1 /******************************************************************************
2 *
3 * Copyright (C) 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 <assert.h>
22 #include <dlfcn.h>
23 #include <pthread.h>
24 #include <string.h>
25
26 #include "btcore/include/module.h"
27 #include "osi/include/allocator.h"
28 #include "osi/include/hash_functions.h"
29 #include "osi/include/hash_map.h"
30 #include "osi/include/log.h"
31 #include "osi/include/osi.h"
32
33 typedef enum {
34 MODULE_STATE_NONE = 0,
35 MODULE_STATE_INITIALIZED = 1,
36 MODULE_STATE_STARTED = 2
37 } module_state_t;
38
39 static const size_t number_of_metadata_buckets = 42;
40 static hash_map_t *metadata;
41 // Include this lock for now for correctness, while the startup sequence is being refactored
42 static pthread_mutex_t metadata_lock;
43
44 static bool call_lifecycle_function(module_lifecycle_fn function);
45 static module_state_t get_module_state(const module_t *module);
46 static void set_module_state(const module_t *module, module_state_t state);
47
module_management_start(void)48 void module_management_start(void) {
49 metadata = hash_map_new(
50 number_of_metadata_buckets,
51 hash_function_pointer,
52 NULL,
53 osi_free,
54 NULL
55 );
56
57 pthread_mutex_init(&metadata_lock, NULL);
58 }
59
module_management_stop(void)60 void module_management_stop(void) {
61 if (!metadata)
62 return;
63
64 hash_map_free(metadata);
65 metadata = NULL;
66
67 pthread_mutex_destroy(&metadata_lock);
68 }
69
get_module(const char * name)70 const module_t *get_module(const char *name) {
71 module_t* module = (module_t *)dlsym(RTLD_DEFAULT, name);
72 assert(module);
73 return module;
74 }
75
module_init(const module_t * module)76 bool module_init(const module_t *module) {
77 assert(metadata != NULL);
78 assert(module != NULL);
79 assert(get_module_state(module) == MODULE_STATE_NONE);
80
81 LOG_INFO(LOG_TAG, "%s Initializing module \"%s\"", __func__, module->name);
82 if (!call_lifecycle_function(module->init)) {
83 LOG_ERROR(LOG_TAG, "%s Failed to initialize module \"%s\"",
84 __func__, module->name);
85 return false;
86 }
87 LOG_INFO(LOG_TAG, "%s Initialized module \"%s\"", __func__, module->name);
88
89 set_module_state(module, MODULE_STATE_INITIALIZED);
90 return true;
91 }
92
module_start_up(const module_t * module)93 bool module_start_up(const module_t *module) {
94 assert(metadata != NULL);
95 assert(module != NULL);
96 // TODO(zachoverflow): remove module->init check once automagic order/call is in place.
97 // This hack is here so modules which don't require init don't have to have useless calls
98 // as we're converting the startup sequence.
99 assert(get_module_state(module) == MODULE_STATE_INITIALIZED || module->init == NULL);
100
101 LOG_INFO(LOG_TAG, "%s Starting module \"%s\"", __func__, module->name);
102 if (!call_lifecycle_function(module->start_up)) {
103 LOG_ERROR(LOG_TAG, "%s Failed to start up module \"%s\"",
104 __func__, module->name);
105 return false;
106 }
107 LOG_INFO(LOG_TAG, "%s Started module \"%s\"", __func__, module->name);
108
109 set_module_state(module, MODULE_STATE_STARTED);
110 return true;
111 }
112
module_shut_down(const module_t * module)113 void module_shut_down(const module_t *module) {
114 assert(metadata != NULL);
115 assert(module != NULL);
116 module_state_t state = get_module_state(module);
117 assert(state <= MODULE_STATE_STARTED);
118
119 // Only something to do if the module was actually started
120 if (state < MODULE_STATE_STARTED)
121 return;
122
123 LOG_INFO(LOG_TAG, "%s Shutting down module \"%s\"", __func__, module->name);
124 if (!call_lifecycle_function(module->shut_down)) {
125 LOG_ERROR(LOG_TAG, "%s Failed to shutdown module \"%s\". Continuing anyway.",
126 __func__, module->name);
127 }
128 LOG_INFO(LOG_TAG, "%s Shutdown of module \"%s\" completed",
129 __func__, module->name);
130
131 set_module_state(module, MODULE_STATE_INITIALIZED);
