Extremely slow clipboard operation when some clipboard monitor application running

[cuiliang]

Description

When running software that includes clipboard monitoring features, all WPF applications on the computer may become extremely slow when performing clipboard copy operations. Meanwhile, other programs such as Winform applications, browsers, and Windows Notepad operate normally.
Symptoms: When selecting "Copy" (or "Cut") from the right-click menu in any text box, it takes 0.5 to 1 second for the menu to close.

QQ2024515-84422.mp4

Compared to winform application:

QQ2024515-85941.mp4

Reproduction Steps

TestClipboard.zip

1. Download and unzip the above TestClipboard.zip file, and unzip to a folder.
2. Sample application was based on .Net8, you should have .Net8 installed on your computer.
3. Start the applications in the following order. (Order is important) 1) WpfApp1.exe 2) ClipobardMonitor.exe 3) InsideClipboard.exe

4. Select some text in WpfApp1.exe window, right click, then select COPY menu. it will close with big delay.

default.mp4

Expected behavior

Copy operation should complete immediately.

Actual behavior

Copy will complete with big delay and UI freeze.

Regression?

This problem exists for a long time, both .NET framework and .Net8.

Known Workarounds

No workgorund.

Impact

Very bad user experience.

Configuration

No response

Other information

Time was costed in System.Windows.Clipboard.CriticalSetDataObject, It fails to olesetclipboard and retry many times with Sleep().

[rampaa]

+1. This is really annoying.