/usr/include/android/utils/SharedBuffer.h is in android-libutils-dev 1:6.0.1+r16-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | /*
* Copyright (C) 2005 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_SHARED_BUFFER_H
#define ANDROID_SHARED_BUFFER_H
#include <stdint.h>
#include <sys/types.h>
// ---------------------------------------------------------------------------
namespace android {
class SharedBuffer
{
public:
/* flags to use with release() */
enum {
eKeepStorage = 0x00000001
};
/*! allocate a buffer of size 'size' and acquire() it.
* call release() to free it.
*/
static SharedBuffer* alloc(size_t size);
/*! free the memory associated with the SharedBuffer.
* Fails if there are any users associated with this SharedBuffer.
* In other words, the buffer must have been release by all its
* users.
*/
static ssize_t dealloc(const SharedBuffer* released);
//! access the data for read
inline const void* data() const;
//! access the data for read/write
inline void* data();
//! get size of the buffer
inline size_t size() const;
//! get back a SharedBuffer object from its data
static inline SharedBuffer* bufferFromData(void* data);
//! get back a SharedBuffer object from its data
static inline const SharedBuffer* bufferFromData(const void* data);
//! get the size of a SharedBuffer object from its data
static inline size_t sizeFromData(const void* data);
//! edit the buffer (get a writtable, or non-const, version of it)
SharedBuffer* edit() const;
//! edit the buffer, resizing if needed
SharedBuffer* editResize(size_t size) const;
//! like edit() but fails if a copy is required
SharedBuffer* attemptEdit() const;
//! resize and edit the buffer, loose it's content.
SharedBuffer* reset(size_t size) const;
//! acquire/release a reference on this buffer
void acquire() const;
/*! release a reference on this buffer, with the option of not
* freeing the memory associated with it if it was the last reference
* returns the previous reference count
*/
int32_t release(uint32_t flags = 0) const;
//! returns wether or not we're the only owner
inline bool onlyOwner() const;
private:
inline SharedBuffer() { }
inline ~SharedBuffer() { }
SharedBuffer(const SharedBuffer&);
SharedBuffer& operator = (const SharedBuffer&);
// 16 bytes. must be sized to preserve correct alignment.
mutable int32_t mRefs;
size_t mSize;
uint32_t mReserved[2];
};
// ---------------------------------------------------------------------------
const void* SharedBuffer::data() const {
return this + 1;
}
void* SharedBuffer::data() {
return this + 1;
}
size_t SharedBuffer::size() const {
return mSize;
}
SharedBuffer* SharedBuffer::bufferFromData(void* data) {
return data ? static_cast<SharedBuffer *>(data)-1 : 0;
}
const SharedBuffer* SharedBuffer::bufferFromData(const void* data) {
return data ? static_cast<const SharedBuffer *>(data)-1 : 0;
}
size_t SharedBuffer::sizeFromData(const void* data) {
return data ? bufferFromData(data)->mSize : 0;
}
bool SharedBuffer::onlyOwner() const {
return (mRefs == 1);
}
}; // namespace android
// ---------------------------------------------------------------------------
#endif // ANDROID_VECTOR_H
|