gh-98257: Make _PyEval_SetTrace() reentrant (#98258)

Make sys.setprofile() and sys.settrace() functions reentrant.  They
can no long fail with: RuntimeError("Cannot install a trace function
while another trace function is being installed").

Make _PyEval_SetTrace() and _PyEval_SetProfile() functions reentrant,
rather than detecting and rejecting reentrant calls. Only delete the
reference to function arguments once the new function is fully set,
when a reentrant call is safe. Call also _PySys_Audit() earlier.

2 files changed, 4 insertions, 12 deletions

diff --git a/Lib/test/test_sys_setprofile.py b/Lib/test/test_sys_setprofile.py
index 4c3053a..acae433 100644
--- a/Lib/test/test_sys_setprofile.py
+++ b/Lib/test/test_sys_setprofile.py
@@ -437,12 +437,8 @@ class TestEdgeCases(unittest.TestCase):
                 sys.setprofile(bar)
 
         sys.setprofile(A())
-        with support.catch_unraisable_exception() as cm:
-            sys.setprofile(foo)
-            self.assertEqual(cm.unraisable.object, A.__del__)
-            self.assertIsInstance(cm.unraisable.exc_value, RuntimeError)
-
-        self.assertEqual(sys.getprofile(), foo)
+        sys.setprofile(foo)
+        self.assertEqual(sys.getprofile(), bar)
 
 
     def test_same_object(self):
diff --git a/Lib/test/test_sys_settrace.py b/Lib/test/test_sys_settrace.py
index 4f577c2..a448f80 100644
--- a/Lib/test/test_sys_settrace.py
+++ b/Lib/test/test_sys_settrace.py
@@ -2796,12 +2796,8 @@ class TestEdgeCases(unittest.TestCase):
                 sys.settrace(bar)
 
         sys.settrace(A())
-        with support.catch_unraisable_exception() as cm:
-            sys.settrace(foo)
-            self.assertEqual(cm.unraisable.object, A.__del__)
-            self.assertIsInstance(cm.unraisable.exc_value, RuntimeError)
-
-        self.assertEqual(sys.gettrace(), foo)
+        sys.settrace(foo)
+        self.assertEqual(sys.gettrace(), bar)
 
 
     def test_same_object(self):