# SPDX-FileCopyrightText: Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: LicenseRef-NvidiaProprietary
#
# NVIDIA CORPORATION, its affiliates and licensors retain all intellectual
# property and proprietary rights in and to this material, related
# documentation and any modifications thereto. Any use, reproduction,
# disclosure or distribution of this material and related documentation
# without an express license agreement from NVIDIA CORPORATION or
# its affiliates is strictly prohibited.

"""This package is responsible for defining data thread and work queue.

Data thread is a daemon thread that plays the role of a consumer. It will
consume the works (provided by the data center) in the work queue.
"""

from queue import Queue
from threading import Event, Thread

class WorkQueue(Queue):
    def __init__(self):
        super().__init__(maxsize=0)
        self.consumable = Event()

    def add_work(self, work):
        self.put(work)
        self.consumable.set()

class DataThread(Thread):
    def __init__(self, work_queue):
        Thread.__init__(self)
        self.work_queue = work_queue

    def run(self):
        while True:
            self.work_queue.consumable.wait()
            if not self.work_queue.empty():
                work = self.work_queue.get()
                work()  # start working
                self.work_queue.task_done()

            if self.work_queue.empty():
                self.work_queue.consumable.clear()

# Instantiate singletons
work_queue = WorkQueue()
data_thread = DataThread(work_queue)
data_thread.daemon = True
data_thread.start()