[RESOLVED] Return value from threads

[Thildemar]

I have an application that will ping all IP's on a subnet each on a seperate thread. This works great, except I can not get results from all of those threads. I would like any thread that gets a vaid ping responce to save the IP it pinged in an array, but if I have The threads try and write to an array they all attempt to acces about at the same time and no data gets written. What is the best way to obtain a list of output for each thread in a thread array when they are all running the same procedure at the same time? If i am not clear enough let me know and I will post some code =)

[jmcilhinney]

I strongly suggest that you follow the Articles -> Advanced .NET link in my signature and read the Managed Threading section. Synchronising threads is one of the most fundamental tasks when using multiple threads.

[Thildemar]

Thats a lot of good info, but where it ultimately got me is use the synclock function, which i tried with no luck at all.

Public Class MainClass
    Private Threads(256) As Threading.Thread
    Private PingObjects(256) As PingClass
    Private Sub MySub()
        For I As Integer = 0 To 255
            PingObjects(I) = New PingClass
            Threads(I) = New Threading.Thread(AddressOf PingObjects(I).collect)
            Threads(I).IsBackground = True
            Threads(I).Start()
        Next
    End Sub
End Class
Public Class PingClass
    Public Sub collect()
'Ping Ips on subnet
'if IP is valid
form1.listbox1.items.add(IP) 'DOES NOT WRITE even with synclock block around it
 
    End Sub
End Class

How can I get sync lock to work appropriately for this (I have looked over its articles and tried to duplicate their examples several ways with no luck...)

[Thildemar]

Ok I found a solution in case anyone else has this issue this worked quite well:

Public Class MainClass
    Private Threads(256) As Threading.Thread
    Private PingObjects(256) As PingClass
    Private Sub MySub()
 
        For I As Integer = 0 To 255
            PingObjects(I) = New PingClass
            Threads(I) = New Threading.Thread(AddressOf PingObjects(I).collect)
            Threads(I).IsBackground = True
            Threads(I).Start()
        Next
for I as integer = 0 to 255
threads(i).join
if Threads(i).ip <> "" then
   listbox1.items.add(threads(i).ip)
end if
next
 
    End Sub
End Class
Public Class PingClass
public ip as string
    Public Sub collect()
'Ping Ips on subnet
'if IP is valid
ip = [VALID IP]
    End Sub
End Class