/// <summary>
/// Initializes a new instance of the <see cref="ConcurrentQueue{T}"/> class that contains elements copied
/// from the specified collection.
/// </summary>
/// <param name="collection">
/// The collection whose elements are copied to the new <see cref="ConcurrentQueue{T}"/>.
/// </param>
/// <exception cref="System.ArgumentNullException">The <paramref name="collection"/> argument is null.</exception>
public ConcurrentQueue(IEnumerable <T> collection)
{
if (collection == null)
{
throw new ArgumentNullException(nameof(collection));
}
_crossSegmentLock = new object();
// Determine the initial segment size. We'll use the default,
// unless the collection is known to be larger than that, in which
// case we round its length up to a power of 2, as all segments must
// be a power of 2 in length.
int length = InitialSegmentLength;
if (collection is ICollection <T> c)
{
int count = c.Count;
if (count > length)
{
length = Math.Min(RoundUpToPowerOf2(count), MaxSegmentLength);
}
}
// Initialize the segment and add all of the data to it.
_tail = _head = new ConcurrentQueueSegment <T>(length);
foreach (T item in collection)
{
Enqueue(item);
}
_fixedSize = false;
}
/// <summary>
/// Initializes a new instance of the <see cref="ConcurrentQueue{T}"/> class.
/// </summary>
/// <param name="initialCapacity">The initial capacity of the <see cref="ConcurrentQueue{T}"/>.</param>
/// <param name="isFixedSize">
/// If <see langword="true"/>, the the <see cref="ConcurrentQueue{T}"/> cannot grow in size.
/// Operations on a fixed-size queue are lockless.
/// </param>
public ConcurrentQueue(int initialCapacity, bool isFixedSize)
{
initialCapacity = RoundUpToPowerOf2(initialCapacity);
_crossSegmentLock = new object();
_tail = _head = new ConcurrentQueueSegment <T>(initialCapacity);
_fixedSize = isFixedSize;
}
