Improve memory safety and alignment handling

- Updated `.gitignore` to include `.vscode/` and clarified comments.
- Introduced `SafeHandle` for managing memory alignment and safe access.
- Refactored `UnsafeArray<T>` to add bounds checking and alignment logic.
- Added `IUnsafeHashCollection<T>` for specialized hash-based collections.
- Refactored `UnsafeHashMap<TKey, TValue>` and `UnsafeHashSet<T>` to use `HashMapHelper<TKey>` with alignment support.
- Made `UnsafeSlotMap<T>` methods `readonly` for immutability.
- Enhanced `HashMapHelper<TKey>` with alignment-aware buffer management and validation.
- Updated benchmarks to use `UnsafeArray<Vector256<int>>` and added capacity checks.
- Incremented assembly version to `1.1.3` in `Misaki.HighPerformance.LowLevel.csproj`.
- Updated `Program.cs` to run `CollectionBenchmark` and demonstrate safe disposal handling.

Misaki.HighPerformance.LowLevel/Buffer/SafeHandle.cs

@@ -0,0 +1,31 @@
+namespace Misaki.HighPerformance.LowLevel.Buffer;
+
+public unsafe struct SafeHandle
+{
+    private const nuint _ALIGNMENT = 16u;
+
+    public int valid;
+
+    public static nuint GetAlignWithHeader(nuint baseAlign)
+    {
+        return Math.Max(_ALIGNMENT, baseAlign);
+    }
+
+    public static nuint GetPaddedHeaderSize(nuint baseAlign)
+    {
+        var headerBaseSize = (nuint)sizeof(SafeHandle);
+        var dataAlignment = Math.Max(_ALIGNMENT, baseAlign);
+        return (headerBaseSize + (dataAlignment - 1u)) & ~(dataAlignment - 1u);
+    }
+
+    public static SafeHandle* GetSafeHandle(void* ptr, nuint baseAlign)
+    {
+        if (ptr == null)
+        {
+            return null;
+        }
+
+        var alignedHeaderSize = GetPaddedHeaderSize(baseAlign);
+        return (SafeHandle*)((byte*)ptr - alignedHeaderSize);
+    }
+}

Misaki.HighPerformance.LowLevel/Collections/Contracts/IUnsafeCollection.cs

@@ -24,7 +24,7 @@ public unsafe interface IUnsafeCollection : IDisposable
     void* GetUnsafePtr();
 }
 
-public unsafe interface IUnsafeCollection<T> : IUnsafeCollection, IEnumerable<T>
+public interface IUnsafeCollection<T> : IUnsafeCollection, IEnumerable<T>
     where T : unmanaged
 {
     /// <summary>
@@ -44,7 +44,40 @@ public unsafe interface IUnsafeCollection<T> : IUnsafeCollection, IEnumerable<T>
     void Resize(int newSize, AllocationOption option);
 }
 
-public unsafe interface IUnTypedCollection : IUnsafeCollection
+public interface IUnsafeHashCollection<T> : IEnumerable<T>, IDisposable
+    where T : unmanaged
+{
+    /// <summary>
+    /// Indicates whether the object has been created. Returns true if the object is created, otherwise false.
+    /// </summary>
+    bool IsCreated
+    {
+        get;
+    }
+
+    /// <summary>
+    /// Gets the number of elements in a collection. The value is read-only.
+    /// </summary>
+    int Count
+    {
+        get;
+    }
+
+    /// <summary>
+    /// Removes all elements from the collection. The collection will be empty after this operation.
+    /// </summary>
+    void Clear();
+
+    /// <summary>
+    /// Changes the size of a collection to the specified value.
+    /// </summary>
+    /// <remarks>This is to adjust the element count of the collection, not the size of the underlying buffer in memory.</remarks>
+    /// <param name="newSize">Specifies the new size to which the collection should be adjusted.</param>
+    /// <param name="option">Specifies allocation options that may affect how memory is managed during the resize operation.</param>
+    void Resize(int newSize, AllocationOption option);
+}
+
+public interface IUnTypedCollection : IUnsafeCollection
 {
     /// <summary>
     /// The total size of the buffer in bytes.

