I've try to get the sensor data in Android native layer, and it worked. And now,
I want to receive sensor data in a worker thread. Here is my code, First, the
native function HelloThread is called, and it will create a thread to
register and receive sensor data, but it's fail, the callback get_sensor_events
hasn't been called.
Thanks in advance.
void* threadFunction(void* irrelevant)
{
int tid = syscall(__NR_gettid);
LOGI("thread id(thread function) = %d", tid);
looper = ALooper_forThread();
while(looper == NULL)
{
looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
if(looper == NULL)
continue;
else
break;
}
LOGI("Finished prepare");
sensorManager = NULL;
accSensor = NULL;
gyroSensor = NULL;
magSensor = NULL;
sensor_data = (void*)malloc(1000);
if(looper == NULL)
LOGI("Looper is null");
sensorManager = ASensorManager_getInstance();
if(sensorManager == NULL)
LOGI("sensorManager == NULL");
accSensor = ASensorManager_getDefaultSensor(sensorManager, ASENSOR_TYPE_ACCELEROMETER);
gyroSensor = ASensorManager_getDefaultSensor(sensorManager, ASENSOR_TYPE_GYROSCOPE);
magSensor = ASensorManager_getDefaultSensor(sensorManager, ASENSOR_TYPE_MAGNETIC_FIELD);
if(accSensor == NULL)
LOGI("accSensor == NULL");
if(gyroSensor == NULL)
LOGI("gyroSensor == NULL");
if(magSensor == NULL)
LOGI("magSensor == NULL");
sensorEventQueue = ASensorManager_createEventQueue(sensorManager, looper, 3, get_sensor_events, sensor_data);
LOGI("Finished ASensorManager_createEventQueue()");
if(accSensor)
{
ASensorEventQueue_enableSensor(sensorEventQueue, accSensor);
ASensorEventQueue_setEventRate(sensorEventQueue, accSensor, 20000);
}
if(gyroSensor)
{
ASensorEventQueue_enableSensor(sensorEventQueue, gyroSensor);
ASensorEventQueue_setEventRate(sensorEventQueue, gyroSensor, 20000);
}
if(magSensor)
{
ASensorEventQueue_enableSensor(sensorEventQueue, magSensor);
ASensorEventQueue_setEventRate(sensorEventQueue, magSensor, 20000);
}
LOGI("Finish enable sensor");
HasAllocateLooper = true;
}
static int get_sensor_events(int fd, int events, void* data) {
ASensorEvent event;
int tid = syscall(__NR_gettid);
LOGI("thread id(get sensor data) = %d", tid);
while (ASensorEventQueue_getEvents(sensorEventQueue, &event, 1) > 0) {
if(event.type == ASENSOR_TYPE_ACCELEROMETER) {
LOGI("Acc:%f,%f,%f, time = %f", event.acceleration.x, event.acceleration.y, event.acceleration.z, ((double)(event.timestamp-lastAccTime))/1000000000.0);
lastAccTime = event.timestamp;
}
else if(event.type == ASENSOR_TYPE_GYROSCOPE) {
LOGI("Gyro:%f,%f,%f, time = %f", event.acceleration.x, event.acceleration.y, event.acceleration.z, ((double)(event.timestamp-lastGyroTime))/1000000000.0);
lastGyroTime = event.timestamp;
}
else if(event.type == ASENSOR_TYPE_MAGNETIC_FIELD) {
LOGI("Mag:%f,%f,%f, time = %f", event.acceleration.x, event.acceleration.y, event.acceleration.z, ((double)(event.timestamp-lastMagTime))/1000000000.0);
lastMagTime = event.timestamp;
}
}
//should return 1 to continue receiving callbacks, or 0 to unregister
return 1;
}
JNIEXPORT jint JNICALL Java_asus_ndksample_MainActivity_HelloThread
(JNIEnv * env, jobject obj)
{
int tid = syscall(__NR_gettid);
LOGI("thread id(Java thread) = %d", tid);
int ret = 0;
pthread_t hThread;
pthread_create(&hThread, NULL, &threadFunction, (void *)1);
while(true)
{
if(HasAllocateLooper)
{
break;
}
}
return ret;
}
Add following code to the end of method
threadFunction
and then have a try, it should work.