给下列代码添加注释:def vision(): imgQueue = mp.Queue() # 先进先出队列,实现不同进程数据交互 Mps = []#存储进程对象的列表 Mps.append(mp.Process(target=imgRead, args=(imgQueue,))) [Mp.start() for Mp in Mps]#启动所有进程 # Mps[0].join() while imgQueue.empty(): pass while True: Key = input('Press Q or q to quit:') if Key == 'Q' or Key == 'q': break [Mp.terminate() for Mp in Mps]#终止所有进程 #torch.multiprocessing.set_start_method('spawn') if __name__ == '__main__': torch.multiprocessing.set_start_method('spawn') vision()
时间: 2024-04-08 14:33:22 浏览: 14
```python
def vision():
imgQueue = mp.Queue() # 创建一个先进先出队列,用于实现不同进程之间的数据交互
Mps = [] # 存储进程对象的列表
Mps.append(mp.Process(target=imgRead, args=(imgQueue,))) # 创建一个进程对象,目标函数为imgRead,传入参数为imgQueue
[Mp.start() for Mp in Mps] # 启动所有进程
while imgQueue.empty(): # 当队列为空时,循环等待
pass
while True:
Key = input('Press Q or q to quit:') # 获取用户输入的按键信息
if Key == 'Q' or Key == 'q': # 如果按键为Q或q,则跳出循环
break
[Mp.terminate() for Mp in Mps] # 终止所有进程
# torch.multiprocessing.set_start_method('spawn')
if __name__ == '__main__':
torch.multiprocessing.set_start_method('spawn')
vision()
```
相关问题
给下列代码添加注释:def reach_cb(msg): global reached reached = msg.data def socket_cb(msg): global color color = msg.data def nothing(x): pass def imgRead(imgQueue): # %% 从摄像头读取数据 # cam = cv2.VideoCapture(0) global old_angle cam = cv2.VideoCapture(gstreamer_pipeline(flip_method=0), cv2.CAP_GSTREAMER) if not cam.isOpened(): print("Unable to open camera") else: print('Open camera success!') sub_reached = rospy.Subscriber('/reached',Bool,reach_cb) done_pub = rospy.Publisher('/done',Bool,queue_size=10) sub_color = rospy.Subscriber('/detector_trafficlight', Bool, socket_cb) # true检测红色,false检测蓝色 cmd_vel_pub=rospy.Publisher('/ackermann_cmd',AckermannDrive,queue_size=10)
```python
# 定义一个回调函数,用于接收/reached话题的消息,并将消息数据保存到全局变量reached中
def reach_cb(msg):
global reached
reached = msg.data
# 定义一个回调函数,用于接收/detector_trafficlight话题的消息,并将消息数据保存到全局变量color中
def socket_cb(msg):
global color
color = msg.data
# 定义一个空函数,用于占位,不执行任何操作
def nothing(x):
pass
# 定义一个函数,用于从摄像头读取图像数据
def imgRead(imgQueue):
# 使用gstreamer_pipeline函数打开摄像头并获取摄像头对象cam
cam = cv2.VideoCapture(gstreamer_pipeline(flip_method=0), cv2.CAP_GSTREAMER)
# 判断摄像头是否成功打开
if not cam.isOpened():
print("Unable to open camera")
else:
print('Open camera success!')
# 创建一个订阅器,订阅/reached话题,当有新消息时,调用回调函数reach_cb处理消息
sub_reached = rospy.Subscriber('/reached', Bool, reach_cb)
# 创建一个发布器,用于向/done话题发布消息,消息类型为Bool,队列大小为10
done_pub = rospy.Publisher('/done', Bool, queue_size=10)
# 创建一个订阅器,订阅/detector_trafficlight话题,当有新消息时,调用回调函数socket_cb处理消息
sub_color = rospy.Subscriber('/detector_trafficlight', Bool, socket_cb) # true检测红色,false检测蓝色
# 创建一个发布器,用于向/ackermann_cmd话题发布消息,消息类型为AckermannDrive,队列大小为10
cmd_vel_pub = rospy.Publisher('/ackermann_cmd', AckermannDrive, queue_size=10)
```
import queueimport threadingfrom concurrent.futures import ThreadPoolExecutor, as_completedfrom threading import Eventdef push_data(data_queue: queue.Queue): while not stop_event.is_set(): data = "123" data_queue.put(data) stop_event.wait(0.5)def process_data(data): # 处理数据逻辑 print("Processing data:", data)if __name__ == '__main__': data_queue = queue.Queue() stop_event = Event() # 创建线程池 with ThreadPoolExecutor(max_workers=5) as executor: # 启动数据生产线程 t = threading.Thread(target=push_data, args=(data_queue,)) t.start() # 从队列中获取数据并处理 while not stop_event.is_set(): try: data = data_queue.get(timeout=1) except queue.Empty: continue # 提交任务到线程池 future = executor.submit(process_data, data) future.add_done_callback(lambda f: f.result()) # 关闭数据生产线程 stop_event.set() t.join() 代码优化,不要 Event
可以使用 `threading.Event` 代替 `queue.Queue` 来控制线程的结束。`threading.Event` 是一个线程同步的工具,可以让一个或多个线程等待某个事件的发生。具体地,可以创建一个 `Event` 对象,调用 `wait()` 方法等待事件的发生,调用 `set()` 方法通知事件的发生。
下面是一个使用 `Event` 改写后的代码:
```python
import queue
import threading
from concurrent.futures import ThreadPoolExecutor, as_completed
def push_data(data_list: list):
while data_list:
data = data_list.pop()
data_queue.put(data)
def process_data(data):
# 处理数据逻辑
print("Processing data:", data)
if __name__ == '__main__':
data_queue = queue.Queue()
data_list = ["123", "456", "789"]
# 创建线程池
with ThreadPoolExecutor(max_workers=5) as executor:
# 启动数据生产线程
t = threading.Thread(target=push_data, args=(data_list,))
t.start()
# 从队列中获取数据并处理
while True:
try:
data = data_queue.get(timeout=1)
except queue.Empty:
if not t.is_alive():
break
else:
continue
# 提交任务到线程池
future = executor.submit(process_data, data)
future.add_done_callback(lambda f: f.result())
t.join()
```
在这个代码中,我们将数据存储在一个普通的列表中,用一个专门的线程 `push_data` 来将数据逐一放入队列中。主线程不断从队列中获取数据并处理,如果队列为空并且 `push_data` 线程已经结束,则主线程也结束。这样就可以避免使用 `Event` 对象了。