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"""This sub-module contains various rebinning and pre-processing engines
defined at the Python level. 
"""

__author__ = "Jerome Kieffer"
__contact__ = "Jerome.Kieffer@ESRF.eu"
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"
__date__ = "16/10/2020"
__status__ = "development"

import logging
logger = logging.getLogger(__name__)
from threading import Semaphore


class Engine(object):
    """This class defines a regrid-engine with its locking mechanism"""

    def __init__(self, engine=None):
        """Constructor of the class"""
        self.lock = Semaphore()
        self.engine = engine

    def reset(self):
        with self.lock:
            self.engine = None

    def set_engine(self, engine):
        "should be called from a locked region"
        self.engine = engine