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Diffstat (limited to 'lib/common_test/src/ct_hooks_lock.erl')
-rw-r--r-- | lib/common_test/src/ct_hooks_lock.erl | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/lib/common_test/src/ct_hooks_lock.erl b/lib/common_test/src/ct_hooks_lock.erl new file mode 100644 index 0000000000..98794201bb --- /dev/null +++ b/lib/common_test/src/ct_hooks_lock.erl @@ -0,0 +1,132 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2004-2010. 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% +%% + +%%% @doc Common Test Framework test execution control module. +%%% +%%% <p>This module is a proxy for calling and handling locks in +%%% common test hooks.</p> + +-module(ct_hooks_lock). + +-behaviour(gen_server). + +%% API +-export([start/1, stop/1, request/0, release/0]). + +%% 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, { id, locked = false, requests = [] }). + +%%%=================================================================== +%%% API +%%%=================================================================== + +%% @doc Starts the server +start(Id) -> + case gen_server:start({local, ?SERVER}, ?MODULE, Id, []) of + {error,{already_started, Pid}} -> + {ok,Pid}; + Else -> + Else + end. + +stop(Id) -> + try + gen_server:call(?SERVER, {stop,Id}) + catch exit:{noproc,_} -> + stopped + end. + +request() -> + try + gen_server:call(?SERVER,{request,self()},infinity) + catch exit:{noproc,_} -> + locked + end. + +release() -> + try + gen_server:call(?SERVER,{release,self()}) + catch exit:{noproc,_} -> + unlocked + end. + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +%% @doc Initiates the server +init(Id) -> + {ok, #state{ id = Id }}. + +%% @doc Handling call messages +handle_call({stop,Id}, _From, #state{ id = Id, requests = Reqs } = State) -> + [gen_server:reply(Req, locker_stopped) || {Req,_ReqId} <- Reqs], + {stop, normal, stopped, State}; +handle_call({stop,_Id}, _From, State) -> + {reply, stopped, State}; +handle_call({request, Pid}, _From, #state{ locked = false, + requests = [] } = State) -> + Ref = monitor(process, Pid), + {reply, locked, State#state{ locked = {true, Pid, Ref}} }; +handle_call({request, Pid}, From, #state{ requests = Reqs } = State) -> + {noreply, State#state{ requests = Reqs ++ [{From,Pid}] }}; +handle_call({release, Pid}, _From, #state{ locked = {true, Pid, Ref}, + requests = []} = State) -> + demonitor(Ref,[flush]), + {reply, unlocked, State#state{ locked = false }}; +handle_call({release, Pid}, _From, + #state{ locked = {true, Pid, Ref}, + requests = [{NextFrom,NextPid}|Rest]} = State) -> + demonitor(Ref,[flush]), + gen_server:reply(NextFrom,locked), + NextRef = monitor(process, NextPid), + {reply,unlocked,State#state{ locked = {true, NextPid, NextRef}, + requests = Rest } }; +handle_call({release, _Pid}, _From, State) -> + {reply, not_locked, State}. + +%% @doc Handling cast messages +handle_cast(_Msg, State) -> + {noreply, State}. + +%% @doc Handling all non call/cast messages +handle_info({'DOWN',Ref,process,Pid,_}, + #state{ locked = {true, Pid, Ref}, + requests = [{NextFrom,NextPid}|Rest] } = State) -> + gen_server:reply(NextFrom, locked), + NextRef = monitor(process, NextPid), + {noreply,State#state{ locked = {true, NextPid, NextRef}, + requests = Rest } }. + +%% @doc This function is called by a gen_server when it is about to terminate. +terminate(_Reason, _State) -> + ok. + +%% @doc Convert process state when code is changed +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%% ------------------------------------------------------------------------- +%% Internal Functions +%% ------------------------------------------------------------------------- |