Oct 18, 2018 · Mar 6, 2019 · Jun 20, 2019
diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reflection;
    /// </summary>
    public class PythonEngine : IDisposable
    {
        private const int NUM_GENERATIONS = 3;

        private static DelegateManager delegateManager;
        private static bool initialized;
        private static IntPtr _pythonHome = IntPtr.Zero;
        private static IntPtr _programName = IntPtr.Zero;
        private static IntPtr _pythonPath = IntPtr.Zero;
        private static IntPtr _refChain = IntPtr.Zero;
        private static IntPtr[] _generations;


        public PythonEngine()
        {
                initialized = true;
                Exceptions.Clear();

                _generations = GetGCGenerations();
 #if PYTHON_WITH_PYDEBUG
                _refChain = GetRefChainHead();
 #endif
                // Make sure we clean up properly on app domain unload.
                AppDomain.CurrentDomain.DomainUnload += OnDomainUnload;


                ExecuteShutdownHandlers();

                Runtime.Shutdown();
                ResetGC();

                initialized = false;
            }
        }
                }
            }
        }

        internal static void ResetGC()
        {
            ClearGC();
 #if PYTHON_WITH_PYDEBUG
            ResetRefChain();
 #endif
        }

        private static void ClearGC()
        {
            Debug.Assert(_generations != null);
            foreach (IntPtr head in _generations)
            {
                // gc.gc_next
                Marshal.WriteIntPtr(head, 0, head);
                // gc.gc_prev
                Marshal.WriteIntPtr(head, IntPtr.Size, head);
            }
        }

        private static IntPtr[] GetGCGenerations()
        {
            int GCHeadOffset = IntPtr.Size == 4 ? 24 : 32;
            IntPtr op = Runtime._PyObject_GC_New(Runtime.PyTypeType);
            Runtime.PyObject_GC_Track(op);
            IntPtr g = Runtime._Py_AS_GC(op);
            // According to _PyObjct_GC_TRACK and PyGC_Head strcture, g is the g->gc.gc_next
            // It also become the GEN_HEAD(0) now
            IntPtr[] gens = new IntPtr[NUM_GENERATIONS];
            for (int i = 0; i < NUM_GENERATIONS; i++)
            {
                gens[i] = g;
                g += GCHeadOffset;
            }
            Runtime.PyObject_GC_UnTrack(op);
            Runtime.PyObject_GC_Del(op);
            return gens;
        }

 #if PYTHON_WITH_PYDEBUG
        private static void ResetRefChain()
        {
            Debug.Assert(_refChain != IntPtr.Zero);
            Marshal.WriteIntPtr(_refChain, ObjectOffset._ob_next, _refChain);
            Marshal.WriteIntPtr(_refChain, ObjectOffset._ob_prev, _refChain);
        }

        private static IntPtr GetRefChainHead()
        {
            IntPtr op = Runtime._PyObject_GC_New(Runtime.PyBaseObjectType);
            IntPtr refchain = Marshal.ReadIntPtr(op, ObjectOffset._ob_prev);
            Runtime.PyObject_GC_Del(op);
            return refchain;
        }
 #endif
    }

    public enum RunFlagType
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
        internal static extern IntPtr _PyObject_GetDictPtr(IntPtr obj);

        [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
        internal static extern IntPtrPyObject_GC_New(IntPtr tp);
        internal static extern IntPtr_PyObject_GC_New(IntPtr tp);

        [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
        internal static extern void PyObject_GC_Del(IntPtr tp);
        [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
        internal static extern void PyMem_Free(IntPtr ptr);

        internal static IntPtr _Py_AS_GC(IntPtr op)
        {
            return op - IntPtr.Size;
        }

