1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_BUFFER_HUB_METADATA_H_
#define ANDROID_BUFFER_HUB_METADATA_H_
#include <android-base/unique_fd.h>
#include <ui/BufferHubDefs.h>
namespace android {
namespace {
using base::unique_fd;
} // namespace
class BufferHubMetadata {
public:
// Creates a new BufferHubMetadata backed by an ashmem region.
//
// @param userMetadataSize Size in bytes of the user defined metadata. The entire metadata
// shared memory region to be allocated is the size of canonical
// BufferHubDefs::MetadataHeader plus userMetadataSize.
static BufferHubMetadata create(size_t userMetadataSize);
// Imports an existing BufferHubMetadata from an ashmem FD.
//
// @param ashmemFd Ashmem file descriptor representing an ashmem region.
static BufferHubMetadata import(unique_fd ashmemFd);
BufferHubMetadata() = default;
BufferHubMetadata(BufferHubMetadata&& other) { *this = std::move(other); }
~BufferHubMetadata();
BufferHubMetadata& operator=(BufferHubMetadata&& other) {
if (this != &other) {
mUserMetadataSize = other.mUserMetadataSize;
other.mUserMetadataSize = 0;
mAshmemFd = std::move(other.mAshmemFd);
// The old raw mMetadataHeader pointer must be cleared, otherwise the destructor will
// automatically mummap() the shared memory.
mMetadataHeader = other.mMetadataHeader;
other.mMetadataHeader = nullptr;
}
return *this;
}
// Returns true if the metadata is valid, i.e. the metadata has a valid ashmem fd and the ashmem
// has been mapped into virtual address space.
bool isValid() const { return mAshmemFd.get() != -1 && mMetadataHeader != nullptr; }
size_t userMetadataSize() const { return mUserMetadataSize; }
size_t metadataSize() const { return mUserMetadataSize + BufferHubDefs::kMetadataHeaderSize; }
const unique_fd& ashmemFd() const { return mAshmemFd; }
BufferHubDefs::MetadataHeader* metadataHeader() { return mMetadataHeader; }
private:
BufferHubMetadata(size_t userMetadataSize, unique_fd ashmemFd,
BufferHubDefs::MetadataHeader* metadataHeader);
BufferHubMetadata(const BufferHubMetadata&) = delete;
void operator=(const BufferHubMetadata&) = delete;
size_t mUserMetadataSize = 0;
unique_fd mAshmemFd;
BufferHubDefs::MetadataHeader* mMetadataHeader = nullptr;
};
} // namespace android
#endif // ANDROID_BUFFER_HUB_METADATA_H_
|
