Add a shorter timeout for retrieving clipboard data

src/EditorFeatures/Core/StringCopyPaste/WpfStringCopyPasteService.cs

@@ -5,24 +5,28 @@
 using System;
 using System.Composition;
 using System.Runtime.InteropServices;
+using System.Threading;
+
 // Use of System.Windows.Forms over System.Windows is intentional here.  S.W.F has logic in its clipboard impl to help
 // with common errors.
 using System.Windows.Forms;
 using Microsoft.CodeAnalysis.ErrorReporting;
 using Microsoft.CodeAnalysis.Host.Mef;
+using IComDataObject = System.Runtime.InteropServices.ComTypes.IDataObject;
 
 namespace Microsoft.CodeAnalysis.Editor.StringCopyPaste;
 
 [ExportWorkspaceService(typeof(IStringCopyPasteService), ServiceLayer.Host), Shared]
-internal sealed class WpfStringCopyPasteService : IStringCopyPasteService
+[method: ImportingConstructor]
+[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+internal sealed class WpfStringCopyPasteService() : IStringCopyPasteService
 {
-    private const string RoslynFormat = nameof(RoslynFormat);
+    // Similar to what WinForms does, except that instead of blocking for up to 1s, we only block for up to 250ms.
+    // https://github.com/dotnet/winforms/blob/0f76e65878b1a0958175f17c4360b8198f8b36ba/src/System.Windows.Forms/src/System/Windows/Forms/Clipboard.cs#L31
+    private const int RetryTimes = 5;
+    private const int RetryDelay = 50;
 
-    [ImportingConstructor]
-    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
-    public WpfStringCopyPasteService()
-    {
-    }
+    private const string RoslynFormat = nameof(RoslynFormat);
 
     private static string GetFormat(string key)
         => $"{RoslynFormat}-{key}";
@@ -33,7 +37,9 @@ public bool TrySetClipboardData(string key, string data)
 
         try
         {
-            var dataObject = Clipboard.GetDataObject();
+            var dataObject = GetDataObject();
+            if (dataObject is null)
+                return false;
 
             var copy = new DataObject();
 
@@ -45,9 +51,7 @@ public bool TrySetClipboardData(string key, string data)
 
             copy.SetData(GetFormat(key), data);
 
-            // Similar to what WinForms does, except that instead of blocking for up to 1s, we only block for up to 250ms.
-            // https://github.com/dotnet/winforms/blob/0f76e65878b1a0958175f17c4360b8198f8b36ba/src/System.Windows.Forms/src/System/Windows/Forms/Clipboard.cs#L31
-            Clipboard.SetDataObject(copy, copy: false, retryTimes: 5, retryDelay: 50);
+            Clipboard.SetDataObject(copy, copy: false, RetryTimes, RetryDelay);
             return true;
         }
         catch (ExternalException ex) when ((uint)ex.ErrorCode == CLIPBRD_E_CANT_OPEN)
@@ -62,11 +66,58 @@ public bool TrySetClipboardData(string key, string data)
         return false;
     }
 
+    /// <summary>
+    /// Similar to <see cref="Clipboard.GetDataObject"/> except that this will only block a max of 250ms, not a full second.
+    /// </summary>
+    private static IDataObject? GetDataObject()
+        => GetDataObject(RetryTimes, RetryDelay);
+
+    /// <summary>
+    /// Copied from https://github.com/dotnet/winforms/blob/0f76e65878b1a0958175f17c4360b8198f8b36ba/src/System.Windows.Forms/src/System/Windows/Forms/Clipboard.cs#L139
+    /// </summary>
+    private static IDataObject? GetDataObject(int retryTimes, int retryDelay)
+    {
+        IComDataObject? dataObject = null;
+        int hr;
+        var retry = retryTimes;
+        do
+        {
+            hr = OleGetClipboard(ref dataObject);
+            if (hr != 0)
+            {
+                if (retry == 0)
+                    return null;
+
+                retry--;
+                Thread.Sleep(millisecondsTimeout: retryDelay);
+            }
+        }
+        while (hr != 0);
+
+        if (dataObject is not null)
+        {
+            if (dataObject is IDataObject ido && !Marshal.IsComObject(dataObject))
+            {
+                return ido;
+            }
+
+            return new DataObject(dataObject);
+        }
+
+        return null;
+    }
+
+    [DllImport("ole32.dll", ExactSpelling = true)]
+    public static extern int OleGetClipboard(ref IComDataObject? data);
+
     public string? TryGetClipboardData(string key)
     {
         try
         {
-            var dataObject = Clipboard.GetDataObject();
+            var dataObject = GetDataObject();
+            if (dataObject is null)
+                return null;
+
             var format = GetFormat(key);
             if (dataObject.GetDataPresent(format))
             {