Use more trim-friendly patterns for Type.DefaultBinder and CultureData

src/coreclr/System.Private.CoreLib/src/System/Attribute.CoreCLR.cs

@@ -391,7 +391,7 @@ private static Type[] GetIndexParameterTypes(PropertyInfo element)
                 return indexParamTypes;
             }
 
-            return Type.EmptyTypes;
+            return [];
         }
 
         private static void AddAttributesToList(List<Attribute> attributeList, Attribute[] attributes, Dictionary<Type, AttributeUsageAttribute> types)

src/coreclr/System.Private.CoreLib/src/System/Reflection/Emit/RuntimeTypeBuilder.cs

@@ -1259,13 +1259,13 @@ private RuntimeConstructorBuilder DefineDefaultConstructorNoLock(MethodAttribute
 
                 if (inst is TypeBuilderInstantiation)
                     con = GetConstructor(inst, genericTypeDefinition.GetConstructor(
-                        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, EmptyTypes, null)!);
+                        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, [], null)!);
                 else
                     con = inst.GetConstructor(
-                        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, EmptyTypes, null);
+                        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, [], null);
             }
 
-            con ??= m_typeParent!.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, EmptyTypes, null);
+            con ??= m_typeParent!.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, [], null);
 
             if (con == null)
                 throw new NotSupportedException(SR.NotSupported_NoParentDefaultConstructor);

src/coreclr/System.Private.CoreLib/src/System/Reflection/MdFieldInfo.cs

@@ -122,15 +122,9 @@ public override Type FieldType
             }
         }
 
-        public override Type[] GetRequiredCustomModifiers()
-        {
-            return Type.EmptyTypes;
-        }
+        public override Type[] GetRequiredCustomModifiers() => [];
 
-        public override Type[] GetOptionalCustomModifiers()
-        {
-            return Type.EmptyTypes;
-        }
+        public override Type[] GetOptionalCustomModifiers() => [];
 
         #endregion
     }

src/coreclr/System.Private.CoreLib/src/System/Reflection/ModifiedType.CoreCLR.cs

@@ -30,6 +30,6 @@ internal static Type Create(Type unmodifiedType, Signature? signature, int param
 
         private Type[] GetCustomModifiers(bool required) =>
              (_typeSignature._signature != null) ?
-                _typeSignature._signature.GetCustomModifiersAtOffset(_typeSignature._offset, required) : EmptyTypes;
+                _typeSignature._signature.GetCustomModifiersAtOffset(_typeSignature._offset, required) : [];
     }
 }

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeCustomAttributeData.cs

@@ -1575,7 +1575,7 @@ private static void AddCustomAttributes(
 
                             RuntimePropertyInfo? property = (RuntimePropertyInfo?)(type is null ?
                                 attributeType.GetProperty(name) :
-                                attributeType.GetProperty(name, type, Type.EmptyTypes)) ??
+                                attributeType.GetProperty(name, type, [])) ??
                                 throw new CustomAttributeFormatException(SR.Format(SR.RFLCT_InvalidPropFail, name));
                             RuntimeMethodInfo setMethod = property.GetSetMethod(true)!;
 

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.CoreCLR.cs

@@ -447,7 +447,7 @@ internal RuntimeType[] GetGenericArgumentsInternal() =>
             RuntimeMethodHandle.GetMethodInstantiationInternal(this);
 
         public override Type[] GetGenericArguments() =>
-            RuntimeMethodHandle.GetMethodInstantiationPublic(this) ?? Type.EmptyTypes;
+            RuntimeMethodHandle.GetMethodInstantiationPublic(this) ?? [];
 
         public override MethodInfo GetGenericMethodDefinition()
         {

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeParameterInfo.cs

@@ -287,7 +287,7 @@ public override bool HasDefaultValue
                 if (IsOptional)
                 {
                     // If the argument is marked as optional then the default value is Missing.Value.
-                    defaultValue = Type.Missing;
+                    defaultValue = Missing.Value;
                 }
                 #endregion
             }
@@ -434,16 +434,12 @@ private static DateTime GetRawDateTimeConstant(CustomAttributeData attr)
 