132 }
133
module_clean_up(const module_t * module)134 void module_clean_up(const module_t *module) {
135 assert(metadata != NULL);
136 assert(module != NULL);
137 module_state_t state = get_module_state(module);
138 assert(state <= MODULE_STATE_INITIALIZED);
139
140 // Only something to do if the module was actually initialized
141 if (state < MODULE_STATE_INITIALIZED)
142 return;
143
144 LOG_INFO(LOG_TAG, "%s Cleaning up module \"%s\"", __func__, module->name);
145 if (!call_lifecycle_function(module->clean_up)) {
146 LOG_ERROR(LOG_TAG, "%s Failed to cleanup module \"%s\". Continuing anyway.",
147 __func__, module->name);
148 }
149 LOG_INFO(LOG_TAG, "%s Cleanup of module \"%s\" completed",
150 __func__, module->name);
151
152 set_module_state(module, MODULE_STATE_NONE);
153 }
154
call_lifecycle_function(module_lifecycle_fn function)155 static bool call_lifecycle_function(module_lifecycle_fn function) {
156 // A NULL lifecycle function means it isn't needed, so assume success
157 if (!function)
158 return true;
159
160 future_t *future = function();
161
162 // A NULL future means synchronous success
163 if (!future)
164 return true;
165
166 // Otherwise fall back to the future
167 return future_await(future);
168 }
169
get_module_state(const module_t * module)170 static module_state_t get_module_state(const module_t *module) {
171 pthread_mutex_lock(&metadata_lock);
172 module_state_t *state_ptr = hash_map_get(metadata, module);
173 pthread_mutex_unlock(&metadata_lock);
174
175 return state_ptr ? *state_ptr : MODULE_STATE_NONE;
176 }
177
set_module_state(const module_t * module,module_state_t state)178 static void set_module_state(const module_t *module, module_state_t state) {
179 pthread_mutex_lock(&metadata_lock);
180
181 module_state_t *state_ptr = hash_map_get(metadata, module);
182 if (!state_ptr) {
183 state_ptr = osi_malloc(sizeof(module_state_t));
184 hash_map_set(metadata, module, state_ptr);
185 }
186
187 pthread_mutex_unlock(&metadata_lock);
188
189 *state_ptr = state;
190 }
191
192 // TODO(zachoverflow): remove when everything modulized
193 // Temporary callback-wrapper-related code
194
195 typedef struct {
196 const module_t *module;
197 thread_t *lifecycle_thread;
198 thread_t *callback_thread; // we don't own this thread
199 thread_fn callback;
200 bool success;
201 } callbacked_wrapper_t;
202
203 static void run_wrapped_start_up(void *context);
204 static void post_result_to_callback(void *context);
205
module_start_up_callbacked_wrapper(const module_t * module,thread_t * callback_thread,thread_fn callback)206 void module_start_up_callbacked_wrapper(
207 const module_t *module,
208 thread_t *callback_thread,
209 thread_fn callback) {
210 callbacked_wrapper_t *wrapper = osi_calloc(sizeof(callbacked_wrapper_t));
211
212 wrapper->module = module;
213 wrapper->lifecycle_thread = thread_new("module_wrapper");
214 wrapper->callback_thread = callback_thread;
215 wrapper->callback = callback;
216
217 // Run the actual module start up
218 thread_post(wrapper->lifecycle_thread, run_wrapped_start_up, wrapper);
219 }
220
run_wrapped_start_up(void * context)221 static void run_wrapped_start_up(void *context) {
222 assert(context);
223
224 callbacked_wrapper_t *wrapper = context;
225 wrapper->success = module_start_up(wrapper->module);
226
227 // Post the result back to the callback
228 thread_post(wrapper->callback_thread, post_result_to_callback, wrapper);
229 }
230
post_result_to_callback(void * context)231 static void post_result_to_callback(void *context) {
232 assert(context);
233
234 callbacked_wrapper_t *wrapper = context;
235
236 // Save the values we need for callback
237 void *result = wrapper->success ? FUTURE_SUCCESS : FUTURE_FAIL;
238 thread_fn callback = wrapper->callback;
239
240 // Clean up the resources we used
241 thread_free(wrapper->lifecycle_thread);
242 osi_free(wrapper);
243
244 callback(result);
245 }
246