| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "os/handler.h" |
| |
| #include <sys/eventfd.h> |
| #include <cstring> |
| #include <unistd.h> |
| |
| #include "os/log.h" |
| #include "os/reactor.h" |
| #include "os/utils.h" |
| |
| #ifndef EFD_SEMAPHORE |
| #define EFD_SEMAPHORE 1 |
| #endif |
| |
| namespace bluetooth { |
| namespace os { |
| |
| Handler::Handler(Thread* thread) |
| : thread_(thread), |
| fd_(eventfd(0, EFD_SEMAPHORE | EFD_NONBLOCK)) { |
| ASSERT(fd_ != -1); |
| |
| reactable_ = thread_->GetReactor()->Register(fd_, [this] { this->handle_next_event(); }, nullptr); |
| } |
| |
| Handler::~Handler() { |
| thread_->GetReactor()->Unregister(reactable_); |
| reactable_ = nullptr; |
| |
| int close_status; |
| RUN_NO_INTR(close_status = close(fd_)); |
| ASSERT(close_status != -1); |
| } |
| |
| void Handler::Post(Closure closure) { |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| tasks_.emplace(std::move(closure)); |
| } |
| uint64_t val = 1; |
| auto write_result = eventfd_write(fd_, val); |
| ASSERT(write_result != -1); |
| } |
| |
| void Handler::Clear() { |
| std::lock_guard<std::mutex> lock(mutex_); |
| |
| std::queue<Closure> empty; |
| std::swap(tasks_, empty); |
| |
| uint64_t val; |
| while (eventfd_read(fd_, &val) == 0) { |
| } |
| } |
| |
| void Handler::handle_next_event() { |
| Closure closure; |
| uint64_t val = 0; |
| auto read_result = eventfd_read(fd_, &val); |
| if (read_result == -1 && errno == EAGAIN) { |
| // We were told there was an item, but it was removed before we got there |
| // (aka the queue was cleared). Not a fatal error, so just bail. |
| return; |
| } |
| |
| ASSERT(read_result != -1); |
| |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| closure = std::move(tasks_.front()); |
| tasks_.pop(); |
| } |
| closure(); |
| } |
| |
| } // namespace os |
| } // namespace bluetooth |