System.AccessViolationException occurs when tried to run a python file multiple times.

[murtazabasu]

Environment

Environment
Pythonnet version: Runtime Version v4.0.30319
Python version: conda (3.7)
Operating System: Windows 10
.NET Runtime: 4.6.1

Details

Hello, I need to run a python file multiple times . I have a server - client interface where multiple client should be able to execute run a python file. one after the other.

In the below code:

I try to execute a python file two times. I notice that the first time it runs perfectly but for the second time it throws an AccessViolationException saying it Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

class Program
   {
       static void Main(string[] args)
       {
           for (int i = 0; i <= 2; i++)
           {
               connectPython();
               i += 1;
           }
           Console.ReadKey();
       }
       static void connectPython()
       {
           IPythonConnector python = new PythonConnector();
           python.EstablishConnection();
           try
           {
               dynamic mainFile;
               using (Py.GIL())
               {
                   mainFile = Py.Import("main");
               }
               dynamic running = mainFile.main();
           }
           finally
           {
               PythonEngine.Shutdown();
           }
       }

[lostmsu]

This behavior is well-known if the file you're trying to run references certain libraries like numpy, that do not support Python engine restart. You might want to try not calling PythonEngine.Shutdown() at all.

If that's not the case, you must provide an example, that we can run locally.

[magnusjjj]

You were a little bit quick to close this one :P.
I don't have access to the code now. But I made a pure python one.

All you need to do is start a thread that has no exit, say, a while True: inside it, with, oh, a print statement for good measure.

Then restart the script. I'd say roughly half or a third of the time it will throw an access violation.
This is apparantly a limitation of the python runtime itself.