Merge pull request #9551 from h3xds1nz/dependency-property-hashtable-lock

Optimize DependencyProperty lookup/registration performance, remove allocs

Author: harshit7962

src/Microsoft.DotNet.Wpf/src/WindowsBase/System/Windows/DependencyProperty.cs

@@ -257,10 +257,10 @@ private static void RegisterParameterValidation(string name, Type propertyType,
 
         private static DependencyProperty RegisterCommon(string name, Type propertyType, Type ownerType, PropertyMetadata defaultMetadata, ValidateValueCallback validateValueCallback)
         {
-            FromNameKey key = new FromNameKey(name, ownerType);
+            FromNameKey key = new(name, ownerType);
             lock (Synchronized)
             {
-                if (PropertyFromName.Contains(key))
+                if (PropertyFromName.ContainsKey(key))
                 {
                     throw new ArgumentException(SR.Format(SR.PropertyAlreadyRegistered, name, ownerType.Name));
                 }
@@ -761,11 +761,11 @@ public DependencyProperty AddOwner(Type ownerType, PropertyMetadata typeMetadata
 
             // Map owner type to this property
             // Build key
-            FromNameKey key = new FromNameKey(Name, ownerType);
+            FromNameKey key = new(Name, ownerType);
 
             lock (Synchronized)
             {
-                if (PropertyFromName.Contains(key))
+                if (PropertyFromName.ContainsKey(key))
                 {
                     throw new ArgumentException(SR.Format(SR.PropertyAlreadyRegistered, Name, ownerType.Name));
                 }
@@ -776,13 +776,11 @@ public DependencyProperty AddOwner(Type ownerType, PropertyMetadata typeMetadata
                 OverrideMetadata(ownerType, typeMetadata);
             }
 
-
             lock (Synchronized)
             {
                 PropertyFromName[key] = this;
             }
 
-
             return this;
         }
 
@@ -979,19 +977,17 @@ internal static DependencyProperty FromName(string name, Type ownerType)
             ArgumentNullException.ThrowIfNull(name);
             ArgumentNullException.ThrowIfNull(ownerType);
 
-            FromNameKey key = new FromNameKey(name, ownerType);
-
-            while ((dp == null) && (ownerType != null))
+            while (ownerType != null)
             {
                 // Ensure static constructor of type has run
-                MS.Internal.WindowsBase.SecurityHelper.RunClassConstructor(ownerType);
+                SecurityHelper.RunClassConstructor(ownerType);
 
                 // Locate property
-                key.UpdateNameKey(ownerType);
-
+                FromNameKey key = new(name, ownerType);
                 lock (Synchronized)
                 {
-                    dp = (DependencyProperty)PropertyFromName[key];
+                    if (PropertyFromName.TryGetValue(key, out dp))
+                        return dp;
                 }
 
                 ownerType = ownerType.BaseType;
@@ -1033,7 +1029,7 @@ internal static bool IsValidType(object value, Type propertyType)
             return true;
         }
 
-        private class FromNameKey
+        private readonly struct FromNameKey : IEquatable<FromNameKey>
         {
             public FromNameKey(string name, Type ownerType)
             {
@@ -1043,39 +1039,25 @@ public FromNameKey(string name, Type ownerType)
                 _hashCode = _name.GetHashCode() ^ _ownerType.GetHashCode();
             }
 
-            public void UpdateNameKey(Type ownerType)
-            {
-                _ownerType = ownerType;
-
-                _hashCode = _name.GetHashCode() ^ _ownerType.GetHashCode();
-            }
-
             public override int GetHashCode()
             {
                 return _hashCode;
             }
 
             public override bool Equals(object o)
             {
-                if ((o != null) && (o is FromNameKey))
-                {
-                    return Equals((FromNameKey)o);
-                }
-                else
-                {
-                    return false;
-                }
+                return o is FromNameKey key && Equals(key);
             }
 
             public bool Equals(FromNameKey key)
             {
-                return (_name.Equals(key._name) && (_ownerType == key._ownerType));
+                return _name.Equals(key._name) && _ownerType == key._ownerType;
             }
 
-            private string _name;
-            private Type _ownerType;
+            private readonly string _name;
+            private readonly Type _ownerType;
 
-            private int _hashCode;
+            private readonly int _hashCode;
         }
 
 
@@ -1198,13 +1180,13 @@ private enum Flags : int
         /* property */ internal static ItemStructList<DependencyProperty> RegisteredPropertyList = new ItemStructList<DependencyProperty>(768);
 
         // Synchronized: Covered by DependencyProperty.Synchronized
-        private static Hashtable PropertyFromName = new Hashtable();
+        private static readonly Dictionary<FromNameKey, DependencyProperty> PropertyFromName = new();
 
         // Synchronized: Covered by DependencyProperty.Synchronized
         private static int GlobalIndexCount;
 
         // Global, cross-object synchronization
-        internal static object Synchronized = new object();
+        internal static readonly Lock Synchronized = new();
 
         // Nullable Type
         private static Type NullableType = typeof(Nullable<>);