1 /*
2 * Copyright (C) 2015 Intel Corporation
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 <cutils/log.h>
18 #include <sys/epoll.h>
19 #include <string.h>
20 #include <errno.h>
21 #include <hardware/sensors.h>
22 #include "AcquisitionThread.hpp"
23 #include "Utils.hpp"
24
acquisitionRoutine(void * param)25 void* AcquisitionThread::acquisitionRoutine(void *param) {
26 AcquisitionThread *acquisitionThread = reinterpret_cast<AcquisitionThread *>(param);
27 Sensor *sensor = nullptr;
28 int64_t timestamp = 0;
29 struct timespec target_time;
30 int rc = 0;
31 sensors_event_t data;
32
33 if (acquisitionThread == nullptr) {
34 ALOGE("%s: The acquisition thread was not initialized", __func__);
35 return nullptr;
36 }
37
38 sensor = acquisitionThread->sensor;
39 if (sensor == nullptr) {
40 ALOGE("%s: The acquisition thread doesn't have an associated sensor", __func__);
41 return nullptr;
42 }
43
44 /* initialize sensor data structure */
45 memset(&data, 0, sizeof(sensors_event_t));
46 data.version = sizeof(sensors_event_t);
47 data.sensor = sensor->getHandle();
48 data.type = sensor->getType();
49
50 pthread_mutex_lock(&acquisitionThread->pthreadMutex);
51
52 /* get current timestamp */
53 timestamp = get_timestamp_monotonic();
54
55 /* loop until the thread is canceled */
56 while(acquisitionThread->getWritePipeFd() != -1) {
57 /* get one event from the sensor */
58 if (sensor->pollEvents(&data, 1) != 1) {
59 ALOGE("%s: Sensor %d: Cannot read data", __func__, data.sensor);
60 goto exit;
61 }
62
63 /* send the data over the pipe to the main thread */
64 rc = write(acquisitionThread->getWritePipeFd(), &data, sizeof(sensors_event_t));
65 if (rc != sizeof(sensors_event_t)) {
66 ALOGE("%s: Sensor %d: Cannot write data to pipe", __func__, data.sensor);
67 goto exit;
68 }
69
70 if (acquisitionThread->getWritePipeFd() == -1) {
71 ALOGE("%s: Sensor %d: The write pipe file descriptor is invalid", __func__, data.sensor);
72 goto exit;
73 }
74
75 timestamp += sensor->getDelay();
76 set_timestamp(&target_time, timestamp);
77 pthread_cond_timedwait(&acquisitionThread->pthreadCond, &acquisitionThread->pthreadMutex, &target_time);
78 }
79
80 exit:
81 pthread_mutex_unlock(&acquisitionThread->pthreadMutex);
82 return nullptr;
83 }
84
AcquisitionThread(int pollFd,Sensor * sensor)85 AcquisitionThread::AcquisitionThread(int pollFd, Sensor *sensor)
86 : pollFd(pollFd), sensor(sensor), initialized(false) {
87 pipeFds[0] = pipeFds[1] = -1;
88 }
89
init()90 bool AcquisitionThread::init() {
91 struct epoll_event ev;
92 int rc;
93
94 memset(&ev, 0, sizeof(ev));
95
96 if (initialized) {
97 ALOGE("%s: acquisition thread already initialized", __func__);
98 return false;
99 }
100
101 /* create condition variable & mutex for quick thread release */
102 rc = pthread_condattr_init(&pthreadCondAttr);
103 if (rc != 0) {
104 ALOGE("%s: Cannot initialize the pthread condattr", __func__);
105 return false;
106 }
107 rc = pthread_condattr_setclock(&pthreadCondAttr, CLOCK_MONOTONIC);
108 if (rc != 0) {
109 ALOGE("%s: Cannot set the clock of condattr to monotonic", __func__);
110 return false;
111 }
112 rc = pthread_cond_init(&pthreadCond, &pthreadCondAttr);
113 if (rc != 0) {
