private void SplitBlock(BestFitAllocator.Block block, uint size)
{
Debug.Assert(block.size > size);
BestFitAllocator.Block block2 = this.m_BlockPool.Get();
block2.next = block.next;
block2.nextAvailable = block.nextAvailable;
block2.prev = block;
block2.prevAvailable = block;
block2.start = block.start + size;
block2.end = block.end;
bool flag = block2.next != null;
if (flag)
{
block2.next.prev = block2;
}
bool flag2 = block2.nextAvailable != null;
if (flag2)
{
block2.nextAvailable.prevAvailable = block2;
}
block.next = block2;
block.nextAvailable = block2;
block.end = block2.start;
}
internal HeapStatistics GatherStatistics()
{
HeapStatistics heapStatistics = default(HeapStatistics);
for (BestFitAllocator.Block block = this.m_FirstBlock; block != null; block = block.next)
{
bool allocated = block.allocated;
if (allocated)
{
heapStatistics.numAllocs += 1u;
heapStatistics.allocatedSize += block.size;
}
else
{
heapStatistics.freeSize += block.size;
heapStatistics.availableBlocksCount += 1u;
heapStatistics.largestAvailableBlock = Math.Max(heapStatistics.largestAvailableBlock, block.size);
}
heapStatistics.blockCount += 1u;
}
heapStatistics.totalSize = this.totalSize;
heapStatistics.highWatermark = this.m_HighWatermark;
bool flag = heapStatistics.freeSize > 0u;
if (flag)
{
heapStatistics.fragmentation = (float)((heapStatistics.freeSize - heapStatistics.largestAvailableBlock) / heapStatistics.freeSize) * 100f;
}
return(heapStatistics);
}
public Alloc Allocate(uint size)
{
BestFitAllocator.Block block = this.BestFitFindAvailableBlock(size);
bool flag = block == null;
Alloc result;
if (flag)
{
result = default(Alloc);
}
else
{
Debug.Assert(block.size >= size);
Debug.Assert(!block.allocated);
bool flag2 = size != block.size;
if (flag2)
{
this.SplitBlock(block, size);
}
Debug.Assert(block.size == size);
bool flag3 = block.end > this.m_HighWatermark;
if (flag3)
{
this.m_HighWatermark = block.end;
}
bool flag4 = block == this.m_FirstAvailableBlock;
if (flag4)
{
this.m_FirstAvailableBlock = this.m_FirstAvailableBlock.nextAvailable;
}
bool flag5 = block.prevAvailable != null;
if (flag5)
{
block.prevAvailable.nextAvailable = block.nextAvailable;
}
bool flag6 = block.nextAvailable != null;
if (flag6)
{
block.nextAvailable.prevAvailable = block.prevAvailable;
}
block.allocated = true;
block.prevAvailable = (block.nextAvailable = null);
result = new Alloc
{
start = block.start,
size = block.size,
handle = block
};
}
return(result);
}
private BestFitAllocator.Block BestFitFindAvailableBlock(uint size)
{
BestFitAllocator.Block block = this.m_FirstAvailableBlock;
BestFitAllocator.Block result = null;
uint num = 4294967295u;
while (block != null)
{
bool flag = block.size >= size && num > block.size;
if (flag)
{
result = block;
num = block.size;
}
block = block.nextAvailable;
}
return(result);
}
private BestFitAllocator.Block CoalesceBlockWithPrevious(BestFitAllocator.Block block)
{
Debug.Assert(block.prevAvailable.end == block.start);
Debug.Assert(block.prev.nextAvailable == block);
BestFitAllocator.Block prev = block.prev;
prev.next = block.next;
bool flag = block.next != null;
if (flag)
{
block.next.prev = prev;
}
prev.nextAvailable = block.nextAvailable;
bool flag2 = block.nextAvailable != null;
if (flag2)
{
block.nextAvailable.prevAvailable = block.prevAvailable;
}
prev.end = block.end;
this.m_BlockPool.Return(block);
return(prev);
}
public BestFitAllocator(uint size)
{
this.< totalSize > k__BackingField = size;
this.m_FirstBlock = (this.m_FirstAvailableBlock = this.m_BlockPool.Get());
this.m_FirstAvailableBlock.end = size;
}
public void Free(Alloc alloc)
{
BestFitAllocator.Block block = (BestFitAllocator.Block)alloc.handle;
bool flag = !block.allocated;
if (flag)
{
Debug.Assert(false, "Severe error: UIR allocation double-free");
}
else
{
Debug.Assert(block.allocated);
Debug.Assert(block.start == alloc.start);
Debug.Assert(block.size == alloc.size);
bool flag2 = block.end == this.m_HighWatermark;
if (flag2)
{
bool flag3 = block.prev != null;
if (flag3)
{
this.m_HighWatermark = (block.prev.allocated ? block.prev.end : block.prev.start);
}
else
{
this.m_HighWatermark = 0u;
}
}
block.allocated = false;
BestFitAllocator.Block block2 = this.m_FirstAvailableBlock;
BestFitAllocator.Block block3 = null;
while (block2 != null && block2.start < block.start)
{
block3 = block2;
block2 = block2.nextAvailable;
}
bool flag4 = block3 == null;
if (flag4)
{
Debug.Assert(block.prevAvailable == null);
block.nextAvailable = this.m_FirstAvailableBlock;
this.m_FirstAvailableBlock = block;
}
else
{
block.prevAvailable = block3;
block.nextAvailable = block3.nextAvailable;
block3.nextAvailable = block;
}
bool flag5 = block.nextAvailable != null;
if (flag5)
{
block.nextAvailable.prevAvailable = block;
}
bool flag6 = block.prevAvailable == block.prev && block.prev != null;
if (flag6)
{
block = this.CoalesceBlockWithPrevious(block);
}
bool flag7 = block.nextAvailable == block.next && block.next != null;
if (flag7)
{
block = this.CoalesceBlockWithPrevious(block.next);
}
}
}
