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
|
/*
* Copyright 2009, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// This file contains the implementation of IdAllocator.
#include "gpu/command_buffer/client/id_allocator.h"
namespace command_buffer {
IdAllocator::IdAllocator() : bitmap_(1) { bitmap_[0] = 0; }
static const unsigned int kBitsPerUint32 = sizeof(Uint32) * 8; // NOLINT
// Looks for the first non-full entry, and return the first free bit in that
// entry. If all the entries are full, it will return the first bit of an entry
// that would be appended, but doesn't actually append that entry to the vector.
unsigned int IdAllocator::FindFirstFree() const {
size_t size = bitmap_.size();
for (unsigned int i = 0; i < size; ++i) {
Uint32 value = bitmap_[i];
if (value != 0xffffffffU) {
for (unsigned int j = 0; j < kBitsPerUint32; ++j) {
if (!(value & (1 << j))) return i * kBitsPerUint32 + j;
}
DLOG(FATAL) << "Code should not reach here.";
}
}
return size*kBitsPerUint32;
}
// Sets the correct bit in the proper entry, resizing the vector if needed.
void IdAllocator::SetBit(unsigned int bit, bool value) {
size_t size = bitmap_.size();
if (bit >= size * kBitsPerUint32) {
size_t newsize = bit / kBitsPerUint32 + 1;
bitmap_.resize(newsize);
for (size_t i = size; i < newsize; ++i) bitmap_[i] = 0;
}
Uint32 mask = 1U << (bit % kBitsPerUint32);
if (value) {
bitmap_[bit / kBitsPerUint32] |= mask;
} else {
bitmap_[bit / kBitsPerUint32] &= ~mask;
}
}
// Gets the bit from the proper entry. This doesn't resize the vector, just
// returns false if the bit is beyond the last entry.
bool IdAllocator::GetBit(unsigned int bit) const {
size_t size = bitmap_.size();
if (bit / kBitsPerUint32 >= size) return false;
Uint32 mask = 1U << (bit % kBitsPerUint32);
return (bitmap_[bit / kBitsPerUint32] & mask) != 0;
}
} // namespace command_buffer
|
