R/Ryujinx.HLE/HOS/Kernel/Process/KContextIdManager.cs

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using Ryujinx.Common;
using System;
namespace Ryujinx.HLE.HOS.Kernel.Process
{
class KContextIdManager
{
private const int IdMasksCount = 8;
private int[] _idMasks;
private int _nextFreeBitHint;
public KContextIdManager()
{
_idMasks = new int[IdMasksCount];
}
public int GetId()
{
lock (_idMasks)
{
int id = 0;
if (!TestBit(_nextFreeBitHint))
{
id = _nextFreeBitHint;
}
else
{
for (int index = 0; index < IdMasksCount; index++)
{
int mask = _idMasks[index];
int firstFreeBit = BitUtils.CountLeadingZeros32((mask + 1) & ~mask);
if (firstFreeBit < 32)
{
int baseBit = index * 32 + 31;
id = baseBit - firstFreeBit;
break;
}
else if (index == IdMasksCount - 1)
{
throw new InvalidOperationException("Maximum number of Ids reached!");
}
}
}
_nextFreeBitHint = id + 1;
SetBit(id);
return id;
}
}
public void PutId(int id)
{
lock (_idMasks)
{
ClearBit(id);
}
}
private bool TestBit(int bit)
{
return (_idMasks[_nextFreeBitHint / 32] & (1 << (_nextFreeBitHint & 31))) != 0;
}
private void SetBit(int bit)
{
_idMasks[_nextFreeBitHint / 32] |= (1 << (_nextFreeBitHint & 31));
}
private void ClearBit(int bit)
{
_idMasks[_nextFreeBitHint / 32] &= ~(1 << (_nextFreeBitHint & 31));
}
}
}