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 "os/handler.h"
18
19 #include <cstring>
20
21 #include "common/bind.h"
22 #include "common/callback.h"
23 #include "os/log.h"
24 #include "os/reactor.h"
25 #include "os/utils.h"
26
27 namespace bluetooth {
28 namespace os {
29 using common::OnceClosure;
30
Handler(Thread * thread)31 Handler::Handler(Thread* thread) : tasks_(new std::queue<OnceClosure>()), thread_(thread) {
32 event_ = thread_->GetReactor()->NewEvent();
33 reactable_ = thread_->GetReactor()->Register(
34 event_->Id(), common::Bind(&Handler::handle_next_event, common::Unretained(this)), common::Closure());
35 }
36
~Handler()37 Handler::~Handler() {
38 {
39 std::lock_guard<std::mutex> lock(mutex_);
40 ASSERT_LOG(was_cleared(), "Handlers must be cleared before they are destroyed");
41 }
42 event_->Close();
43 }
44
Post(OnceClosure closure)45 void Handler::Post(OnceClosure closure) {
46 {
47 std::lock_guard<std::mutex> lock(mutex_);
48 if (was_cleared()) {
49 LOG_WARN("Posting to a handler which has been cleared");
50 return;
51 }
52 tasks_->emplace(std::move(closure));
53 }
54 event_->Notify();
55 }
56
Clear()57 void Handler::Clear() {
58 std::queue<OnceClosure>* tmp = nullptr;
59 {
60 std::lock_guard<std::mutex> lock(mutex_);
61 ASSERT_LOG(!was_cleared(), "Handlers must only be cleared once");
62 std::swap(tasks_, tmp);
63 }
64 delete tmp;
65
66 event_->Clear();
67
68 thread_->GetReactor()->Unregister(reactable_);
69 reactable_ = nullptr;
70 }
71
WaitUntilStopped(std::chrono::milliseconds timeout)72 void Handler::WaitUntilStopped(std::chrono::milliseconds timeout) {
73 ASSERT(reactable_ == nullptr);
74 ASSERT(thread_->GetReactor()->WaitForUnregisteredReactable(timeout));
75 }
76
handle_next_event()77 void Handler::handle_next_event() {
78 common::OnceClosure closure;
79 {
80 std::lock_guard<std::mutex> lock(mutex_);
81 bool has_data = event_->Read();
82
83 if (was_cleared()) {
84 return;
85 }
86 ASSERT_LOG(has_data, "Notified for work but no work available");
87
88 closure = std::move(tasks_->front());
89 tasks_->pop();
90 }
91 std::move(closure).Run();
92 }
93
94 } // namespace os
95 } // namespace bluetooth
96