我试图在python服务器(第一台PC)和UWP客户端应用程序(第二台PC)之间创建一个TCP客户机/服务器程序。 我想模拟一个每10毫秒发送一条消息的快速python服务器和一个带有更新功能的较慢的UWP应用程序,更新功能必须显示每40毫秒接收的最后一条消息
为此,在UWP端,我创建了一个任务,该任务读取python发送的消息,将其保存在变量(this.message
)中,并打印它。Update
函数读取此变量,并每隔40ms打印一次(每次打印后等待40ms)
客户机/服务器交换工作正常,但我得到一个奇怪的行为。Update
函数有时会“阻塞”相同的值,请参见输出:
...
[Task] Message = 1105, Ts = 1626767660488
[Task] Message = 1106, Ts = 1626767660495
[Task] Message = 1107, Ts = 1626767660502
[Task] Message = 1108, Ts = 1626767660508
[Task] Message = 1109, Ts = 1626767660512
[Task] Message = 1110, Ts = 1626767660516
[Task] Message = 1111, Ts = 1626767660519
[Task] Message = 1112, Ts = 1626767660523
[Task] Message = 1113, Ts = 1626767660527
[Task] Message = 1114, Ts = 1626767660530
[Task] Message = 1115, Ts = 1626767660534
[Task] Message = 1116, Ts = 1626767660537
[Task] Message = 1117, Ts = 1626767660541
[Update] Message = 1107
[Task] Message = 1118, Ts = 1626767660546
[Task] Message = 1119, Ts = 1626767660551
[Task] Message = 1120, Ts = 1626767660554
[Task] Message = 1121, Ts = 1626767660558
[Task] Message = 1122, Ts = 1626767660562
[Update] Message = 1122
[Update] Message = 1122
[Task] Message = 1123, Ts = 1626767660693
[Task] Message = 1124, Ts = 1626767660697
[Task] Message = 1125, Ts = 1626767660701
[Task] Message = 1126, Ts = 1626767660705
[Task] Message = 1127, Ts = 1626767660708
[Task] Message = 1128, Ts = 1626767660712
[Task] Message = 1129, Ts = 1626767660716
[Task] Message = 1130, Ts = 1626767660720
[Task] Message = 1131, Ts = 1626767660724
[Task] Message = 1132, Ts = 1626767660727
[Task] Message = 1133, Ts = 1626767660731
[Task] Message = 1134, Ts = 1626767660735
[Task] Message = 1135, Ts = 1626767660739
[Task] Message = 1136, Ts = 1626767660742
[Task] Message = 1137, Ts = 1626767660746
[Update] Message = 1124
[Task] Message = 1138, Ts = 1626767660757
[Task] Message = 1139, Ts = 1626767660760
[Task] Message = 1140, Ts = 1626767660764
[Task] Message = 1141, Ts = 1626767660768
[Task] Message = 1142, Ts = 1626767660772
[Task] Message = 1143, Ts = 1626767660775
[Update] Message = 1143
[Task] Message = 1144, Ts = 1626767660834
[Task] Message = 1145, Ts = 1626767660841
[Task] Message = 1146, Ts = 1626767660848
[Task] Message = 1147, Ts = 1626767660856
[Task] Message = 1148, Ts = 1626767660862
[Task] Message = 1149, Ts = 1626767660869
[Task] Message = 1150, Ts = 1626767660875
...
Python端:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', 4444))
print("[SERVER TCP] Waiting connection ...")
sock.listen(1)
client_socket, address = sock.accept()
data = client_socket.recv(1024)
print(data)
print("[SERVER TCP] Connection done")
x = 0
while True:
x = x + 1
msg = f"{x}\n"
client_socket.send(msg.encode())
sys.stdout.write(msg)
time.sleep(0.01)
UWP应用程序端(MainPage.xaml.cs):
using System;
using System.IO;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
using System.Threading.Tasks;
using System.Diagnostics;
namespace ClientUWP
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
volatile String message;
Task T;
public MainPage()
{
this.InitializeComponent();
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
this.StartClient();
this.Update();
}
private async void StartClient()
{
try
{
var streamSocket = new Windows.Networking.Sockets.StreamSocket();
var hostName = new Windows.Networking.HostName("192.168.1.50");
string PortNumber = "4444";
string request = "Hello, World!";
await streamSocket.ConnectAsync(hostName, PortNumber);
using (Stream outputStream = streamSocket.OutputStream.AsStreamForWrite())
{
using (var streamWriter = new StreamWriter(outputStream))
{
await streamWriter.WriteLineAsync(request);
await streamWriter.FlushAsync();
}
}
T = Task.Run(() =>
{
using (Stream inputStream = streamSocket.InputStream.AsStreamForRead())
{
using (StreamReader streamReader = new StreamReader(inputStream))
{
while (true)
{
this.message = streamReader.ReadLine();
Debug.WriteLine("[Task] Message = : " + this.message);
}
}
}
});
}
catch (Exception ex)
{
Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
Debug.WriteLine(webErrorStatus.ToString());
}
}
private async void Update()
{
while (true)
{
Debug.WriteLine("[Update] Message = " + this.message);
await Task.Delay(40);
}
T.Wait();
}
}
}
你知道如何解决这个问题吗?谢谢
更新帖子:
当我在Task
中打印时间戳时,似乎Task
会冻结,直到Update
函数结束
根据Arya的回答,由于外部因素,几乎不可能保证两次操作之间的精确间隔。正如我在评论中提到的,您可以或多或少地定期触发对
message
的阅读,并避免阅读两次,如下所示(这是一个Console NET Framework应用程序;无需完全更改您所做的操作,我只是适应了非UWP应用程序):其输出如下所示:
您以固定的时间间隔获得
Timer
(以前的Update
)读取,并且没有重复。如果您需要更精确的间隔,那么它将变得更加棘手(请参见this answer)。但不确定您的场景是否需要这样做您的数据本质上是一个随机输出。影响输出的原因有很多,如网络延迟、CPU使用率。例如,如果您的网络延迟为160ms,则在这160ms期间,您的客户端无法接收消息,但您的更新方法将继续,这将导致连续出现四条更新消息
因此,我建议你不要把这两项任务分开,你可以在一项任务中完成。您可以计算消息编号,而不是使用
Task.Delay(40)
来确定何时打印更新消息,换句话说,您可以每40条消息打印一条更新消息相关问题 更多 >
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