%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2000-2010. 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(httpd_manager).
-include("httpd.hrl").
-behaviour(gen_server).
%% Application internal API
-export([start/2, start_link/2, start_link/3, start_link/4, stop/1, reload/2]).
-export([new_connection/1, done_connection/1]).
-export([config_lookup/2, config_lookup/3,
config_multi_lookup/2, config_multi_lookup/3,
config_match/2, config_match/3]).
%% gen_server exports
-export([init/1,
handle_call/3, handle_cast/2, handle_info/2,
terminate/2,
code_change/3]).
%% Management exports
-export([block/2, block/3, unblock/1]).
-export([get_admin_state/1, get_usage_state/1]).
-export([is_busy/1,is_busy/2,is_busy_or_blocked/1,is_blocked/1]). %% ???????
-export([get_status/1, get_status/2]).
-export([c/1]).
-record(state,{socket_type = ip_comm,
config_file,
config_db = null,
connections, %% Current request handlers
admin_state = unblocked,
blocker_ref = undefined,
blocking_tmr = undefined,
status = []}).
%%TODO: Clean up this module!
c(Port) ->
Ref = httpd_util:make_name("httpd",undefined,Port),
call(Ref, fake_close).
%%
%% External API
%%
%% Deprecated
start(ConfigFile, ConfigList) ->
Port = proplists:get_value(port,ConfigList,80),
Addr = proplists:get_value(bind_address, ConfigList),
Name = make_name(Addr,Port),
gen_server:start({local,Name},?MODULE,
[ConfigFile, ConfigList, 15000, Addr, Port],[]).
%% Deprecated
start_link(ConfigFile, ConfigList) ->
start_link(ConfigFile, ConfigList, 15000).
start_link(ConfigFile, ConfigList, AcceptTimeout) ->
Port = proplists:get_value(port, ConfigList, 80),
Addr = proplists:get_value(bind_address, ConfigList),
Name = make_name(Addr, Port),
gen_server:start_link({local, Name},?MODULE,
[ConfigFile, ConfigList, AcceptTimeout, Addr, Port],[]).
start_link(ConfigFile, ConfigList, AcceptTimeout, ListenSocket) ->
Port = proplists:get_value(port, ConfigList, 80),
Addr = proplists:get_value(bind_address, ConfigList),
Name = make_name(Addr, Port),
gen_server:start_link({local, Name},?MODULE,
[ConfigFile, ConfigList, AcceptTimeout, Addr,
Port, ListenSocket],[]).
stop(ServerRef) ->
call(ServerRef, stop).
reload(ServerRef, Conf) ->
call(ServerRef, {reload, Conf}).
%%%----------------------------------------------------------------
block(ServerRef, disturbing) ->
call(ServerRef,block);
block(ServerRef, non_disturbing) ->
do_block(ServerRef, non_disturbing, infinity).
block(ServerRef, Method, Timeout) ->
do_block(ServerRef, Method, Timeout).
%% The reason for not using call here, is that the manager cannot
%% _wait_ for completion of the requests. It must be able to do
%% do other things at the same time as the blocking goes on.
do_block(ServerRef, Method, infinity) ->
Ref = make_ref(),
cast(ServerRef, {block, Method, infinity, self(), Ref}),
receive
{block_reply, Reply, Ref} ->
Reply
end;
do_block(ServerRef,Method,Timeout) when Timeout > 0 ->
Ref = make_ref(),
cast(ServerRef,{block,Method,Timeout,self(),Ref}),
receive
{block_reply,Reply,Ref} ->
Reply
end.
%%%----------------------------------------------------------------
%% unblock
unblock(ServerRef) ->
call(ServerRef,unblock).
%% get admin/usage state
get_admin_state(ServerRef) ->
call(ServerRef,get_admin_state).
get_usage_state(ServerRef) ->
call(ServerRef,get_usage_state).
%% get_status
get_status(ServerRef) ->
gen_server:call(ServerRef,get_status).
get_status(ServerRef,Timeout) ->
gen_server:call(ServerRef,get_status,Timeout).
