__init__.py 文件源码

def init_process_group(backend):
    global _initialized
    if _initialized:
        raise RuntimeError("trying to initialize torch.distributed twice!")
    torch._C._dist_init_process_group(backend)
    _initialized = True
    import torch.distributed.collectives as collectives
    extend_scope(collectives)
    assert torch._C._dist_init_extension(False, reduce_op, group)