Question

现在我正在开发一个工具，可以让我测量使用VB6和带有以太网屏蔽的arduino UNO的网络连接之间的延迟。现在我面临服务器代码（VB6程序）的一些问题。我有2个不同端口的winsocks，他们都在监听arduino客户端连接。现在，如果我只有一个活动连接没有出错，一切正常，但只要第二个客户端连接整个服务器就开始变得疯狂。突然它报告连接的第一个客户端丢失了连接，所以简而言之，服务器不希望一次连接2个客户端，但我确实需要它：/出了什么问题？

我将快速解释通过winsock发送到服务器或从服务器发送的确定命令。

"SERVER_SLEEP" Is a command that the server sends to all clients that will tell them to enter a power saving mode. "SERVER_REQUESTS_DATA" Is a command that the server sends to a specific client and forces the client to send information like Device name and firmware version. "RESPOND_MESSAGE" Is a command that the server sends to all clients and the client is forced to respond to see if we still have an connection. "DEVICE_NAME=" Is a command that the client sends to the server when it just connects, It is required before we show that we have an connection by putting it into the listbox. (after the = comes the device name) "DEVICE_NAME_REP=" Is a command that the client sends to the server when the server requests information about the client, the reason i have 2 of them is because i couldn't reuse the previous one since then it would become way to complicated. (after the = comes the device name) "DEVICE_FIRMWARE=" Is a command that the client sends to the server when the server requests information about the client. (after the = comes the device firmware version) "DEVICE_OK=" Is a command that the client sends to the server when the server requests an answer to check if we still have an connection. (after the = comes the device name) "DEVICE_REBOOTING" Is a command that the client sends to the server when it goes out of sleep mode (it goes out of that mode when the server comes back online again after it was closed) After the client send that message it immediately closes the connection again and the device is forced to reboot to make sure nothing goes wrong.

我的代码：

Dim DeviceIP1 As String
Dim DeviceIP2 As String
Dim UpdateListStatus As Integer

Private Sub Command1_Click()
MsgBox Socket1.State
MsgBox Socket2.State
End Sub

Private Sub Command3_Click()
If Dir(App.Path & "\TH.exe") <> "" Then 'Traceroute Helper application i wrote before, Works 100% and is not relevant for the issue i am facing
Shell App.Path & "\TH.exe " & DeviceIP, vbNormalFocus
Else
MsgBox "Missing file!" & vbNewLine & "File TH.exe is required for the requested operation!", vbCritical + vbSystemModal, "Missing file"
End If
End Sub

Private Sub Form_Load()
Socket1.Listen
Socket2.Listen
End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
Dim msg As VbMsgBoxResult
msg = MsgBox("Are you sure you want to exit?" & vbNewLine & "All the clients will be put into sleep mode.", vbYesNo + vbQuestion + vbSystemModal, "Quit")
If msg = vbYes Then
  Form3.Show
  Cancel = True
  Form1.Visible = False
Else
  Cancel = True
End If
End Sub

Private Sub List1_Click()
On Error GoTo errhandler
Dim ClientFound As Boolean
DeviceIP = Mid(List1.Text, InStr(List1.Text, "-") + 1)
DeviceIP = LTrim(DeviceIP)
DeviceIPLabel.Caption = "Device IP: " & DeviceIP
Form2.Show
    If Socket1.RemoteHostIP = DeviceIP Then
    Socket1.SendData ("SERVER_REQUESTS_DATA")
    ElseIf Socket2.RemoteHostIP = DeviceIP Then
    Socket2.SendData ("SERVER_REQUESTS_DATA")
    End If
Exit Sub
errhandler:
If Err.Number = 40006 Then
MsgBox "Socket error!" & vbNewLine & "The requested device might be offline.", vbCritical + vbSystemModal, "Socket error"
Unload Form2
End If
End Sub

Private Sub UpdateList_Timer()
On Error Resume Next
If List1.ListCount > 0 Then
If UpdateListStatus = 0 Then
TempList.Clear

Socket1.SendData ("RESPOND_MESSAGE")
Socket2.SendData ("RESPOND_MESSAGE")

UpdateListStatus = 1
UpdateList.Interval = 5000
ElseIf UpdateListStatus = 1 Then
List1.Clear
For x = 0 To TempList.ListCount
List1.AddItem (TempList.List(x))
Next x

For X2 = 0 To List1.ListCount
If List1.List(X2) = "" Then 'Check if we have any items that are nothing
List1.RemoveItem (X2)
End If
Next X2

Label1.Caption = "Connected clients: " & List1.ListCount
UpdateListStatus = 0
UpdateList.Interval = 10000
End If
End If
End Sub

