1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "module.h"
18 
19 using ::bluetooth::os::Handler;
20 using ::bluetooth::os::Thread;
21 
22 namespace bluetooth {
23 
24 constexpr std::chrono::milliseconds kModuleStopTimeout = std::chrono::milliseconds(20);
25 
26 ModuleFactory::ModuleFactory(std::function<Module*()> ctor) : ctor_(ctor) {
27 }
28 
29 std::string Module::ToString() const {
30   return "Module";
31 }
32 
33 Handler* Module::GetHandler() const {
34   ASSERT_LOG(handler_ != nullptr, "Can't get handler when it's not started");
35   return handler_;
36 }
37 
38 const ModuleRegistry* Module::GetModuleRegistry() const {
39   return registry_;
40 }
41 
42 Module* Module::GetDependency(const ModuleFactory* module) const {
43   for (auto& dependency : dependencies_.list_) {
44     if (dependency == module) {
45       return registry_->Get(module);
46     }
47   }
48 
49   ASSERT_LOG(false, "Module was not listed as a dependency in ListDependencies");
50 }
51 
52 Module* ModuleRegistry::Get(const ModuleFactory* module) const {
53   auto instance = started_modules_.find(module);
54   ASSERT(instance != started_modules_.end());
55   return instance->second;
56 }
57 
58 bool ModuleRegistry::IsStarted(const ModuleFactory* module) const {
59   return started_modules_.find(module) != started_modules_.end();
60 }
61 
62 void ModuleRegistry::Start(ModuleList* modules, Thread* thread) {
63   for (auto it = modules->list_.begin(); it != modules->list_.end(); it++) {
64     Start(*it, thread);
65   }
66 }
67 
68 void ModuleRegistry::set_registry_and_handler(Module* instance, Thread* thread) const {
69   instance->registry_ = this;
70   instance->handler_ = new Handler(thread);
71 }
72 
73 Module* ModuleRegistry::Start(const ModuleFactory* module, Thread* thread) {
74   auto started_instance = started_modules_.find(module);
75   if (started_instance != started_modules_.end()) {
76     return started_instance->second;
77   }
78 
79   Module* instance = module->ctor_();
80   set_registry_and_handler(instance, thread);
81 
82   instance->ListDependencies(&instance->dependencies_);
83   Start(&instance->dependencies_, thread);
84 
85   instance->Start();
86   start_order_.push_back(module);
87   started_modules_[module] = instance;
88   return instance;
89 }
90 
91 void ModuleRegistry::StopAll() {
92   // Since modules were brought up in dependency order, it is safe to tear down by going in reverse order.
93   for (auto it = start_order_.rbegin(); it != start_order_.rend(); it++) {
94     auto instance = started_modules_.find(*it);
95     ASSERT(instance != started_modules_.end());
96 
97     // Clear the handler before stopping the module to allow it to shut down gracefully.
98     instance->second->handler_->Clear();
99     instance->second->handler_->WaitUntilStopped(kModuleStopTimeout);
100     instance->second->Stop();
101 
102     delete instance->second->handler_;
103     delete instance->second;
104     started_modules_.erase(instance);
105   }
106 
107   ASSERT(started_modules_.empty());
108   start_order_.clear();
109 }
110 
111 os::Handler* ModuleRegistry::GetModuleHandler(const ModuleFactory* module) const {
112   auto started_instance = started_modules_.find(module);
113   if (started_instance != started_modules_.end()) {
114     return started_instance->second->GetHandler();
115   }
116   return nullptr;
117 }
118 }  // namespace bluetooth
119