I often encounter memory access-related crash issues when using Pythonnet

[hellofengge]

Environment

• Pythonnet version:3.1.0-preview2023-11-04
• Python version: 3.9
• Operating System: Windows
• .NET Runtime: .NET 6

Details

I often encounter memory access-related crash issues when using Pythonnet. While debugging one of the dump files in Visual Studio, the problem appears to be in the following section of the Runtime.cs code:

internal unsafe static NewReference PyObject_GetAttrString(BorrowedReference pointer, string name)
{
    using StrPtr strPtr = new StrPtr(name, Encoding.UTF8);
    return Delegates.PyObject_GetAttrString(pointer, strPtr);
}

The error message is 0xC0000005: Access violation. My .NET version is .NET 6, and the operating system is Windows 11. During program initialization, I call PythonEngine.BeginAllowThreads(), and I've added locks around every access to Python attributes and functions. Sample code is provided below.

public object Invoke(MethodInfo methodInfo, object instance, Type[] typeArguments, object[] arguments, Func<object[], object> invoker)
{
	object result = null;
	using (Jvl.GIL())
	{
		string name = Name ?? methodInfo.Name;
		PyObject[] args = arguments.Select((object x) => x.ToPython()).ToArray();
		if (methodInfo.IsStatic)
		{
			PyObject pyObject2 = (((methodInfo.DeclaringType?.GetField(_moduleFiledName, BindingFlags.Static | BindingFlags.NonPublic))?.GetValue(null) is PyObject pyObject) ? pyObject.InvokeMethod(name, args) : null);
			result = ((typeof(void) == methodInfo.ReturnType) ? null : pyObject2?.AsManagedObject(methodInfo.ReturnType));
		}
		else
		{
			if (!(instance is IPythonObject pythonObject))
			{
				throw new PythonMapperException();
			}
			PyObject pyObject3 = pythonObject.PyObject.InvokeMethod(name, args);
			result = ((typeof(void) == methodInfo.ReturnType) ? null : pyObject3.AsManagedObject(methodInfo.ReturnType));
		}
	}
	return result;
}


public class Jvl : IDisposable
{
    #region Fields

    private readonly bool _isTrace = false;
    private readonly IDisposable _state;
    private bool _disposedValue;

    #endregion Fields

    #region Private Constructors

    private Jvl() : this(false)
    {

    }

    private Jvl(bool isTrace)
    {
        _isTrace = isTrace;
        Trace();
        _state = Py.GIL();
    }

    #endregion Private Constructors

    #region Public Methods

    /// <summary>
    /// 检查环境是否正确
    /// </summary>
    /// <param name="path"></param>
    /// <returns></returns>
    public static bool CheckPythonEnvironment(string path, string targetFolderRelativePath = "Lib/site-packages/pyjvl2")
    {
        if (string.IsNullOrEmpty(path)) return false;
        if (!Directory.Exists(path)) return false;
        string targetFolderPath = Path.Combine(path, targetFolderRelativePath);
        return Directory.Exists(targetFolderPath);
    }

    public static Jvl GIL(bool isTrace = false) => new Jvl(isTrace);
    private static IntPtr? _threadState;

    public static void Initialize(string path, bool allowThreads = false)
    {
        if (string.IsNullOrEmpty(path))
        {
            throw new ArgumentNullException(nameof(path));
        }
        if (!PythonEngine.IsInitialized)
        {
            PythonEngine.Shutdown();
            var python39Dll = Path.Combine(path, "python39.dll");
            var python39Dlls = Path.Combine(path, "DLLs");
            var sitePackages = Path.Combine(path, "Lib", "site-packages");
            var lib = Path.Combine(path, "lib");
            Runtime.PythonDLL = python39Dll;
            PythonEngine.PythonPath += $@"{path};{python39Dlls};{sitePackages};{lib};";
            PythonEngine.Initialize();
        }
        if (allowThreads && _threadState is null)
        {
            _threadState = PythonEngine.BeginAllowThreads();
        }
        CodecRegister.Register();
    }
    public void Dispose()
    {
        // 不要更改此代码。请将清理代码放入“Dispose(bool disposing)”方法中
        Dispose(disposing: true);
        GC.SuppressFinalize(this);
    }

    #endregion Public Methods

    #region Protected Methods

    protected void Dispose(bool disposing)
    {
        if (!_disposedValue)
        {
            if (disposing)
            {
                Trace();
                _state.Dispose();
            }

            // TODO: 释放未托管的资源(未托管的对象)并重写终结器
            // TODO: 将大型字段设置为 null
            _disposedValue = true;
        }
    }

    #endregion Protected Methods

    #region Private Methods

    // // TODO: 仅当“Dispose(bool disposing)”拥有用于释放未托管资源的代码时才替代终结器
    // ~Jvl()
    // {
    //     // 不要更改此代码。请将清理代码放入“Dispose(bool disposing)”方法中
    //     Dispose(disposing: false);
    // }
    private void Trace()
    {
        if (_isTrace)
        {
            StringBuilder stringBuilder = new StringBuilder();
            StackTrace st = new StackTrace(true);
            foreach (var sf in st.GetFrames())
            {
                stringBuilder.AppendLine($"FileName:{sf.GetFileName()}  FullName:{sf?.GetMethod()?.DeclaringType?.FullName} Function:{sf?.GetMethod()?.Name} Line:{sf?.GetFileLineNumber()}");
            }
            Debug.WriteLine(stringBuilder.ToString());
        }
    }

    #endregion Private Methods
}

    print('TODO')

• If there was a crash, please include the traceback here.

    print('TODO')

[hellofengge]

Operating System: Windows11

[hellofengge]

Now, I have identified that the direct cause of the problem is that my Python code is maintaining a set, and my C # code is also traversing this set, which can cause the process to crash during the C # traversal process