__init__.py 文件源码

def reduce(tensor, dst, op=reduce_op.SUM, group=group.WORLD):
    """Reduces the tensor data across all machines.

    Only the process with rank ``dst`` is going to receive the final result.

    Arguments:
        tensor (Tensor): Input and output of the collective. The function
            operates in-place.
        dst (int): Destination rank
        op (optional): One of the values from ``torch.distributed.reduce_op``
            enum.  Specifies an operation used for element-wise reductions.
        group (optional): Group of the collective.
    """
    assert torch.distributed._initialized == _INITIALIZED_PG, \
        "collective only supported in process-group mode"
    return torch._C._dist_reduce(tensor, dst, op, group)