1 /*
2  * Copyright (C) 2017 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 #include <atomic>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <audio_utils/fifo_writer_T.h>
21 
22 template <typename T>
memcpyWords(T * dst,const T * src,uint32_t count)23 static inline void memcpyWords(T *dst, const T *src, uint32_t count)
24 {
25     switch (count) {
26     case 0: break;
27 // TODO templatize here also, but first confirm no performance regression compared to current
28 #define _(n) \
29     case n: { \
30         struct s##n { T a[n]; }; \
31         *(struct s##n *)dst = *(const struct s##n *)src; \
32         break; \
33     }
34     _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) _(9) _(10) _(11) _(12) _(13) _(14) _(15) _(16)
35 #undef _
36     default:
37         memcpy(dst, src, count * sizeof(T));
38         break;
39     }
40 }
41 
42 template <typename T>
audio_utils_fifo_writer_T(audio_utils_fifo & fifo)43 audio_utils_fifo_writer_T<T>::audio_utils_fifo_writer_T(audio_utils_fifo& fifo) :
44     mLocalRear(0), mFrameCountP2(fifo.mFrameCountP2), mBuffer((T *) fifo.mBuffer),
45     mWriterRear(fifo.mWriterRear)
46 {
47     if (fifo.mFrameSize != sizeof(T) || fifo.mFudgeFactor != 0) {
48         abort();
49     }
50 }
51 
52 template <typename T>
~audio_utils_fifo_writer_T()53 audio_utils_fifo_writer_T<T>::~audio_utils_fifo_writer_T()
54 {
55 }
56 
57 template <typename T>
write(const T * buffer,uint32_t count)58 void audio_utils_fifo_writer_T<T>::write(const T *buffer, uint32_t count)
59         __attribute__((no_sanitize("integer")))     // mLocalRear += can wrap
60 {
61     uint32_t availToWrite = mFrameCountP2;
62     if (availToWrite > count) {
63         availToWrite = count;
64     }
65     uint32_t rearOffset = mLocalRear & (mFrameCountP2 - 1);
66     uint32_t part1 = mFrameCountP2 - rearOffset;
67     if (part1 >  availToWrite) {
68         part1 = availToWrite;
69     }
70     memcpyWords(&mBuffer[rearOffset], buffer, part1);
71     // TODO apply this simplification to other copies of the code
72     uint32_t part2 = availToWrite - part1;
73     memcpyWords(&mBuffer[0], &buffer[part1], part2);
74     mLocalRear += availToWrite;
75 }
76 
77 // Instantiate for the specific types we need, which is currently just int32_t and int64_t.
78 
79 template class audio_utils_fifo_writer_T<int32_t>;
80 template class audio_utils_fifo_writer_T<int64_t>;
81