ROS2 （python）构造服务端和客户端

本文主要是介绍ROS2 （python）构造服务端和客户端，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

要注意：服务端和客户端的名字要统一

什么是线程死锁

A需要等B把装满水的桶放下才能把水桶提走
B需要等A把水桶提走才能把自己的装满

假设A和B都要站在位置C工作
A：站在工位C将小桶水倒进大桶里
B：从C位置将装满水的大桶拎走
那么假设时刻D
B发现大桶里没有装满水因此在位置C等待水满
A发现B在位置C等待于是扛着自己的小水桶等B离开
造成死锁

客户端

import rclpy
from rclpy.node import Node
from std_msgs.msg import String
from village_interface.srv import BorrowMoneyclass BaiPiaoNode(Node):def __init__(self, name):super().__init__(name)self.get_logger().info("大家好，我是李三，李四他哥，我可以白嫖李四的小说！")self.sub_ = self.create_subscription(String,"sexy_gril",self.recv_callback,10)self.borrow_client = self.create_client(BorrowMoney,"borrow_money")def recv_callback(self, novel):self.get_logger().info("李三：我已经收到了：%s" % novel.data)def borrow_response_callback(self, response):"""借钱回调函数"""if response.success:self.get_logger().info("借到%d钱了，去吃麻辣烫" % response.money)else:self.get_logger().info("真抠门，连几块钱都不借")def main(args=None):rclpy.init(args=args)node = BaiPiaoNode("li3")rclpy.spin(node=node)rclpy.shutdown()

服务端

import rclpy
from rclpy.node import Node
from std_msgs.msg import String,UInt32
from village_interface.srv import BorrowMoneyclass WriterNode(Node):def __init__(self,name):super().__init__(name)self.get_logger().info('大家好，我是%s.' % name)# String 话题消息类型# "sexy_gril" 话题名# 10 话题发布类型# self.create_publisher(消息类型, 话题名, 发布频率)# 创建发布者self.pub_novel = self.create_publisher(String, "sexy_gril", 10)# self.create_subscription(消息类型,话题名,回调函数,队列长度)# 创建订阅者self.sub_money = self.create_subscription(UInt32,"sexy_gril_money",self.rev_money_callback,10)# 创建客户端self.borrow_server = self.create_service(BorrowMoney,"borrow_money",self.borrowmoney_callback)self.timer_period = 5self.timer = self.create_timer(self.timer_period,self.timer_callback)self.counter = 0self.count = 80# 创建服务端回调函数def borrowmoney_callback(self, request, response):"""request: 来自客户端的请求数据response：来自服务端的响应数据"""self.get_logger().info("收到来自：%s的请求，目前账户里有%d元"%(request.name,self.count))if request.money <= self.count * 0.1: response.success = Trueresponse.money = request.moneyself.count -= request.moneyself.get_logger().info("借钱成功，借出%d元，目前账户结余%d"%(request.money,self.count))else:response.success = Falseresponse.money = 0self.get_logger().info("借钱失败！！")return responsedef timer_callback(self):msg = String()msg.data = '第%d回:潋滟湖 %d 次偶遇胡艳娘' %(self.counter,self.counter)self.pub_novel.publish(msg=msg)self.get_logger().info("发布消息: %s" % msg.data)self.counter = self.counter + 1def rev_money_callback(self,money):self.count = self.count + money.dataself.get_logger().info("收到了%d的钱"%money.data)def hello(args=None):rclpy.init(args=args)li3_node = WriterNode("li4")rclpy.spin(li3_node)rclpy.shutdown()