code: def all_gather_v2(
      t,
      group_size,
      group_key,
      instance_key,
      communication_hint="auto",
      timeout=0,
      ordering_token=None,
      name=None,
  ):
      """Accumulates tensors collectively, across devices, along first dimension.
  
      Args:
        t: the tensor to participate in the accumulation.
        group_size: an int32 tensor, the total number of tensors to be collectively
          accumulated. Each must reside on a different device. Should be a positive
          integer.
        group_key: an int32 tensor identifying the group of devices.
        instance_key: an int32 tensor identifying the participating group of Ops.
        communication_hint: preferred collective communication. The implementation
          may fall back to another mechanism. Options include `auto`, `ring`, and
          `nccl`.
        timeout: a float. If set to a non zero, set a completion timeout to detect
          staleness. If the timer goes off, a DeadlineExceededError is raised. The
          timeout value in seconds. This feature is experimental.
        ordering_token: a resource tensor on the same device as the op to order
          the collectives in a per-device manner by auto control dependency.
          This argument can be omited when there is one collective Op per
          `tf.function`, or when explicit control dependency is used instead of
          auto control dependency.
        name: name of the Op.
  
      Returns:
        An Op implementing the distributed operation.
      """
      if ordering_token is not None:
          ordering_token = [ordering_token]
      else:
          ordering_token = []
  
      return gen_collective_ops.collective_gather_v2(
          t,
          group_size=group_size,
          group_key=group_key,
          instance_key=instance_key,
          communication_hint=communication_hint.lower(),
          timeout_seconds=timeout,
          is_stateless=False,
          ordering_token=ordering_token,
          name=name,
      )
  
file_path: tensorflow-upstream/tensorflow/python/ops/collective_ops.py
imports: from tensorflow.python.ops import gen_collective_ops
label_desc: Use image node_id 5 for calling a global function with example usage: all_gather_v2(t, group_size, group_key, instance_key, communication_hint, timeout, ordering_token, name) and returns: gen_collective_ops