Thread-safety of System.Net.WebSockets.ClientWebSocket

Question

The document is unclear about the thread safety of the System.Net.WebSockets.ClientWebSocket class.

Is it safe to call the SendAsync method from multiple threads simultaneously？

Answer 1

It's thread safe enough to get some work done.

According to the source (credit to Michael Kropat for discussing it at https://www.codetinkerer.com/2018/06/05/aspnet-core-websockets.html )

Thread-safety:

• It’s acceptable to call ReceiveAsync and SendAsync in parallel. One of each may run concurrently.
• It’s acceptable to have a pending ReceiveAsync while CloseOutputAsync or CloseAsync is called.
• Attempting to invoke any other operations in parallel may corrupt the instance. Attempting to invoke a send operation while another is in progress or a receive operation while another is in progress will result in an exception.