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 <bluetooth/log.h>
24 #include <dlfcn.h>
25 #include <string.h>
26
27 #include <mutex>
28 #include <unordered_map>
29
30 #include "common/message_loop_thread.h"
31 #include "os/log.h"
32
33 using bluetooth::common::MessageLoopThread;
34 using namespace bluetooth;
35
36 typedef enum {
37 MODULE_STATE_NONE = 0,
38 MODULE_STATE_INITIALIZED = 1,
39 MODULE_STATE_STARTED = 2
40 } module_state_t;
41
42 static std::unordered_map<const module_t*, module_state_t> metadata;
43
44 // TODO(jamuraa): remove this lock after the startup sequence is clean
45 static std::mutex metadata_mutex;
46
47 static bool call_lifecycle_function(module_lifecycle_fn function);
48 static module_state_t get_module_state(const module_t* module);
49 static void set_module_state(const module_t* module, module_state_t state);
50
module_management_start(void)51 void module_management_start(void) {}
52
module_management_stop(void)53 void module_management_stop(void) { metadata.clear(); }
54
get_module(const char * name)55 const module_t* get_module(const char* name) {
56 module_t* module = (module_t*)dlsym(RTLD_DEFAULT, name);
57 log::assert_that(module != nullptr, "assert failed: module != nullptr");
58 return module;
59 }
60
module_init(const module_t * module)61 bool module_init(const module_t* module) {
62 log::assert_that(module != NULL, "assert failed: module != NULL");
63 log::assert_that(
64 get_module_state(module) == MODULE_STATE_NONE,
65 "assert failed: get_module_state(module) == MODULE_STATE_NONE");
66
67 if (!call_lifecycle_function(module->init)) {
68 log::error("Failed to initialize module \"{}\"", 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 log::assert_that(module != NULL, "assert failed: 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 log::assert_that(get_module_state(module) == MODULE_STATE_INITIALIZED ||
84 module->init == NULL,
85 "assert failed: get_module_state(module) == "
86 "MODULE_STATE_INITIALIZED || module->init == NULL");
87
88 log::info("Starting module \"{}\"", module->name);
89 if (!call_lifecycle_function(module->start_up)) {
90 log::error("Failed to start up module \"{}\"", module->name);
91 return false;
92 }
93 log::info("Started module \"{}\"", module->name);
94
95 set_module_state(module, MODULE_STATE_STARTED);
96 return true;
97 }
98
module_shut_down(const module_t * module)99 void module_shut_down(const module_t* module) {
100 log::assert_that(module != NULL, "assert failed: module != NULL");
101 module_state_t state = get_module_state(module);
102 log::assert_that(state <= MODULE_STATE_STARTED,
103 "assert failed: state <= MODULE_STATE_STARTED");
104
105 // Only something to do if the module was actually started
106 if (state < MODULE_STATE_STARTED) return;
107
108 log::info("Shutting down module \"{}\"", module->name);
109 if (!call_lifecycle_function(module->shut_down)) {
110 log::error("Failed to shutdown module \"{}\". Continuing anyway.",
111 module->name);
112 }
113 log::info("Shutdown of module \"{}\" completed", module->name);
114
115 set_module_state(module, MODULE_STATE_INITIALIZED);
116 }
117
module_clean_up(const module_t * module)118 void module_clean_up(const module_t* module) {
119 log::assert_that(module != NULL, "assert failed: module != NULL");
120 module_state_t state = get_module_state(module);
121 log::assert_that(state <= MODULE_STATE_INITIALIZED,
122 "assert failed: state <= MODULE_STATE_INITIALIZED");
123
124 // Only something to do if the module was actually initialized
125 if (state < MODULE_STATE_INITIALIZED) return;
126
127 log::info("Cleaning up module \"{}\"", module->name);
128 if (!call_lifecycle_function(module->clean_up)) {
129 log::error("Failed to cleanup module \"{}\". Continuing anyway.",
130 module->name);
131 }
132 log::info("Cleanup of module \"{}\" completed", module->name);
133
134 set_module_state(module, MODULE_STATE_NONE);
135 }
136
call_lifecycle_function(module_lifecycle_fn function)137 static bool call_lifecycle_function(module_lifecycle_fn function) {
138 // A NULL lifecycle function means it isn't needed, so assume success
139 if (!function) return true;
140
141 future_t* future = function();
142
143 // A NULL future means synchronous success
144 if (!future) return true;
145
146 // Otherwise fall back to the future
147 return future_await(future);
148 }
149
get_module_state(const module_t * module)150 static module_state_t get_module_state(const module_t* module) {
151 std::lock_guard<std::mutex> lock(metadata_mutex);
152 auto map_ptr = metadata.find(module);
153
154 return (map_ptr != metadata.end()) ? map_ptr->second : MODULE_STATE_NONE;
155 }
156
set_module_state(const module_t * module,module_state_t state)157 static void set_module_state(const module_t* module, module_state_t state) {
158 std::lock_guard<std::mutex> lock(metadata_mutex);
159 metadata[module] = state;
160 }
161