?? HashSet? ???????

??:

.NET Framework? ?? HashSet? ?? ??? ???? ????. ?? ?? ??? ??? ???? ????? ??? ? ????. ? ????? ?? HashSet? ???? ???? .NET Framework?? HashSet? ?? ?????? ??? ???? ???? ??? ??? ?????.

??? ?? ??? ?? ??:

? ?? ?? ??? ??? ?? ?????? ??? HashSet ??? ??? ????. ?? ?? HashSet? ??? ????(?: ??)?? ???? ??? ? ????. ?? ?? ??? ? ??? ?????.

public class ConcurrentHashSet<T>
{
    private readonly HashSet<T> _hashSet = new HashSet<T>();
    private readonly object _syncRoot = new object();

    public bool Add(T item)
    {
        lock (_syncRoot)
        {
            return _hashSet.Add(item);
        }
    }

    public bool Remove(T item)
    {
        lock (_syncRoot)
        {
            return _hashSet.Remove(item);
        }
    }

    // 其他操作可以類似地實現(xiàn)
}

ConcurrentDictionary ??:

? ?? ?? ??? System.Collections.Concurrent ???????? ConcurrentDictionary ???? ???? ????. HashSet? ??? ??? ??? ????? ??? ??? ??? ?? ?????? ??? ??? ?????. ?-? ?(?? HashSet? ???? ?? ?? ??)? ???? ?? ??? ??? ? ????.

private ConcurrentDictionary<T, byte> _concurrentDictionary = new ConcurrentDictionary<T, byte>();

public bool Add(T item)
{
    byte dummyValue = 0;
    return _concurrentDictionary.TryAdd(item, dummyValue);
}

public bool Remove(T item)
{
    byte dummyValue;
    return _concurrentDictionary.TryRemove(item, out dummyValue);
}

// 其他操作可以類似地實現(xiàn)

??:

??? ??? ? ?? ??? ?????.

• ??? ???: ? ?? ?? ?? ??? ??? ?? ?????? ??? ???? ?????.
• ??: ?? ???? ??? ?? ??? ConcurrentDictionary?? ? ?? ??? ?? ? ????.
• ???: ConcurrentDictionary? ? ???? ???? ??? ?????.
• HashSet? ?? ???: ConcurrentDictionary? HashSet?? ???? ???? ?? HashSet ?? ??? ??? ? ????.

??:

?? HashSet? ???? ??? ?? ?????? ??? ??? ????? ConcurrentDictionary? ???? ??? ? ????. ? ??? ??? ??????? ?? ?? ??? ??? ??? ???? ?? ?????.

? ??? .NET Framework?? Concurrent HashSet? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!