Add Channel.CreateUnboundedPrioritized

src/libraries/System.Threading.Channels/ref/System.Threading.Channels.csproj

@@ -5,13 +5,17 @@
 
   <ItemGroup>
     <Compile Include="System.Threading.Channels.cs" />
-    <Compile Include="System.Threading.Channels.netcoreapp.cs" Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))"/>
+    <Compile Include="System.Threading.Channels.netstandard21.cs" Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))"/>
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime/ref/System.Runtime.csproj" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
+    <Compile Include="System.Threading.Channels.netcoreapp.cs" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="$(SystemThreadingTasksExtensionsVersion)" />
     <ProjectReference Include="$(LibrariesProjectRoot)Microsoft.Bcl.AsyncInterfaces\ref\Microsoft.Bcl.AsyncInterfaces.csproj" />

src/libraries/System.Threading.Channels/ref/System.Threading.Channels.netcoreapp.cs

@@ -4,14 +4,17 @@
 // Changes to this file must follow the https://aka.ms/api-review process.
 // ------------------------------------------------------------------------------
 
+using System.Collections.Generic;
+
 namespace System.Threading.Channels
 {
-    public partial class ChannelClosedException : System.InvalidOperationException
+    public partial class Channel
+    {
+        public static System.Threading.Channels.Channel<T> CreateUnboundedPrioritized<T>() { throw null; }
+        public static System.Threading.Channels.Channel<T> CreateUnboundedPrioritized<T>(System.Threading.Channels.UnboundedPrioritizedChannelOptions<T> options) { throw null; }
+    }
+    public sealed partial class UnboundedPrioritizedChannelOptions<T> : System.Threading.Channels.ChannelOptions
     {
-#if NET8_0_OR_GREATER
-        [System.ObsoleteAttribute("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId = "SYSLIB0051", UrlFormat = "https://aka.ms/dotnet-warnings/{0}")]
-        [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
-#endif
-        protected ChannelClosedException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) { }
+        public System.Collections.Generic.IComparer<T>? Comparer { get; set; }
     }
 }

src/libraries/System.Threading.Channels/ref/System.Threading.Channels.netstandard21.cs

@@ -0,0 +1,17 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// ------------------------------------------------------------------------------
+// Changes to this file must follow the https://aka.ms/api-review process.
+// ------------------------------------------------------------------------------
+
+namespace System.Threading.Channels
+{
+    public partial class ChannelClosedException : System.InvalidOperationException
+    {
+#if NET8_0_OR_GREATER
+        [System.ObsoleteAttribute("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId = "SYSLIB0051", UrlFormat = "https://aka.ms/dotnet-warnings/{0}")]
+        [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
+#endif
+        protected ChannelClosedException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) { }
+    }
+}

