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
133
134
135
136
137
138
|
%% The contents of this file are subject to the Mozilla Public License
%% Version 1.1 (the "License"); you may not use this file except in
%% compliance with the License. You may obtain a copy of the License
%% at http://www.mozilla.org/MPL/
%%
%% 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.
%%
%% The Original Code is RabbitMQ.
%%
%% The Initial Developer of the Original Code is VMware, Inc.
%% Copyright (c) 2007-2013 VMware, Inc. All rights reserved.
%%
-module(app_utils).
-export([load_applications/1, start_applications/1, start_applications/2,
stop_applications/1, stop_applications/2, app_dependency_order/2,
wait_for_applications/1]).
-ifdef(use_specs).
-type error_handler() :: fun((atom(), any()) -> 'ok').
-spec load_applications([atom()]) -> 'ok'.
-spec start_applications([atom()]) -> 'ok'.
-spec stop_applications([atom()]) -> 'ok'.
-spec start_applications([atom()], error_handler()) -> 'ok'.
-spec stop_applications([atom()], error_handler()) -> 'ok'.
-spec wait_for_applications([atom()]) -> 'ok'.
-spec app_dependency_order([atom()], boolean()) -> [digraph:vertex()].
-endif.
%%---------------------------------------------------------------------------
%% Public API
load_applications(Apps) ->
load_applications(queue:from_list(Apps), sets:new()),
ok.
start_applications(Apps) ->
start_applications(
Apps, fun (App, Reason) ->
throw({error, {cannot_start_application, App, Reason}})
end).
stop_applications(Apps) ->
stop_applications(
Apps, fun (App, Reason) ->
throw({error, {cannot_stop_application, App, Reason}})
end).
start_applications(Apps, ErrorHandler) ->
manage_applications(fun lists:foldl/3,
fun application:start/1,
fun application:stop/1,
already_started,
ErrorHandler,
Apps).
stop_applications(Apps, ErrorHandler) ->
manage_applications(fun lists:foldr/3,
fun application:stop/1,
fun application:start/1,
not_started,
ErrorHandler,
Apps).
wait_for_applications(Apps) ->
[wait_for_application(App) || App <- Apps], ok.
app_dependency_order(RootApps, StripUnreachable) ->
{ok, G} = rabbit_misc:build_acyclic_graph(
fun (App, _Deps) -> [{App, App}] end,
fun (App, Deps) -> [{Dep, App} || Dep <- Deps] end,
[{App, app_dependencies(App)} ||
{App, _Desc, _Vsn} <- application:loaded_applications()]),
try
case StripUnreachable of
true -> digraph:del_vertices(G, digraph:vertices(G) --
digraph_utils:reachable(RootApps, G));
false -> ok
end,
digraph_utils:topsort(G)
after
true = digraph:delete(G)
end.
%%---------------------------------------------------------------------------
%% Private API
wait_for_application(Application) ->
case lists:keymember(Application, 1, application:which_applications()) of
true -> ok;
false -> timer:sleep(1000),
wait_for_application(Application)
end.
load_applications(Worklist, Loaded) ->
case queue:out(Worklist) of
{empty, _WorkList} ->
ok;
{{value, App}, Worklist1} ->
case sets:is_element(App, Loaded) of
true -> load_applications(Worklist1, Loaded);
false -> case application:load(App) of
ok -> ok;
{error, {already_loaded, App}} -> ok;
Error -> throw(Error)
end,
load_applications(
queue:join(Worklist1,
queue:from_list(app_dependencies(App))),
sets:add_element(App, Loaded))
end
end.
app_dependencies(App) ->
case application:get_key(App, applications) of
undefined -> [];
{ok, Lst} -> Lst
end.
manage_applications(Iterate, Do, Undo, SkipError, ErrorHandler, Apps) ->
Iterate(fun (App, Acc) ->
case Do(App) of
ok -> [App | Acc];
{error, {SkipError, _}} -> Acc;
{error, Reason} ->
lists:foreach(Undo, Acc),
ErrorHandler(App, Reason)
end
end, [], Apps),
ok.
|
