Thank you.
In my original program what I would like to do is the following:
I have a TCP component in the main program and it is connected to an IP
address where it gets data.
As it receives data, I would like to send that data right away to all the
clients connected to the main program.
Each client connection is a thread (session class).
I found that the client is missing some data that the main program sends.
Therefore, in the main program, I check to see if
the Message member has been cleared before changing its value, that way I
know it has been written by the session thread.
So, if a thread hasn't written its data to the client yet, move on to the
next thread and then go back and check again on those threads that we skip
in the previous pass.
To simplify the program, I wrote a simple program using a timer (instead of
receiving data from a TCP component), and every milisecond it sets the
Message variable from the session class.
This is the complete code from the simplyfied program:
'****************Main program*************************
Imports System.Threading
Private Structure SessionInfo
Dim Session As SessionClass
Dim Thread As Threading.Thread
End Structure
Private Client(0) As SessionInfo
Private LastClient As Integer
Private m_cnt As Long
Public Function RegisterClient(ByRef Session As SessionClass, ByRef Thread
As Threading.Thread) As Boolean
Dim nIndex As Integer
Dim nMaxClients As Integer
RegisterClient = False
nMaxClients = Val(MaxClients.Text)
Monitor.Enter(Client)
For nIndex = 0 To LastClient - 1
If Client(nIndex).Session Is Nothing Then
Client(nIndex).Session = Session
Client(nIndex).Thread = Thread
RegisterClient = True
Monitor.Exit(Client)
Exit Function
End If
Next
ReDim Preserve Client(LastClient)
Client(LastClient).Session = Session
Client(LastClient).Thread = Thread
LastClient = LastClient + 1
RegisterClient = True
Monitor.Exit(Client)
End Function
Public Function UnregisterClient(ByRef Session As SessionClass) As Boolean
Dim nIndex As Integer
UnregisterClient = False
Monitor.Enter(Client)
For nIndex = 0 To LastClient - 1
If Client(nIndex).Session Is Session Then
Client(nIndex).Session = Nothing
Client(nIndex).Thread = Nothing
UnregisterClient = True
Exit For
End If
Next
Monitor.Exit(Client)
End Function
Private Sub TestButton_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles TestButton.Click
Dim oSession As SessionClass
Dim oThread As Threading.Thread
Static nSession As Long
nSession = nSession + 1
oSession = New SessionClass
oSession.Server = Me
oThread = New Threading.Thread(AddressOf oSession.ThreadMain)
oThread.ApartmentState = ApartmentState.STA
oThread.Name = "Session" & CLng(nSession)
oThread.Start()
Timer1.Enabled = True
End Sub
Sub Test()
Dim arr() As Long
Dim lMax As Long
Dim bLoop As Boolean
Dim x As Long
Dim nIndex As Integer
Monitor.Enter(Client)
For nIndex = 0 To LastClient - 1
If Not Client(nIndex).Session Is Nothing Then
If Client(nIndex).Session.Message = "" Then
Client(nIndex).Session.Message = m_cnt
Else
lMax = lMax + 1
ReDim Preserve arr(lMax)
arr(lMax) = nIndex
End If
End If
Next
If lMax > 0 Then bLoop = True Else bLoop = False
'--------------------------------------->>>>>the following takes up to 100%
CPU<<<<<<-------------------------------------------------------
Do While bLoop
bLoop = False
For x = 1 To lMax
nIndex = arr(x)
If nIndex > -1 Then
If Not Client(nIndex).Session Is Nothing Then
If Client(nIndex).Session.Message = "" Then
Client(nIndex).Session.Message = m_cnt
arr(x) = -1
Else
bLoop = True
End If
End If
End If
Next
Loop
Monitor.Exit(Client)
End Sub
'---------------------------------------
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Timer1.Tick
m_cnt = m_cnt + 1
Test()
End Sub
'*************Session.vb********************
Imports System.Threading
Public Class SessionClass
Public Server As ServerForm
Public Message As String
Private Terminated As Boolean
Public Sub ThreadMain()
Dim nThreadId As Integer
Dim strThreadName As String
Dim strBuffer As String
Dim nResult As Integer
Dim sw As StreamWriter
If Server.RegisterClient(Me, Thread.CurrentThread()) = False Then
Exit Sub
End If
Do While Not Terminated
If Len(Me.Message) > 0 Then
Me.Message = ""
End If
Loop
Server.UnregisterClient(Me)
Exit Sub
End Sub
Public Sub Terminate()
Terminated = True
End Sub
"Patrice" <sc****@chez.com> wrote in message
news:O1**************@TK2MSFTNGP05.phx.gbl...
