Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/corefx/src/System.Composition.AttributedModel/dir.props

@@ -0,0 +1,8 @@
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\dir.props" />
+  <PropertyGroup>
+    <PackageVersion>1.1.0</PackageVersion>
+    <AssemblyVersion>1.0.32.0</AssemblyVersion>
+  </PropertyGroup>
+</Project>
+

external/corefx/src/System.Composition.AttributedModel/pkg/System.Composition.AttributedModel.builds

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <Project Include="System.Composition.AttributedModel.pkgproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.traversal.targets))\dir.traversal.targets" />
+</Project>

external/corefx/src/System.Composition.AttributedModel/pkg/System.Composition.AttributedModel.pkgproj

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <ItemGroup>
+    <ProjectReference Include="..\src\System.Composition.AttributedModel.builds">
+      <SupportedFramework>net45;netcore45;netcoreapp1.0;wp8;wpa81;$(AllXamarinFrameworks)</SupportedFramework>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>

external/corefx/src/System.Composition.AttributedModel/src/Configurations.props

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <BuildConfigurations>
+      netstandard1.0;
+      netstandard;
+    </BuildConfigurations>
+  </PropertyGroup>
+</Project>

external/corefx/src/System.Composition.AttributedModel/src/System.Composition.AttributedModel.csproj

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <PropertyGroup>
+    <ProjectGuid>{C6257381-C624-494A-A9D9-5586E60856EA}</ProjectGuid>
+    <RootNamespace>System.Composition</RootNamespace>
+    <AssemblyName>System.Composition.AttributedModel</AssemblyName>
+    <PackageTargetFramework Condition="'$(TargetGroup)' == 'netstandard1.0'">netstandard1.0;portable-net45+win8+wp8+wpa81</PackageTargetFramework>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='netstandard1.0-Debug|AnyCPU'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='netstandard1.0-Release|AnyCPU'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='netstandard-Debug|AnyCPU'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='netstandard-Release|AnyCPU'" />
+  <ItemGroup>
+    <Compile Include="System\Composition\Convention\AttributedModelProvider.cs" />
+    <Compile Include="System\Composition\ExportAttribute.cs" />
+    <Compile Include="System\Composition\ExportMetadataAttribute.cs" />
+    <Compile Include="System\Composition\ImportAttribute.cs" />
+    <Compile Include="System\Composition\ImportingConstructorAttribute.cs" />
+    <Compile Include="System\Composition\ImportManyAttribute.cs" />
+    <Compile Include="System\Composition\ImportMetadataConstraintAttribute.cs" />
+    <Compile Include="System\Composition\MetadataAttributeAttribute.cs" />
+    <Compile Include="System\Composition\OnImportsSatisfiedAttribute.cs" />
+    <Compile Include="System\Composition\PartMetadataAttribute.cs" />
+    <Compile Include="System\Composition\PartNotDiscoverableAttribute.cs" />
+    <Compile Include="System\Composition\SharedAttribute.cs" />
+    <Compile Include="System\Composition\SharingBoundaryAttribute.cs" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetGroup)' == 'netstandard1.0'">
+    <Reference Include="System.Diagnostics.Debug" />
+    <Reference Include="System.Diagnostics.Tools" />
+    <Reference Include="System.Reflection" />
+    <Reference Include="System.Runtime" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/Convention/AttributedModelProvider.cs

@@ -0,0 +1,30 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using System.Reflection;
+
+namespace System.Composition.Convention
+{
+    /// <summary>
+    /// Provider of augmented reflection data in support of conventions.
+    /// </summary>
+    public abstract class AttributedModelProvider
+    {
+        /// <summary>
+        /// Provide the list of attributes applied to the specified member.
+        /// </summary>
+        /// <param name="reflectedType">The reflectedType the type used to retrieve the memberInfo.</param>
+        /// <param name="member">The member to supply attributes for.</param>
+        /// <returns>The list of applied attributes.</returns>
+        public abstract IEnumerable<Attribute> GetCustomAttributes(System.Type reflectedType, MemberInfo member);
+
+        /// <summary>
+        /// <param name="reflectedType">The reflectedType the type used to retrieve the parameterInfo.</param>
+        /// <param name="parameter">The member to supply attributes for.</param>
+        /// <returns>The list of applied attributes.</returns>
+        /// </summary>
+        public abstract IEnumerable<Attribute> GetCustomAttributes(System.Type reflectedType, ParameterInfo parameter);
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ExportAttribute.cs

