ismohamed
asked on
Threading in Vb.Net 2008
Hi Experts,
I hav a problem with threads.
I have a function which reads data from a Multicast group. All this data is gathered in some buffers. I then need to access the buffer through another function. Once the buffer is accesed, I need to empty those buffers. The Thread is just reading data all the time and putting it into a buffer. I have tried to pause the thread but with no luck.
What / how would be the best way? I have attached some of the code.
I hav a problem with threads.
I have a function which reads data from a Multicast group. All this data is gathered in some buffers. I then need to access the buffer through another function. Once the buffer is accesed, I need to empty those buffers. The Thread is just reading data all the time and putting it into a buffer. I have tried to pause the thread but with no luck.
What / how would be the best way? I have attached some of the code.
Public Sub StartReadThread()
m_thread = New Thread(AddressOf ReadData)
m_thread.IsBackground = True
m_thread.Start()
End Sub
Private Shared Sub ReadData()
'Do something to recieve data into some Buffer(s)
End Sub
Public function GetBuffer(mydata() as byte) as byte
dim myBuf as byte()
myBuf = myReadBuf
redim myReadBuf(0)
return myBuf
end funtion
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ASKER
Hi Idle,
Just to be sure, the code you attached, in the GetBuffer you still mean to refer to MySync and not MyLock right? I do not see you declaring MyLock anywhere, that is why I am asking.
Forget above comment, i had some code error regarding the DLL, but still in Delphi I cannot get it to sync and in VB.net I can when using my DLL
Just to be sure, the code you attached, in the GetBuffer you still mean to refer to MySync and not MyLock right? I do not see you declaring MyLock anywhere, that is why I am asking.
Forget above comment, i had some code error regarding the DLL, but still in Delphi I cannot get it to sync and in VB.net I can when using my DLL
Yes...sorry. There's a typo in there (serious pitfall of coding in the browser).
ASKER
Idle mind,
Ok I have narrowed down the error. Is there anyway I can safely handle the thread in Getbuffer. The reason I am asking is that when I start the thread in my DLL, at some poin the Delphi code comes up with a runtime error. This has definately something to do with the Thread. The SyncLock, I assume is some sort of a pause. Is there anything else I can do to ensure that the thread is not ongoing?
I get a runtime error 7c812aebin Delphi.
Ok I have narrowed down the error. Is there anyway I can safely handle the thread in Getbuffer. The reason I am asking is that when I start the thread in my DLL, at some poin the Delphi code comes up with a runtime error. This has definately something to do with the Thread. The SyncLock, I assume is some sort of a pause. Is there anything else I can do to ensure that the thread is not ongoing?
I get a runtime error 7c812aebin Delphi.
In lieu of SyncLock, I think you could setup some boolean flags that you manually toggle and check in your loop/functions...
ASKER
Idle mind,
SyncLock worked as I previously said perfectly and you have been awarded the points.
The problem I was running into was when I was running the code as a DLL and using the DLL in Delphi, I got a runtime error. I tried to add the boolean flags (also before posting the code), with no help.
I ended up changing the GetBuffer function to a procedure instead as this is what was causing the runtime error in Delphi and my DLL. I guess Delphi does not like functions and threads too well.
SyncLock worked as I previously said perfectly and you have been awarded the points.
The problem I was running into was when I was running the code as a DLL and using the DLL in Delphi, I got a runtime error. I tried to add the boolean flags (also before posting the code), with no help.
I ended up changing the GetBuffer function to a procedure instead as this is what was causing the runtime error in Delphi and my DLL. I guess Delphi does not like functions and threads too well.
ASKER
I think the above solution worked and I am going to award you the points, thank you for that.
But, what I have done is the above code is running in a DLL. This DLL is used in a Delphi project. Whenever I call the GetBuffer Function from the Delphi Application the application halts. If I run the dll in a VB.NET project everything is fine. Any suggestions?