# `Vllm.Distributed.DeviceCommunicatorBase`
[🔗](https://github.com/nshkrdotcom/vllm/blob/v0.3.0/lib/snakebridge_generated/vllm/distributed/device_communicator_base.ex#L7)

Base class for device-specific communicator.

It can use the `cpu_group` to initialize the communicator.
If the device has PyTorch integration (PyTorch can recognize its
communication backend), the `device_group` will also be given.

# `t`

```elixir
@opaque t()
```

# `all_gather`

```elixir
@spec all_gather(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.all_gather`.

## Parameters

- `input_` (term())
- `dim` (integer() default: -1)

## Returns

- `term()`

# `all_gatherv`

```elixir
@spec all_gatherv(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.all_gatherv`.

## Parameters

- `input_` (term())
- `dim` (integer() default: 0)
- `sizes` (term() default: None)

## Returns

- `term()`

# `all_reduce`

```elixir
@spec all_reduce(SnakeBridge.Ref.t(), term(), keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.all_reduce`.

## Parameters

- `input_` (term())

## Returns

- `term()`

# `combine`

```elixir
@spec combine(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Combine the hidden states and router logits from the appropriate device.

This is a no-op in the base class.

## Parameters

- `hidden_states` (term())
- `is_sequence_parallel` (boolean() default: False)

## Returns

- `term()`

# `destroy`

```elixir
@spec destroy(
  SnakeBridge.Ref.t(),
  keyword()
) :: {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.destroy`.

## Returns

- `term()`

# `dispatch`

```elixir
@spec dispatch(SnakeBridge.Ref.t(), term(), term(), [term()], keyword()) ::
  {:ok, {term(), term()}} | {:error, Snakepit.Error.t()}
```

Dispatch the hidden states and router logits to the appropriate device.

This is a no-op in the base class.

## Parameters

- `hidden_states` (term())
- `router_logits` (term())
- `is_sequence_parallel` (boolean() default: False)
- `extra_tensors` (term() default: None)

## Returns

- `{term(), term()}`

# `gather`

```elixir
@spec gather(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

NOTE: We assume that the input tensor is on the same device across

all the ranks.
NOTE: `dst` is the local rank of the destination rank.

## Parameters

- `input_` (term())
- `dst` (integer() default: 0)
- `dim` (integer() default: -1)

## Returns

- `term()`

# `new`

```elixir
@spec new(term(), [term()], keyword()) ::
  {:ok, SnakeBridge.Ref.t()} | {:error, Snakepit.Error.t()}
```

Initialize self.  See help(type(self)) for accurate signature.

## Parameters

- `cpu_group` (term())
- `device` (term() default: None)
- `device_group` (term() default: None)
- `unique_name` (String.t() default: '')

# `prepare_communication_buffer_for_model`

```elixir
@spec prepare_communication_buffer_for_model(SnakeBridge.Ref.t(), term(), keyword()) ::
  {:ok, nil} | {:error, Snakepit.Error.t()}
```

Prepare the communication buffer for the model.

## Parameters

- `model` (term())

## Returns

- `nil`

# `recv`

```elixir
@spec recv(SnakeBridge.Ref.t(), term(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Receives a tensor from the source rank.

## Parameters

- `size` (term())
- `dtype` (term())
- `src` (term() default: None)

## Returns

- `term()`

# `reduce_scatter`

```elixir
@spec reduce_scatter(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.reduce_scatter`.

## Parameters

- `input_` (term())
- `dim` (integer() default: -1)

## Returns

- `term()`

# `reduce_scatterv`

```elixir
@spec reduce_scatterv(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, term()} | {:error, Snakepit.Error.t()}
```

Python method `DeviceCommunicatorBase.reduce_scatterv`.

## Parameters

- `input_` (term())
- `dim` (integer() default: -1)
- `sizes` (term() default: None)

## Returns

- `term()`

# `send`

```elixir
@spec send(SnakeBridge.Ref.t(), term(), [term()], keyword()) ::
  {:ok, nil} | {:error, Snakepit.Error.t()}
```

Sends a tensor to the destination rank in a blocking way

## Parameters

- `tensor` (term())
- `dst` (term() default: None)

## Returns

- `nil`

---

*Consult [api-reference.md](api-reference.md) for complete listing*