%%
%% Internal API
%%
%% new_connection
new_connection(Manager) ->
gen_server:call(Manager, {new_connection, self()}, infinity).
%% done
done_connection(Manager) ->
gen_server:cast(Manager, {done_connection, self()}).
%% is_busy(ServerRef) -> true | false
%%
%% Tests if the server is (in usage state) busy,
%% i.e. has rached the heavy load limit.
%%
is_busy(ServerRef) ->
gen_server:call(ServerRef,is_busy).
is_busy(ServerRef,Timeout) ->
gen_server:call(ServerRef,is_busy,Timeout).
%% is_busy_or_blocked(ServerRef) -> busy | blocked | false
%%
%% Tests if the server is busy (usage state), i.e. has rached,
%% the heavy load limit, or blocked (admin state) .
%%
is_busy_or_blocked(ServerRef) ->
gen_server:call(ServerRef,is_busy_or_blocked).
%% is_blocked(ServerRef) -> true | false
%%
%% Tests if the server is blocked (admin state) .
%%
is_blocked(ServerRef) ->
gen_server:call(ServerRef,is_blocked).
%%
%% Module API. Theese functions are intended for use from modules only.
%%
config_lookup(Port, Query) ->
config_lookup(undefined, Port, Query).
config_lookup(Addr, Port, Query) ->
Name = httpd_util:make_name("httpd",Addr,Port),
gen_server:call(whereis(Name), {config_lookup, Query}).
config_multi_lookup(Port, Query) ->
config_multi_lookup(undefined,Port,Query).
config_multi_lookup(Addr,Port, Query) ->
Name = httpd_util:make_name("httpd",Addr,Port),
gen_server:call(whereis(Name), {config_multi_lookup, Query}).
config_match(Port, Pattern) ->
config_match(undefined,Port,Pattern).
config_match(Addr, Port, Pattern) ->
Name = httpd_util:make_name("httpd",Addr,Port),
gen_server:call(whereis(Name), {config_match, Pattern}).
%%
%% Server call-back functions
%%
%% init
init([ConfigFile, ConfigList, AcceptTimeout, Addr, Port]) ->
process_flag(trap_exit, true),
case (catch do_init(ConfigFile, ConfigList, AcceptTimeout, Addr, Port)) of
{error, Reason} ->
String = lists:flatten(
io_lib:format("Failed initiating web server: "
"~n~p"
"~n~p"
"~n", [ConfigFile, Reason])),
error_logger:error_report(String),
{stop, {error, Reason}};
{ok, State} ->
{ok, State}
end;
init([ConfigFile, ConfigList, AcceptTimeout, Addr, Port, ListenInfo]) ->
process_flag(trap_exit, true),
case (catch do_init(ConfigFile, ConfigList, AcceptTimeout,
Addr, Port, ListenInfo)) of
{error, Reason} ->
String = lists:flatten(
io_lib:format("Failed initiating web server: "
"~n~p"
"~n~p"
"~n", [ConfigFile, Reason])),
error_logger:error_report(String),
{stop, {error, Reason}};
{ok, State} ->
{ok, State}
end.
do_init(ConfigFile, ConfigList, AcceptTimeout, Addr, Port) ->
NewConfigFile = proplists:get_value(file, ConfigList, ConfigFile),
ConfigDB = do_initial_store(ConfigList),
SocketType = httpd_conf:lookup_socket_type(ConfigDB),
case httpd_acceptor_sup:start_acceptor(SocketType, Addr,
Port, ConfigDB, AcceptTimeout) of
{ok, _Pid} ->
Status = [{max_conn, 0},
{last_heavy_load, never},
{last_connection, never}],
State = #state{socket_type = SocketType,
config_file = NewConfigFile,
config_db = ConfigDB,
connections = [],
status = Status},
{ok, State};
Else ->
Else
end.
