handle_cast(Msg, State#state{mq=R}); +process_q(State = #state{mq=[{call,From,Msg}|R]}) -> + handle_call(Msg, From, State#state{mq=R}). + +%%---------------------------------------------------------------------- +%% Func: terminate/2 +%% Purpose: Shutdown the server +%% Returns: any (ignored by gen_server) +%%---------------------------------------------------------------------- +terminate(Reason, State) -> + terminate_proc(?MODULE, Reason, State). + +%%---------------------------------------------------------------------- +%% Func: code_change/3 +%% Purpose: Upgrade process when its code is to be changed +%% Returns: {ok, NewState} +%%---------------------------------------------------------------------- + + +code_change(_, {state, SUP, PN, GD, TMS, EC}, _) -> + {ok, #state{supervisor=SUP, pending_negotiators=PN, + going_down = GD, tm_started =TMS, early_connects = EC}}; + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%%%---------------------------------------------------------------------- +%%% Internal functions +%%%---------------------------------------------------------------------- + +process_config_args([]) -> + ok; +process_config_args([C|T]) -> + V = get_env(C), + dbg_out("Env ~p: ~p~n", [C, V]), + mnesia_lib:set(C, V), + process_config_args(T). + +set_env(E,Val) -> + mnesia_lib:set(E, check_type(E,Val)), + ok. + +get_env(E) -> + case ?catch_val(E) of + {'EXIT', _} -> + case application:get_env(mnesia, E) of + {ok, Val} -> + check_type(E, Val); + undefined -> + check_type(E, default_env(E)) + end; + Val -> + Val + end. + +env() -> + [ + access_module, + auto_repair, + backup_module, + debug, + dir, + dump_log_load_regulation, + dump_log_time_threshold, + dump_log_update_in_place, + dump_log_write_threshold, + embedded_mnemosyne, + event_module, + extra_db_nodes, + ignore_fallback_at_startup, + fallback_error_function, + max_wait_for_decision, + schema_location, + core_dir, + pid_sort_order, + no_table_loaders, + dc_dump_limit + ]. + +default_env(access_module) -> + mnesia; +default_env(auto_repair) -> + true; +default_env(backup_module) -> + mnesia_backup; +default_env(debug) -> + none; +default_env(dir) -> + Name = lists:concat(["Mnesia.", node()]), + filename:absname(Name); +default_env(dump_log_load_regulation) -> + false; +default_env(dump_log_time_threshold) -> + timer:minutes(3); +default_env(dump_log_update_in_place) -> + true; +default_env(dump_log_write_threshold) -> + 1000; +default_env(embedded_mnemosyne) -> + false; +default_env(event_module) -> + mnesia_event; +default_env(extra_db_nodes) -> + []; +default_env(ignore_fallback_at_startup) -> + false; +default_env(fallback_error_function) -> + {mnesia, lkill}; +default_env(max_wait_for_decision) -> + infinity; +default_env(schema_location) -> + opt_disc; +default_env(core_dir) -> + false; +default_env(pid_sort_order) -> + false; +default_env(no_table_loaders) -> + 2; +default_env(dc_dump_limit) -> + 4. + +check_type(Env, Val) -> + case catch do_check_type(Env, Val) of + {'EXIT', _Reason} -> + exit({bad_config, Env, Val}); + NewVal -> + NewVal + end. + +do_check_type(access_module, A) when is_atom(A) -> A; +do_check_type(auto_repair, B) -> bool(B); +do_check_type(backup_module, B) when is_atom(B) -> B; +do_check_type(debug, debug) -> debug; +do_check_type(debug, false) -> none; +do_check_type(debug, none) -> none; +do_check_type(debug, trace) -> trace; +do_check_type(debug, true) -> debug; +do_check_type(debug, verbose) -> verbose; +do_check_type(dir, V) -> filename:absname(V); +do_check_type(dump_log_load_regulation, B) -> bool(B); +do_check_type(dump_log_time_threshold, I) when is_integer(I), I > 0 -> I; +do_check_type(dump_log_update_in_place, B) -> bool(B); +do_check_type(dump_log_write_threshold, I) when is_integer(I), I > 0 -> I; +do_check_type(event_module, A) when is_atom(A) -> A; +do_check_type(ignore_fallback_at_startup, B) -> bool(B); +do_check_type(fallback_error_function, {Mod, Func}) + when is_atom(Mod), is_atom(Func) -> {Mod, Func}; +do_check_type(embedded_mnemosyne, B) -> bool(B); +do_check_type(extra_db_nodes, L) when is_list(L) -> + Fun = fun(N) when N == node() -> false; + (A) when is_atom(A) -> true + end, + lists:filter(Fun, L); +do_check_type(max_wait_for_decision, infinity) -> infinity; +do_check_type(max_wait_for_decision, I) when is_integer(I), I > 0 -> I; +do_check_type(schema_location, M) -> media(M); +do_check_type(core_dir, "false") -> false; +do_check_type(core_dir, false) -> false; +do_check_type(core_dir, Dir) when is_list(Dir) -> Dir; +do_check_type(pid_sort_order, r9b_plain) -> r9b_plain; +do_check_type(pid_sort_order, "r9b_plain") -> r9b_plain; +do_check_type(pid_sort_order, standard) -> standard; +do_check_type(pid_sort_order, "standard") -> standard; +do_check_type(pid_sort_order, _) -> false; +do_check_type(no_table_loaders, N) when is_integer(N), N > 0 -> N; +do_check_type(dc_dump_limit,N) when is_number(N), N > 0 -> N. + +bool(true) -> true; +bool(false) -> false. + +media(disc) -> disc; +media(opt_disc) -> opt_disc; +media(ram) -> ram. + +patch_env(Env, Val) -> + case catch do_check_type(Env, Val) of + {'EXIT', _Reason} -> + {error, {bad_type, Env, Val}}; + NewVal -> + application_controller:set_env(mnesia, Env, NewVal), + NewVal + end. + +detect_partitioned_network(Mon, Node) -> + detect_inconcistency([Node], running_partitioned_network), + unlink(Mon), + exit(normal). + +detect_inconcistency([], _Context) -> + ok; +detect_inconcistency(Nodes, Context) -> + Downs = [N || N <- Nodes, mnesia_recover:has_mnesia_down(N)], + {Replies, _BadNodes} = + rpc:multicall(Downs, ?MODULE, has_remote_mnesia_down, [node()]), + report_inconsistency(Replies, Context, ok). + +has_remote_mnesia_down(Node) -> + HasDown = mnesia_recover:has_mnesia_down(Node), + Master = mnesia_recover:get_master_nodes(schema), + if + HasDown == true, Master == [] -> + {true, node()}; + true -> + {false, node()} + end. + +report_inconsistency([{true, Node} | Replies], Context, _Status) -> + %% Oops, Mnesia is already running on the + %% other node AND we both regard each + %% other as down. The database is + %% potentially inconsistent and we has to + %% do tell the applications about it, so + %% they may perform some clever recovery + %% action. + Msg = {inconsistent_database, Context, Node}, + mnesia_lib:report_system_event(Msg), + report_inconsistency(Replies, Context, inconsistent_database); +report_inconsistency([{false, _Node} | Replies], Context, Status) -> + report_inconsistency(Replies, Context, Status); +report_inconsistency([{badrpc, _Reason} | Replies], Context, Status) -> + report_inconsistency(Replies, Context, Status); +report_inconsistency([], _Context, Status) -> + Status. |