1 /*
2 * Copyright 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 #define LOG_TAG "FifoControllerBase"
18 //#define LOG_NDEBUG 0
19 #include <utils/Log.h>
20
21 #include <stdint.h>
22 #include "FifoControllerBase.h"
23
24 using android::FifoControllerBase;
25 using android::fifo_frames_t;
26
FifoControllerBase(fifo_frames_t capacity,fifo_frames_t threshold)27 FifoControllerBase::FifoControllerBase(fifo_frames_t capacity, fifo_frames_t threshold)
28 : mCapacity(capacity)
29 , mThreshold(threshold)
30 {
31 }
32
getFullFramesAvailable()33 fifo_frames_t FifoControllerBase::getFullFramesAvailable() {
34 fifo_frames_t temp = 0;
35 __builtin_sub_overflow(getWriteCounter(), getReadCounter(), &temp);
36 return temp;
37 }
38
getReadIndex()39 fifo_frames_t FifoControllerBase::getReadIndex() {
40 // % works with non-power of two sizes
41 return (fifo_frames_t) ((uint64_t)getReadCounter() % mCapacity);
42 }
43
advanceReadIndex(fifo_frames_t numFrames)44 void FifoControllerBase::advanceReadIndex(fifo_frames_t numFrames) {
45 fifo_counter_t temp = 0;
46 __builtin_add_overflow(getReadCounter(), numFrames, &temp);
47 setReadCounter(temp);
48 }
49
getEmptyFramesAvailable()50 fifo_frames_t FifoControllerBase::getEmptyFramesAvailable() {
51 return (int32_t)(mThreshold - getFullFramesAvailable());
52 }
53
getWriteIndex()54 fifo_frames_t FifoControllerBase::getWriteIndex() {
55 // % works with non-power of two sizes
56 return (fifo_frames_t) ((uint64_t)getWriteCounter() % mCapacity);
57 }
58
advanceWriteIndex(fifo_frames_t numFrames)59 void FifoControllerBase::advanceWriteIndex(fifo_frames_t numFrames) {
60 fifo_counter_t temp = 0;
61 __builtin_add_overflow(getWriteCounter(), numFrames, &temp);
62 setWriteCounter(temp);
63 }
64
setThreshold(fifo_frames_t threshold)65 void FifoControllerBase::setThreshold(fifo_frames_t threshold) {
66 if (threshold > mCapacity) {
67 threshold = mCapacity;
68 } else if (threshold < 0) {
69 threshold = 0;
70 }
71 mThreshold = threshold;
72 }
73