fix drain

Author: kumaraditya303

Lib/asyncio/base_events.py

@@ -1295,8 +1295,8 @@ async def _sendfile_fallback(self, transp, file, offset, count):
                 read = await self.run_in_executor(None, file.readinto, view)
                 if not read:
                     return total_sent  # EOF
-                await proto.drain()
                 transp.write(view[:read])
+                await proto.drain()
                 total_sent += read
         finally:
             if total_sent > 0 and hasattr(file, 'seek'):

Tools/tsan/suppressions_free_threading.txt

@@ -13,9 +13,11 @@
 # These warnings trigger directly in a CPython function.
 
 race_top:assign_version_tag
+race_top:_multiprocessing_SemLock_acquire_impl
 race_top:_Py_slot_tp_getattr_hook
 race_top:dump_traceback
 race_top:fatal_error
+race_top:_multiprocessing_SemLock_release_impl
 race_top:_PyFrame_GetCode
 race_top:_PyFrame_Initialize
 race_top:_PyObject_TryGetInstanceAttribute