1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2004-2011. 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
%% -------------------------------------------------------------------------
|
