#encoding = utf8

import threading
from queue import Queue


class SyncQueue:
    def __init__(self, maxsize):
        self._queue = Queue(maxsize)
        self._condition = threading.Condition()

    def put(self, item):
        with self._condition:
            while self._queue.full():
                self._condition.wait()
            self._queue.put(item)
            self._condition.notify()

    def get(self):
        with self._condition:
            while self._queue.empty():
                self._condition.wait()
            item = self._queue.get()
            self._condition.notify()
            return item

    def clear(self):
        with self._condition:
            while not self._queue.empty():
                self._queue.get()
                self._queue.task_done()
            self._condition.notify_all()

    def size(self):
        return self._queue.qsize()