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 "common/message_loop_thread.h"
31 #include "osi/include/allocator.h"
32 #include "osi/include/log.h"
33 #include "osi/include/osi.h"
34
35 using bluetooth::common::MessageLoopThread;
36
37 typedef enum {
38 MODULE_STATE_NONE = 0,
39 MODULE_STATE_INITIALIZED = 1,
40 MODULE_STATE_STARTED = 2
41 } module_state_t;
42
43 static std::unordered_map<const module_t*, module_state_t> metadata;
44
45 // TODO(jamuraa): remove this lock after the startup sequence is clean
46 static std::mutex metadata_mutex;
47
48 static bool call_lifecycle_function(module_lifecycle_fn function);
49 static module_state_t get_module_state(const module_t* module);
50 static void set_module_state(const module_t* module, module_state_t state);
51
module_management_start(void)52 void module_management_start(void) {}
53
module_management_stop(void)54 void module_management_stop(void) { metadata.clear(); }
55
get_module(const char * name)56 const module_t* get_module(const char* name) {
57 module_t* module = (module_t*)dlsym(RTLD_DEFAULT, name);
58 CHECK(module);
59 return module;
60 }
61
module_init(const module_t * module)62 bool module_init(const module_t* module) {
63 CHECK(module != NULL);
64 CHECK(get_module_state(module) == MODULE_STATE_NONE);
65
66 if (!call_lifecycle_function(module->init)) {
67 LOG_ERROR("%s Failed to initialize module \"%s\"", __func__, module->name);
68 return false;
69 }
70
71 set_module_state(module, MODULE_STATE_INITIALIZED);
72 return true;
73 }
74
module_start_up(const module_t * module)75 bool module_start_up(const module_t* module) {
76 CHECK(module != NULL);
77 // TODO(zachoverflow): remove module->init check once automagic order/call is
78 // in place.
79 // This hack is here so modules which don't require init don't have to have
80 // useless calls
81 // as we're converting the startup sequence.
82 CHECK(get_module_state(module) == MODULE_STATE_INITIALIZED ||
83 module->init == NULL);
84
85 LOG_INFO("%s Starting module \"%s\"", __func__, module->name);
86 if (!call_lifecycle_function(module->start_up)) {
87 LOG_ERROR("%s Failed to start up module \"%s\"", __func__, module->name);
88 return false;
89 }
90 LOG_INFO("%s Started module \"%s\"", __func__, module->name);
91
92 set_module_state(module, MODULE_STATE_STARTED);
93 return true;
94 }
95
module_shut_down(const module_t * module)96 void module_shut_down(const module_t* module) {
97 CHECK(module != NULL);
98 module_state_t state = get_module_state(module);
99 CHECK(state <= MODULE_STATE_STARTED);
100
101 // Only something to do if the module was actually started
102 if (state < MODULE_STATE_STARTED) return;
103
104 LOG_INFO("%s Shutting down module \"%s\"", __func__, module->name);
105 if (!call_lifecycle_function(module->shut_down)) {
106 LOG_ERROR("%s Failed to shutdown module \"%s\". Continuing anyway.",
107 __func__, module->name);
108 }
109 LOG_INFO("%s Shutdown of module \"%s\" completed", __func__, module->name);
110
111 set_module_state(module, MODULE_STATE_INITIALIZED);
112 }
113
module_clean_up(const module_t * module)114 void module_clean_up(const module_t* module) {
115 CHECK(module != NULL);
116 module_state_t state = get_module_state(module);
117 CHECK(state <= MODULE_STATE_INITIALIZED);
118
119 // Only something to do if the module was actually initialized
120 if (state < MODULE_STATE_INITIALIZED) return;
121
122 LOG_INFO("%s Cleaning up module \"%s\"", __func__, module->name);
123 if (!call_lifecycle_function(module->clean_up)) {
124 LOG_ERROR("%s Failed to cleanup module \"%s\". Continuing anyway.",
125 __func__, module->name);
126 }
127 LOG_INFO("%s Cleanup of module \"%s\" completed", __func__, module->name);
128
129 set_module_state(module, MODULE_STATE_NONE);
130 }
131
call_lifecycle_function(module_lifecycle_fn function)132 static bool call_lifecycle_function(module_lifecycle_fn function) {
133 // A NULL lifecycle function means it isn't needed, so assume success
134 if (!function) return true;
135
136 future_t* future = function();
137
138 // A NULL future means synchronous success
139 if (!future) return true;
140
141 // Otherwise fall back to the future
142 return future_await(future);
143 }
144
get_module_state(const module_t * module)145 static module_state_t get_module_state(const module_t* module) {
146 std::lock_guard<std::mutex> lock(metadata_mutex);
147 auto map_ptr = metadata.find(module);
148
149 return (map_ptr != metadata.end()) ? map_ptr->second : MODULE_STATE_NONE;
150 }
151
set_module_state(const module_t * module,module_state_t state)152 static void set_module_state(const module_t* module, module_state_t state) {
153 std::lock_guard<std::mutex> lock(metadata_mutex);
154 metadata[module] = state;
155 }
156