TryPeek()

bool System.Collections.Concurrent.ConcurrentQueueSegment< T >.TryPeek ( [MaybeNullWhen(false)] out T result, bool resultUsed )

inline

Definition at line 98 of file ConcurrentQueueSegment.cs.

    {
        if (resultUsed)
        {
            _preservedForObservation = true;
            Interlocked.MemoryBarrier();
        }
        Slot[] slots = _slots;
        SpinWait spinWait = default(SpinWait);
        while (true)
        {
            int num = Volatile.Read(ref _headAndTail.Head);
            int num2 = num & _slotsMask;
            int num3 = Volatile.Read(ref slots[num2].SequenceNumber);
            int num4 = num3 - (num + 1);
            if (num4 == 0)
            {
                result = (resultUsed ? slots[num2].Item : default(T));
                return true;
            }
            if (num4 < 0)
            {
                bool frozenForEnqueues = _frozenForEnqueues;
                int num5 = Volatile.Read(ref _headAndTail.Tail);
                if (num5 - num <= 0 || (frozenForEnqueues && num5 - FreezeOffset - num <= 0))
                {
                    break;
                }
                spinWait.SpinOnce(-1);
            }
        }
        result = default(T);
        return false;
    }

References System.Collections.Concurrent.ConcurrentQueueSegment< T >._frozenForEnqueues, System.Collections.Concurrent.ConcurrentQueueSegment< T >._headAndTail, System.Collections.Concurrent.ConcurrentQueueSegment< T >._preservedForObservation, System.Collections.Concurrent.ConcurrentQueueSegment< T >._slots, System.Collections.Concurrent.ConcurrentQueueSegment< T >._slotsMask, System.Collections.Concurrent.ConcurrentQueueSegment< T >.FreezeOffset, System.Collections.Concurrent.PaddedHeadAndTail.Head, System.Collections.Concurrent.ConcurrentQueueSegment< T >.Slot.Item, System.Threading.Interlocked.MemoryBarrier(), System.Threading.Volatile.Read(), System.Threading.SpinWait.SpinOnce(), and System.Collections.Concurrent.PaddedHeadAndTail.Tail.