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      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 
     21 // TODO templatize int32_t
     22 
     23 #include <audio_utils/fifo_writer32.h>
     24 
     25 static inline void memcpyWords(int32_t *dst, const int32_t *src, uint32_t count)
     26 {
     27     switch (count) {
     28     case 0: break;
     29 // TODO templatize here also, but first confirm no performance regression compared to current
     30 #define _(n) \
     31     case n: { \
     32         struct s##n { int32_t a[n]; }; \
     33         *(struct s##n *)dst = *(const struct s##n *)src; \
     34         break; \
     35     }
     36     _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) _(9) _(10) _(11) _(12) _(13) _(14) _(15) _(16)
     37 #undef _
     38     default:
     39         memcpy(dst, src, count * sizeof(int32_t));
     40         break;
     41     }
     42 }
     43 
     44 audio_utils_fifo_writer32::audio_utils_fifo_writer32(audio_utils_fifo& fifo) :
     45     mLocalRear(0), mFrameCountP2(fifo.mFrameCountP2), mBuffer((int32_t *) fifo.mBuffer),
     46     mWriterRear(fifo.mWriterRear)
     47 {
     48     if (fifo.mFrameSize != sizeof(int32_t) || fifo.mFudgeFactor != 0 ||
     49             ((size_t) mBuffer & ((sizeof(int32_t) - 1))) != 0) {
     50         abort();
     51     }
     52 }
     53 
     54 audio_utils_fifo_writer32::~audio_utils_fifo_writer32()
     55 {
     56 }
     57 
     58 void audio_utils_fifo_writer32::write(const int32_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