91 lines
2.5 KiB
C++
91 lines
2.5 KiB
C++
/*
|
|
* Copyright (C) 2013 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include <hardware/sensors.h>
|
|
#include <algorithm>
|
|
#include <pthread.h>
|
|
#include <cutils/log.h>
|
|
|
|
#include "SensorEventQueue.h"
|
|
|
|
SensorEventQueue::SensorEventQueue(int capacity) {
|
|
mCapacity = capacity;
|
|
|
|
mStart = 0;
|
|
mSize = 0;
|
|
mData = new sensors_event_t[mCapacity];
|
|
pthread_cond_init(&mSpaceAvailableCondition, NULL);
|
|
}
|
|
|
|
SensorEventQueue::~SensorEventQueue() {
|
|
delete[] mData;
|
|
mData = NULL;
|
|
pthread_cond_destroy(&mSpaceAvailableCondition);
|
|
}
|
|
|
|
int SensorEventQueue::getWritableRegion(int requestedLength, sensors_event_t** out) {
|
|
if (mSize == mCapacity || requestedLength <= 0) {
|
|
*out = NULL;
|
|
return 0;
|
|
}
|
|
// Start writing after the last readable record.
|
|
int firstWritable = (mStart + mSize) % mCapacity;
|
|
|
|
int lastWritable = firstWritable + requestedLength - 1;
|
|
|
|
// Don't go past the end of the data array.
|
|
if (lastWritable > mCapacity - 1) {
|
|
lastWritable = mCapacity - 1;
|
|
}
|
|
// Don't go into the readable region.
|
|
if (firstWritable < mStart && lastWritable >= mStart) {
|
|
lastWritable = mStart - 1;
|
|
}
|
|
*out = &mData[firstWritable];
|
|
return lastWritable - firstWritable + 1;
|
|
}
|
|
|
|
void SensorEventQueue::markAsWritten(int count) {
|
|
mSize += count;
|
|
}
|
|
|
|
int SensorEventQueue::getSize() {
|
|
return mSize;
|
|
}
|
|
|
|
sensors_event_t* SensorEventQueue::peek() {
|
|
if (mSize == 0) return NULL;
|
|
return &mData[mStart];
|
|
}
|
|
|
|
void SensorEventQueue::dequeue() {
|
|
if (mSize == 0) return;
|
|
if (mSize == mCapacity) {
|
|
pthread_cond_broadcast(&mSpaceAvailableCondition);
|
|
}
|
|
mSize--;
|
|
mStart = (mStart + 1) % mCapacity;
|
|
}
|
|
|
|
// returns true if it waited, or false if it was a no-op.
|
|
bool SensorEventQueue::waitForSpace(pthread_mutex_t* mutex) {
|
|
bool waited = false;
|
|
while (mSize == mCapacity) {
|
|
waited = true;
|
|
pthread_cond_wait(&mSpaceAvailableCondition, mutex);
|
|
}
|
|
return waited;
|
|
}
|