No way to programmatically stop execution about ironpython3

[DJSures]

You can create an exception type...

public class PythonStopException : Exception {
}

Use a cancellation token and source, or a volatile bool. You choose...

    volatile bool _cancelRequested = false;

Create a delegate for the Trace that checks the cancelation token or volatile bool

    private TracebackDelegate OnTraceback(TraceBackFrame frame, string result, object payload) {

      if (_cancelRequested)
        throw new PythonStopException();

      return OnTraceback;
    }

in your thread to launch the script, initialize the engine and set the trace to the ontraceback delegate...

      _engine = IronPython.Hosting.Python.CreateEngine();
      _engine.SetTrace(OnTraceback);

Make sure you catch the exception for the PythonStopException that you made, so it doesn't roll down as an error in your try/catch surrounding the Execute()

try {
   _engine.Execute(script)
} catch (PythonStopException) {
} 

[slozier]

Glad you found a solution.

Thanks for the suggestion; however, that is deprecated as well.

Just a side note, it's not really deprecated. It was marked as Obsolete right off the bat to discourage its use. See https://learn.microsoft.com/en-us/dotnet/fundamentals/syslib-diagnostics/syslib0046

[slozier]

There's the System.Runtime.ControlledExecution which we might be usable instead of Thread.Abort although I haven't had a chance to try it out myself...

[DJSures]

There's the System.Runtime.ControlledExecution which we might be usable instead of Thread.Abort although I haven't had a chance to try it out myself...

Thanks for the suggestion; however, that is deprecated as well. Do you have another suggestion? Isn't there a place in the IronPython library where we can insert a cancellationtoken to be checked during execution? I don't need it to be a Task or async. That's fine, i just need to somehow cancel the execution of a script from another thread.

[Muny]

FWIW, I check for cancellation inside a Traceback callback (scriptEngine.SetTrace()), and raise an exception if so. It probably has somewhat of a performance impact, and it won't immediately cancel things like sleep().

I do wish there was a neater solution.

[wally96334]

I am trying to resolve the same problem.

#1779

My approach is to spin off an app domain, then trash the app domain in the event that execution is to be aborted.

[DJSures]

FWIW, I check for cancellation inside a Traceback callback (scriptEngine.SetTrace()), and raise an exception if so. It probably has somewhat of a performance impact, and it won't immediately cancel things like sleep().

I do wish there was a neater solution.

That sounds like a good solution but i can't seem to find SetTrace() in the ScriptEngine. Do you have an example to share 🙏

*EDIT: nevermind, i was creating the runtime differently. I found it by creating the engine. Thanks! I'll go ahead and try this.

[DJSures]

FWIW, I check for cancellation inside a Traceback callback (scriptEngine.SetTrace()), and raise an exception if so. It probably has somewhat of a performance impact, and it won't immediately cancel things like sleep().

I do wish there was a neater solution.

That works flawlessly!! Thank you so much. I was in a bit of a panic - and this is far more elegant than Thread.Abort().