Misaki.HighPerformance.LowLevel/Collections/UnsafeArray.cs

@@ -3,6 +3,7 @@ using Misaki.HighPerformance.LowLevel.Collections.Contracts;
 using Misaki.HighPerformance.LowLevel.Contracts;
 using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Collections;
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
 namespace Misaki.HighPerformance.LowLevel.Collections;
@@ -57,13 +58,7 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get
         {
-#if ENABLE_COLLECTION_CHECKS
-            if (index < 0 || index >= _count)
-            {
-                throw new ArgumentOutOfRangeException(nameof(index), "Index is out of range.");
-            }
-#endif
-
+            CheckIndexBounds(index);
             return ref UnsafeUtility.ReadArrayElementRef<T>(_buffer, index);
         }
     }
@@ -73,24 +68,21 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get
         {
-#if ENABLE_COLLECTION_CHECKS
-            if (index >= _count)
-            {
-                throw new ArgumentOutOfRangeException(nameof(index), "Index is out of range.");
-            }
-#endif
-
+            CheckIndexBounds((int)index);
             return ref UnsafeUtility.ReadArrayElementRef<T>(_buffer, index);
         }
     }
 
     public readonly bool IsCreated
     {
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        get => _buffer != null;
+        get
+        {
+            var handle = SafeHandle.GetSafeHandle(_buffer, AlignOf<T>());
+            return handle != null && Volatile.Read(ref handle->valid) == 1;
+        }
     }
 
-    public Enumerator GetEnumerator() => new ((UnsafeArray<T>*)UnsafeUtility.AddressOf(ref this));
+    public Enumerator GetEnumerator() => new((UnsafeArray<T>*)UnsafeUtility.AddressOf(ref this));
     IEnumerator<T> IEnumerable<T>.GetEnumerator() => GetEnumerator();
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
 
@@ -111,13 +103,20 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     /// <exception cref="ArgumentOutOfRangeException">Thrown when the specified number of elements is less than or equal to zero.</exception>
     public UnsafeArray(int count, ref AllocationHandle handle, AllocationOption allocationOption = AllocationOption.None)
     {
-        if (count <= 0)
+        if (count < 0)
         {
-            throw new ArgumentOutOfRangeException(nameof(count), "Count must be greater than zero.");
+            throw new ArgumentOutOfRangeException(nameof(count), "Count can not be less than zero.");
         }
 
+        var tAlign = AlignOf<T>();
+        var headerSize = SafeHandle.GetPaddedHeaderSize(tAlign);
+        var sizeWithHeader = (nuint)(count * sizeof(T)) + headerSize;
+        var alignment = SafeHandle.GetAlignWithHeader(tAlign);
+
+        var buff = handle.Alloc(handle.Allocator, sizeWithHeader, alignment, allocationOption);
+
+        _buffer = (T*)((byte*)buff + headerSize);
         _handle = (AllocationHandle*)Unsafe.AsPointer(ref handle);
-        _buffer = (T*)handle.Alloc(_handle->Allocator, (uint)count * (uint)sizeof(T), (uint)AlignOf<T>(), allocationOption);
         _count = count;
     }
 
@@ -149,7 +148,32 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
         _count = count;
     }
 
-    public ReadOnlyUnsafeCollection<T> AsReadOnly()
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private readonly void ThrowIfNotCreated()
+    {
+        if (!IsCreated)
+        {
+            throw new InvalidOperationException("The UnsafeArray is not created.");
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    [Conditional("ENABLE_COLLECTION_CHECKS")]
+    private readonly void CheckIndexBounds(int index)
+    {
+        ThrowIfNotCreated();
+        if (index >= _count)
+        {
+            throw new ArgumentOutOfRangeException(nameof(index), "Index is out of range.");
+        }
+    }
+
+    /// <summary>
+    /// Returns a read-only view of the current collection.
+    /// </summary>
+    /// <returns>A <see cref="ReadOnlyUnsafeCollection{T}"/> that provides a read-only view of the elements in the current collection.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public readonly ReadOnlyUnsafeCollection<T> AsReadOnly()
     {
         return new ReadOnlyUnsafeCollection<T>(_buffer, _count);
     }
@@ -157,6 +181,8 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     /// <inheritdoc/>
     public void Resize(int newSize, AllocationOption option = AllocationOption.None)
     {
+        ThrowIfNotCreated();
+
         if (newSize == Count)
         {
             return;
@@ -171,6 +197,7 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void Clear()
     {
+        ThrowIfNotCreated();
         MemClear(_buffer, (nuint)(Count * sizeof(T)));
     }
 
