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 "osi/include/allocator.h"
27 #include "osi/include/hash_map.h"
28 #include "btcore/include/module.h"
29 #include "osi/include/osi.h"
30 #include "osi/include/hash_functions.h"
31 #include "osi/include/log.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 if (!call_lifecycle_function(module->init)) {
82 LOG_ERROR("%s failed to initialize \"%s\"", __func__, module->name);
83 return false;
84 }
85
86 set_module_state(module, MODULE_STATE_INITIALIZED);
87 return true;
88 }
89
module_start_up(const module_t * module)90 bool module_start_up(const module_t *module) {
91 assert(metadata != NULL);
92 assert(module != NULL);
93 // TODO(zachoverflow): remove module->init check once automagic order/call is in place.
94 // This hack is here so modules which don't require init don't have to have useless calls
95 // as we're converting the startup sequence.
96 assert(get_module_state(module) == MODULE_STATE_INITIALIZED || module->init == NULL);
97
98 if (!call_lifecycle_function(module->start_up)) {
99 LOG_ERROR("%s failed to start up \"%s\"", __func__, module->name);
100 return false;
101 }
102
103 set_module_state(module, MODULE_STATE_STARTED);
104 return true;
105 }
106
module_shut_down(const module_t * module)107 void module_shut_down(const module_t *module) {
108 assert(metadata != NULL);
109 assert(module != NULL);
110 module_state_t state = get_module_state(module);
111 assert(state <= MODULE_STATE_STARTED);
112
113 // Only something to do if the module was actually started
114 if (state < MODULE_STATE_STARTED)
115 return;
116
117 if (!call_lifecycle_function(module->shut_down))
118 LOG_ERROR("%s found \"%s\" reported failure during shutdown. Continuing anyway.", __func__, module->name);
119
120 set_module_state(module, MODULE_STATE_INITIALIZED);
121 }
122
module_clean_up(const module_t * module)123 void module_clean_up(const module_t *module) {
124 assert(metadata != NULL);
125 assert(module != NULL);
126 module_state_t state = get_module_state(module);
127 assert(state <= MODULE_STATE_INITIALIZED);
128
129 // Only something to do if the module was actually initialized
130 if (state < MODULE_STATE_INITIALIZED)
131 return;
132
133 if (!call_lifecycle_function(module->clean_up))
134 LOG_ERROR("%s found \"%s\" reported failure during cleanup. Continuing anyway.", __func__, module->name);
135
136 set_module_state(module, MODULE_STATE_NONE);
137 }
138
call_lifecycle_function(module_lifecycle_fn function)139 static bool call_lifecycle_function(module_lifecycle_fn function) {
140 // A NULL lifecycle function means it isn't needed, so assume success
141 if (!function)
142 return true;
143
144 future_t *future = function();
145
146 // A NULL future means synchronous success
147 if (!future)
148 return true;
149
150 // Otherwise fall back to the future
151 return future_await(future);
152 }
153
get_module_state(const module_t * module)154 static module_state_t get_module_state(const module_t *module) {
155 pthread_mutex_lock(&metadata_lock);
156 module_state_t *state_ptr = hash_map_get(metadata, module);
157 pthread_mutex_unlock(&metadata_lock);
158
159 return state_ptr ? *state_ptr : MODULE_STATE_NONE;
160 }
161
set_module_state(const module_t * module,module_state_t state)162 static void set_module_state(const module_t *module, module_state_t state) {
163 pthread_mutex_lock(&metadata_lock);
164
165 module_state_t *state_ptr = hash_map_get(metadata, module);
166 if (!state_ptr) {
167 state_ptr = osi_malloc(sizeof(module_state_t));
168 hash_map_set(metadata, module, state_ptr);
169 }
170
171 pthread_mutex_unlock(&metadata_lock);
172
173 *state_ptr = state;
174 }
175
176 // TODO(zachoverflow): remove when everything modulized
177 // Temporary callback-wrapper-related code
178
179 typedef struct {
180 const module_t *module;
181 thread_t *lifecycle_thread;
182 thread_t *callback_thread; // we don't own this thread
183 thread_fn callback;
184 bool success;
185 } callbacked_wrapper_t;
186
187 static void run_wrapped_start_up(void *context);
188 static void post_result_to_callback(void *context);
189
module_start_up_callbacked_wrapper(const module_t * module,thread_t * callback_thread,thread_fn callback)190 void module_start_up_callbacked_wrapper(
191 const module_t *module,
192 thread_t *callback_thread,
193 thread_fn callback) {
194 callbacked_wrapper_t *wrapper = osi_calloc(sizeof(callbacked_wrapper_t));
195
196 wrapper->module = module;
197 wrapper->lifecycle_thread = thread_new("module_wrapper");
198 wrapper->callback_thread = callback_thread;
199 wrapper->callback = callback;
200
201 // Run the actual module start up
202 thread_post(wrapper->lifecycle_thread, run_wrapped_start_up, wrapper);
203 }
204
run_wrapped_start_up(void * context)205 static void run_wrapped_start_up(void *context) {
206 assert(context);
207
208 callbacked_wrapper_t *wrapper = context;
209 wrapper->success = module_start_up(wrapper->module);
210
211 // Post the result back to the callback
212 thread_post(wrapper->callback_thread, post_result_to_callback, wrapper);
213 }
214
post_result_to_callback(void * context)215 static void post_result_to_callback(void *context) {
216 assert(context);
217
218 callbacked_wrapper_t *wrapper = context;
219
220 // Save the values we need for callback
221 void *result = wrapper->success ? FUTURE_SUCCESS : FUTURE_FAIL;
222 thread_fn callback = wrapper->callback;
223
224 // Clean up the resources we used
225 thread_stop(wrapper->lifecycle_thread);
226 osi_free(wrapper);
227
228 callback(result);
229 }
230