fix: code didn't fill the request of the exercise

Chapter-2/Socket-Programming-Assignment-2/UDPHeartbeatClient.py

@@ -2,11 +2,18 @@
 from socket import *
 import time
 serverName = '127.0.0.1'
-serverPort = 12000
+serverPort = 12001
 clientSocket = socket(AF_INET, SOCK_DGRAM)
-while True:
-    time1 = time.time()
-    outputdata = 'Heartbeat ' + str(time1)
-    clientSocket.sendto(outputdata.encode(), (serverName, serverPort))
-    time.sleep(10)
 
+sequence_number = 0;# 序列号
+while True:
+    try:
+        time1 = time.time()
+        outputdata =  f'Heartbeat {sequence_number} {time1}'
+        clientSocket.sendto(outputdata.encode(), (serverName, serverPort))
+        sequence_number+=1
+        time.sleep(10)
+    except KeyboardInterrupt:
+        print("Heartbeat Client is closed")
+        break
+clientSocket.close()

Chapter-2/Socket-Programming-Assignment-2/UDPHeartbeatServer.py

@@ -1,18 +1,55 @@
-#改为Python3格式
-# UDPPingerServer.py
-# We will need the following module to generate randomized lost packets
-import time
 from socket import *
+import time
+import threading
+
+def check_clients():
+    """定期检查客户端状态的线程函数"""
+    while True:
+        try:
+            current_time = time.time()
+            # 检查所有客户端状态
+            for client_address, last_seen in list(client_last_seen.items()):
+                if current_time - last_seen > 30:  # 如果超过30秒没收到心跳
+                    print(f"客户端 {client_address} maybe已断开")
+                    del client_last_seen[client_address]
+            time.sleep(1)  # 每秒检查一次
+        except:
+            break
 
-# Create a UDP socket
-# Notice the use of SOCK_DGRAM for UDP packets
+# 创建服务器socket
+serverPort = 12001
 serverSocket = socket(AF_INET, SOCK_DGRAM)
-# Assign IP address and port number to socket
-serverSocket.bind(('', 12000))
+serverSocket.bind(('', serverPort))
+
+client_last_seen = {}  # 记录每个客户端最后一次心跳的时间
+print(f"服务器启动，监听端口 {serverPort}...")
+
+# 启动检查线程
+check_thread = threading.Thread(target=check_clients)
+check_thread.daemon = True  # 设置为守护线程，这样主程序退出时线程也会退出
+check_thread.start()
 
 while True:
-    message, address = serverSocket.recvfrom(1024)
-    message = message.decode()
-    message = message.split()[1]
-    timeDiff = time.time() - float(message)
-    print("receive RTT:", timeDiff)
+    try:
+        message, address = serverSocket.recvfrom(1024)
+        current_time = time.time()
+        message = message.decode()
+
+        # 解析消息
+        _, sequence_number, send_time = message.split()
+        send_time = float(send_time)
+
+        # 计算延迟时间
+        delay = current_time - send_time
+
+        # 更新客户端最后一次心跳时间
+        client_last_seen[address] = current_time
+
+        print(f"收到来自 {address} 的心跳包 #{sequence_number}, 延迟: {delay:.3f}秒")
+
+    except KeyboardInterrupt:
+        print("\n服务器停止运行")
+        serverSocket.close()
+        break
+    except Exception as e:
+        print(f"发生错误: {e}")