@@ -178,6 +205,7 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void* GetUnsafePtr()
     {
+        ThrowIfNotCreated();
         return _buffer;
     }
 
@@ -190,6 +218,8 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     public readonly UnsafeArray<U> Reinterpret<U>()
         where U : unmanaged
     {
+        ThrowIfNotCreated();
+
         var totalSize = (nuint)(Count * sizeof(T));
         if (totalSize % (nuint)sizeof(U) != 0)
         {

Misaki.HighPerformance.LowLevel/Collections/UnsafeHashMap.cs

@@ -7,7 +7,7 @@ using System.Runtime.CompilerServices;
 
 namespace Misaki.HighPerformance.LowLevel.Collections;
 
-public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePair<TKey, TValue>>
+public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeHashCollection<KeyValuePair<TKey, TValue>>
     where TKey : unmanaged, IEquatable<TKey> where TValue : unmanaged
 {
     public struct Enumerator : IEnumerator<KeyValuePair<TKey, TValue>>
@@ -32,11 +32,11 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
         }
     }
 
-    private HashMapHelper<TKey> _hashMap;
+    private HashMapHelper<TKey> _helper;
 
-    public readonly int Count => _hashMap.Count;
-    public readonly int Capacity => _hashMap.Capacity;
-    public readonly bool IsCreated => _hashMap.IsCreated;
+    public readonly int Count => _helper.Count;
+    public readonly int Capacity => _helper.Capacity;
+    public readonly bool IsCreated => _helper.IsCreated;
 
     /// <summary>
     /// Gets and sets values by key.
@@ -49,7 +49,7 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
     {
         get
         {
-            if (!_hashMap.TryGetValue<TValue>(key, out var result))
+            if (!_helper.TryGetValue<TValue>(key, out var result))
             {
                 throw new ArgumentException($"Key: {key} is not present.");
             }
@@ -59,10 +59,10 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
 
         set
         {
-            var idx = _hashMap.Find(key);
+            var idx = _helper.Find(key);
             if (-1 != idx)
             {
-                UnsafeUtility.WriteArrayElement(_hashMap.Buffer, idx, value);
+                UnsafeUtility.WriteArrayElement(_helper.Buffer, idx, value);
                 return;
             }
 
@@ -84,7 +84,7 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
 
     public UnsafeHashMap(int capacity, ref AllocationHandle handle, AllocationOption allocationOption = AllocationOption.None)
     {
-        _hashMap = new HashMapHelper<TKey>(capacity, sizeof(TValue), HashMapHelper<TKey>.MINIMAL_CAPACITY, ref handle, allocationOption);
+        _helper = new HashMapHelper<TKey>(capacity, sizeof(TValue), (int)AlignOf<TValue>(), HashMapHelper<TKey>.MINIMAL_CAPACITY, ref handle, allocationOption);
     }
 
     public UnsafeHashMap(int capacity, Allocator allocator, AllocationOption allocationOption = AllocationOption.None)
@@ -101,10 +101,10 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
     /// <returns>True if the key-value pair was added.</returns>
     public bool TryAdd(TKey key, TValue item)
     {
-        var idx = _hashMap.TryAdd(key);
+        var idx = _helper.TryAdd(key);
         if (idx != -1)
         {
-            UnsafeUtility.WriteArrayElement(_hashMap.Buffer, idx, item);
+            UnsafeUtility.WriteArrayElement(_helper.Buffer, idx, item);
             return true;
         }
 
@@ -134,7 +134,7 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
     /// <returns>True if the value was present.</returns>
     public bool Remove(TKey key)
     {
-        return -1 != _hashMap.TryRemove(key);
+        return -1 != _helper.TryRemove(key);
     }
 
