Cysharp/UniTask · error · ArgumentOutOfRangeException

capacity

Error message

capacity

What it means

Thrown by MinimumQueue's constructor when capacity is negative. MinimumQueue is an internal optimized circular-buffer queue used by ArrayPool and player-loop runners. The guard is standard argument validation; end users of UniTask should never instantiate this type directly.

Source

Thrown at src/UniTask/Assets/Plugins/UniTask/Runtime/Internal/MinimumQueue.cs:21

using System;
using System.Runtime.CompilerServices;

namespace Cysharp.Threading.Tasks.Internal
{
    // optimized version of Standard Queue<T>.
    internal class MinimumQueue<T>
    {
        const int MinimumGrow = 4;
        const int GrowFactor = 200;

        T[] array;
        int head;
        int tail;
        int size;

        public MinimumQueue(int capacity)
        {
            if (capacity < 0) throw new ArgumentOutOfRangeException("capacity");
            array = new T[capacity];
            head = tail = size = 0;
        }

        public int Count
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get { return size; }
        }

        public T Peek()
        {
            if (size == 0) ThrowForEmptyQueue();
            return array[head];
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Enqueue(T item)

View on GitHub (pinned to ceac8d6946)

Solutions

1. Do not instantiate MinimumQueue directly — it is an internal implementation detail.
2. If encountered, verify the UniTask source is unmodified and matches the expected version.

// MinimumQueue is internal — do not instantiate it directly.
// This guard protects UniTask's internal data structures.
// No user-facing validation is needed.

When it happens

Trigger: Internal: would only fire if ArrayPool or a player-loop runner passed a negative capacity during construction, which cannot happen with the default UniTask source. Direct instantiation by code that references the internal type.

Common situations: Not applicable for normal UniTask usage. Would indicate modified/corrupted UniTask source or incorrect reflection-based access to internal types.

Related errors

• minimumLength
• EmptyQueue
• Delay does not allow minus delayFrameCount. dueTimeFrameCoun
• Delay does not allow minus periodFrameCount. periodFrameCoun
• Delay does not allow minus intervalFrameCount. intervalFrame

AI-assisted analysis of Cysharp/UniTask@ceac8d6946 (2026-08-13). Data as JSON: /api/errors/a1b2fca6b3ad10cf. Report an issue: GitHub.