How to get non-current thread's stacktrace?

Question

It is possible to get stacktrace using System.Diagnostics.StackTrace, but thread has to be suspended. Suspend and Resume function are obsolete, so I expect that better way e

Answer 1

As mentioned in my comment, the proposed solution above does still have a tiny probability for a deadlock. Please find my version below.

private static StackTrace GetStackTrace(Thread targetThread) {
using (ManualResetEvent fallbackThreadReady = new ManualResetEvent(false), exitedSafely = new ManualResetEvent(false)) {
    Thread fallbackThread = new Thread(delegate() {
        fallbackThreadReady.Set();
        while (!exitedSafely.WaitOne(200)) {
            try {
                targetThread.Resume();
            } catch (Exception) {/*Whatever happens, do never stop to resume the target-thread regularly until the main-thread has exited safely.*/}
        }
    });
    fallbackThread.Name = "GetStackFallbackThread";
    try {
        fallbackThread.Start();
        fallbackThreadReady.WaitOne();
        //From here, you have about 200ms to get the stack-trace.
        targetThread.Suspend();
        StackTrace trace = null;
        try {
            trace = new StackTrace(targetThread, true);
        } catch (ThreadStateException) {
            //failed to get stack trace, since the fallback-thread resumed the thread
            //possible reasons:
            //1.) This thread was just too slow (not very likely)
            //2.) The deadlock ocurred and the fallbackThread rescued the situation.
            //In both cases just return null.
        }
        try {
            targetThread.Resume();
        } catch (ThreadStateException) {/*Thread is running again already*/}
        return trace;
    } finally {
        //Just signal the backup-thread to stop.
        exitedSafely.Set();
        //Join the thread to avoid disposing "exited safely" too early. And also make sure that no leftover threads are cluttering iis by accident.
        fallbackThread.Join();
    }
}
}

I think, the ManualResetEventSlim "fallbackThreadReady" is not really necessary, but why risk anything in this delicate case?