What are you trying to do ? I don't see where Client(nIndex).Session is
initialized (I just see oSession being inialized). IMO you are stuck in a
tight loop so...
--
"fniles" <fn****@pfmail.com> a écrit dans le message de news:
ez**************@TK2MSFTNGP05.phx.gbl...I am having problem with thread. I have a Session class with public string
variable (called Message) that I set from my Main program. In the session
class it checks for the value of Message while inside it's "read loop"
waiting for data from the client. In the main program, I check to see if
the Message member has been cleared before changing its value, that way
you know it has been written by the
session thread. The idea would be that if a thread hasn't written its
data to the client yet, move on to the next thread and then go back and
check again on those threads that we're ready in the previous pass.
But, by doing this, the CPU usage is 100%.
Is there any way to do this without driving CPU usage to 100% ?
Thanks a lot.
'****************Main program*************************
Imports System.Threading
Private Structure SessionInfo
Dim Session As SessionClass
Dim Thread As Threading.Thread
End Structure
Private Client(0) As SessionInfo
Private LastClient As Integer
Private m_cnt As Long
Private Sub TestButton_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles TestButton.Click
Dim oSession As SessionClass
Dim oThread As Threading.Thread
Static nSession As Long
nSession = nSession + 1
oSession = New SessionClass
oSession.Server = Me
oThread = New Threading.Thread(AddressOf oSession.ThreadMain)
oThread.ApartmentState = ApartmentState.STA
oThread.Name = "Session" & CLng(nSession)
oThread.Start()
Timer1.Enabled = True
End Sub
Sub Test()
Dim arr() As Long
Dim lMax As Long
Dim bLoop As Boolean
Dim x As Long
Dim nIndex As Integer
Monitor.Enter(Client)
For nIndex = 0 To LastClient - 1
If Not Client(nIndex).Session Is Nothing Then
If Client(nIndex).Session.Message = "" Then
Client(nIndex).Session.Message = m_cnt
Else
lMax = lMax + 1
ReDim Preserve arr(lMax)
arr(lMax) = nIndex
End If
End If
Next
If lMax > 0 Then bLoop = True Else bLoop = False
'--------------------------------------->>>>>the following takes up to
100% CPU<<<<<<--------------------------------------------------------
Do While bLoop
bLoop = False
For x = 1 To lMax
nIndex = arr(x)
If nIndex > -1 Then
If Not Client(nIndex).Session Is Nothing Then
If Client(nIndex).Session.Message = "" Then
Client(nIndex).Session.Message = m_cnt
arr(x) = -1
Else
bLoop = True
End If
End If
End If
Next
Loop
Monitor.Exit(Client)
End Sub
'---------------------------------------
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Timer1.Tick
m_cnt = m_cnt + 1
Test()
End Sub
'*************Session.vb********************
Imports System.Threading
Public Class SessionClass
Public Server As ServerForm
Public Message As String
Private Terminated As Boolean
Public Sub ThreadMain()
Dim nThreadId As Integer
Dim strThreadName As String
Dim strBuffer As String
Dim nResult As Integer
Dim sw As StreamWriter
If Server.RegisterClient(Me, Thread.CurrentThread()) = False Then
Exit Sub
End If
Do While Not Terminated
If Len(Me.Message) > 0 Then
Me.Message = ""
End If
Loop
Server.UnregisterClient(Me)
Exit Sub
End Sub
Public Sub Terminate()
Terminated = True
End Sub