@@ -0,0 +1,94 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies that a type, property, field, or method provides a particular export.
+    /// </summary>
+    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes")]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property,
+                    AllowMultiple = true, Inherited = false)]
+    public class ExportAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ExportAttribute"/> class, exporting the
+        ///     type or member marked with this attribute under the default contract name.
+        /// </summary>
+        public ExportAttribute()
+            : this((string)null, (Type)null)
+        {
+        }
+
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ExportAttribute"/> class, exporting the
+        ///     type or member marked with this attribute under a contract name derived from the 
+        ///     specified type.
+        /// </summary>
+        /// <param name="contractType">
+        ///     A <see cref="Type"/> of which to derive the contract name to export the type or 
+        ///     member marked with this attribute, under; or <see langword="null"/> to use the 
+        ///     default contract name.
+        /// </param>
+        public ExportAttribute(Type contractType)
+            : this((string)null, contractType)
+        {
+        }
+
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ExportAttribute"/> class, exporting the
+        ///     type or member marked with this attribute under the specified contract name.
+        /// </summary>
+        /// <param name="contractName">
+        ///      A <see cref="String"/> containing the contract name to export the type or member 
+        ///      marked with this attribute, under; or <see langword="null"/> or an empty string 
+        ///      ("") to use the default contract name.
+        /// </param>
+        public ExportAttribute(string contractName)
+            : this(contractName, (Type)null)
+        {
+        }
+
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ExportAttribute"/> class, exporting the
+        ///     type or member marked with this attribute under the specified contract name.
+        /// </summary>
+        /// <param name="contractName">
+        ///      A <see cref="String"/> containing the contract name to export the type or member 
+        ///      marked with this attribute, under; or <see langword="null"/> or an empty string 
+        ///      ("") to use the default contract name.
+        /// </param>
+        /// <param name="contractType">
+        ///     A <see cref="Type"/> of which to derive the contract name to export the type or 
+        ///     member marked with this attribute, under; or <see langword="null"/> to use the 
+        ///     default contract name.
+        /// </param>
+        public ExportAttribute(string contractName, Type contractType)
+        {
+            ContractName = contractName;
+            ContractType = contractType;
+        }
+
+        /// <summary>
+        ///     Gets the contract name to export the type or member under.
+        /// </summary>
+        /// <value>
+        ///      A <see cref="String"/> containing the contract name to export the type or member 
+        ///      marked with this attribute, under. The default value is an empty string ("").
+        /// </value>
+        public string ContractName { get; private set; }
+
+        /// <summary>
+        ///     Get the contract type that is exported by the member that this attribute is attached to.
+        /// </summary>
+        /// <value>
+        ///     A <see cref="Type"/> of the export that is be provided. The default value is
+        ///     <see langword="null"/> which means that the type will be obtained by looking at the type on
+        ///     the member that this export is attached to. 
+        /// </value>
+        public Type ContractType { get; private set; }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ExportMetadataAttribute.cs

@@ -0,0 +1,50 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies metadata for a type, property, field, or method marked with the
+    ///     <see cref="ExportAttribute"/>.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface | AttributeTargets.Property,
+                    AllowMultiple = true, Inherited = false)]
+    public sealed class ExportMetadataAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ExportMetadataAttribute"/> with the 
+        ///     specified name and metadata value.
+        /// </summary>
+        /// <param name="name">
+        ///     A <see cref="String"/> containing the name of the metadata value; or 
+        ///     <see langword="null"/> to set the <see cref="Name"/> property to an empty 
+        ///     string ("").
+        /// </param>
+        /// <param name="value">
+        ///     An <see cref="object"/> containing the metadata value. This can be 
+        ///     <see langword="null"/>.
+        /// </param>
+        public ExportMetadataAttribute(string name, object value)
+        {
+            Name = name ?? string.Empty;
+            Value = value;
+        }
+
+        /// <summary>
+        ///     Gets the name of the metadata value.
+        /// </summary>
+        /// <value>
+        ///     A <see cref="String"/> containing the name of the metadata value.
+        /// </value>
+        public string Name { get; private set; }
+
+        /// <summary>
+        ///     Gets the metadata value.
+        /// </summary>
+        /// <value>
+        ///     An <see cref="object"/> containing the metadata value.
+        /// </value>
+        public object Value { get; private set; }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ImportAttribute.cs