     /// <summary>
@@ -145,7 +145,7 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
     /// <returns>True if the key was present.</returns>
     public bool TryGetValue(TKey key, out TValue item)
     {
-        return _hashMap.TryGetValue(key, out item);
+        return _helper.TryGetValue(key, out item);
     }
 
     /// <summary>
@@ -155,51 +155,51 @@ public unsafe struct UnsafeHashMap<TKey, TValue> : IUnsafeCollection<KeyValuePai
     /// <returns>True if the key was present.</returns>
     public bool ContainsKey(TKey key)
     {
-        return -1 != _hashMap.Find(key);
+        return -1 != _helper.Find(key);
     }
 
     /// <summary>
     /// Sets the capacity to match what it would be if it had been originally initialized with all its entries.
     /// </summary>
-    public void TrimExcess() => _hashMap.TrimExcess();
+    public void TrimExcess() => _helper.TrimExcess();
 
     public void Resize(int newSize, AllocationOption option = AllocationOption.None)
     {
-        _hashMap.Resize(newSize);
+        _helper.Resize(newSize);
     }
 
     public void Clear()
     {
-        _hashMap.Clear();
+        _helper.Clear();
     }
 
     /// <summary>
     /// Retrieves an array of keys from the hash map.
     /// </summary>
     /// <returns>An array containing the keys stored in the hash map.</returns>
-    public UnsafeArray<TKey> GetKeyArray(Allocator allocator) => _hashMap.GetKeyArray(allocator);
+    public UnsafeArray<TKey> GetKeyArray(Allocator allocator) => _helper.GetKeyArray(allocator);
 
     /// <summary>
     /// Retrieves an array of values from the underlying hash map.
     /// </summary>
     /// <returns>An UnsafeArray containing the values stored in the hash map.</returns>
-    public UnsafeArray<TValue> GetValueArray(Allocator allocator) => _hashMap.GetValueArray<TValue>(allocator);
+    public UnsafeArray<TValue> GetValueArray(Allocator allocator) => _helper.GetValueArray<TValue>(allocator);
 
     /// <summary>
     /// Retrieves an array of key-value pairs from the hash map. The keys are of type TKey and the values are of type
     /// TValue.
     /// </summary>
     /// <returns>Returns an UnsafeArray containing KeyValuePair objects.</returns>
-    public UnsafeArray<KeyValuePair<TKey, TValue>> GetKeyValueArrays(Allocator allocator) => _hashMap.GetKeyValueArrays<TValue>(allocator);
+    public UnsafeArray<KeyValuePair<TKey, TValue>> GetKeyValueArrays(Allocator allocator) => _helper.GetKeyValueArrays<TValue>(allocator);
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void* GetUnsafePtr()
     {
-        return _hashMap.Buffer;
+        return _helper.Buffer;
     }
 
     public void Dispose()
     {
-        _hashMap.Dispose();
+        _helper.Dispose();
     }
 }

Misaki.HighPerformance.LowLevel/Collections/UnsafeHashSet.cs

@@ -12,7 +12,7 @@ namespace Misaki.HighPerformance.LowLevel.Collections;
 /// removing, and checking for values.
 /// </summary>
 /// <typeparam name="T">Represents an unmanaged type that can be compared for equality.</typeparam>
-public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
+public unsafe struct UnsafeHashSet<T> : IUnsafeHashCollection<T>, IEnumerable<T>
     where T : unmanaged, IEquatable<T>
 {
     public struct Enumerator : IEnumerator<T>
@@ -37,11 +37,11 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
         }
     }
 
-    private HashMapHelper<T> _hashMap;
+    private HashMapHelper<T> _helper;
 