114 ALOGE("%s: Cannot intialize the pthread structure", __func__);
115 return false;
116 }
117 rc = pthread_mutex_init(&pthreadMutex, nullptr);
118 if (rc != 0) {
119 ALOGE("%s: Cannot initialize the mutex associated with the pthread cond", __func__);
120 goto mutex_err;
121 }
122
123 /* create pipe to signal events to the main thread */
124 rc = pipe2(pipeFds, O_NONBLOCK);
125 if (rc != 0) {
126 ALOGE("%s: Cannot initialize pipe", __func__);
127 goto pipe_err;
128 }
129
130 ev.events = EPOLLIN;
131 ev.data.u32 = sensor->getHandle();
132
133 /* add read pipe fd to pollFd */
134 rc = epoll_ctl(pollFd, EPOLL_CTL_ADD, pipeFds[0] , &ev);
135 if (rc != 0) {
136 ALOGE("%s: Cannot add the read file descriptor to poll set", __func__);
137 goto epoll_err;
138 }
139
140 /* launch the thread */
141 rc = pthread_create(&pthread, nullptr, acquisitionRoutine, (void *)this);
142 if (rc != 0) {
143 ALOGE("%s: Cannot create acquisition pthread", __func__);
144 goto thread_create_err;
145 }
146
147 initialized = true;
148 return true;
149
150 thread_create_err:
151 epoll_ctl(pollFd, EPOLL_CTL_DEL, pipeFds[0], nullptr);
152 epoll_err:
153 close(pipeFds[0]);
154 close(pipeFds[1]);
155 pipeFds[0] = pipeFds[1] = -1;
156 pipe_err:
157 pthread_mutex_destroy(&pthreadMutex);
158 mutex_err:
159 pthread_cond_destroy(&pthreadCond);
160 return false;
161 }
162
generateFlushCompleteEvent()163 bool AcquisitionThread::generateFlushCompleteEvent() {
164 sensors_event_t data;
165 int rc;
166
167 if (!initialized) {
168 return false;
169 }
170
171 /* batching is not supported; return one META_DATA_FLUSH_COMPLETE event */
172 memset(&data, 0, sizeof(sensors_event_t));
173 data.version = META_DATA_VERSION;
174 data.type = SENSOR_TYPE_META_DATA;
175 data.meta_data.sensor = sensor->getHandle();
176 data.meta_data.what = META_DATA_FLUSH_COMPLETE;
177
178 /*
179 * Send the event via the associated pipe. It doesn't need to be in a loop
180 * as O_NONBLOCK is enabled and the number of bytes is <= PIPE_BUF.
181 * If there is room to write n bytes to the pipe, then write succeeds
182 * immediately, writing all n bytes; otherwise write fails.
183 */
184 rc = write(getWritePipeFd(), &data, sizeof(sensors_event_t));
185 if (rc != sizeof(sensors_event_t)) {
186 ALOGE("%s: not all data has been sent over the pipe", __func__);
187 return false;
188 }
189
190 return true;
191 }
192
wakeup()193 int AcquisitionThread::wakeup() {
194 if (initialized) {
195 return pthread_cond_signal(&pthreadCond);
196 }
197
198 return -EINVAL;
199 }
200
~AcquisitionThread()201 AcquisitionThread::~AcquisitionThread() {
202 int readPipeEnd, writePipeEnd;
203
204 if (initialized) {
205 readPipeEnd = pipeFds[0];
206 writePipeEnd = pipeFds[1];
207 epoll_ctl(pollFd, EPOLL_CTL_DEL, readPipeEnd, nullptr);
208
209 /* take the mutex to correctly signal the thread */
210 pthread_mutex_lock(&pthreadMutex);
211 pipeFds[0] = pipeFds[1] = -1;
212 close(readPipeEnd);
213 close(writePipeEnd);
214
215 /* wakeup and wait for the thread */
216 pthread_cond_signal(&pthreadCond);
217 pthread_mutex_unlock(&pthreadMutex);
218 pthread_join(pthread, nullptr);
219
220 pthread_cond_destroy(&pthreadCond);
221 pthread_mutex_destroy(&pthreadMutex);
222 }
223 }
224