@@ -0,0 +1,55 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies that a property, field, or parameter imports a particular export.
+    /// </summary>
+    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes")]
+    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Parameter,
+                    AllowMultiple = false, Inherited = false)]
+    public class ImportAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ImportAttribute"/> class, importing the 
+        ///     export without a contract name.
+        /// </summary>
+        public ImportAttribute()
+            : this((string)null)
+        {
+        }
+
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ImportAttribute"/> class, importing the
+        ///     export with the specified contract name.
+        /// </summary>
+        /// <param name="contractName">
+        ///      A <see cref="String"/> containing the contract name of the export to import, or 
+        ///      <see langword="null"/> or an empty string ("") to use the default contract name.
+        /// </param>
+        public ImportAttribute(string contractName)
+        {
+            ContractName = contractName;
+        }
+
+        /// <summary>
+        ///     Gets the contract name of the export to import.
+        /// </summary>
+        /// <value>
+        ///      A <see cref="String"/> containing the contract name of the export to import. The 
+        ///      default value is null.
+        /// </value>
+        public string ContractName { get; private set; }
+
+        /// <summary>
+        ///     Gets or sets a value indicating whether the property, field or parameter will be left 
+        ///     at its default value when an export with the contract name is not present in 
+        ///     the container.
+        /// </summary>
+        public bool AllowDefault { get; set; }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ImportManyAttribute.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies that a property, field, or parameter imports a particular set of exports.
+    /// </summary>
+    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes")]
+    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Parameter,
+                    AllowMultiple = false, Inherited = false)]
+    public class ImportManyAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ImportManyAttribute"/> class, importing the 
+        ///     set of exports without a contract name.
+        /// </summary>
+        public ImportManyAttribute()
+            : this((string)null)
+        {
+        }
+
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ImportManyAttribute"/> class, importing the
+        ///     set of exports with the specified contract name.
+        /// </summary>
+        /// <param name="contractName">
+        ///      A <see cref="String"/> containing the contract name of the exports to import, or 
+        ///      <see langword="null"/>.
+        /// </param>
+        public ImportManyAttribute(string contractName)
+        {
+            ContractName = contractName;
+        }
+
+        /// <summary>
+        ///     Gets the contract name of the exports to import.
+        /// </summary>
+        /// <value>
+        ///      A <see cref="String"/> containing the contract name of the exports to import. The 
+        ///      default value is null.
+        /// </value>
+        public string ContractName { get; private set; }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ImportMetadataConstraintAttribute.cs

@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    /// When applied on an import, requires certain metadata values on the exporter.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property, Inherited = false)]
+    public sealed class ImportMetadataConstraintAttribute : Attribute
+    {
+        private readonly string _name;
+        private readonly object _value;
+
+        /// <summary>
+        /// Require a specific metadata value on the exporter.
+        /// </summary>
+        /// <param name="name">The name of the metadata item to match.</param>
+        /// <param name="value">The value to match.</param>
+        public ImportMetadataConstraintAttribute(string name, object value)
+        {
+            _name = name;
+            _value = value;
+        }
+
+        /// <summary>
+        /// The metadata key to match.
+        /// </summary>
+        public string Name { get { return _name; } }
+
+        /// <summary>
+        /// The value to match.
+        /// </summary>
+        public object Value { get { return _value; } }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/ImportingConstructorAttribute.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies that a constructor should be used when constructing an attributed part.
+    /// </summary>
+    /// <remarks>
+    ///     By default, only a default parameter-less constructor, if available, is used to 
+    ///     construct an attributed part. Use this attribute to indicate that a specific constructor 
+    ///     should be used.
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Constructor, AllowMultiple = false, Inherited = false)]
+    public sealed class ImportingConstructorAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="ImportingConstructorAttribute"/> class.
+        /// </summary>
+        public ImportingConstructorAttribute()
+        {
+        }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/MetadataAttributeAttribute.cs

@@ -0,0 +1,22 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies that an attribute can be used to provide metadata for a type, property, field,
+    ///     or method marked with the <see cref="ExportAttribute"/>.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class,
+                    AllowMultiple = false, Inherited = true)]
+    public sealed class MetadataAttributeAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="MetadataAttributeAttribute"/> class.
+        /// </summary>
+        public MetadataAttributeAttribute()
+        {
+        }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/OnImportsSatisfiedAttribute.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    /// When applied to a void, parameterless instance method on a part,
+    /// MEF will call that method when composition of the part has
+    /// completed. The method must be public or internal.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Method, Inherited = false)]
+    public sealed class OnImportsSatisfiedAttribute : Attribute
+    {
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/PartMetadataAttribute.cs

