import time
import threading


class GlobalClock:
    """
    Deterministic monotonic event clock.
    Used for replay + ordering across distributed nodes.
    """

    _lock = threading.Lock()
    _counter = 0

    @classmethod
    def tick(cls) -> float:
        with cls._lock:
            cls._counter += 1
            return time.time() + (cls._counter * 1e-9)

    @classmethod
    def reset(cls):
        with cls._lock:
            cls._counter = 0