public object Pop()
{
if (countFree == 0)
{
Debug.Assert(false);
throw new InvalidOperationException();
}
countFree--;
countInUse++;
int i = countFree & (blockSize - 1);
object item = currentFreeItemsBlock.Items[i];
currentFreeItemsBlock.Items[i] = null;
#if DEBUG
if (!freed.ContainsKey(item))
{
Debug.Assert(false);
throw new InvalidOperationException();
}
freed.Remove(item);
#endif
if (i == 0) // this container is now empty
{
sharedEmptyBlocksList.Push(currentFreeItemsBlock); // give back
// transfer extra to here (or it's null)
currentFreeItemsBlock = extraFreeItemsBlock;
extraFreeItemsBlock = null;
if (currentFreeItemsBlock == null)
{
currentFreeItemsBlock = sharedFreeItemsList.TryPop(); // try to get a new set of free items
if (currentFreeItemsBlock != null)
{
Debug.Assert(currentFreeItemsBlock.BlockSize == blockSize);
countFree += blockSize;
#if DEBUG
for (int j = 0; j < currentFreeItemsBlock.Items.Length; j++)
{
freed.Add(currentFreeItemsBlock.Items[j], false);
}
Debug.Assert(countFree == freed.Count);
#endif
}
}
}
return(item);
}
public void Push(object item)
{
#if DEBUG
if (freed.ContainsKey(item))
{
Debug.Assert(false);
throw new ArgumentException();
}
#endif
int i = countFree & (blockSize - 1);
if (i == 0) // full
{
// we're drowning in free objects - push to shared freelist
if (extraFreeItemsBlock != null)
{
#if DEBUG
for (int j = 0; j < extraFreeItemsBlock.Items.Length; j++)
{
freed.Remove(extraFreeItemsBlock.Items[j]);
}
#endif
countFree -= blockSize;
sharedFreeItemsList.Push(extraFreeItemsBlock);
extraFreeItemsBlock = null;
#if DEBUG
Debug.Assert(countFree == freed.Count);
#endif
}
// transfer current free block to extra (or might be null)
extraFreeItemsBlock = currentFreeItemsBlock;
currentFreeItemsBlock = null;
// create new current container for freed items
currentFreeItemsBlock = sharedEmptyBlocksList.TryPop();
if (currentFreeItemsBlock == null)
{
currentFreeItemsBlock = new Block(blockSize);
}
}
currentFreeItemsBlock.Items[i] = item;
countFree++;
countInUse--;
#if DEBUG
freed.Add(item, false);
Debug.Assert(countFree == freed.Count);
#endif
}