@@ -0,0 +1,49 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    ///     Specifies metadata for a type to be used as a part.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+    public class PartMetadataAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="PartMetadataAttribute"/> with the 
+        ///     specified name and metadata value.
+        /// </summary>
+        /// <param name="name">
+        ///     A <see cref="String"/> containing the name of the metadata value; or 
+        ///     <see langword="null"/> to use an empty string ("").
+        /// </param>
+        /// <param name="value">
+        ///     An <see cref="object"/> containing the metadata value. This can be 
+        ///     <see langword="null"/>.
+        /// </param>
+        public PartMetadataAttribute(string name, object value)
+        {
+            if (name == null) throw new ArgumentNullException(nameof(name));
+
+            Name = name;
+            Value = value;
+        }
+
+        /// <summary>
+        ///     Gets the name of the metadata value.
+        /// </summary>
+        /// <value>
+        ///     A <see cref="String"/> containing the name of the metadata value.
+        /// </value>
+        public string Name { get; private set; }
+
+        /// <summary>
+        ///     Gets the metadata value.
+        /// </summary>
+        /// <value>
+        ///     An <see cref="object"/> containing the metadata value.
+        /// </value>
+        public object Value { get; private set; }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/PartNotDiscoverableAttribute.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    /// Place on a type that should not be discovered as a MEF part.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
+    public sealed class PartNotDiscoverableAttribute : Attribute
+    {
+        /// <summary>
+        ///     Initializes a new instance of the <see cref="PartNotDiscoverableAttribute"/> class.
+        /// </summary>
+        public PartNotDiscoverableAttribute()
+        {
+        }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/SharedAttribute.cs

@@ -0,0 +1,44 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Composition
+{
+    /// <summary>
+    /// Marks a part as being constrained to sharing within the named boundary.
+    /// </summary>
+    /// <example>
+    /// [Export,
+    ///  Shared("HttpRequest")]
+    /// public class HttpResponseWriter { }
+    /// </example>
+    /// <seealso cref="SharingBoundaryAttribute"/>
+    [AttributeUsage(AttributeTargets.Class, Inherited = false)]
+    public class SharedAttribute : PartMetadataAttribute
+    {
+        private const string SharingBoundaryPartMetadataName = "SharingBoundary";
+
+        /// <summary>
+        /// Mark a part as globally shared.
+        /// </summary>
+        public SharedAttribute()
+            : base(SharingBoundaryPartMetadataName, null)
+        {
+        }
+
+        /// <summary>
+        /// Construct a <see cref="SharedAttribute"/> for the specified
+        /// boundary name.
+        /// </summary>
+        /// <param name="sharingBoundaryName">The boundary outside of which this part is inaccessible.</param>
+        public SharedAttribute(string sharingBoundaryName)
+            : base(SharingBoundaryPartMetadataName, sharingBoundaryName)
+        {
+        }
+
+        /// <summary>
+        /// he boundary outside of which this part is inaccessible.
+        /// </summary>
+        public string SharingBoundary { get { return (string)base.Value; } }
+    }
+}

external/corefx/src/System.Composition.AttributedModel/src/System/Composition/SharingBoundaryAttribute.cs

@@ -0,0 +1,43 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+
+namespace System.Composition
+{
+    /// <summary>
+    /// Applied to an import for ExportFactory{T}, this attribute marks the
+    /// boundary of a sharing scope. The ExportLifetimeContext{T} instances
+    /// returned from the factory will be boundaries for sharing of components that are bounded
+    /// by the listed boundary names.
+    /// </summary>
+    /// <example>
+    /// [Import, SharingBoundary("HttpRequest")]
+    /// public ExportFactory&lt;HttpRequestHandler&gt; HandlerFactory { get; set; }
+    /// </example>
+    /// <seealso cref="SharedAttribute" />
+    [AttributeUsage(AttributeTargets.Parameter | AttributeTargets.Property, Inherited = false)]
+    [MetadataAttribute]
+    [CLSCompliant(false)]
+    public sealed class SharingBoundaryAttribute : Attribute
+    {
+        private readonly string[] _sharingBoundaryNames;
+
+        /// <summary>
+        /// Construct a <see cref="SharingBoundaryAttribute"/> for the specified boundary names.
+        /// </summary>
+        /// <param name="sharingBoundaryNames">Boundaries implemented by the created ExportLifetimeContext{T}s.</param>
+        public SharingBoundaryAttribute(params string[] sharingBoundaryNames)
+        {
+            if (sharingBoundaryNames == null) throw new ArgumentNullException(nameof(sharingBoundaryNames));
+
+            _sharingBoundaryNames = sharingBoundaryNames;
+        }
+
+        /// <summary>
+        /// Boundaries implemented by the created ExportLifetimeContext{T}s.
+        /// </summary>
+        public ReadOnlyCollection<string> SharingBoundaryNames { get { return new ReadOnlyCollection<string>(_sharingBoundaryNames); } }
+    }
+}