do_init(ConfigFile, ConfigList, AcceptTimeout, Addr, Port, ListenInfo) ->
NewConfigFile = proplists:get_value(file, ConfigList, ConfigFile),
ConfigDB = do_initial_store(ConfigList),
SocketType = httpd_conf:lookup_socket_type(ConfigDB),
case httpd_acceptor_sup:start_acceptor(SocketType, Addr,
Port, ConfigDB,
AcceptTimeout, ListenInfo) of
{ok, _Pid} ->
Status = [{max_conn,0}, {last_heavy_load,never},
{last_connection,never}],
State = #state{socket_type = SocketType,
config_file = NewConfigFile,
config_db = ConfigDB,
connections = [],
status = Status},
{ok, State};
Else ->
Else
end.
do_initial_store(ConfigList) ->
case httpd_conf:store(ConfigList) of
{ok, ConfigDB} ->
ConfigDB;
{error, Reason} ->
throw({error, Reason})
end.
%% handle_call
handle_call(stop, _From, State) ->
{stop, normal, ok, State};
handle_call({config_lookup, Query}, _From, State) ->
Res = httpd_util:lookup(State#state.config_db, Query),
{reply, Res, State};
handle_call({config_multi_lookup, Query}, _From, State) ->
Res = httpd_util:multi_lookup(State#state.config_db, Query),
{reply, Res, State};
handle_call({config_match, Query}, _From, State) ->
Res = ets:match_object(State#state.config_db, Query),
{reply, Res, State};
handle_call(get_status, _From, State) ->
ManagerStatus = manager_status(self()),
S1 = [{current_conn,length(State#state.connections)}|State#state.status]++
[ManagerStatus],
{reply,S1,State};
handle_call(is_busy, _From, State) ->
Reply = case get_ustate(State) of
busy ->
true;
_ ->
false
end,
{reply,Reply,State};
handle_call(is_busy_or_blocked, _From, State) ->
Reply =
case get_astate(State) of
unblocked ->
case get_ustate(State) of
busy ->
busy;
_ ->
false
end;
_ ->
blocked
end,
{reply,Reply,State};
handle_call(is_blocked, _From, State) ->
Reply =
case get_astate(State) of
unblocked ->
false;
_ ->
true
end,
{reply,Reply,State};
handle_call(get_admin_state, _From, State) ->
Reply = get_astate(State),
{reply,Reply,State};
handle_call(get_usage_state, _From, State) ->
Reply = get_ustate(State),
{reply,Reply,State};
handle_call({reload, Conf}, _From, State)
when State#state.admin_state =:= blocked ->
case handle_reload(Conf, State) of
{stop, Reply,S1} ->
{stop, Reply, S1};
{_, Reply, S1} ->
{reply,Reply,S1}
end;
handle_call({reload, _}, _From, State) ->
{reply,{error,{invalid_admin_state,State#state.admin_state}},State};
handle_call(block, _From, State) ->
{Reply,S1} = handle_block(State),
{reply,Reply,S1};
handle_call(unblock, {From,_Tag}, State) ->
{Reply,S1} = handle_unblock(State,From),
{reply, Reply, S1};
handle_call({new_connection, Pid}, _From, State) ->
{Status, NewState} = handle_new_connection(State, Pid),
{reply, Status, NewState};
handle_call(Request, From, State) ->
String =
lists:flatten(
io_lib:format("Unknown request "
"~n ~p"
"~nto manager (~p)"
"~nfrom ~p",
[Request, self(), From])),
report_error(State,String),
{reply, ok, State}.
%% handle_cast
handle_cast({done_connection, Pid}, State) ->
S1 = handle_done_connection(State, Pid),
{noreply, S1};
handle_cast({block, disturbing, Timeout, From, Ref}, State) ->
S1 = handle_block(State, Timeout, From, Ref),
{noreply,S1};
handle_cast({block, non_disturbing, Timeout, From, Ref}, State) ->
S1 = handle_nd_block(State, Timeout, From, Ref),
{noreply,S1};
handle_cast(Message, State) ->
String =
lists:flatten(
io_lib:format("Unknown message "
"~n ~p"
"~nto manager (~p)",
[Message, self()])),
report_error(State, String),
{noreply, State}.