        //====================================================================
        // Python exception API
Original file line number	Diff line number	Diff line change
		@@ -1,5 +1,6 @@
		using System;
		using System.Collections.Generic;
		using System.Diagnostics;
		using System.IO;
		using System.Linq;
		using System.Reflection;
Expand All		@@ -12,11 +13,16 @@ namespace Python.Runtime
		/// </summary>
		public class PythonEngine : IDisposable
		{
		private const int NUM_GENERATIONS = 3;

		private static DelegateManager delegateManager;
		private static bool initialized;
		private static IntPtr _pythonHome = IntPtr.Zero;
		private static IntPtr _programName = IntPtr.Zero;
		private static IntPtr _pythonPath = IntPtr.Zero;
		private static IntPtr _refChain = IntPtr.Zero;
		private static IntPtr[] _generations;


		public PythonEngine()
		{
Expand DownExpand Up		@@ -169,6 +175,10 @@ public static void Initialize(IEnumerable<string> args, bool setSysArgv = true,
		initialized = true;
		Exceptions.Clear();

		_generations = GetGCGenerations();
		#if PYTHON_WITH_PYDEBUG
		_refChain = GetRefChainHead();
		#endif
		// Make sure we clean up properly on app domain unload.
		AppDomain.CurrentDomain.DomainUnload += OnDomainUnload;

Expand DownExpand Up		@@ -318,6 +328,9 @@ public static void Shutdown()

		ExecuteShutdownHandlers();

		Runtime.Shutdown();
		ResetGC();

		initialized = false;
		}
		}
Expand DownExpand Up		@@ -598,6 +611,62 @@ internal static PyObject RunString(string code, IntPtr? globals, IntPtr? locals,
		}
		}
		}

		internal static void ResetGC()
		{
		ClearGC();
		#if PYTHON_WITH_PYDEBUG
		ResetRefChain();
		#endif
		}

		private static void ClearGC()
		{
		Debug.Assert(_generations != null);
		foreach (IntPtr head in _generations)
		{
		// gc.gc_next
		Marshal.WriteIntPtr(head, 0, head);
		// gc.gc_prev
		Marshal.WriteIntPtr(head, IntPtr.Size, head);
		}
		}

		private static IntPtr[] GetGCGenerations()
		{
		int GCHeadOffset = IntPtr.Size == 4 ? 24 : 32;
		IntPtr op = Runtime._PyObject_GC_New(Runtime.PyTypeType);
		Runtime.PyObject_GC_Track(op);
		IntPtr g = Runtime._Py_AS_GC(op);
		// According to _PyObjct_GC_TRACK and PyGC_Head strcture, g is the g->gc.gc_next
		// It also become the GEN_HEAD(0) now
		IntPtr[] gens = new IntPtr[NUM_GENERATIONS];
		for (int i = 0; i < NUM_GENERATIONS; i++)
		{
		gens[i] = g;
		g += GCHeadOffset;
		}
		Runtime.PyObject_GC_UnTrack(op);
		Runtime.PyObject_GC_Del(op);
		return gens;
		}

		#if PYTHON_WITH_PYDEBUG
		private static void ResetRefChain()
		{
		Debug.Assert(_refChain != IntPtr.Zero);
		Marshal.WriteIntPtr(_refChain, ObjectOffset._ob_next, _refChain);
		Marshal.WriteIntPtr(_refChain, ObjectOffset._ob_prev, _refChain);
		}

		private static IntPtr GetRefChainHead()
		{
		IntPtr op = Runtime._PyObject_GC_New(Runtime.PyBaseObjectType);
		IntPtr refchain = Marshal.ReadIntPtr(op, ObjectOffset._ob_prev);
		Runtime.PyObject_GC_Del(op);
		return refchain;
		}
		#endif
		}

		public enum RunFlagType
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1872,7 +1872,7 @@ internal static IntPtr PyType_GenericAlloc(IntPtr type, long n)
		internal static extern IntPtr _PyObject_GetDictPtr(IntPtr obj);

		[DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
		internal static extern IntPtrPyObject_GC_New(IntPtr tp);
		internal static extern IntPtr_PyObject_GC_New(IntPtr tp);

		[DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
		internal static extern void PyObject_GC_Del(IntPtr tp);
Expand DownExpand Up		@@ -1907,6 +1907,10 @@ internal static IntPtr PyMem_Realloc(IntPtr ptr, long size)
		[DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
		internal static extern void PyMem_Free(IntPtr ptr);

		internal static IntPtr _Py_AS_GC(IntPtr op)
		{
		return op - IntPtr.Size;
		}

		//====================================================================
		// Python exception API
Expand Down