aboutsummaryrefslogtreecommitdiff
path: root/src/Ryujinx.Horizon/HeapAllocator.cs
blob: 40ff14d095e531d23180711d1ae9db423a77cad6 (plain) (blame)
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
using Ryujinx.Common;
using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace Ryujinx.Horizon
{
    class HeapAllocator
    {
        private const ulong InvalidAddress = ulong.MaxValue;

        private struct Range : IComparable<Range>
        {
            public ulong Offset { get; }
            public ulong Size   { get; }

            public Range(ulong offset, ulong size)
            {
                Offset = offset;
                Size   = size;
            }

            public int CompareTo(Range other)
            {
                return Offset.CompareTo(other.Offset);
            }
        }

        private readonly List<Range> _freeRanges;
        private ulong _currentHeapSize;

        public HeapAllocator()
        {
            _freeRanges      = new List<Range>();
            _currentHeapSize = 0;
        }

        public ulong Allocate(ulong size, ulong alignment = 1UL)
        {
            ulong address = AllocateImpl(size, alignment);

            if (address == InvalidAddress)
            {
                ExpandHeap(size + alignment - 1UL);

                address = AllocateImpl(size, alignment);

                Debug.Assert(address != InvalidAddress);
            }

            return address;
        }

        private void ExpandHeap(ulong expansionSize)
        {
            ulong oldHeapSize = _currentHeapSize;
            ulong newHeapSize = BitUtils.AlignUp(oldHeapSize + expansionSize, 0x200000UL);

            _currentHeapSize = newHeapSize;

            HorizonStatic.Syscall.SetHeapSize(out ulong heapAddress, newHeapSize).AbortOnFailure();

            Free(heapAddress + oldHeapSize, newHeapSize - oldHeapSize);
        }

        private ulong AllocateImpl(ulong size, ulong alignment)
        {
            for (int i = 0; i < _freeRanges.Count; i++)
            {
                var range = _freeRanges[i];

                ulong alignedOffset = BitUtils.AlignUp(range.Offset, alignment);
                ulong sizeDelta     = alignedOffset - range.Offset;
                ulong usableSize    = range.Size - sizeDelta;

                if (sizeDelta < range.Size && usableSize >= size)
                {
                    _freeRanges.RemoveAt(i);

                    if (sizeDelta != 0)
                    {
                        InsertFreeRange(range.Offset, sizeDelta);
                    }

                    ulong endOffset     = range.Offset + range.Size;
                    ulong remainingSize = endOffset - (alignedOffset + size);
                    if (remainingSize != 0)
                    {
                        InsertFreeRange(endOffset - remainingSize, remainingSize);
                    }

                    return alignedOffset;
                }
            }

            return InvalidAddress;
        }

        public void Free(ulong offset, ulong size)
        {
            InsertFreeRangeComingled(offset, size);
        }

        private void InsertFreeRange(ulong offset, ulong size)
        {
            var range = new Range(offset, size);
            int index = _freeRanges.BinarySearch(range);
            if (index < 0)
            {
                index = ~index;
            }

            _freeRanges.Insert(index, range);
        }

        private void InsertFreeRangeComingled(ulong offset, ulong size)
        {
            ulong endOffset = offset + size;
            var range = new Range(offset, size);
            int index = _freeRanges.BinarySearch(range);
            if (index < 0)
            {
                index = ~index;
            }

            if (index < _freeRanges.Count && _freeRanges[index].Offset == endOffset)
            {
                endOffset = _freeRanges[index].Offset + _freeRanges[index].Size;
                _freeRanges.RemoveAt(index);
            }

            if (index > 0 && _freeRanges[index - 1].Offset + _freeRanges[index - 1].Size == offset)
            {
                offset = _freeRanges[index - 1].Offset;
                _freeRanges.RemoveAt(--index);
            }

            range = new Range(offset, endOffset - offset);

            _freeRanges.Insert(index, range);
        }
    }
}