%% handle_info
handle_info({block_timeout, Method}, State) ->
S1 = handle_block_timeout(State,Method),
{noreply, S1};
handle_info({'DOWN', Ref, process, _Object, _Info}, State) ->
S1 =
case State#state.blocker_ref of
Ref ->
handle_blocker_exit(State);
_ ->
%% Not our blocker, so ignore
State
end,
{noreply, S1};
handle_info({'EXIT', _, normal}, State) ->
{noreply, State};
handle_info({'EXIT', _, blocked}, S) ->
{noreply, S};
handle_info({'EXIT', Pid, Reason}, State) ->
S1 = check_connections(State, Pid, Reason),
{noreply, S1};
handle_info(Info, State) ->
String =
lists:flatten(
io_lib:format("Unknown info "
"~n ~p"
"~nto manager (~p)",
[Info, self()])),
report_error(State, String),
{noreply, State}.
%% terminate
terminate(_, #state{config_db = Db}) ->
httpd_conf:remove_all(Db),
ok.
%% code_change({down,ToVsn}, State, Extra)
%%
code_change({down,_ToVsn}, State, _Extra) ->
{ok,State};
%% code_change(FromVsn, State, Extra)
%%
code_change(_FromVsn, State, _Extra) ->
{ok,State}.
%% -------------------------------------------------------------------------
%% check_connection
%%
%%
%%
%%
check_connections(#state{connections = []} = State, _Pid, _Reason) ->
State;
check_connections(#state{connections = Connections} = State, Pid, _Reason) ->
State#state{connections = lists:delete(Pid, Connections)}.
%% -------------------------------------------------------------------------
%% handle_[new | done]_connection
%%
%%
%%
%%
handle_new_connection(State, Handler) ->
UsageState = get_ustate(State),
AdminState = get_astate(State),
handle_new_connection(UsageState, AdminState, State, Handler).
handle_new_connection(busy, unblocked, State, _Handler) ->
Status = update_heavy_load_status(State#state.status),
{{reject, busy},
State#state{status = Status}};
handle_new_connection(_UsageState, unblocked, State, Handler) ->
Connections = State#state.connections,
Status = update_connection_status(State#state.status,
length(Connections)+1),
link(Handler),
{{ok, accept},
State#state{connections = [Handler|Connections], status = Status}};
handle_new_connection(_UsageState, _AdminState, State, _Handler) ->
{{reject, blocked},
State}.
handle_done_connection(#state{admin_state = shutting_down,
connections = Connections} = State, Handler) ->
unlink(Handler),
case lists:delete(Handler, Connections) of
[] -> % Ok, block complete
demonitor_blocker(State#state.blocker_ref),
{Tmr,From,Ref} = State#state.blocking_tmr,
stop_block_tmr(Tmr),
From ! {block_reply,ok,Ref},
State#state{admin_state = blocked, connections = [],
blocker_ref = undefined};
Connections1 ->
State#state{connections = Connections1}
end;
handle_done_connection(#state{connections = Connections} = State, Handler) ->
State#state{connections = lists:delete(Handler, Connections)}.
%% -------------------------------------------------------------------------
%% handle_block
%%
%%
%%
%%
handle_block(#state{admin_state = AdminState} = S) ->
handle_block(S, AdminState).
handle_block(S,unblocked) ->
%% Kill all connections
[kill_handler(Pid) || Pid <- S#state.connections],
{ok,S#state{connections = [], admin_state = blocked}};
handle_block(S,blocked) ->
{ok,S};
handle_block(S,shutting_down) ->
{{error,shutting_down},S}.
kill_handler(Pid) ->
exit(Pid, blocked).
handle_block(S,Timeout,From,Ref) when Timeout >= 0 ->
do_block(S,Timeout,From,Ref);
handle_block(S,Timeout,From,Ref) ->
Reply = {error,{invalid_block_request,Timeout}},
From ! {block_reply,Reply,Ref},
S.
do_block(S,Timeout,From,Ref) ->
case S#state.connections of
[] ->
%% Already in idle usage state => go directly to blocked
From ! {block_reply,ok,Ref},
S#state{admin_state = blocked};
_ ->
%% Active or Busy usage state => go to shutting_down
%% Make sure we get to know if blocker dies...