src/libraries/System.Threading.Channels/src/System.Threading.Channels.csproj

@@ -14,16 +14,10 @@ System.Threading.Channel&lt;T&gt;</PackageDescription>
   <ItemGroup>
     <Compile Include="System\VoidResult.cs" />
     <Compile Include="System\Threading\Channels\AsyncOperation.cs" />
-    <Compile Include="System\Threading\Channels\AsyncOperation.netcoreapp.cs"
-             Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'" />
-    <Compile Include="System\Threading\Channels\AsyncOperation.netstandard.cs"
-             Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
     <Compile Include="System\Threading\Channels\BoundedChannel.cs" />
     <Compile Include="System\Threading\Channels\BoundedChannelFullMode.cs" />
     <Compile Include="System\Threading\Channels\Channel.cs" />
     <Compile Include="System\Threading\Channels\ChannelClosedException.cs" />
-    <Compile Include="System\Threading\Channels\ChannelClosedException.netcoreapp.cs"
-             Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))" />
     <Compile Include="System\Threading\Channels\ChannelOptions.cs" />
     <Compile Include="System\Threading\Channels\ChannelReader.cs" />
     <Compile Include="System\Threading\Channels\ChannelUtilities.cs" />
@@ -32,21 +26,25 @@ System.Threading.Channel&lt;T&gt;</PackageDescription>
     <Compile Include="System\Threading\Channels\Channel_2.cs" />
     <Compile Include="System\Threading\Channels\IDebugEnumerator.cs" />
     <Compile Include="System\Threading\Channels\SingleConsumerUnboundedChannel.cs" />
-    <Compile Include="System\Threading\Channels\TaskCompletionSource.cs"
-             Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'"/>
     <Compile Include="System\Threading\Channels\UnboundedChannel.cs" />
-    <Compile Include="$(CommonPath)Internal\Padding.cs"
-             Link="Common\Internal\Padding.cs" />
-    <Compile Include="$(CommonPath)System\Collections\Concurrent\IProducerConsumerQueue.cs"
-             Link="Common\System\Collections\Concurrent\IProducerConsumerQueue.cs" />
-    <Compile Include="$(CommonPath)System\Collections\Concurrent\MultiProducerMultiConsumerQueue.cs"
-             Link="Common\System\Collections\Concurrent\MultiProducerMultiConsumerQueue.cs" />
-    <Compile Include="$(CommonPath)System\Collections\Concurrent\SingleProducerSingleConsumerQueue.cs"
-             Link="Common\System\Collections\Concurrent\SingleProducerSingleConsumerQueue.cs" />
-    <Compile Include="$(CommonPath)System\Collections\Generic\Deque.cs"
-             Link="Common\System\Collections\Generic\Deque.cs" />
-    <Compile Include="$(CommonPath)System\Obsoletions.cs"
-             Link="Common\System\Obsoletions.cs" />
+    <Compile Include="$(CommonPath)Internal\Padding.cs" Link="Common\Internal\Padding.cs" />
+    <Compile Include="$(CommonPath)System\Collections\Concurrent\IProducerConsumerQueue.cs" Link="Common\System\Collections\Concurrent\IProducerConsumerQueue.cs" />
+    <Compile Include="$(CommonPath)System\Collections\Concurrent\MultiProducerMultiConsumerQueue.cs" Link="Common\System\Collections\Concurrent\MultiProducerMultiConsumerQueue.cs" />
+    <Compile Include="$(CommonPath)System\Collections\Concurrent\SingleProducerSingleConsumerQueue.cs" Link="Common\System\Collections\Concurrent\SingleProducerSingleConsumerQueue.cs" />
+    <Compile Include="$(CommonPath)System\Collections\Generic\Deque.cs" Link="Common\System\Collections\Generic\Deque.cs" />
+    <Compile Include="$(CommonPath)System\Obsoletions.cs" Link="Common\System\Obsoletions.cs" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
+    <Compile Include="System\Threading\Channels\AsyncOperation.netstandard.cs" />
+    <Compile Include="System\Threading\Channels\TaskCompletionSource.cs" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
+    <Compile Include="System\Threading\Channels\AsyncOperation.netcoreapp.cs" />
+    <Compile Include="System\Threading\Channels\Channel.netcoreapp.cs" />
+    <Compile Include="System\Threading\Channels\ChannelOptions.netcoreapp.cs" />
+    <Compile Include="System\Threading\Channels\UnboundedPriorityChannel.cs" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
@@ -57,6 +55,10 @@ System.Threading.Channel&lt;T&gt;</PackageDescription>
     <Reference Include="System.Threading.ThreadPool" />
   </ItemGroup>
 
