| /* |
| * 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 <unistd.h> |
| |
| #include <cstring> |
| |
| #include "common/bind.h" |
| #include "common/callback.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 { |
| using common::OnceClosure; |
| |
| Handler::Handler(Thread* thread) |
| : tasks_(new std::queue<OnceClosure>()), thread_(thread), fd_(eventfd(0, EFD_SEMAPHORE | EFD_NONBLOCK)) { |
| ASSERT(fd_ != -1); |
| reactable_ = thread_->GetReactor()->Register( |
| fd_, common::Bind(&Handler::handle_next_event, common::Unretained(this)), common::Closure()); |
| } |
| |
| Handler::~Handler() { |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| ASSERT_LOG(was_cleared(), "Handlers must be cleared before they are destroyed"); |
| } |
| |
| int close_status; |
| RUN_NO_INTR(close_status = close(fd_)); |
| ASSERT(close_status != -1); |
| } |
| |
| void Handler::Post(OnceClosure closure) { |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| if (was_cleared()) { |
| LOG_WARN("Posting to a handler which has been cleared"); |
| return; |
| } |
| tasks_->emplace(std::move(closure)); |
| } |
| uint64_t val = 1; |
| auto write_result = eventfd_write(fd_, val); |
| ASSERT(write_result != -1); |
| } |
| |
| void Handler::Clear() { |
| std::queue<OnceClosure>* tmp = nullptr; |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| ASSERT_LOG(!was_cleared(), "Handlers must only be cleared once"); |
| std::swap(tasks_, tmp); |
| } |
| delete tmp; |
| |
| uint64_t val; |
| while (eventfd_read(fd_, &val) == 0) { |
| } |
| |
| thread_->GetReactor()->Unregister(reactable_); |
| reactable_ = nullptr; |
| } |
| |
| void Handler::WaitUntilStopped(std::chrono::milliseconds timeout) { |
| ASSERT(reactable_ == nullptr); |
| ASSERT(thread_->GetReactor()->WaitForUnregisteredReactable(timeout)); |
| } |
| |
| void Handler::handle_next_event() { |
| common::OnceClosure closure; |
| { |
| std::lock_guard<std::mutex> lock(mutex_); |
| uint64_t val = 0; |
| auto read_result = eventfd_read(fd_, &val); |
| |
| if (was_cleared()) { |
| return; |
| } |
| ASSERT_LOG(read_result != -1, "eventfd read error %d %s", errno, strerror(errno)); |
| |
| closure = std::move(tasks_->front()); |
| tasks_->pop(); |
| } |
| std::move(closure).Run(); |
| } |
| |
| } // namespace os |
| } // namespace bluetooth |