I have a thread that goes out and attempts to make a connection. In the thread, I make a call to a third party library. Sometimes, this call hangs, and never returns. On the UI thread, I want to be able to cancel the connection attempt by aborting the thread, which should abort the hung call to the third party library.
I’ve called Thread.Abort, but have now read that Thread.Abort only works when control returns to managed code. I have observed that this is true, because the thread never aborts, and I’ve been sitting on Thread.Join for ten minutes now. What should I do with this hung thread? Should I just null the reference and move on? I’d like to be as clean as possible–
This function in your third-party library doesn’t have a timeout or cancel function? If so, that’s pretty poor design. There’s not going to be any pretty solution here, methinks…
Unfortunately, there’s no way you’re going to get around it, short of using the Win32 API to kill the thread manually, which is certainly not going to be clean. However, if this third-party library is not giving you any other options, it may be the thing to do. The
TerminateThreadfunction is what you’ll want to use, but observe the warning! To get the thread ID to pass to this function, you have to use another Win32 API call (theThreadclass doesn’t expose it directly). The approach here will be to set the value of a volatile class variable to the result ofGetCurrentThreadIdat the start of the managed thread method, and then use this thread ID later to terminate the thread.