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 <fcntl.h>
19 #include <qemud.h>
20 #include <qemu_pipe_bp.h>
21 #include <sys/epoll.h>
22 #include <sys/socket.h>
23 #include "gnss_hw_conn.h"
24 #include "gnss_hw_listener.h"
25
26 namespace {
27 constexpr char kCMD_QUIT = 'q';
28 constexpr char kCMD_START = 'a';
29 constexpr char kCMD_STOP = 'o';
30
epollCtlAdd(int epollFd,int fd)31 int epollCtlAdd(int epollFd, int fd) {
32 int ret;
33
34 /* make the fd non-blocking */
35 ret = TEMP_FAILURE_RETRY(fcntl(fd, F_GETFL));
36 if (ret < 0) {
37 return ret;
38 }
39 ret = TEMP_FAILURE_RETRY(fcntl(fd, F_SETFL, ret | O_NONBLOCK));
40 if (ret < 0) {
41 return ret;
42 }
43
44 struct epoll_event ev;
45 ev.events = EPOLLIN;
46 ev.data.fd = fd;
47
48 return TEMP_FAILURE_RETRY(epoll_ctl(epollFd, EPOLL_CTL_ADD, fd, &ev));
49 }
50 } // namespace
51
52 namespace goldfish {
53
GnssHwConn(const DataSink * sink)54 GnssHwConn::GnssHwConn(const DataSink* sink) {
55 m_devFd.reset(qemu_pipe_open_ns("qemud", "gps", O_RDWR));
56 if (!m_devFd.ok()) {
57 ALOGE("%s:%d: qemu_pipe_open_ns failed", __PRETTY_FUNCTION__, __LINE__);
58 return;
59 }
60
61 if (!::android::base::Socketpair(AF_LOCAL, SOCK_STREAM, 0,
62 &m_callersFd, &m_threadsFd)) {
63 ALOGE("%s:%d: Socketpair failed", __PRETTY_FUNCTION__, __LINE__);
64 m_devFd.reset();
65 return;
66 }
67
68 m_thread = std::thread([this, sink]() {
69 sink->gnssStatus(ahg10::IGnssCallback::GnssStatusValue::ENGINE_ON);
70 workerThread(m_devFd.get(), m_threadsFd.get(), sink);
71 sink->gnssStatus(ahg10::IGnssCallback::GnssStatusValue::ENGINE_OFF);
72 });
73 }
74
~GnssHwConn()75 GnssHwConn::~GnssHwConn() {
76 if (m_thread.joinable()) {
77 sendWorkerThreadCommand(kCMD_QUIT);
78 m_thread.join();
79 }
80 }
81
ok() const82 bool GnssHwConn::ok() const {
83 return m_thread.joinable();
84 }
85
start()86 bool GnssHwConn::start() {
87 return ok() && sendWorkerThreadCommand(kCMD_START);
88 }
89
stop()90 bool GnssHwConn::stop() {
91 return ok() && sendWorkerThreadCommand(kCMD_STOP);
92 }
93
workerThread(int devFd,int threadsFd,const DataSink * sink)94 void GnssHwConn::workerThread(int devFd, int threadsFd, const DataSink* sink) {
95 const unique_fd epollFd(epoll_create1(0));
96 if (!epollFd.ok()) {
97 ALOGE("%s:%d: epoll_create1 failed", __PRETTY_FUNCTION__, __LINE__);
98 ::abort();
99 }
100
101 epollCtlAdd(epollFd.get(), devFd);
102 epollCtlAdd(epollFd.get(), threadsFd);
103
104 GnssHwListener listener(sink);
105 bool running = false;
106
107 while (true) {
108 struct epoll_event events[2];
109 const int kTimeoutMs = 60000;
110 const int n = TEMP_FAILURE_RETRY(epoll_wait(epollFd.get(),
111 events, 2,
112 kTimeoutMs));
113 if (n < 0) {
114 ALOGE("%s:%d: epoll_wait failed with '%s'",
115 __PRETTY_FUNCTION__, __LINE__, strerror(errno));
116 continue;
117 }
118
119 for (int i = 0; i < n; ++i) {
120 const struct epoll_event* ev = &events[i];
121 const int fd = ev->data.fd;
122 const int ev_events = ev->events;
123
124 if (fd == devFd) {
125 if (ev_events & (EPOLLERR | EPOLLHUP)) {
126 ALOGE("%s:%d: epoll_wait: devFd has an error, ev_events=%x",
127 __PRETTY_FUNCTION__, __LINE__, ev_events);
128 ::abort();
129 } else if (ev_events & EPOLLIN) {
130 char buf[64];
131 while (true) {
132 int n = TEMP_FAILURE_RETRY(read(fd, buf, sizeof(buf)));
133 if (n > 0) {
134 if (running) {
135 for (int i = 0; i < n; ++i) {
136 listener.consume(buf[i]);
137 }
138 }
139 } else {
140 break;
141 }
142 }
143 }
144 } else if (fd == threadsFd) {
145 if (ev_events & (EPOLLERR | EPOLLHUP)) {
146 ALOGE("%s:%d: epoll_wait: threadsFd has an error, ev_events=%x",
147 __PRETTY_FUNCTION__, __LINE__, ev_events);
148 ::abort();
149 } else if (ev_events & EPOLLIN) {
150 const int cmd = workerThreadRcvCommand(fd);
151 switch (cmd) {
152 case kCMD_QUIT:
153 return;
154
155 case kCMD_START:
156 if (!running) {
157 listener.reset();
158 sink->gnssStatus(ahg10::IGnssCallback::GnssStatusValue::SESSION_BEGIN);
159 running = true;
160 }
161 break;
162
163 case kCMD_STOP:
164 if (running) {
165 running = false;
166 sink->gnssStatus(ahg10::IGnssCallback::GnssStatusValue::SESSION_END);
167 }
168 break;
169
170 default:
171 ALOGE("%s:%d: workerThreadRcvCommand returned unexpected command, cmd=%d",
172 __PRETTY_FUNCTION__, __LINE__, cmd);
173 ::abort();
174 break;
175 }
176 }
177 } else {
178 ALOGE("%s:%d: epoll_wait() returned unexpected fd",
179 __PRETTY_FUNCTION__, __LINE__);
180 }
181 }
182 }
183 }
184
workerThreadRcvCommand(const int fd)185 int GnssHwConn::workerThreadRcvCommand(const int fd) {
186 char buf;
187 if (TEMP_FAILURE_RETRY(read(fd, &buf, 1)) == 1) {
188 return buf;
189 } else {
190 return -1;
191 }
192 }
193
sendWorkerThreadCommand(char cmd) const194 bool GnssHwConn::sendWorkerThreadCommand(char cmd) const {
195 return TEMP_FAILURE_RETRY(write(m_callersFd.get(), &cmd, 1)) == 1;
196 }
197
198 } // namespace goldfish
199