prevent crash during debugging when attempting to inspect PyObject without GIL

lostmsu · lostmsu · commit d5514fe0ab68 · 2021-07-07T11:11:58.000-07:00
diff --git a/src/runtime/Util.cs b/src/runtime/Util.cs
@@ -7,6 +7,8 @@ internal static class Util
     {
         internal const string UnstableApiMessage =
             "This API is unstable, and might be changed or removed in the next minor release";
+        internal const string MinimalPythonVersionRequired =
+            "Only Python 3.5 or newer is supported";
 
         internal static Int64 ReadCLong(IntPtr tp, int offset)
         {
diff --git a/src/runtime/debughelper.cs b/src/runtime/debughelper.cs
@@ -144,5 +144,13 @@ public static void AssertHasReferences(IntPtr obj)
             long refcount = Runtime.Refcount(obj);
             Debug.Assert(refcount > 0, "Object refcount is 0 or less");
         }
+
+        [Conditional("DEBUG")]
+        public static void EnsureGIL()
+        {
+            Debug.Assert(HaveInterpreterLock(), "GIL must be acquired");
+        }
+
+        public static bool HaveInterpreterLock() => Runtime.PyGILState_Check() == 1;
     }
 }
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -16,6 +16,7 @@ namespace Python.Runtime
     /// for details.
     /// </summary>
     [Serializable]
+    [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     public partial class PyObject : DynamicObject, IEnumerable<PyObject>, IDisposable
     {
 #if TRACE_ALLOC
@@ -1069,6 +1070,10 @@ public override string ToString()
             return result;
         }
 
+        string DebuggerDisplay => DebugUtil.HaveInterpreterLock()
+            ? this.ToString()
+            : $"pyobj at 0x{this.obj:X} (get Py.GIL to see more info)";
+
 
         /// <summary>
         /// Equals Method
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
@@ -832,7 +832,7 @@ internal static unsafe long Refcount(IntPtr op)
 
         internal static IntPtr PyThreadState_Swap(IntPtr key) => Delegates.PyThreadState_Swap(key);
 
-
+        internal static int PyGILState_Check() => Delegates.PyGILState_Check();
         internal static IntPtr PyGILState_Ensure() => Delegates.PyGILState_Ensure();
 
 
@@ -2302,6 +2302,14 @@ static Delegates()
                 PyThread_get_thread_ident = (delegate* unmanaged[Cdecl]<int>)GetFunctionByName(nameof(PyThread_get_thread_ident), GetUnmanagedDll(_PythonDll));
                 PyThread_set_key_value = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr, int>)GetFunctionByName(nameof(PyThread_set_key_value), GetUnmanagedDll(_PythonDll));
                 PyThreadState_Swap = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr>)GetFunctionByName(nameof(PyThreadState_Swap), GetUnmanagedDll(_PythonDll));
+                try
+                {
+                    PyGILState_Check = (delegate* unmanaged[Cdecl]<int>)GetFunctionByName(nameof(PyGILState_Check), GetUnmanagedDll(_PythonDll));
+                }
+                catch (MissingMethodException e)
+                {
+                    throw new NotSupportedException(Util.MinimalPythonVersionRequired, innerException: e);
+                }
                 PyGILState_Ensure = (delegate* unmanaged[Cdecl]<IntPtr>)GetFunctionByName(nameof(PyGILState_Ensure), GetUnmanagedDll(_PythonDll));
                 PyGILState_Release = (delegate* unmanaged[Cdecl]<IntPtr, void>)GetFunctionByName(nameof(PyGILState_Release), GetUnmanagedDll(_PythonDll));
                 PyGILState_GetThisThreadState = (delegate* unmanaged[Cdecl]<IntPtr>)GetFunctionByName(nameof(PyGILState_GetThisThreadState), GetUnmanagedDll(_PythonDll));
@@ -2605,6 +2613,7 @@ static Delegates()
             internal static delegate* unmanaged[Cdecl]<int> PyThread_get_thread_ident { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr, int> PyThread_set_key_value { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr> PyThreadState_Swap { get; }
+            internal static delegate* unmanaged[Cdecl]<int> PyGILState_Check { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr> PyGILState_Ensure { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, void> PyGILState_Release { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr> PyGILState_GetThisThreadState { get; }

Original file line number	Diff line number	Diff line change
`@@ -7,6 +7,8 @@ internal static class Util`
`7`	`7`	`{`
`8`	`8`	`internal const string UnstableApiMessage =`
`9`	`9`	`"This API is unstable, and might be changed or removed in the next minor release";`
	`10`	`+ internal const string MinimalPythonVersionRequired =`
	`11`	`+ "Only Python 3.5 or newer is supported";`
`10`	`12`
`11`	`13`	`internal static Int64 ReadCLong(IntPtr tp, int offset)`
`12`	`14`	`{`
Original file line number	Diff line number	Diff line change
`@@ -144,5 +144,13 @@ public static void AssertHasReferences(IntPtr obj)`
`144`	`144`	`long refcount = Runtime.Refcount(obj);`
`145`	`145`	`Debug.Assert(refcount > 0, "Object refcount is 0 or less");`
`146`	`146`	`}`
	`147`	`+`
	`148`	`+ [Conditional("DEBUG")]`
	`149`	`+ public static void EnsureGIL()`
	`150`	`+ {`
	`151`	`+ Debug.Assert(HaveInterpreterLock(), "GIL must be acquired");`
	`152`	`+ }`
	`153`	`+`
	`154`	`+ public static bool HaveInterpreterLock() => Runtime.PyGILState_Check() == 1;`
`147`	`155`	`}`
`148`	`156`	`}`