         public override Type[] GetRequiredCustomModifiers()
         {
-            return m_signature is null ?
-                Type.EmptyTypes :
-                m_signature.GetCustomModifiers(PositionImpl + 1, true);
+            return m_signature is null ? [] : m_signature.GetCustomModifiers(PositionImpl + 1, true);
         }
 
         public override Type[] GetOptionalCustomModifiers()
         {
-            return m_signature is null ?
-                Type.EmptyTypes :
-                m_signature.GetCustomModifiers(PositionImpl + 1, false);
+            return m_signature is null ? [] : m_signature.GetCustomModifiers(PositionImpl + 1, false);
         }
 
         public override Type GetModifiedParameterType() =>

src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs

@@ -578,14 +578,14 @@ internal static Type[] GetInterfaces(RuntimeType type)
         [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "RuntimeTypeHandle_GetConstraints")]
         private static partial void GetConstraints(QCallTypeHandle handle, ObjectHandleOnStack types);
 
-        internal Type[] GetConstraints()
+        internal Type[]? GetConstraints()
         {
             Type[]? types = null;
             RuntimeTypeHandle nativeHandle = GetNativeHandle();
 
             GetConstraints(new QCallTypeHandle(ref nativeHandle), ObjectHandleOnStack.Create(ref types));
 
-            return types!;
+            return types;
         }
 
         [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "QCall_GetGCHandleForTypeHandle")]
@@ -744,12 +744,12 @@ internal RuntimeType[] GetInstantiationInternal()
             return types!;
         }
 
-        internal Type[] GetInstantiationPublic()
+        internal Type[]? GetInstantiationPublic()
         {
             Type[]? types = null;
             RuntimeTypeHandle nativeHandle = GetNativeHandle();
             GetInstantiation(new QCallTypeHandle(ref nativeHandle), ObjectHandleOnStack.Create(ref types), Interop.BOOL.FALSE);
-            return types!;
+            return types;
         }
 
         [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "RuntimeTypeHandle_Instantiate")]
@@ -1229,12 +1229,12 @@ internal static RuntimeType[] GetMethodInstantiationInternal(RuntimeMethodHandle
             return types!;
         }
 
-        internal static Type[] GetMethodInstantiationPublic(IRuntimeMethodInfo method)
+        internal static Type[]? GetMethodInstantiationPublic(IRuntimeMethodInfo method)
         {
-            RuntimeType[]? types = null;
+            Type[]? types = null;
             GetMethodInstantiation(EnsureNonNullMethodInfo(method).Value, ObjectHandleOnStack.Create(ref types), Interop.BOOL.FALSE);
             GC.KeepAlive(method);
-            return types!;
+            return types;
         }
 
         [MethodImpl(MethodImplOptions.InternalCall)]

src/coreclr/System.Private.CoreLib/src/System/RuntimeType.CoreCLR.cs

@@ -3542,8 +3542,7 @@ internal RuntimeType[] GetGenericArgumentsInternal()
 
         public override Type[] GetGenericArguments()
         {
-            Type[] types = GetRootElementType().TypeHandle.GetInstantiationPublic();
-            return types ?? EmptyTypes;
+            return GetRootElementType().TypeHandle.GetInstantiationPublic() ?? [];
         }
 
         [RequiresUnreferencedCode("If some of the generic arguments are annotated (either with DynamicallyAccessedMembersAttribute, or generic constraints), trimming can't validate that the requirements of those annotations are met.")]
@@ -3636,8 +3635,7 @@ public override Type[] GetGenericParameterConstraints()
             if (!IsGenericParameter)
                 throw new InvalidOperationException(SR.Arg_NotGenericParameter);
 
-            Type[] constraints = new RuntimeTypeHandle(this).GetConstraints();
-            return constraints ?? EmptyTypes;
+            return new RuntimeTypeHandle(this).GetConstraints() ?? [];
         }
         #endregion
 
@@ -3756,7 +3754,7 @@ public override Type[] GetFunctionPointerCallingConventions()
             }
 
             // Requires a modified type to return the modifiers.
-            return EmptyTypes;
+            return [];
         }
 
         public override Type[] GetFunctionPointerParameterTypes()
@@ -3771,7 +3769,7 @@ public override Type[] GetFunctionPointerParameterTypes()
 
             if (parameters.Length == 1)
             {
-                return EmptyTypes;
+                return [];
             }
 
             return parameters.AsSpan(1).ToArray();
@@ -3844,7 +3842,7 @@ private void CreateInstanceCheckThis()
                 int consCount = 0;
 
