def __init__(self, size=1000):
        self.size = size
        self.coroutines_running = set()
        self.sem = semaphore.Semaphore(size)
        self.no_coros_running = event.Event()
:param size: maximum number of active greenlets
dataset/ETHPy150Open veegee/guv/guv/greenpool.py/GreenPool.__init__