1 /*
2 * Copyright (C) 2016 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 "AAudioService"
18 //#define LOG_NDEBUG 0
19 #include <utils/Log.h>
20
21 #include <sys/mman.h>
22
23 #include "binding/RingBufferParcelable.h"
24 #include "binding/AudioEndpointParcelable.h"
25
26 #include "SharedRingBuffer.h"
27
28 using namespace android;
29 using namespace aaudio;
30
~SharedRingBuffer()31 SharedRingBuffer::~SharedRingBuffer()
32 {
33 if (mSharedMemory != nullptr) {
34 delete mFifoBuffer;
35 munmap(mSharedMemory, mSharedMemorySizeInBytes);
36 mSharedMemory = nullptr;
37 }
38 if (mFileDescriptor != -1) {
39 ALOGV("SharedRingBuffer: LEAK? close(mFileDescriptor = %d)\n", mFileDescriptor);
40 close(mFileDescriptor);
41 mFileDescriptor = -1;
42 }
43 }
44
allocate(fifo_frames_t bytesPerFrame,fifo_frames_t capacityInFrames)45 aaudio_result_t SharedRingBuffer::allocate(fifo_frames_t bytesPerFrame,
46 fifo_frames_t capacityInFrames) {
47 mCapacityInFrames = capacityInFrames;
48
49 // Create shared memory large enough to hold the data and the read and write counters.
50 mDataMemorySizeInBytes = bytesPerFrame * capacityInFrames;
51 mSharedMemorySizeInBytes = mDataMemorySizeInBytes + (2 * (sizeof(fifo_counter_t)));
52 mFileDescriptor = ashmem_create_region("AAudioSharedRingBuffer", mSharedMemorySizeInBytes);
53 ALOGV("SharedRingBuffer::allocate() LEAK? mFileDescriptor = %d\n", mFileDescriptor);
54 if (mFileDescriptor < 0) {
55 ALOGE("SharedRingBuffer::allocate() ashmem_create_region() failed %d", errno);
56 return AAUDIO_ERROR_INTERNAL;
57 }
58
59 int err = ashmem_set_prot_region(mFileDescriptor, PROT_READ|PROT_WRITE); // TODO error handling?
60 if (err < 0) {
61 ALOGE("SharedRingBuffer::allocate() ashmem_set_prot_region() failed %d", errno);
62 close(mFileDescriptor);
63 return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
64 }
65
66 // Map the fd to memory addresses.
67 mSharedMemory = (uint8_t *) mmap(0, mSharedMemorySizeInBytes,
68 PROT_READ|PROT_WRITE,
69 MAP_SHARED,
70 mFileDescriptor, 0);
71 if (mSharedMemory == MAP_FAILED) {
72 ALOGE("SharedRingBuffer::allocate() mmap() failed %d", errno);
73 close(mFileDescriptor);
74 return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
75 }
76
77 // Get addresses for our counters and data from the shared memory.
78 fifo_counter_t *readCounterAddress =
79 (fifo_counter_t *) &mSharedMemory[SHARED_RINGBUFFER_READ_OFFSET];
80 fifo_counter_t *writeCounterAddress =
81 (fifo_counter_t *) &mSharedMemory[SHARED_RINGBUFFER_WRITE_OFFSET];
82 uint8_t *dataAddress = &mSharedMemory[SHARED_RINGBUFFER_DATA_OFFSET];
83
84 mFifoBuffer = new FifoBuffer(bytesPerFrame, capacityInFrames,
85 readCounterAddress, writeCounterAddress, dataAddress);
86 return AAUDIO_OK;
87 }
88
fillParcelable(AudioEndpointParcelable & endpointParcelable,RingBufferParcelable & ringBufferParcelable)89 void SharedRingBuffer::fillParcelable(AudioEndpointParcelable &endpointParcelable,
90 RingBufferParcelable &ringBufferParcelable) {
91 int fdIndex = endpointParcelable.addFileDescriptor(mFileDescriptor, mSharedMemorySizeInBytes);
92 ringBufferParcelable.setupMemory(fdIndex,
93 SHARED_RINGBUFFER_DATA_OFFSET,
94 mDataMemorySizeInBytes,
95 SHARED_RINGBUFFER_READ_OFFSET,
96 SHARED_RINGBUFFER_WRITE_OFFSET,
97 sizeof(fifo_counter_t));
98 ringBufferParcelable.setBytesPerFrame(mFifoBuffer->getBytesPerFrame());
99 ringBufferParcelable.setFramesPerBurst(1);
100 ringBufferParcelable.setCapacityInFrames(mCapacityInFrames);
101 }
102