Class ExceptionWrapper

torch/_utils.py:690–722

r"""Wraps an exception plus traceback to communicate across threads

class ExceptionWrapper:
    r"""Wraps an exception plus traceback to communicate across threads"""

    def __init__(self, exc_info=None, where="in background"):
        # It is important that we don't store exc_info, see
        # NOTE [ Python Traceback Reference Cycle Problem ]
        if exc_info is None:
            exc_info = sys.exc_info()
        self.exc_type = exc_info[0]
        self.exc_msg = "".join(traceback.format_exception(*exc_info))
        self.where = where

    def reraise(self):
        r"""Reraises the wrapped exception in the current thread"""
        # Format a message such as: "Caught ValueError in DataLoader worker
        # process 2. Original Traceback:", followed by the traceback.
        msg = f"Caught {self.exc_type.__name__} {self.where}.\nOriginal {self.exc_msg}"
        if self.exc_type == KeyError:
            # KeyError calls repr() on its argument (usually a dict key). This
            # makes stack traces unreadable. It will not be changed in Python
            # (https://bugs.python.org/issue2651), so we work around it.
            msg = KeyErrorMessage(msg)
        elif getattr(self.exc_type, "message", None):
            # Some exceptions have first argument as non-str but explicitly
            # have message field
            raise self.exc_type(message=msg)
        try:
            exception = self.exc_type(msg)
        except TypeError:
            # If the exception takes multiple arguments, don't try to
            # instantiate since we don't know how to
            raise RuntimeError(msg) from None
        raise exception


def _get_available_device_type():