Initialise synchronisation-related attributes in polymorphic method so each

class can do so as it requires.

Co-authored-by: Duprat <yduprat@gmail.com>

Author: duaneg

Lib/multiprocessing/popen_fork.py

@@ -18,9 +18,12 @@ def __init__(self, process_obj):
         util._flush_std_streams()
         self.returncode = None
         self.finalizer = None
+        self._init_locking()
+        self._launch(process_obj)
+
+    def _init_locking(self):
         self._exit_condition = threading.Condition()
         self._exit_blockers = 0
-        self._launch(process_obj)
 
     def duplicate_for_child(self, fd):
         return fd

Lib/multiprocessing/popen_forkserver.py

@@ -33,9 +33,11 @@ class Popen(popen_fork.Popen):
 
     def __init__(self, process_obj):
         self._fds = []
-        self._lock = threading.Lock()
         super().__init__(process_obj)
 
+    def _init_locking(self):
+        self._lock = threading.Lock()
+
     def duplicate_for_child(self, fd):
         self._fds.append(fd)
         return len(self._fds) - 1