1 /* 2 * Copyright (C) 2022 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 #pragma once 18 19 #include <array> 20 21 #include <android-base/result.h> 22 23 namespace android { 24 namespace init { 25 26 // A FIFO for inter-process communication that uses a Unix pipe internally. 27 class InterprocessFifo { 28 public: 29 template <typename T> 30 using Result = ::android::base::Result<T>; 31 32 InterprocessFifo() noexcept; 33 InterprocessFifo(const InterprocessFifo& orig) noexcept = delete; 34 InterprocessFifo(InterprocessFifo&& orig) noexcept; 35 InterprocessFifo& operator=(const InterprocessFifo& orig) noexcept = delete; 36 InterprocessFifo& operator=(InterprocessFifo&& orig) noexcept = delete; 37 ~InterprocessFifo() noexcept; 38 void CloseReadFd() noexcept; 39 void CloseWriteFd() noexcept; 40 void Close() noexcept; 41 Result<void> Initialize() noexcept; 42 Result<void> Write(uint8_t byte) noexcept; 43 Result<uint8_t> Read() noexcept; 44 45 private: 46 static void CloseFd(int& fd) noexcept; 47 48 std::array<int, 2> fds_; 49 }; 50 51 } // namespace init 52 } // namespace android 53