gh-159117: Preserve sys.setprofile callbacks when destroying a tracing profiler

Author: Cha-Imaa

Lib/test/test_profiling/test_tracing_profiler.py

@@ -118,6 +118,22 @@ def test_profile_enable_disable(self):
         prof.disable()
         self.assertIs(sys.monitoring.get_tool(sys.monitoring.PROFILER_ID), None)
 
+    def test_dealloc_does_not_disable_sys_profile(self):
+        self.addCleanup(sys.setprofile, sys.getprofile())
+        self.addCleanup(sys.monitoring.free_tool_id, sys.monitoring.PROFILER_ID)
+
+        def callback(frame, event, arg):
+            pass
+
+        prof = self.profilerclass()
+        prof.enable()
+        sys.setprofile(callback)
+        # Release the monitoring callbacks so the enabled profiler can be
+        # destroyed without an explicit disable().
+        sys.monitoring.free_tool_id(sys.monitoring.PROFILER_ID)
+        del prof
+        self.assertIs(sys.getprofile(), callback)
+
     def test_profile_as_context_manager(self):
         prof = self.profilerclass()
         # Make sure we clean ourselves up if the test fails for some reason.

Misc/NEWS.d/next/Library/2026-10-18-05-48-00.gh-issue-159117.i4Jk8P.rst

@@ -0,0 +1,2 @@
+Prevent deallocation of a :mod:`profiling.tracing` profiler from disabling an
+unrelated :func:`sys.setprofile` callback.

Modules/_lsprof.c

@@ -4,8 +4,6 @@
 
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
-#include "pycore_ceval.h"         // _PyEval_SetProfile()
-#include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "pycore_time.h"          // _PyTime_FromSecondsObject()
 #include "pycore_typeobject.h"    // _PyType_GetModuleState()
 #include "pycore_unicodeobject.h" // _PyUnicode_EqualToASCIIString()
@@ -982,13 +980,6 @@ profiler_dealloc(PyObject *op)
 {
     ProfilerObject *self = ProfilerObject_CAST(op);
     PyObject_GC_UnTrack(self);
-    if (self->flags & POF_ENABLED) {
-        PyThreadState *tstate = _PyThreadState_GET();
-        if (_PyEval_SetProfile(tstate, NULL, NULL) < 0) {
-            PyErr_FormatUnraisable("Exception ignored while "
-                                   "destroying _lsprof profiler");
-        }
-    }
 
     /* Drop the external timer before flushing: it is Python code, and the
        profiler can be deallocated by the garbage collector. */