Using the synchronized decorator

from threading import RLock
from wrapt import synchronized  # https://stackoverflow.com/a/29403915

# These locks are for our synchronized decorator
_WATCHDOG_LOCK = RLock()

    @synchronized(_WATCHDOG_LOCK)
    def watchdog(self):
        self.log.debug("watchdog called")
        
    def activate(self):
            self.start_poller(150, self.watchdog, None)