/// <summary>
/// Marks a range of memory as free by adding it to the tree.
/// This function will automatically compact the tree when it determines there are multiple ranges of free memory adjacent to each other.
/// </summary>
/// <param name="va">Virtual address at which to deallocate</param>
/// <param name="size">Size of the allocation in bytes</param>
public void DeallocateRange(ulong va, ulong size)
{
lock (_tree)
{
Logger.Debug?.Print(LogClass.ServiceNv, $"Deallocating address range from 0x{va:X} to 0x{(va + size):X}.");
ulong freeAddressStartPosition = _tree.Floor(va);
if (freeAddressStartPosition != InvalidAddress)
{
LinkedListNode <ulong> node = _dictionary[freeAddressStartPosition];
ulong targetPrevAddress = _dictionary[freeAddressStartPosition].Previous != null ? _dictionary[_dictionary[freeAddressStartPosition].Previous.Value].Value : InvalidAddress;
ulong targetNextAddress = _dictionary[freeAddressStartPosition].Next != null ? _dictionary[_dictionary[freeAddressStartPosition].Next.Value].Value : InvalidAddress;
ulong expandedStart = va;
ulong expandedEnd = va + size;
while (targetPrevAddress != InvalidAddress)
{
ulong prevAddress = targetPrevAddress;
ulong prevEndAddress = _tree.Get(targetPrevAddress);
if (prevEndAddress >= expandedStart)
{
expandedStart = targetPrevAddress;
LinkedListNode <ulong> prevPtr = _dictionary[prevAddress];
if (prevPtr.Previous != null)
{
targetPrevAddress = prevPtr.Previous.Value;
}
else
{
targetPrevAddress = InvalidAddress;
}
node = node.Previous;
_tree.Remove(prevAddress);
_list.Remove(_dictionary[prevAddress]);
_dictionary.Remove(prevAddress);
}
else
{
break;
}
}
while (targetNextAddress != InvalidAddress)
{
ulong nextAddress = targetNextAddress;
ulong nextEndAddress = _tree.Get(targetNextAddress);
if (nextAddress <= expandedEnd)
{
expandedEnd = Math.Max(expandedEnd, nextEndAddress);
LinkedListNode <ulong> nextPtr = _dictionary[nextAddress];
if (nextPtr.Next != null)
{
targetNextAddress = nextPtr.Next.Value;
}
else
{
targetNextAddress = InvalidAddress;
}
_tree.Remove(nextAddress);
_list.Remove(_dictionary[nextAddress]);
_dictionary.Remove(nextAddress);
}
else
{
break;
}
}
Logger.Debug?.Print(LogClass.ServiceNv, $"Deallocation resulted in new free range from 0x{expandedStart:X} to 0x{expandedEnd:X}.");
_tree.Add(expandedStart, expandedEnd);
LinkedListNode <ulong> nodePtr = _list.AddAfter(node, expandedStart);
_dictionary[expandedStart] = nodePtr;
}
}
}