-    public readonly int Count => _hashMap.Count;
-    public readonly int Capacity => _hashMap.Capacity;
-    public readonly bool IsCreated => _hashMap.IsCreated;
+    public readonly int Count => _helper.Count;
+    public readonly int Capacity => _helper.Capacity;
+    public readonly bool IsCreated => _helper.IsCreated;
 
     public Enumerator GetEnumerator() => new((HashMapHelper<T>*)UnsafeUtility.AddressOf(ref this));
     IEnumerator<T> IEnumerable<T>.GetEnumerator() => GetEnumerator();
@@ -57,7 +57,7 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
 
     public UnsafeHashSet(int capacity, ref AllocationHandle handle, AllocationOption allocationOption = AllocationOption.None)
     {
-        _hashMap = new HashMapHelper<T>(capacity, 0, HashMapHelper<T>.MINIMAL_CAPACITY, ref handle, allocationOption);
+        _helper = new HashMapHelper<T>(capacity, 0, 0, HashMapHelper<T>.MINIMAL_CAPACITY, ref handle, allocationOption);
     }
 
     public UnsafeHashSet(int capacity, Allocator allocator, AllocationOption allocationOption = AllocationOption.None)
@@ -72,7 +72,7 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
     /// <returns>True if the value was not already present.</returns>
     public bool Add(T item)
     {
-        return -1 != _hashMap.TryAdd(item);
+        return -1 != _helper.TryAdd(item);
     }
 
     /// <summary>
@@ -82,7 +82,7 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
     /// <returns>True if the value was present.</returns>
     public bool Remove(T item)
     {
-        return -1 != _hashMap.TryRemove(item);
+        return -1 != _helper.TryRemove(item);
     }
 
     /// <summary>
@@ -92,13 +92,13 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
     /// <returns>True if the value was present.</returns>
     public bool Contains(T item)
     {
-        return -1 != _hashMap.Find(item);
+        return -1 != _helper.Find(item);
     }
 
     /// <summary>
     /// Sets the capacity to match what it would be if it had been originally initialized with all its entries.
     /// </summary>
-    public void TrimExcess() => _hashMap.TrimExcess();
+    public void TrimExcess() => _helper.TrimExcess();
 
     /// <summary>
     /// Returns an array with a copy of this set's values (in no particular order).
@@ -107,27 +107,27 @@ public unsafe struct UnsafeHashSet<T> : IUnsafeCollection<T>, IEnumerable<T>
     /// <returns>An array with a copy of the set's values.</returns>
     public UnsafeArray<T> ToNativeArray(Allocator allocator)
     {
-        return _hashMap.GetKeyArray(allocator);
+        return _helper.GetKeyArray(allocator);
     }
 
     public void Resize(int newSize, AllocationOption option = AllocationOption.None)
     {
-        _hashMap.Resize(newSize);
+        _helper.Resize(newSize);
     }
 
     public void Clear()
     {
-        _hashMap.Clear();
+        _helper.Clear();
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void* GetUnsafePtr()
     {
-        return _hashMap.Buffer;
+        return _helper.Buffer;
     }
 
     public void Dispose()
     {
-        _hashMap.Dispose();
+        _helper.Dispose();
     }
 }

Misaki.HighPerformance.LowLevel/Collections/UnsafeSlotMap.cs

@@ -206,7 +206,7 @@ public unsafe struct UnsafeSlotMap<T> : IUnsafeCollection<T>
     /// <param name="value">When this method returns, contains the element at the specified slot and generation if found; otherwise, the
     /// default value for type <typeparamref name="T"/>.</param>
     /// <returns>true if the element at the specified slot index and generation is found; otherwise, false.</returns>
-    public bool TryGetElementAt(int slotIndex, int generation, out T value)
+    public readonly bool TryGetElementAt(int slotIndex, int generation, out T value)
     {
         if (slotIndex < 0 || slotIndex >= _capacity)
         {
@@ -232,7 +232,7 @@ public unsafe struct UnsafeSlotMap<T> : IUnsafeCollection<T>
     /// <returns>The element of type <see cref="T"/> stored at the specified slot and generation.</returns>
     /// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="slotIndex"/> is less than zero or greater than or equal to the capacity.</exception>
     /// <exception cref="InvalidOperationException">Thrown when the specified slot is not occupied or the generation does not match.</exception>
-    public T GetElementAt(int slotIndex, int generation)
+    public readonly T GetElementAt(int slotIndex, int generation)
     {
         if (slotIndex < 0 || slotIndex >= _capacity)
         {

