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using System;
using System.Threading;

/// <summary>
/// An array with wrap-around access for LockFreeWorkStealingDeque based on the paper
/// "Dynamic Circular Work-Stealing Deque", authors David Chase and Yossi Lev.
/// https://www.dre.vanderbilt.edu/~schmidt/PDF/work-stealing-dequeue.pdf
/// Modified to support negative indices.
/// </summary>
public class CircularArray<T> {
	private int size;
	private T[] segment;
	private uint mask;

	public int Size { get { return size; } }

	public CircularArray (int sizePoT) {
		this.size = sizePoT;
		segment = new T[sizePoT];
		mask = (uint)(sizePoT - 1);
	}

	public T Get (int i) {
		return this.segment[((uint)i) & mask];
	}

	public void Put (int i, T item) {
		this.segment[((uint)i) & mask] = item;
	}

	public CircularArray<T> Grow (int b, int t, int newSizePoT) {
		CircularArray<T> a = new CircularArray<T>(newSizePoT);
		for (int i = t; i < b; i++) {
			a.Put(i, this.Get(i));
		}
		return a;
	}
}