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 namespace android; // TODO just import names needed
25
FifoControllerBase(fifo_frames_t capacity,fifo_frames_t threshold)26 FifoControllerBase::FifoControllerBase(fifo_frames_t capacity, fifo_frames_t threshold)
27 : mCapacity(capacity)
28 , mThreshold(threshold)
29 {
30 }
31
~FifoControllerBase()32 FifoControllerBase::~FifoControllerBase() {
33 }
34
getFullFramesAvailable()35 fifo_frames_t FifoControllerBase::getFullFramesAvailable() {
36 fifo_frames_t temp = 0;
37 __builtin_sub_overflow(getWriteCounter(), getReadCounter(), &temp);
38 return temp;
39 }
40
getReadIndex()41 fifo_frames_t FifoControllerBase::getReadIndex() {
42 // % works with non-power of two sizes
43 return (fifo_frames_t) ((uint64_t)getReadCounter() % mCapacity);
44 }
45
advanceReadIndex(fifo_frames_t numFrames)46 void FifoControllerBase::advanceReadIndex(fifo_frames_t numFrames) {
47 fifo_counter_t temp = 0;
48 __builtin_add_overflow(getReadCounter(), numFrames, &temp);
49 setReadCounter(temp);
50 }
51
getEmptyFramesAvailable()52 fifo_frames_t FifoControllerBase::getEmptyFramesAvailable() {
53 return (int32_t)(mThreshold - getFullFramesAvailable());
54 }
55
getWriteIndex()56 fifo_frames_t FifoControllerBase::getWriteIndex() {
57 // % works with non-power of two sizes
58 return (fifo_frames_t) ((uint64_t)getWriteCounter() % mCapacity);
59 }
60
advanceWriteIndex(fifo_frames_t numFrames)61 void FifoControllerBase::advanceWriteIndex(fifo_frames_t numFrames) {
62 fifo_counter_t temp = 0;
63 __builtin_add_overflow(getWriteCounter(), numFrames, &temp);
64 setWriteCounter(temp);
65 }
66
setThreshold(fifo_frames_t threshold)67 void FifoControllerBase::setThreshold(fifo_frames_t threshold) {
68 if (threshold > mCapacity) {
69 threshold = mCapacity;
70 } else if (threshold < 0) {
71 threshold = 0;
72 }
73 mThreshold = threshold;
74 }
75