Misaki.HighPerformance.LowLevel/Misaki.HighPerformance.LowLevel.csproj

@@ -6,7 +6,7 @@
     <Nullable>enable</Nullable>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <Authors>Misaki</Authors>
-    <AssemblyVersion>1.1.2</AssemblyVersion>
+    <AssemblyVersion>1.1.3</AssemblyVersion>
     <Version>$(AssemblyVersion)</Version>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
     <PackageProjectUrl>https://git.personalnas.com/Misaki/Misaki.HighPerformance.git</PackageProjectUrl>

Misaki.HighPerformance.LowLevel/Utilities/HashMapHelper.cs

@@ -16,7 +16,7 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
         public int bucketIndex;
         public int nextIndex;
 
-        public unsafe Enumerator(HashMapHelper<TKey>* data)
+        public Enumerator(HashMapHelper<TKey>* data)
         {
             buffer = data;
             index = -1;
@@ -73,6 +73,7 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     private int _allocatedIndex;
     private int _firstFreeIndex;
 
+    private readonly int _alignment;
     private readonly int _sizeOfTValue;
     private readonly int _log2MinGrowth;
 
@@ -86,55 +87,90 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public readonly int Capacity => _capacity;
 
-    public readonly bool IsCreated => _buffer != null;
-
     public readonly bool IsEmpty => !IsCreated || _count == 0;
 
-    private static int CalculateDataSize(int capacity, int bucketCapacity, int sizeOfTValue, out int outKeyOffset, out int outNextOffset, out int outBucketOffset)
+    public readonly bool IsCreated
     {
-        var sizeOfTKey = sizeof(TKey);
-        var sizeOfInt = sizeof(int);
+        get
+        {
+            var handle = SafeHandle.GetSafeHandle(_buffer, (nuint)_alignment);
+            return handle != null && Volatile.Read(ref handle->valid) == 1;
+        }
+    }
 
-        var valuesSize = sizeOfTValue * capacity;
-        var keysSize = sizeOfTKey * capacity;
-        var nextSize = sizeOfInt * capacity;
-        var bucketSize = sizeOfInt * bucketCapacity;
-        var totalSize = valuesSize + keysSize + nextSize + bucketSize;
+    private static int CalculateDataSize(int capacity, int bucketCapacity, int sizeOfTValue, int alignment, out int outValueOffset, out int outKeyOffset, out int outNextOffset, out int outBucketOffset)
+    {
+        static int AlignUp(int size, int align)
+        {
+            return (size + (align - 1)) & ~(align - 1);
+        }
 
-        outKeyOffset = 0 + valuesSize;
-        outNextOffset = outKeyOffset + keysSize;
-        outBucketOffset = outNextOffset + nextSize;
+        var headerSize = SafeHandle.GetPaddedHeaderSize((nuint)alignment);
+
+        var valuesSize = (sizeOfTValue * capacity);
+        var valuesSizePadded = AlignUp(valuesSize, alignment);
+
+        var keysSize = (sizeof(TKey) * capacity);
+        var keysSizePadded = AlignUp(keysSize, alignment);
+
+        var nextSize = (sizeof(int) * capacity);
+        var nextSizePadded = AlignUp(nextSize, alignment);
+
+        // Buckets are the last item, doesn't need padding after it
+        var bucketSize = (sizeof(int) * bucketCapacity);
+
+        outValueOffset = (int)headerSize;
+        outKeyOffset = outValueOffset + valuesSizePadded;
+        outNextOffset = outKeyOffset + keysSizePadded;
+        outBucketOffset = outNextOffset + nextSizePadded;
+
+        // Total size is header + all buffers
+        var totalSize = (int)headerSize + outKeyOffset + keysSizePadded + nextSizePadded + bucketSize;
 
         return totalSize;
     }
 
-    public HashMapHelper(int capacity, int sizeOfTValue, uint minGrowth, ref AllocationHandle handle, AllocationOption allocationOption)
+    public HashMapHelper(int capacity, int sizeOfTValue, int alignOfTValue, uint minGrowth, ref AllocationHandle handle, AllocationOption allocationOption)
     {
         if (capacity <= 0)
         {
             throw new ArgumentOutOfRangeException(nameof(capacity), "Capacity must be greater than zero.");
         }
 
