rblockingdeque用法

rblockingdeque用法
rblockingdeque是一个线程安全的双向队列，支持在队列两端插入和删除元素，并且在队列为空时可以阻塞等待元素的到来。

rblockingdeque的使用方法如下：
1. 导入rblockingdeque模块
```
from collections import deque
from threading import RLock, Condition
class rblockingdeque:
def __init__(self):
self.deque = deque()
self.lock = RLock()
self.condition = Condition(self.lock)
```
2. 在队列两端插入和删除元素
```
def appendleft(self, item):
with self.lock:
self.deque.appendleft(item)
self.condition.notify()
def append(self, item):
with self.lock:
self.deque.append(item)
self.condition.notify()
def popleft(self):
with self.lock:
while not self.deque:
self.condition.wait()
return self.deque.popleft()
def pop(self):
with self.lock:
while not self.deque:
self.condition.wait()
return self.deque.pop()
```
3. 在队列为空时可以阻塞等待元素的到来 ```
def popleft(self):
with self.lock:
while not self.deque:
self.condition.wait()
return self.deque.popleft()
def pop(self):
with self.lock:
while not self.deque:
self.condition.wait()
return self.deque.pop()
```
以上就是rblockingdeque的使用方法。

需要注意的是，rblockingdeque采用了Condition条件变量来实现等待和通知的功能，这样可以避免线程占用过多的CPU资源。