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
24 using namespace android;
25 using namespace aaudio;
26
~SharedMemoryProxy()27 SharedMemoryProxy::~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
open(int originalFD,int32_t capacityInBytes)40 aaudio_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