-        if (sizeOfTValue <= 0)
+        if (sizeOfTValue < 0 || alignOfTValue < 0)
         {
-            throw new ArgumentOutOfRangeException(nameof(sizeOfTValue), "Size of TValue must be greater than zero.");
+            throw new ArgumentOutOfRangeException(nameof(sizeOfTValue), "Size or alignment of TValue can not be less than zero.");
         }
 
         _capacity = CalcCapacityCeilPow2(capacity);
         _bucketCapacity = _capacity * 2;
 
+        var alignOfKey = (int)AlignOf<TKey>();
+        var alignOfInt = (int)AlignOf<int>();
+        var maxDataAlign = Math.Max(Math.Max(alignOfTValue, alignOfKey), alignOfInt);
+
+        _alignment = (int)SafeHandle.GetAlignWithHeader((nuint)maxDataAlign);
         _sizeOfTValue = sizeOfTValue;
         _log2MinGrowth = BitOperations.Log2(minGrowth);
 
         _handle = (AllocationHandle*)Unsafe.AsPointer(ref handle);
 
-        var totalSize = CalculateDataSize(_capacity, _bucketCapacity, sizeOfTValue,
-            out var keyOffset, out var nextOffset, out var bucketOffset);
+        var totalSize = CalculateDataSize(_capacity, _bucketCapacity, sizeOfTValue, _alignment,
+            out var valueOffset, out var keyOffset, out var nextOffset, out var bucketOffset);
 
-        AllocateBuffer(totalSize, keyOffset, nextOffset, bucketOffset, allocationOption);
+        AllocateBuffer(totalSize, valueOffset, keyOffset, nextOffset, bucketOffset, _alignment, allocationOption);
         Clear();
     }
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private readonly void ThrowIfNotCreated()
+    {
+        if (!IsCreated)
+        {
+            throw new InvalidOperationException("The HashMapHelper is not created.");
+        }
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static int CeilPow2(int x)
     {
@@ -174,20 +210,20 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private void AllocateBuffer(int totalSize, int keyOffset, int nextOffset, int bucketOffset, AllocationOption allocationOption)
+    private void AllocateBuffer(int totalSize, int valueOffset, int keyOffset, int nextOffset, int bucketOffset, int alignment, AllocationOption allocationOption)
     {
-        var alignSize = sizeof(TKey) > sizeof(int) ? AlignOf<TKey>() : AlignOf<int>();
+        var buf = (byte*)_handle->Alloc(_handle->Allocator, (uint)totalSize, (nuint)alignment, allocationOption);
 
-        _buffer = (byte*)_handle->Alloc(_handle->Allocator, (uint)totalSize, (uint)alignSize, allocationOption);
+        _buffer = buf + valueOffset;
         _keys = (TKey*)(_buffer + keyOffset);
         _next = (int*)(_buffer + nextOffset);
         _buckets = (int*)(_buffer + bucketOffset);
     }
 
-    internal void ResizeExact(int newCapacity, int newBucketCapacity)
+    private void ResizeExact(int newCapacity, int newBucketCapacity)
     {
-        var totalSize = CalculateDataSize(newCapacity, newBucketCapacity, _sizeOfTValue,
-            out var keyOffset, out var nextOffset, out var bucketOffset);
+        var totalSize = CalculateDataSize(newCapacity, newBucketCapacity, _sizeOfTValue, _alignment,
+            out var valueOffset, out var keyOffset, out var nextOffset, out var bucketOffset);
 
         var oldBuffer = _buffer;
         var oldKeys = _keys;
@@ -195,7 +231,7 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
         var oldBuckets = _buckets;
         var oldBucketCapacity = _bucketCapacity;
 
-        AllocateBuffer(totalSize, keyOffset, nextOffset, bucketOffset, AllocationOption.None);
+        AllocateBuffer(totalSize, valueOffset, keyOffset, nextOffset, bucketOffset, _alignment, AllocationOption.None);
         _capacity = newCapacity;
         _bucketCapacity = newBucketCapacity;
 
