1 /* 2 * Copyright (C) 2015 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 #ifndef RING_BUFFER_H_ 18 19 #define RING_BUFFER_H_ 20 21 #include <media/stagefright/foundation/ABase.h> 22 23 #include <hardware/sensors.h> 24 #include <utils/threads.h> 25 26 namespace android { 27 28 struct RingBuffer { 29 explicit RingBuffer(size_t size); 30 ~RingBuffer(); 31 32 ssize_t write(const sensors_event_t *ev, size_t size); 33 ssize_t read(sensors_event_t *ev, size_t size); 34 35 private: 36 Mutex mLock; 37 Condition mNotEmptyCondition; 38 39 size_t mSize; 40 sensors_event_t *mData; 41 size_t mReadPos, mWritePos; 42 43 DISALLOW_EVIL_CONSTRUCTORS(RingBuffer); 44 }; 45 46 struct LockfreeBuffer { 47 LockfreeBuffer(void* buf, size_t size); 48 ~LockfreeBuffer(); 49 50 // support single writer 51 void write(const sensors_event_t *ev, size_t size); 52 private: 53 sensors_event_t *mData; 54 size_t mSize; 55 size_t mWritePos; 56 int32_t mCounter; 57 58 DISALLOW_EVIL_CONSTRUCTORS(LockfreeBuffer); 59 }; 60 61 } // namespace android 62 63 #endif // RING_BUFFER_H_ 64
