like #24694，Interlocked.CompareExchange/Exchange still missing for UIntPtr

[bysdxt]

Background and Motivation

.net5 adds support for native int(nint and nuint), System.Threading.Interlocked should support them too

Proposed API

namespace System.Threading
{
     public static class Interlocked {
+        public static extern UIntPtr CompareExchange(ref UIntPtr location1, UIntPtr value, UIntPtr comparand);
+        public static extern UIntPtr Exchange(ref UIntPtr location1, UIntPtr value);
     }

[GSPP]

This is the set of .NET 5.0 Interlocked methods:

Maybe we should add IntPtr and UIntPtr overloads to Add, Increment, Decrement, And and Or.

Is Interlocked.Read still relevant or does Volatile cover that? If still relevant, adding *Ptr overloads there would make sense, too.

[hamarb123]

This should be higher priority now that there is the nuint keyword.

[timcassell]

+1

I was just looking for Interlocked.Add with nint overload, saddened to see it doesn't exist.

[terrajobst]

• Looks good as proposed

namespace System.Threading
{
    public static class Interlocked
    {
        public static extern UIntPtr CompareExchange(ref UIntPtr location1, UIntPtr value, UIntPtr comparand);
        public static extern UIntPtr Exchange(ref UIntPtr location1, UIntPtr value);
    }
}