                 // We cannot use Type.GetTypeArray here because some of the args might be null
-                Type[] argsType = args.Length != 0 ? new Type[args.Length] : EmptyTypes;
+                Type[] argsType = args.Length != 0 ? new Type[args.Length] : [];
                 for (int i = 0; i < args.Length; i++)
                 {
                     if (args[i] is object arg)

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Runtime/TypeInfos/RuntimeFunctionPointerTypeInfo.cs

@@ -35,7 +35,7 @@ public UnificationKey Key
 
         public override Assembly Assembly => typeof(object).Assembly;
         public override IEnumerable<CustomAttributeData> CustomAttributes => Array.Empty<CustomAttributeData>();
-        public override Type[] GetFunctionPointerCallingConventions() => Type.EmptyTypes;
+        public override Type[] GetFunctionPointerCallingConventions() => [];
 
         public override bool ContainsGenericParameters
         {
@@ -66,7 +66,7 @@ public override bool HasSameMetadataDefinitionAs(MemberInfo other)
         public override Type[] GetFunctionPointerParameterTypes()
         {
             if (_key.ParameterTypes.Length == 0)
-                return Type.EmptyTypes;
+                return [];
 
             Type[] result = new Type[_key.ParameterTypes.Length];
             Array.Copy(_key.ParameterTypes, result, result.Length);

src/coreclr/nativeaot/System.Private.CoreLib/src/System/RuntimeType.NativeAot.cs

@@ -349,7 +349,7 @@ public override Type[] GetInterfaces()
             {
                 int count = pEEType->NumInterfaces;
                 if (count == 0)
-                    return EmptyTypes;
+                    return [];
 
                 Type[] result = new Type[count];
                 for (int i = 0; i < result.Length; i++)
@@ -426,7 +426,7 @@ public override Type[] GenericTypeArguments
                 if (pEEType != null)
                 {
                     if (!pEEType->IsGeneric)
-                        return EmptyTypes;
+                        return [];
 
                     MethodTableList genericArguments = pEEType->GenericArguments;
 
@@ -448,7 +448,7 @@ public override Type[] GetGenericArguments()
                 return GenericTypeArguments;
             if (IsGenericTypeDefinition)
                 return GenericTypeParameters;
-            return EmptyTypes;
+            return [];
         }
 
         public override bool IsGenericParameter
@@ -565,7 +565,7 @@ public override Type[] GetFunctionPointerParameterTypes()
 
                 uint count = pEEType->NumFunctionPointerParameters;
                 if (count == 0)
-                    return EmptyTypes;
+                    return [];
 
                 MethodTableList parameterTypes = pEEType->FunctionPointerParameters;
 
@@ -690,7 +690,7 @@ public override Type[] GetFunctionPointerCallingConventions()
                 throw new InvalidOperationException(SR.InvalidOperation_NotFunctionPointer);
 
             // Requires a modified type to return the modifiers.
-            return EmptyTypes;
+            return [];
         }
 
         [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors)]

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Type.NativeAot.cs

@@ -29,16 +29,17 @@ internal static unsafe RuntimeType GetTypeFromMethodTable(MethodTable* pMT)
             return type ?? GetTypeFromMethodTableSlow(pMT);
         }
 
-        private static class AllocationLockHolder
+        private static class AllocationLock
         {
-            public static readonly Lock AllocationLock = new Lock(useTrivialWaits: true);
+            public static Lock Instance =>
+                field ?? Interlocked.CompareExchange(ref field, new Lock(useTrivialWaits: true), null) ?? field;
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
         private static unsafe RuntimeType GetTypeFromMethodTableSlow(MethodTable* pMT)
         {
             // Allocate and set the RuntimeType under a lock - there's no way to free it if there is a race.
-            using (AllocationLockHolder.AllocationLock.EnterScope())
+            lock (AllocationLock.Instance)
             {
                 ref RuntimeType? runtimeTypeCache = ref Unsafe.AsRef<RuntimeType?>(pMT->WritableData);
                 if (runtimeTypeCache != null)

