src/lerobot/utils/queue.py

#!/usr/bin/env python

# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from queue import Empty
from typing import Any

from torch.multiprocessing import Queue


def get_last_item_from_queue(queue: Queue, block=True, timeout: float = 0.1) -> Any:
    if block:
        try:
            item = queue.get(timeout=timeout)
        except Empty:
            return None
    else:
        item = None

    # Drain queue and keep only the most recent parameters
    try:
        while True:
            item = queue.get_nowait()
    except Empty:
        pass

    return item