gh-118527: Intern code consts in free-threaded build (#118667)

We already intern and immortalize most string constants. In the
free-threaded build, other constants can be a source of reference count
contention because they are shared by all threads running the same code
objects.

1 files changed, 13 insertions, 0 deletions

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index e7b60eb..d192d5b 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -866,8 +866,21 @@ builtin_compile_impl(PyObject *module, PyObject *source, PyObject *filename,
     if (str == NULL)
         goto error;
 
+#ifdef Py_GIL_DISABLED
+    // gh-118527: Disable immortalization of code constants for explicit
+    // compile() calls to get consistent frozen outputs between the default
+    // and free-threaded builds.
+    PyInterpreterState *interp = _PyInterpreterState_GET();
+    int old_value = interp->gc.immortalize.enable_on_thread_created;
+    interp->gc.immortalize.enable_on_thread_created = 0;
+#endif
+
     result = Py_CompileStringObject(str, filename, start[compile_mode], &cf, optimize);
 
+#ifdef Py_GIL_DISABLED
+    interp->gc.immortalize.enable_on_thread_created = old_value;
+#endif
+
     Py_XDECREF(source_copy);
     goto finally;