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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2011. 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%
%%
%% Dynamic Driver Loader and Linker
%%
%% Interface for dynamic library/shared object driver loader/linker.
%% Provides methods for loading, unloading and listing drivers.
-module(erl_ddll).
-export([load_driver/2, load/2,
unload_driver/1, unload/1, reload/2, reload_driver/2,
format_error/1,info/1,info/0, start/0, stop/0]).
%%----------------------------------------------------------------------------
-type path() :: string() | atom().
-type driver() :: string() | atom().
%%----------------------------------------------------------------------------
-spec start() -> {'error', {'already_started', 'undefined'}}.
start() ->
{error, {already_started,undefined}}.
-spec stop() -> 'ok'.
stop() ->
ok.
-spec load_driver(Path :: path(), Driver :: driver()) ->
'ok' | {'error', any()}.
load_driver(Path, Driver) ->
do_load_driver(Path, Driver, [{driver_options,[kill_ports]}]).
-spec load(Path :: path(), Driver :: driver()) ->
'ok' | {'error', any()}.
load(Path, Driver) ->
do_load_driver(Path, Driver, []).
do_load_driver(Path, Driver, DriverFlags) ->
case erl_ddll:try_load(Path, Driver,[{monitor,pending_driver}]++DriverFlags) of
{error, inconsistent} ->
{error,bad_driver_name}; % BC
{error, What} ->
{error,What};
{ok, already_loaded} ->
ok;
{ok,loaded} ->
ok;
{ok, pending_driver, Ref} ->
receive
{'DOWN', Ref, driver, _, load_cancelled} ->
{error, load_cancelled};
{'UP', Ref, driver, _, permanent} ->
{error, permanent};
{'DOWN', Ref, driver, _, {load_failure, Failure}} ->
{error, Failure};
{'UP', Ref, driver, _, loaded} ->
ok
end
end.
do_unload_driver(Driver,Flags) ->
case erl_ddll:try_unload(Driver,Flags) of
{error,What} ->
{error,What};
{ok, pending_process} ->
ok;
{ok, unloaded} ->
ok;
{ok, pending_driver} ->
ok;
{ok, pending_driver, Ref} ->
receive
{'UP', Ref, driver, _, permanent} ->
{error, permanent};
{'UP', Ref, driver, _, unload_cancelled} ->
ok;
{'DOWN', Ref, driver, _, unloaded} ->
ok
end
end.
-spec unload_driver(Driver :: driver()) -> 'ok' | {'error', any()}.
unload_driver(Driver) ->
do_unload_driver(Driver,[{monitor,pending_driver},kill_ports]).
-spec unload(Driver :: driver()) -> 'ok' | {'error', any()}.
unload(Driver) ->
do_unload_driver(Driver,[]).
-spec reload(Path :: path(), Driver :: driver()) ->
'ok' | {'error', any()}.
reload(Path,Driver) ->
do_load_driver(Path, Driver, [{reload,pending_driver}]).
-spec reload_driver(Path :: path(), Driver :: driver()) ->
'ok' | {'error', any()}.
reload_driver(Path,Driver) ->
do_load_driver(Path, Driver, [{reload,pending_driver},
{driver_options,[kill_ports]}]).
-spec format_error(Code :: atom()) -> string().
format_error(Code) ->
case Code of
%% This is the only error code returned only from erlang code...
%% 'permanent' has a translation in the emulator, even though the erlang code uses it to...
load_cancelled ->
"Loading was cancelled from other process";
_ ->
erl_ddll:format_error_int(Code)
end.
-spec info(Driver :: driver()) -> [{atom(), any()}, ...].
info(Driver) ->
[{processes, erl_ddll:info(Driver,processes)},
{driver_options, erl_ddll:info(Driver,driver_options)},
{port_count, erl_ddll:info(Driver,port_count)},
{linked_in_driver, erl_ddll:info(Driver,linked_in_driver)},
{permanent, erl_ddll:info(Driver,permanent)},
{awaiting_load, erl_ddll:info(Driver,awaiting_load)},
{awaiting_unload, erl_ddll:info(Driver,awaiting_unload)}].
-spec info() -> [{string(), [{atom(), any()}]}].
info() ->
{ok,DriverList} = erl_ddll:loaded_drivers(),
[{X,Y} || X <- DriverList,
Y <- [catch info(X)],
is_list(Y), not lists:member({linked_in_driver,true},Y)].
|
