public void Push(T value)
{
FastStackNode <T> bottom;
FastStackNode <T> entry = new FastStackNode <T>
{
Value = value
};
// Atomically replace the bottom of the stack.
while (true)
{
bottom = _bottom;
entry.Next = bottom;
// Try to replace the pointer.
if (Interlocked.CompareExchange(
ref _bottom,
entry,
bottom
) == bottom)
{
// Success.
break;
}
}
}
public T Peek()
{
FastStackNode <T> bottom = _bottom;
if (bottom == null)
{
throw new InvalidOperationException("The stack is empty.");
}
return(bottom.Value);
}
public IEnumerator <T> GetEnumerator()
{
FastStackNode <T> entry = _bottom;
// Start the enumeration.
while (entry != null)
{
yield return(entry.Value);
entry = entry.Next;
}
}
public T Pop()
{
// Atomically replace the bottom of the stack.
while (true)
{
FastStackNode <T> bottom = _bottom;
// If the bottom of the stack is null, the
// stack is empty.
if (bottom == null)
{
throw new InvalidOperationException("The stack is empty.");
}
// Try to replace the pointer.
if (Interlocked.CompareExchange(ref _bottom, bottom.Next, bottom) == bottom)
{
// Success.
Interlocked.Decrement(ref _count);
return(bottom.Value);
}
}
}
