Pool.py

from BasePool import BasePool
class TaskPool(BasePool):

    def __init__(self, *args, **kwargs):
        from gevent import spawn_raw
        from gevent.pool import Pool
        self.Pool = Pool
        super(TaskPool, self).__init__(*args, **kwargs)

    def on_start(self):
        self._pool = self.Pool(self.limit)
        self._quick_put = self._pool.spawn

    def on_stop(self):
        if self._pool is not None:
            self._pool.join()

    def on_apply(self, target, args=None):
        return self._quick_put(target, args)

    def resize(self, n=1):
        delta = self._pool.size - n
        if delta == 0:
            pass
        else: 
            try:
                self._pool.join(timeout = 1)
            except Exception:
                pass
            if delta > 0:
                self.shrink(delta)
            else:
                self.grow(delta)
            # self.grow(abs(delta))
            # self.shrink(delta)

    def grow(self, n=1):
        self._pool._semaphore.counter += n
        self._pool.size += n

    def shrink(self, n=1):
        self._pool._semaphore.counter -= n
        self._pool.size -= n

    @property
    def num_processes(self):
        return len(self._pool)