Private Sub Socket1_DataArrival(ByVal bytesTotal As Long)
On Error Resume Next
Dim TempString As String
Dim TempString2 As String
Dim position As Integer

Socket1.GetData TempString, vbString
    position = InStr(1, TempString, "DEVICE_NAME=")
    If position > 0 Then 'It is a device name command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       List1.AddItem (TempString2 + " - " + Socket1.RemoteHostIP)
       Label1.Caption = "Connected clients: " & List1.ListCount
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_NAME_REP=")
    If position > 0 Then 'It is a device name command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       DeviceNameLabel.Caption = "Device name: " & TempString2
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_FIRMWARE=")
    If position > 0 Then 'It is a device firmware command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       DeviceFirmwareLabel.Caption = "Firmware version: " & TempString2
       Unload Form2 'Since this is the last piece we will be receiving we can close this window
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_OK=")
    If position > 0 Then 'It is a device respond command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       TempList.AddItem (TempString2 + " - " + Socket1.RemoteHostIP)
       Label1.Caption = "Connected clients: " & List1.ListCount
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_REBOOTING")
    If position > 0 Then 'It is a device respond command from a client
       Socket1.Close
       TempString2 = ""
    End If
Text1.Text = Text1.Text & TempString & vbNewLine
TempString = ""
position = 0
TempString2 = ""
End Sub

Private Sub Socket2_DataArrival(ByVal bytesTotal As Long)
On Error Resume Next
Dim TempString As String
Dim TempString2 As String
Dim position As Integer

Socket2.GetData TempString, vbString
    position = InStr(1, TempString, "DEVICE_NAME=")
    If position > 0 Then 'It is a device name command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       List1.AddItem (TempString2 + " - " + Socket2.RemoteHostIP)
       Label1.Caption = "Connected clients: " & List1.ListCount
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_NAME_REP=")
    If position > 0 Then 'It is a device name command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       DeviceNameLabel.Caption = "Device name: " & TempString2
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_FIRMWARE=")
    If position > 0 Then 'It is a device firmware command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       DeviceFirmwareLabel.Caption = "Firmware version: " & TempString2
       Unload Form2 'Since this is the last piece we will be receiving we can close this window
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_OK=")
    If position > 0 Then 'It is a device respond command from a client
       TempString2 = Mid(TempString, InStr(TempString, "=") + 1)
       TempList.AddItem (TempString2 + " - " + Socket2.RemoteHostIP)
       Label1.Caption = "Connected clients: " & List1.ListCount
       TempString2 = ""
    End If
    position = 0
    position = InStr(1, TempString, "DEVICE_REBOOTING")
    If position > 0 Then 'It is a device respond command from a client
       Socket2.Close
       TempString2 = ""
    End If
Text1.Text = Text1.Text & TempString & vbNewLine
TempString = ""
position = 0
TempString2 = ""
End Sub


Private Sub Socket1_ConnectionRequest(ByVal requestID As Long)
If Socket1.State <> sckClosed Then
    Socket1.Close
    ' Accept the request with the requestID
    ' parameter.
    Socket1.Accept requestID
End If
End Sub

Private Sub Socket2_ConnectionRequest(ByVal requestID As Long)
If Socket2.State <> sckClosed Then
    Socket2.Close
    Socket2.Accept requestID 'Allow the connection
End If
End Sub

`

Answer 1

有很多内容需要深入研究（你可能想尝试创建问题的MCVE只是为了让你自己的调试变得更容易），但乍一看这些ConnectionRequest事件处理程序似乎是可疑的对我来说。 Winsock Control ConnectionRequest Event documentation说“使用Accept方法（在新控件实例上）接受传入连接。”你试图以某种方式使用相同的控制实例，这可能是一种方法，但不是标准的方法。

如果内存服务（自从我处理了这个问题以来一直存在），你想在运行时创建一个Control Array Winsock控件和load一个新实例来处理每个新连接（并在连接完成时卸载它）。 “监听”控制和“处理当前连接”控制需要是不同的实例。这样，每个实例都使用自己的状态处理自己的连接，并且侦听器可用于处理任何新的传入连接。

Answer 2

好的，所以我能够为多客户端服务器找到一个非常好的示例代码而且我还能够发现我创建的超时延迟太短了所以这就是它从列表中消失的原因。有时需要10秒钟才能收到响应，超时时间设置为仅5秒MAX。但仍然感谢您试图帮助我：）

示例代码的链接：LINK

VB6 winsock服务器和多个arduino客户端问题

2 个答案: