1 /*
2 * Copyright (C) 2020 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 <log/log.h>
18 #include <sys/epoll.h>
19 #include "multihal_sensors.h"
20
21 namespace goldfish {
22
23 namespace {
epollCtlAdd(int epollFd,int fd)24 int epollCtlAdd(int epollFd, int fd) {
25 struct epoll_event ev;
26 ev.events = EPOLLIN;
27 ev.data.fd = fd;
28 return TEMP_FAILURE_RETRY(epoll_ctl(epollFd, EPOLL_CTL_ADD, fd, &ev));
29 }
30
qemuSensortThreadRcvCommand(const int fd)31 int qemuSensortThreadRcvCommand(const int fd) {
32 char buf;
33 if (TEMP_FAILURE_RETRY(read(fd, &buf, 1)) == 1) {
34 return buf;
35 } else {
36 return -1;
37 }
38 }
39 } // namespace
40
qemuSensorListenerThreadImpl(const int transportFd)41 bool MultihalSensors::qemuSensorListenerThreadImpl(const int transportFd) {
42 const unique_fd epollFd(epoll_create1(0));
43 LOG_ALWAYS_FATAL_IF(!epollFd.ok(), "%s:%d: epoll_create1 failed",
44 __func__, __LINE__);
45
46 epollCtlAdd(epollFd.get(), transportFd);
47 epollCtlAdd(epollFd.get(), m_sensorThreadFd.get());
48
49 while (true) {
50 struct epoll_event events[2];
51 const int kTimeoutMs = 60000;
52 const int n = TEMP_FAILURE_RETRY(epoll_wait(epollFd.get(),
53 events, 2,
54 kTimeoutMs));
55 if (n < 0) {
56 ALOGW("%s:%d: epoll_wait failed with '%s'",
57 __func__, __LINE__, strerror(errno));
58 return true;
59 }
60
61 for (int i = 0; i < n; ++i) {
62 const struct epoll_event* ev = &events[i];
63 const int fd = ev->data.fd;
64 const int ev_events = ev->events;
65
66 if (fd == transportFd) {
67 if (ev_events & (EPOLLERR | EPOLLHUP)) {
68 ALOGW("%s:%d: epoll_wait: transportFd has an error, "
69 "ev_events=%x", __func__, __LINE__, ev_events);
70 return true;
71 } else if (ev_events & EPOLLIN) {
72 std::unique_lock<std::mutex> lock(m_mtx);
73 parseQemuSensorEventLocked(&m_protocolState);
74 }
75 } else if (fd == m_sensorThreadFd.get()) {
76 if (ev_events & (EPOLLERR | EPOLLHUP)) {
77 LOG_ALWAYS_FATAL("%s:%d: epoll_wait: threadFd has an error, "
78 "ev_events=%x", __func__, __LINE__, ev_events);
79 } else if (ev_events & EPOLLIN) {
80 const int cmd = qemuSensortThreadRcvCommand(fd);
81 switch (cmd) {
82 case kCMD_QUIT: return false;
83 case kCMD_RESTART: return true;
84 default:
85 ALOGW("%s:%d: qemuSensortThreadRcvCommand "
86 "returned unexpected command, cmd=%d",
87 __func__, __LINE__, cmd);
88 return true;
89 }
90 }
91 } else {
92 ALOGW("%s:%d: epoll_wait() returned unexpected fd",
93 __func__, __LINE__);
94 return true;
95 }
96 }
97 }
98 }
99
100 } // namespace goldfish
101