1 files changed, 14 insertions, 1 deletions
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 86328e46a7b..3808ecdceb9 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -1578,6 +1578,8 @@ _io_TextIOWrapper_detach_impl(textio *self)
 static int
 _textiowrapper_writeflush(textio *self)
 {
+    _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
+
     if (self->pending_bytes == NULL)
         return 0;
 
@@ -3173,8 +3175,9 @@ _io_TextIOWrapper_close_impl(textio *self)
 }
 
 static PyObject *
-textiowrapper_iternext(PyObject *op)
+textiowrapper_iternext_lock_held(PyObject *op)
 {
+    _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op);
     PyObject *line;
     textio *self = textio_CAST(op);
 
@@ -3210,6 +3213,16 @@ textiowrapper_iternext(PyObject *op)
     return line;
 }
 
+static PyObject *
+textiowrapper_iternext(PyObject *op)
+{
+    PyObject *result;
+    Py_BEGIN_CRITICAL_SECTION(op);
+    result = textiowrapper_iternext_lock_held(op);
+    Py_END_CRITICAL_SECTION();
+    return result;
+}
+
 /*[clinic input]
 @critical_section
 @getter