/// <summary>
/// Allocates an index which corresponds to a buffer.
/// </summary>
/// <returns>Allocated index. If allocation fails, returned index is negative.</returns>
/// <exception cref="InvalidOperationException">Thrown when allocator is exhausted or when buffer cannot be committed.</exception>
public int Allocate()
{
if (FreeList.IsEmpty)
{
#if ENABLE_UNITY_COLLECTIONS_CHECKS
throw new InvalidOperationException("Cannot allocate, allocator is exhausted.");
#else
return(-1);
#endif
}
int lastFreeListIndex = FreeList.Length - 1;
int index = FreeList.Ptr[lastFreeListIndex];
BaselibErrorState errorState;
var range = new VMRange((IntPtr)this[index], (uint)BufferSizeInBytes, VirtualMemoryUtility.DefaultPageSizeInBytes);
VirtualMemoryUtility.CommitMemory(range, out errorState);
if (!errorState.Success)
{
#if ENABLE_UNITY_COLLECTIONS_CHECKS
throw new InvalidOperationException($"Failed to commit address range {range}.");
#else
return(-1);
#endif
}
FreeList.RemoveAtSwapBack(lastFreeListIndex);
return(index);
}
public static bool AddWriterTypeIndex(int typeIndex, ref UnsafeIntList reading, ref UnsafeIntList writing)
{
if (writing.Contains(typeIndex))
{
return(false);
}
var readingIndex = reading.IndexOf(typeIndex);
if (readingIndex != -1)
{
reading.RemoveAtSwapBack(readingIndex);
}
writing.Add(typeIndex);
return(true);
}
public void Free(void *pointer)
{
if (pointer == null)
{
return;
}
var blocks = m_allocations.Length; // how many blocks have we allocated?
for (var i = blocks - 1; i >= 0; --i)
{
var block = (byte *)m_blocks[i]; // get a pointer to the block.
if (pointer >= block && pointer < block + ms_BlockSize) // is the pointer we want to free in this block?
{
#if ENABLE_UNITY_COLLECTIONS_CHECKS
if (m_allocations.Ptr[i] <= 0) // if that block has no allocations, we can't proceed
{
throw new ArgumentException($"Cannot free this pointer from BlockAllocator: no more allocations to free in its block.");
}
#endif
if (--m_allocations.Ptr[i] == 0) // if this was the last allocation in the block,
{
if (i == blocks - 1) // if it's the last block,
{
m_nextByteOffset = 0; // just forget that we allocated anything from it, but keep it for later allocations
}
else
{
AllocatorManager.Free(m_handle, (void *)m_blocks[i]); // delete the block
m_blocks.RemoveAtSwapBack(i); // and forget we ever saw it
m_allocations.RemoveAtSwapBack(i); // and your dog toto, too
}
}
return;
}
}
#if ENABLE_UNITY_COLLECTIONS_CHECKS
throw new ArgumentException($"Cannot free this pointer from BlockAllocator: can't be found in any block.");
#endif
}