MonitorRef = monitor_blocker(From),
Tmr = {start_block_tmr(Timeout,disturbing),From,Ref},
S#state{admin_state = shutting_down,
blocker_ref = MonitorRef, blocking_tmr = Tmr}
end.
handle_nd_block(S,infinity,From,Ref) ->
do_nd_block(S,infinity,From,Ref);
handle_nd_block(S,Timeout,From,Ref) when Timeout >= 0 ->
do_nd_block(S,Timeout,From,Ref);
handle_nd_block(S,Timeout,From,Ref) ->
Reply = {error,{invalid_block_request,Timeout}},
From ! {block_reply,Reply,Ref},
S.
do_nd_block(S,Timeout,From,Ref) ->
case S#state.connections of
[] ->
%% Already in idle usage state => go directly to blocked
From ! {block_reply,ok,Ref},
S#state{admin_state = blocked};
_ ->
%% Active or Busy usage state => go to shutting_down
%% Make sure we get to know if blocker dies...
MonitorRef = monitor_blocker(From),
Tmr = {start_block_tmr(Timeout,non_disturbing),From,Ref},
S#state{admin_state = shutting_down,
blocker_ref = MonitorRef, blocking_tmr = Tmr}
end.
handle_block_timeout(S,Method) ->
%% Time to take this to the road...
demonitor_blocker(S#state.blocker_ref),
handle_block_timeout1(S,Method,S#state.blocking_tmr).
handle_block_timeout1(S,non_disturbing,{_,From,Ref}) ->
From ! {block_reply,{error,timeout},Ref},
S#state{admin_state = unblocked,
blocker_ref = undefined, blocking_tmr = undefined};
handle_block_timeout1(S,disturbing,{_,From,Ref}) ->
[exit(Pid,blocked) || Pid <- S#state.connections],
From ! {block_reply,ok,Ref},
S#state{admin_state = blocked, connections = [],
blocker_ref = undefined, blocking_tmr = undefined};
handle_block_timeout1(S,Method,{_,From,Ref}) ->
From ! {block_reply,{error,{unknown_block_method,Method}},Ref},
S#state{admin_state = blocked, connections = [],
blocker_ref = undefined, blocking_tmr = undefined};
handle_block_timeout1(S, _Method, _TmrInfo) ->
S#state{admin_state = unblocked,
blocker_ref = undefined, blocking_tmr = undefined}.
handle_unblock(S, FromA) ->
handle_unblock(S, FromA, S#state.admin_state).
handle_unblock(S, _FromA, unblocked) ->
{ok,S};
handle_unblock(S, FromA, _AdminState) ->
stop_block_tmr(S#state.blocking_tmr),
case S#state.blocking_tmr of
{_Tmr,FromB,Ref} ->
%% Another process is trying to unblock
%% Inform the blocker
FromB ! {block_reply, {error,{unblocked,FromA}},Ref};
_ ->
ok
end,
{ok,S#state{admin_state = unblocked, blocking_tmr = undefined}}.
%% The blocker died so we give up on the block.
handle_blocker_exit(S) ->
{Tmr,_From,_Ref} = S#state.blocking_tmr,
stop_block_tmr(Tmr),
S#state{admin_state = unblocked,
blocker_ref = undefined, blocking_tmr = undefined}.
%% -------------------------------------------------------------------------
%% handle_reload
%%
%%
%%
%%
handle_reload(undefined, #state{config_file = undefined} = State) ->
{continue, {error, undefined_config_file}, State};
handle_reload(undefined, #state{config_file = ConfigFile} = State) ->
case load_config(ConfigFile) of
{ok, Config} ->
do_reload(Config, State);
{error, Reason} ->
error_logger:error_msg("Bad config file: ~p~n", [Reason]),
{continue, {error, Reason}, State}
end;
handle_reload(Config, State) ->
do_reload(Config, State).
load_config(ConfigFile) ->
case httpd_conf:load(ConfigFile) of
{ok, Config} ->
httpd_conf:validate_properties(Config);
Error ->
Error
end.
