1 /******************************************************************************
2 *
3 * Copyright 2014 Google, Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 ******************************************************************************/
18
19 #define LOG_TAG "bt_core_module"
20
21 #include "btcore/include/module.h"
22
23 #include <base/logging.h>
24 #include <dlfcn.h>
25 #include <string.h>
26
27 #include <mutex>
28 #include <unordered_map>
29
30 #include "check.h"
31 #include "common/message_loop_thread.h"
32 #include "osi/include/allocator.h"
33 #include "osi/include/log.h"
34 #include "osi/include/osi.h"
35
36 using bluetooth::common::MessageLoopThread;
37
38 typedef enum {
39 MODULE_STATE_NONE = 0,
40 MODULE_STATE_INITIALIZED = 1,
41 MODULE_STATE_STARTED = 2
42 } module_state_t;
43
44 static std::unordered_map<const module_t*, module_state_t> metadata;
45
46 // TODO(jamuraa): remove this lock after the startup sequence is clean
47 static std::mutex metadata_mutex;
48
49 static bool call_lifecycle_function(module_lifecycle_fn function);
50 static module_state_t get_module_state(const module_t* module);
51 static void set_module_state(const module_t* module, module_state_t state);
52
module_management_start(void)53 void module_management_start(void) {}
54
module_management_stop(void)55 void module_management_stop(void) { metadata.clear(); }
56
get_module(const char * name)57 const module_t* get_module(const char* name) {
58 module_t* module = (module_t*)dlsym(RTLD_DEFAULT, name);
59 CHECK(module);
60 return module;
61 }
62
module_init(const module_t * module)63 bool module_init(const module_t* module) {
64 CHECK(module != NULL);
65 CHECK(get_module_state(module) == MODULE_STATE_NONE);
66
67 if (!call_lifecycle_function(module->init)) {
68 LOG_ERROR("%s Failed to initialize module \"%s\"", __func__, module->name);
69 return false;
70 }
71
72 set_module_state(module, MODULE_STATE_INITIALIZED);
73 return true;
74 }
75
module_start_up(const module_t * module)76 bool module_start_up(const module_t* module) {
77 CHECK(module != NULL);
78 // TODO(zachoverflow): remove module->init check once automagic order/call is
79 // in place.
80 // This hack is here so modules which don't require init don't have to have
81 // useless calls
82 // as we're converting the startup sequence.
83 CHECK(get_module_state(module) == MODULE_STATE_INITIALIZED ||
84 module->init == NULL);
85
86 LOG_INFO("%s Starting module \"%s\"", __func__, module->name);
87 if (!call_lifecycle_function(module->start_up)) {
88 LOG_ERROR("%s Failed to start up module \"%s\"", __func__, module->name);
89 return false;
90 }
91 LOG_INFO("%s Started module \"%s\"", __func__, module->name);
92
93 set_module_state(module, MODULE_STATE_STARTED);
94 return true;
95 }
96
module_shut_down(const module_t * module)97 void module_shut_down(const module_t* module) {
98 CHECK(module != NULL);
99 module_state_t state = get_module_state(module);
100 CHECK(state <= MODULE_STATE_STARTED);
101
102 // Only something to do if the module was actually started
103 if (state < MODULE_STATE_STARTED) return;
104
105 LOG_INFO("%s Shutting down module \"%s\"", __func__, module->name);
106 if (!call_lifecycle_function(module->shut_down)) {
107 LOG_ERROR("%s Failed to shutdown module \"%s\". Continuing anyway.",
108 __func__, module->name);
109 }
110 LOG_INFO("%s Shutdown of module \"%s\" completed", __func__, module->name);
111
112 set_module_state(module, MODULE_STATE_INITIALIZED);
113 }
114
module_clean_up(const module_t * module)115 void module_clean_up(const module_t* module) {
116 CHECK(module != NULL);
117 module_state_t state = get_module_state(module);
118 CHECK(state <= MODULE_STATE_INITIALIZED);
119
120 // Only something to do if the module was actually initialized
121 if (state < MODULE_STATE_INITIALIZED) return;
122
123 LOG_INFO("%s Cleaning up module \"%s\"", __func__, module->name);
124 if (!call_lifecycle_function(module->clean_up)) {
125 LOG_ERROR("%s Failed to cleanup module \"%s\". Continuing anyway.",
126 __func__, module->name);
127 }
128 LOG_INFO("%s Cleanup of module \"%s\" completed", __func__, module->name);
129
130 set_module_state(module, MODULE_STATE_NONE);
131 }
132
call_lifecycle_function(module_lifecycle_fn function)133 static bool call_lifecycle_function(module_lifecycle_fn function) {
134 // A NULL lifecycle function means it isn't needed, so assume success
135 if (!function) return true;
136
137 future_t* future = function();
138
139 // A NULL future means synchronous success
140 if (!future) return true;
141
142 // Otherwise fall back to the future
143 return future_await(future);
144 }
145
get_module_state(const module_t * module)146 static module_state_t get_module_state(const module_t* module) {
147 std::lock_guard<std::mutex> lock(metadata_mutex);
148 auto map_ptr = metadata.find(module);
149
150 return (map_ptr != metadata.end()) ? map_ptr->second : MODULE_STATE_NONE;
151 }
152
set_module_state(const module_t * module,module_state_t state)153 static void set_module_state(const module_t* module, module_state_t state) {
154 std::lock_guard<std::mutex> lock(metadata_mutex);
155 metadata[module] = state;
156 }
157