Source code for platform_driver.driver_locks

# -*- coding: utf-8 -*- {{{
# ===----------------------------------------------------------------------===
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#                 Component of Eclipse VOLTTRON
#
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#
# Copyright 2023 Battelle Memorial Institute
#
# 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
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# 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
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from gevent.lock import BoundedSemaphore, DummySemaphore
from contextlib import contextmanager

_socket_lock = None

[docs]def configure_socket_lock(max_connections=0):
    global _socket_lock
    if _socket_lock is not None:
        raise RuntimeError("socket_lock already configured!")
    if max_connections < 1:
        _socket_lock = DummySemaphore()
    else:
        _socket_lock = BoundedSemaphore(max_connections)

[docs]@contextmanager
def socket_lock():
    global _socket_lock
    if _socket_lock is None:
        raise RuntimeError("socket_lock not configured!")
    _socket_lock.acquire()
    try:
        yield
    finally:
        _socket_lock.release()

_publish_lock = None

[docs]def configure_publish_lock(max_connections=0):
    global _publish_lock
    if _publish_lock is not None:
        raise RuntimeError("socket_lock already configured!")
    if max_connections < 1:
        _publish_lock = DummySemaphore()
    else:
        _publish_lock = BoundedSemaphore(max_connections)

[docs]@contextmanager
def publish_lock():
    global _publish_lock
    if _publish_lock is None:
        raise RuntimeError("socket_lock not configured!")
    _publish_lock.acquire()
    try:
        yield
    finally:
        _publish_lock.release()