src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ActivatorUtilities.cs

@@ -169,7 +169,7 @@ public static object CreateInstance(
             Type?[] argumentTypes;
             if (parameters.Length == 0)
             {
-                argumentTypes = Type.EmptyTypes;
+                argumentTypes = [];
             }
             else
             {

src/libraries/System.Private.CoreLib/src/System/DefaultBinder.cs

@@ -11,8 +11,10 @@
 
 namespace System
 {
-    internal partial class DefaultBinder : Binder
+    internal class DefaultBinder : Binder
     {
+        internal static readonly DefaultBinder Instance = new DefaultBinder();
+
         // This method is passed a set of methods and must choose the best
         // fit.  The methods all have the same number of arguments and the object
         // array args.  On exit, this method will choice the best fit method
@@ -204,7 +206,7 @@ public sealed override MethodBase BindToMethod(
                             continue;
 
                         // a default value is available
-                        if (defaultValueBinding && args[index] == Type.Missing)
+                        if (defaultValueBinding && args[index] == Missing.Value)
                             continue;
 
                         // the argument was null, so it matches with everything
@@ -876,7 +878,7 @@ private static int FindMostSpecific(ReadOnlySpan<ParameterInfo> p1, int[] paramO
 
             for (int i = 0; i < types.Length; i++)
             {
-                if (args != null && args[i] == Type.Missing)
+                if (args != null && args[i] == Missing.Value)
                     continue;
 
                 Type c1, c2;

src/libraries/System.Private.CoreLib/src/System/Globalization/CultureData.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text;
+using System.Threading;
 
 namespace System.Globalization
 {
@@ -443,12 +444,13 @@ internal sealed partial class CultureData
             if (tempHashTable == null)
             {
                 // No table yet, make a new one
-                tempHashTable = new Dictionary<string, CultureData>();
+                var newTable = new Dictionary<string, CultureData>();
+                tempHashTable = Interlocked.CompareExchange(ref s_cachedRegions, newTable, null) ?? newTable;
             }
             else
             {
                 // Check the hash table
-                lock (s_lock)
+                lock (tempHashTable)
                 {
                     tempHashTable.TryGetValue(hashName, out retVal);
                 }
@@ -481,14 +483,10 @@ internal sealed partial class CultureData
             if (retVal != null && !retVal.IsNeutralCulture)
             {
                 // first add it to the cache
-                lock (s_lock)
+                lock (tempHashTable)
                 {
                     tempHashTable[hashName] = retVal;
                 }
-
-                // Copy the hashtable to the corresponding member variables.  This will potentially overwrite
-                // new tables simultaneously created by a new thread, but maximizes thread safety.
-                s_cachedRegions = tempHashTable;
             }
             else
             {
@@ -658,7 +656,6 @@ private static CultureData CreateCultureWithInvariantData()
 
         // Cache of cultures we've already looked up
         private static volatile Dictionary<string, CultureData>? s_cachedCultures;
-        private static readonly object s_lock = new object();
 
         internal static CultureData? GetCultureData(string? cultureName, bool useUserOverride)
         {
@@ -683,14 +680,15 @@ private static CultureData CreateCultureWithInvariantData()
             if (tempHashTable == null)
             {
                 // No table yet, make a new one
-                tempHashTable = new Dictionary<string, CultureData>();
+                var newTable = new Dictionary<string, CultureData>();
+                tempHashTable = Interlocked.CompareExchange(ref s_cachedCultures, newTable, null) ?? newTable;
             }
             else
             {
                 // Check the hash table
                 bool ret;
                 CultureData? retVal;
-                lock (s_lock)
+                lock (tempHashTable)
                 {
                     ret = tempHashTable.TryGetValue(hashName, out retVal);
                 }
@@ -707,15 +705,11 @@ private static CultureData CreateCultureWithInvariantData()
             }
 
             // Found one, add it to the cache
-            lock (s_lock)
+            lock (tempHashTable)
             {
                 tempHashTable[hashName] = culture;
             }
 
-            // Copy the hashtable to the corresponding member variables.  This will potentially overwrite
-            // new tables simultaneously created by a new thread, but maximizes thread safety.
-            s_cachedCultures = tempHashTable;
-
             return culture;
         }