82 lines
2.4 KiB
Python
82 lines
2.4 KiB
Python
|
#!/usr/bin/env python
|
|||
|
|
# -*- coding: utf-8 -*-
|
|||
|
|
|
|||
|
|
"""
|
|||
|
|
一个适用于MicroPython的、简单的线程安全队列实现。
|
|||
|
|
|
|||
|
|
这个模块提供了一个与标准库 `queue.Queue` 类似的类，
|
|||
|
|
确保在多线程环境下的数据操作是安全的。
|
|||
|
|
"""
|
|||
|
|
|
|||
|
|
import _thread
|
|||
|
|
from collections import deque
|
|||
|
|
|
|||
|
|
class Queue:
|
|||
|
|
"""一个简单的、线程安全的队列。"""
|
|||
|
|
|
|||
|
|
def __init__(self, maxsize=0):
|
|||
|
|
self.maxsize = maxsize
|
|||
|
|
self._lock = _thread.allocate_lock()
|
|||
|
|
# 使用deque可以实现更高效的头部弹出操作 (O(1))
|
|||
|
|
self._items = deque((), maxsize if maxsize > 0 else 1024)
|
|||
|
|
|
|||
|
|
def qsize(self):
|
|||
|
|
"""返回队列中的项目数。"""
|
|||
|
|
with self._lock:
|
|||
|
|
return len(self._items)
|
|||
|
|
|
|||
|
|
def empty(self):
|
|||
|
|
"""如果队列为空，返回True，否则返回False。"""
|
|||
|
|
return self.qsize() == 0
|
|||
|
|
|
|||
|
|
def full(self):
|
|||
|
|
"""如果队列已满，返回True，否则返回False。"""
|
|||
|
|
if self.maxsize <= 0:
|
|||
|
|
return False
|
|||
|
|
return self.qsize() >= self.maxsize
|
|||
|
|
|
|||
|
|
def put(self, item, block=True, timeout=None):
|
|||
|
|
"""将一个项目放入队列。"""
|
|||
|
|
if not block:
|
|||
|
|
return self.put_nowait(item)
|
|||
|
|
|
|||
|
|
# 阻塞式put的简单实现 (在实际应用中更复杂的实现会使用信号量)
|
|||
|
|
while True:
|
|||
|
|
with self._lock:
|
|||
|
|
if not self.full():
|
|||
|
|
self._items.append(item)
|
|||
|
|
return
|
|||
|
|
# 如果队列是满的，短暂休眠后重试
|
|||
|
|
import time
|
|||
|
|
time.sleep_ms(5)
|
|||
|
|
|
|||
|
|
def put_nowait(self, item):
|
|||
|
|
"""等同于 put(item, block=False)。"""
|
|||
|
|
if self.full():
|
|||
|
|
raise OSError("Queue full")
|
|||
|
|
|
|||
|
|
with self._lock:
|
|||
|
|
self._items.append(item)
|
|||
|
|
|
|||
|
|
def get(self, block=True, timeout=None):
|
|||
|
|
"""从队列中移除并返回一个项目。"""
|
|||
|
|
if not block:
|
|||
|
|
return self.get_nowait()
|
|||
|
|
|
|||
|
|
# 阻塞式get的简单实现
|
|||
|
|
while True:
|
|||
|
|
with self._lock:
|
|||
|
|
if self._items:
|
|||
|
|
return self._items.popleft()
|
|||
|
|
# 如果队列是空的，短暂休眠后重试
|
|||
|
|
import time
|
|||
|
|
time.sleep_ms(5)
|
|||
|
|
|
|||
|
|
def get_nowait(self):
|
|||
|
|
"""等同于 get(item, block=False)。"""
|
|||
|
|
if self.empty():
|
|||
|
|
raise OSError("Queue empty")
|
|||
|
|
|
|||
|
|
with self._lock:
|
|||
|
|
return self._items.popleft()
|