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#define LOG_TAG "AAudioService"
18//#define LOG_NDEBUG 0
19#include <utils/Log.h>
20
21#include <aaudio/AAudio.h>
22#include "SharedMemoryProxy.h"
23
24using namespace android;
25using namespace aaudio;
26
27SharedMemoryProxy::~SharedMemoryProxy()
28{
29    if (mOriginalSharedMemory != nullptr) {
30        munmap(mOriginalSharedMemory, mSharedMemorySizeInBytes);
31        mOriginalSharedMemory = nullptr;
32    }
33    if (mProxySharedMemory != nullptr) {
34        munmap(mProxySharedMemory, mSharedMemorySizeInBytes);
35        close(mProxyFileDescriptor);
36        mProxySharedMemory = nullptr;
37    }
38}
39
40aaudio_result_t SharedMemoryProxy::open(int originalFD, int32_t capacityInBytes) {
41    mOriginalFileDescriptor = originalFD;
42    mSharedMemorySizeInBytes = capacityInBytes;
43
44    mProxyFileDescriptor = ashmem_create_region("AAudioProxyDataBuffer", mSharedMemorySizeInBytes);
45    if (mProxyFileDescriptor < 0) {
46        ALOGE("SharedMemoryProxy::open() ashmem_create_region() failed %d", errno);
47        return AAUDIO_ERROR_INTERNAL;
48    }
49    int err = ashmem_set_prot_region(mProxyFileDescriptor, PROT_READ|PROT_WRITE);
50    if (err < 0) {
51        ALOGE("SharedMemoryProxy::open() ashmem_set_prot_region() failed %d", errno);
52        close(mProxyFileDescriptor);
53        mProxyFileDescriptor = -1;
54        return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
55    }
56
57    // Get original memory address.
58    mOriginalSharedMemory = (uint8_t *) mmap(0, mSharedMemorySizeInBytes,
59                         PROT_READ|PROT_WRITE,
60                         MAP_SHARED,
61                         mOriginalFileDescriptor, 0);
62    if (mOriginalSharedMemory == MAP_FAILED) {
63        ALOGE("SharedMemoryProxy::open() original mmap(%d) failed %d (%s)",
64                mOriginalFileDescriptor, errno, strerror(errno));
65        return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
66    }
67
68    // Map the fd to the same memory addresses.
69    mProxySharedMemory = (uint8_t *) mmap(mOriginalSharedMemory, mSharedMemorySizeInBytes,
70                         PROT_READ|PROT_WRITE,
71                         MAP_SHARED,
72                         mProxyFileDescriptor, 0);
73    if (mProxySharedMemory != mOriginalSharedMemory) {
74        ALOGE("SharedMemoryProxy::open() proxy mmap(%d) failed %d", mProxyFileDescriptor, errno);
75        munmap(mOriginalSharedMemory, mSharedMemorySizeInBytes);
76        mOriginalSharedMemory = nullptr;
77        close(mProxyFileDescriptor);
78        mProxyFileDescriptor = -1;
79        return AAUDIO_ERROR_INTERNAL; // TODO convert errno to a better AAUDIO_ERROR;
80    }
81
82    return AAUDIO_OK;
83}
84