do_reload(Config, #state{config_db = Db} = State) ->
case (catch check_constant_values(Db, Config)) of
ok ->
%% If something goes wrong between the remove
%% and the store where fu-ed
httpd_conf:remove_all(Db),
case httpd_conf:store(Config) of
{ok, NewConfigDB} ->
{continue, ok, State#state{config_db = NewConfigDB}};
Error ->
{stop, Error, State}
end;
Error ->
{continue, Error, State}
end.
check_constant_values(Db, Config) ->
%% Check port number
Port = httpd_util:lookup(Db,port),
case proplists:get_value(port,Config) of %% MUST be equal
Port ->
ok;
OtherPort ->
throw({error,{port_number_changed,Port,OtherPort}})
end,
%% Check bind address
Addr = httpd_util:lookup(Db,bind_address),
case proplists:get_value(bind_address, Config) of %% MUST be equal
Addr ->
ok;
OtherAddr ->
throw({error,{addr_changed,Addr,OtherAddr}})
end,
%% Check socket type
SockType = httpd_util:lookup(Db, socket_type),
case proplists:get_value(socket_type, Config) of %% MUST be equal
SockType ->
ok;
OtherSockType ->
throw({error,{sock_type_changed,SockType,OtherSockType}})
end,
ok.
%% get_ustate(State) -> idle | active | busy
%%
%% Retrieve the usage state of the HTTP server:
%% 0 active connection -> idle
%% max_clients active connections -> busy
%% Otherwise -> active
%%
get_ustate(State) ->
get_ustate(length(State#state.connections),State).
get_ustate(0,_State) ->
idle;
get_ustate(ConnectionCnt,State) ->
ConfigDB = State#state.config_db,
case httpd_util:lookup(ConfigDB, max_clients, 150) of
ConnectionCnt ->
busy;
_ ->
active
end.
get_astate(S) -> S#state.admin_state.
%% Timer handling functions
start_block_tmr(infinity,_) ->
undefined;
start_block_tmr(T,M) ->
erlang:send_after(T,self(),{block_timeout,M}).
stop_block_tmr(undefined) ->
ok;
stop_block_tmr(Ref) ->
erlang:cancel_timer(Ref).
%% Monitor blocker functions
monitor_blocker(Pid) when is_pid(Pid) ->
case (catch erlang:monitor(process,Pid)) of
{'EXIT', _Reason} ->
undefined;
MonitorRef ->
MonitorRef
end;
monitor_blocker(_) ->
undefined.
demonitor_blocker(undefined) ->
ok;
demonitor_blocker(Ref) ->
(catch erlang:demonitor(Ref)).
%% Some status utility functions
update_heavy_load_status(Status) ->
update_status_with_time(Status,last_heavy_load).
update_connection_status(Status,ConnCount) ->
S1 = case lists:keysearch(max_conn,1,Status) of
{value, {max_conn, C1}} when ConnCount > C1 ->
lists:keyreplace(max_conn,1,Status,{max_conn,ConnCount});
{value, {max_conn, _C2}} ->
Status;
false ->
[{max_conn, ConnCount} | Status]
end,
update_status_with_time(S1,last_connection).
update_status_with_time(Status,Key) ->
lists:keyreplace(Key,1,Status,{Key,universal_time()}).
universal_time() -> calendar:universal_time().
manager_status(P) ->
Items = [status, message_queue_len, reductions,
heap_size, stack_size],
{manager_status, process_status(P,Items,[])}.
process_status(P,[],L) ->
[{pid,P}|lists:reverse(L)];
process_status(P,[H|T],L) ->
case (catch process_info(P,H)) of
{H, Value} ->
process_status(P,T,[{H,Value}|L]);
_ ->
process_status(P,T,[{H,undefined}|L])
end.
make_name(Addr,Port) ->
httpd_util:make_name("httpd",Addr,Port).
report_error(State,String) ->
Cdb = State#state.config_db,
error_logger:error_report(String),
mod_log:report_error(Cdb,String),
mod_disk_log:report_error(Cdb,String).
%%
call(ServerRef,Request) ->
gen_server:call(ServerRef,Request).
cast(ServerRef,Message) ->
gen_server:cast(ServerRef,Message).