@@ -213,8 +249,10 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
         _handle->Free(_handle->Allocator, oldBuffer);
     }
 
-    internal void Resize(int newCapacity)
+    public void Resize(int newCapacity)
     {
+        ThrowIfNotCreated();
+
         newCapacity = Math.Max(newCapacity, _count);
         var newBucketCapacity = CeilPow2(newCapacity * 2);
 
@@ -228,12 +266,16 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public void TrimExcess()
     {
+        ThrowIfNotCreated();
+
         var capacity = CalcCapacityCeilPow2(_count);
         ResizeExact(capacity, capacity * 2);
     }
 
     public int Find(in TKey key)
     {
+        ThrowIfNotCreated();
+
         if (_allocatedIndex <= 0)
         {
             return -1;
@@ -263,6 +305,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public int TryAdd(in TKey key)
     {
+        ThrowIfNotCreated();
+
         var k = key;
         if (Find(in key) != -1)
         {
@@ -306,6 +350,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public int TryRemove(in TKey key)
     {
+        ThrowIfNotCreated();
+
         if (_capacity == 0)
         {
             return -1;
@@ -357,6 +403,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     public bool TryGetValue<TValue>(in TKey key, out TValue item)
         where TValue : unmanaged
     {
+        ThrowIfNotCreated();
+
         var idx = Find(key);
 
         if (idx != -1)
@@ -371,6 +419,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public bool MoveNextSearch(ref int bucketIndex, ref int nextIndex, out int index)
     {
+        ThrowIfNotCreated();
+
         for (int i = bucketIndex, num = _bucketCapacity; i < num; ++i)
         {
             var idx = _buckets[i];
@@ -394,6 +444,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public bool MoveNext(ref int bucketIndex, ref int nextIndex, out int index)
     {
+        ThrowIfNotCreated();
+
         if (nextIndex != -1)
         {
             index = nextIndex;
@@ -406,6 +458,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     internal UnsafeArray<TKey> GetKeyArray(Allocator allocator)
     {
+        ThrowIfNotCreated();
+
         var result = new UnsafeArray<TKey>(_count, allocator);
 
         for (int i = 0, count = 0, max = result.Count, capacity = _bucketCapacity; i < capacity && count < max; i++)
@@ -425,6 +479,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     internal UnsafeArray<TValue> GetValueArray<TValue>(Allocator allocator)
         where TValue : unmanaged
     {
+        ThrowIfNotCreated();
+
         var result = new UnsafeArray<TValue>(_count, allocator);
 
         for (int i = 0, count = 0, max = result.Count, capacity = _bucketCapacity; i < capacity && count < max; ++i)
@@ -444,6 +500,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
     public UnsafeArray<KeyValuePair<TKey, TValue>> GetKeyValueArrays<TValue>(Allocator allocator)
         where TValue : unmanaged
     {
+        ThrowIfNotCreated();
+
         var result = new UnsafeArray<KeyValuePair<TKey, TValue>>(_count, allocator);
 
         for (int i = 0, count = 0, max = result.Count, capacity = _bucketCapacity; i < capacity && count < max; i++)
@@ -465,6 +523,8 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public void Clear()
     {
+        ThrowIfNotCreated();
+
         MemSet(_buckets, 0xff, (nuint)_bucketCapacity * sizeof(int));
         MemSet(_next, 0xff, (nuint)_capacity * sizeof(int));
 
@@ -475,18 +535,23 @@ public unsafe struct HashMapHelper<TKey> : IDisposable
 
     public void Dispose()
     {
-        if (IsCreated)
+        if (!IsCreated)
+        {
+            return;
+        }
+
+        if (_handle != null)
         {
             _handle->Free(_handle->Allocator, _buffer);
-
-            _buffer = null;
-            _keys = null;
-            _next = null;
-            _buckets = null;
-
-            _count = 0;
-            _capacity = 0;
-            _bucketCapacity = 0;
         }
+
+        _buffer = null;
+        _keys = null;
+        _next = null;
+        _buckets = null;
+
+        _count = 0;
+        _capacity = 0;
+        _bucketCapacity = 0;
     }
 }