Powershell runspaces won't execute - multithreading

Question

I'm at a bit of a loss with the script I am trying to pull.
In short: I want to scan my domain-computers for WinRM connectivity - and I can do that just fine. The problem is, that it takes up to 5 minutes to finish - thats why I want to multithread the task.
Working NON MULTITHREAD code:
# this is normaly a textfile with lots of machine hostnames
$computers = "PC100","PC106","PC124","PC115","PC21"
function checkMachine($computers){
$ErrorActionPreference = "Stop"
foreach ($item in $computers){
#the function contest only performs a ping and returne $true or $false
$connection = ConTest($item)
if($connection){
try{
$winRM = test-wsman -ComputerName $item
if($winRM){
write-host "winRM"
[void] $objListboxLeft.Items.Add($item)
}
}catch{
write-host "NO winRM"
[void] $objListboxCenter.Items.Add($item)
}
}else{
write-host "offline"
[void] $objListboxRight.Items.Add($item)
}
}
}
this is basically just a small portion of what my skript does/will do but it's the part that takes ages.
My failing runspace test - I basically fail to get ANY results at all. Nothing in textboxes, no output on my commandline and I basically have no idea what I am doing wrong.
Multithread code:
function MulticheckMachine($computers){
$ErrorActionPreference = "Stop"
$runspaceCollection = #()
$runspacePool = [RunspaceFactory]::CreateRunspacePool(1,5)
$runspacePool.open()
$scriptBlock = {
Param($item)
$connection = ConTest($item)
if($connection){
try{
test-wsman -ComputerName $item
$winRM = test-wsman -ComputerName $item
if($winRM){
write-host "winRM"
[void] $objListboxLeft.Items.Add($item)
}
}catch{
write-host "NO winRM"
[void] $objListboxCenter.Items.Add($item)
}
}else{
write-host "offline"
[void] $objListboxRight.Items.Add($item)
}
}
Foreach($item in $computers){
$powershell = [PowerShell]::Create().AddScript($scriptBlock).AddArgument($item)
$powershell.runspacePool = $runspacePool
[Collections.Arraylist]$runspaceCollection += New-Object -TypeName PSObject -Property #{
Runspace = $powershell.BeginInvoke()
PowerShell = $powershell
}
$runspaceCollection
}
While($runspaceCollection){
Foreach($runspace in $runspaceCollection.ToArray()){
If($runspace.Runspace.IsCompleted){
$runspace.PowerShell.EndInvoke($runspace.Runspace)
$runspace.PowerShell.Dispose()
$runspaceCollection.Remove($runspace)
}
}
}
}
the runspace code comes from a mix of these guides:
http://blogs.technet.com/b/heyscriptingguy/archive/2013/09/29/weekend-scripter-max-out-powershell-in-a-little-bit-of-time-part-2.aspx
http://newsqlblog.com/2012/05/22/concurrency-in-powershell-multi-threading-with-runspaces/
I hope someone can help me out and tell me where/why I fail. Thanks!

Answer 1

Well, thanks for the hints but the problem was far more basic.
I was trying to get my data at the wrong position. Also, I simplified my script a bit. I don't call functions in functions anymore.
Note1: I did not realize I can/need to work with return values within my scriptblock for the runspace.
Note2: I am now collecting my data and inserting it into my listboxes (or where-ever else I wanted to) at the end of my function within the while loop - where I basically build-back my runspaces.
Note3: All "GUI parts" I reference to are located in a different file and do exist!
I got the duration down to roughly 20 seconds (from almost 5 minutes before)
The number of threads I use is a bit random, it's one of the combinations that works fastest.
Code:
function multiCheckMachine($computers){
$ErrorActionPreference = "Stop"
$runspaceCollection = #()
$runspacePool = [RunspaceFactory]::CreateRunspacePool(1,50)
$runspacePool.open()
$scriptBlock = {
Param($item)
$FQDNitem = "$item.domain.com"
$address = nslookup $FQDNitem
if($address -like "addresses*"){
$address = $address[5] -replace ".* ",""
}else{
$address = $address[4] -replace ".* ",""
}
$con = ping -n 1 $address
if($con[2] -like "*Bytes*"){
$winRM = test-wsman -ComputerName $item
if($winRM){
return "$item.winRM"
}else{
return "$item.NOremote"
}
}else{
return "$item.offline"
}
}
Foreach($item in $computers){
$powershell = [PowerShell]::Create().AddScript($scriptBlock).AddArgument($item)
$powershell.runspacePool = $runspacePool
[Collections.Arraylist]$runspaceCollection += New-Object -TypeName PSObject -Property #{
Runspace = $powershell.BeginInvoke()
PowerShell = $powershell
}
}
While($runspaceCollection){
Foreach($runspace in $runspaceCollection.ToArray()){
If($runspace.Runspace.IsCompleted){
if($runspace.PowerShell.EndInvoke($runspace.Runspace) -like "*winrm"){
[void] $objListboxOnline.Items.Add($runspace.PowerShell.EndInvoke($runspace.Runspace).split(".")[0])
}elseif($runspace.PowerShell.EndInvoke($runspace.Runspace) -like "*NOremote"){
[void] $objListboxNoWinRM.Items.Add($runspace.PowerShell.EndInvoke($runspace.Runspace).split(".")[0])
}elseif($runspace.PowerShell.EndInvoke($runspace.Runspace) -like "*offline"){
[void] $objListboxOffline.Items.Add($runspace.PowerShell.EndInvoke($runspace.Runspace).split(".")[0])
}
$runspace.PowerShell.Dispose()
$runspaceCollection.Remove($runspace)
}
}
}
}