blob: 6e0d03186a487aa5a93216e87cd53e3e22cf4399 [file] [log] [blame]
Bart Van Assche1693f422022-10-19 16:30:15 -07001/*
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#include "interprocess_fifo.h"
18
19#include <android-base/logging.h>
20
21#include <unistd.h>
22
23using ::android::base::ErrnoError;
24using ::android::base::Error;
25using ::android::base::Result;
26
27namespace android {
28namespace init {
29
30InterprocessFifo::InterprocessFifo() noexcept : fds_({-1, -1}) {}
31
32InterprocessFifo::InterprocessFifo(InterprocessFifo&& orig) noexcept : fds_({-1, -1}) {
33 std::swap(fds_, orig.fds_);
34}
35
36InterprocessFifo::~InterprocessFifo() noexcept {
37 Close();
38}
39
40void InterprocessFifo::CloseFd(int& fd) noexcept {
41 if (fd >= 0) {
42 close(fd);
43 fd = -1;
44 }
45}
46
47void InterprocessFifo::CloseReadFd() noexcept {
48 CloseFd(fds_[0]);
49}
50
51void InterprocessFifo::CloseWriteFd() noexcept {
52 CloseFd(fds_[1]);
53}
54
55void InterprocessFifo::Close() noexcept {
56 CloseReadFd();
57 CloseWriteFd();
58}
59
60Result<void> InterprocessFifo::Initialize() noexcept {
61 if (fds_[0] >= 0) {
62 return Error() << "already initialized";
63 }
64 if (pipe(fds_.data()) < 0) { // NOLINT(android-cloexec-pipe)
65 return ErrnoError() << "pipe()";
66 }
67 return {};
68}
69
70Result<uint8_t> InterprocessFifo::Read() noexcept {
71 uint8_t byte;
72 ssize_t count = read(fds_[0], &byte, 1);
73 if (count < 0) {
74 return ErrnoError() << "read()";
75 }
76 if (count == 0) {
77 return Error() << "read() EOF";
78 }
79 DCHECK_EQ(count, 1);
80 return byte;
81}
82
83Result<void> InterprocessFifo::Write(uint8_t byte) noexcept {
84 ssize_t written = write(fds_[1], &byte, 1);
85 if (written < 0) {
86 return ErrnoError() << "write()";
87 }
88 if (written == 0) {
89 return Error() << "write() EOF";
90 }
91 DCHECK_EQ(written, 1);
92 return {};
93}
94
95} // namespace init
96} // namespace android