+  <ItemGroup Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))">
+    <Compile Include="System\Threading\Channels\ChannelClosedException.netcoreapp.cs" />
+  </ItemGroup>
+
   <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'netstandard2.1'))">
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="$(SystemThreadingTasksExtensionsVersion)" />
     <ProjectReference Include="$(LibrariesProjectRoot)Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj" />

src/libraries/System.Threading.Channels/src/System/Threading/Channels/Channel.cs

@@ -4,7 +4,7 @@
 namespace System.Threading.Channels
 {
     /// <summary>Provides static methods for creating channels.</summary>
-    public static class Channel
+    public static partial class Channel
     {
         /// <summary>Creates an unbounded channel usable by any number of readers and writers concurrently.</summary>
         /// <returns>The created channel.</returns>

src/libraries/System.Threading.Channels/src/System/Threading/Channels/Channel.netcoreapp.cs

@@ -0,0 +1,36 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+
+namespace System.Threading.Channels
+{
+    /// <summary>Provides static methods for creating channels.</summary>
+    public static partial class Channel
+    {
+        /// <summary>Creates an unbounded prioritized channel usable by any number of readers and writers concurrently.</summary>
+        /// <returns>The created channel.</returns>
+        /// <remarks>
+        /// <see cref="Comparer{T}.Default"/> is used to determine priority of elements.
+        /// The next item read from the channel will be the element available in the channel with the lowest priority value.
+        /// </remarks>
+        public static Channel<T> CreateUnboundedPrioritized<T>() =>
+            new UnboundedPrioritizedChannel<T>(runContinuationsAsynchronously: true, comparer: null);
+
+        /// <summary>Creates an unbounded prioritized channel subject to the provided options.</summary>
+        /// <typeparam name="T">Specifies the type of data in the channel.</typeparam>
+        /// <param name="options">Options that guide the behavior of the channel.</param>
+        /// <returns>The created channel.</returns>
+        /// <remarks>
+        /// The supplied <paramref name="options"/>' <see cref="UnboundedPrioritizedChannelOptions{T}.Comparer"/> is used to determine priority of elements,
+        /// or <see cref="Comparer{T}.Default"/> if the provided comparer is null.
+        /// The next item read from the channel will be the element available in the channel with the lowest priority value.
+        /// </remarks>
+        public static Channel<T> CreateUnboundedPrioritized<T>(UnboundedPrioritizedChannelOptions<T> options)
+        {
+            ArgumentNullException.ThrowIfNull(options);
+
+            return new UnboundedPrioritizedChannel<T>(!options.AllowSynchronousContinuations, options.Comparer);
+        }
+    }
+}

src/libraries/System.Threading.Channels/src/System/Threading/Channels/ChannelOptions.cs

@@ -39,7 +39,7 @@ public abstract class ChannelOptions
         public bool AllowSynchronousContinuations { get; set; }
     }
 
-    /// <summary>Provides options that control the behavior of <see cref="BoundedChannel{T}"/> instances.</summary>
+    /// <summary>Provides options that control the behavior of instances created by <see cref="M:Channel.CreateBounded"/>.</summary>
     public sealed class BoundedChannelOptions : ChannelOptions
     {
         /// <summary>The maximum number of items the bounded channel may store.</summary>
@@ -94,7 +94,7 @@ public BoundedChannelFullMode FullMode
         }
     }
 
-    /// <summary>Provides options that control the behavior of <see cref="UnboundedChannel{T}"/> instances.</summary>
+    /// <summary>Provides options that control the behavior of instances created by <see cref="M:Channel.CreateUnbounded"/>.</summary>
     public sealed class UnboundedChannelOptions : ChannelOptions
     {
     }

src/libraries/System.Threading.Channels/src/System/Threading/Channels/ChannelOptions.netcoreapp.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+
+namespace System.Threading.Channels
+{
+    /// <summary>Provides options that control the behavior of instances created by <see cref="M:Channel.CreateUnboundedPrioritized"/>.</summary>
+    public sealed class UnboundedPrioritizedChannelOptions<T> : ChannelOptions
+    {
+        /// <summary>Gets or sets the comparer used by the channel to prioritize elements.</summary>
+        public IComparer<T>? Comparer { get; set; }
+    }
+}