pytorch RuntimeError: already started

在visual studio code 中调试pytorch代码（debug）跳出错误 RuntimeError: already started

跑的是pytorch官方例子

当单步执行到

inputs, classes = next(iter(dataloaders['train']))

时候出错，错误提示如下

E00012.128: Exception escaped from start_client

            Traceback (most recent call last):
              File "/home/zeng/.vscode/extensions/ms-python.python-2019.3.6215/pythonFiles/lib/python/ptvsd/log.py", line 110, in g
                return f(*args, **kwargs)
              File "/home/zeng/.vscode/extensions/ms-python.python-2019.3.6215/pythonFiles/lib/python/ptvsd/pydevd_hooks.py", line 74, in start_client
                sock, start_session = daemon.start_client((host, port))
              File "/home/zeng/.vscode/extensions/ms-python.python-2019.3.6215/pythonFiles/lib/python/ptvsd/daemon.py", line 214, in start_client
                with self.started():
              File "/home/zeng/anaconda3/lib/python3.6/contextlib.py", line 81, in __enter__
                return next(self.gen)
              File "/home/zeng/.vscode/extensions/ms-python.python-2019.3.6215/pythonFiles/lib/python/ptvsd/daemon.py", line 110, in started
                self.start()
              File "/home/zeng/.vscode/extensions/ms-python.python-2019.3.6215/pythonFiles/lib/python/ptvsd/daemon.py", line 145, in start
                raise RuntimeError('already started')
            RuntimeError: already started

请教这是什么情况呀？

问题解决，应该是visual studio code的问题，换一个IDE就ok

https://blog.csdn.net/qq_31136635/article/details/80192125

试试：

import multiprocessing
multiprocessing.set_start_method('spawn',True)

如果你的工程是基于pytorch的，那么检查自己的dataLoader，是否使用了num_workers参数。当使用该参数时，可能会报上述错误。解决办法是将num_workers设置为0