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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
//
// Copyright (c) 2002-2011 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// HandleAllocator.cpp: Implements the gl::HandleAllocator class, which is used
// to allocate GL handles.
#include "libANGLE/HandleAllocator.h"
#include <algorithm>
#include <functional>
#include "common/debug.h"
namespace gl
{
struct HandleAllocator::HandleRangeComparator
{
bool operator()(const HandleRange &range, GLuint handle) const { return (range.end < handle); }
};
HandleAllocator::HandleAllocator() : mBaseValue(1), mNextValue(1), mLoggingEnabled(false)
{
mUnallocatedList.push_back(HandleRange(1, std::numeric_limits<GLuint>::max()));
}
HandleAllocator::HandleAllocator(GLuint maximumHandleValue)
: mBaseValue(1), mNextValue(1), mLoggingEnabled(false)
{
mUnallocatedList.push_back(HandleRange(1, maximumHandleValue));
}
HandleAllocator::~HandleAllocator() {}
void HandleAllocator::setBaseHandle(GLuint value)
{
ASSERT(mBaseValue == mNextValue);
mBaseValue = value;
mNextValue = value;
}
GLuint HandleAllocator::allocate()
{
ASSERT(!mUnallocatedList.empty() || !mReleasedList.empty());
// Allocate from released list, logarithmic time for pop_heap.
if (!mReleasedList.empty())
{
std::pop_heap(mReleasedList.begin(), mReleasedList.end(), std::greater<GLuint>());
GLuint reusedHandle = mReleasedList.back();
mReleasedList.pop_back();
if (mLoggingEnabled)
{
WARN() << "HandleAllocator::allocate reusing " << reusedHandle << std::endl;
}
return reusedHandle;
}
// Allocate from unallocated list, constant time.
auto listIt = mUnallocatedList.begin();
GLuint freeListHandle = listIt->begin;
ASSERT(freeListHandle > 0);
if (listIt->begin == listIt->end)
{
mUnallocatedList.erase(listIt);
}
else
{
listIt->begin++;
}
if (mLoggingEnabled)
{
WARN() << "HandleAllocator::allocate allocating " << freeListHandle << std::endl;
}
return freeListHandle;
}
void HandleAllocator::release(GLuint handle)
{
if (mLoggingEnabled)
{
WARN() << "HandleAllocator::release releasing " << handle << std::endl;
}
// Add to released list, logarithmic time for push_heap.
mReleasedList.push_back(handle);
std::push_heap(mReleasedList.begin(), mReleasedList.end(), std::greater<GLuint>());
}
void HandleAllocator::reserve(GLuint handle)
{
if (mLoggingEnabled)
{
WARN() << "HandleAllocator::reserve reserving " << handle << std::endl;
}
// Clear from released list -- might be a slow operation.
if (!mReleasedList.empty())
{
auto releasedIt = std::find(mReleasedList.begin(), mReleasedList.end(), handle);
if (releasedIt != mReleasedList.end())
{
mReleasedList.erase(releasedIt);
std::make_heap(mReleasedList.begin(), mReleasedList.end(), std::greater<GLuint>());
return;
}
}
// Not in released list, reserve in the unallocated list.
auto boundIt = std::lower_bound(mUnallocatedList.begin(), mUnallocatedList.end(), handle,
HandleRangeComparator());
ASSERT(boundIt != mUnallocatedList.end());
GLuint begin = boundIt->begin;
GLuint end = boundIt->end;
if (handle == begin || handle == end)
{
if (begin == end)
{
mUnallocatedList.erase(boundIt);
}
else if (handle == begin)
{
boundIt->begin++;
}
else
{
ASSERT(handle == end);
boundIt->end--;
}
return;
}
ASSERT(begin < handle && handle < end);
// need to split the range
auto placementIt = mUnallocatedList.erase(boundIt);
placementIt = mUnallocatedList.insert(placementIt, HandleRange(handle + 1, end));
mUnallocatedList.insert(placementIt, HandleRange(begin, handle - 1));
}
void HandleAllocator::reset()
{
mUnallocatedList.clear();
mUnallocatedList.push_back(HandleRange(1, std::numeric_limits<GLuint>::max()));
mReleasedList.clear();
mBaseValue = 1;
mNextValue = 1;
}
void HandleAllocator::enableLogging(bool enabled)
{
mLoggingEnabled = enabled;
}
} // namespace gl
|
