With the concept of approximate counters in mind, let's try to implement the data structure in Python, building on our previous design for the lock-based counter. Consider the following Chapter16/example4.py file—specifically, the LockedCounter class and the ApproximateCounter class:
# Chapter16/example4.pyimport threadingimport timeclass LockedCounter: def __init__(self): self.value = 0 self.lock = threading.Lock() def increment(self, x): with self.lock: new_value = self.value + x time.sleep(0.001) # creating a delay self.value = new_value def get_value(self): with self.lock: value = self.value return valueclass ApproximateCounter: def __init__(self, global_counter): self.value = 0 self.lock = ...
