diff --git a/Lib/multiprocessing/process.py b/Lib/multiprocessing/process.py index ce4ce43cfca6fb..8e500dc93dc6bd 100644 --- a/Lib/multiprocessing/process.py +++ b/Lib/multiprocessing/process.py @@ -148,10 +148,16 @@ def is_alive(self): if self is _current_process: return True assert self._parent_pid == os.getpid(), 'can only test a child process' + if self._popen is None: return False - self._popen.poll() - return self._popen.returncode is None + + returncode = self._popen.poll() + if returncode is None: + return True + else: + _children.discard(self) + return False def close(self): '''