# encoding: ascii
# api: powershell
# title: Start-ScriptThreading
# description: Ever wanted to start some threads on a block of code but hated the headache of creating, watching, and collecting job data? This is my attempt to put a bandaid on that issue.
# version: 0.1
# type: function
# author: Kenneth W Hightower JR
# license: CC0
# function: Start-ScriptThreading
# x-poshcode-id: 5757
# x-derived-from-id: 5758
# x-archived: 2015-03-23T20:55:45
# x-published: 2015-02-25T18:11:00
#
# There are some assumptions made in this function, such as assuming you are threading to talk to a bunch of computers. Also assuming you only have one parameter to pass into your custom scriptblock, as well as assuming that the computer is a parameter for your scriptblock.
# I hope you enjoy this nugget as I return to my retirement on Gallifrey…
#
function Start-ScriptThreading{
<#
.SYNOPSIS
Runs a scriptblock against multiple computers simultaneously
.DESCRIPTION
The ThreadedFunction function takes an array (usually a list of computers) and a scriptblock. The scriptblock will be run against
each item in the array expecting each item of the array to also be a parameter expected in the scriptblock.
.PARAMETER arComputers
List of computers to run scriptblock against.
.PARAMETER ScriptBlock
Block of script to run against list from parameter -Computers
.PARAMETER maxThreads
Maximum number of threads to run at a time
.PARAMETER SleepTimer
Time to wait between loops. This is a spacing timer to prevent the main loop from hogging cpu time.
A smaller number may create and check for jobs faster.
A large number will allow the separate threads more cpu time.
Any longer than 1000 milliseconds may render the progress indicator incorectly.
(default is 500 milliseconds)
.PARAMETER MaxWaitAtEnd
Sets a timeout for threads before killing jobs. This timer is started after the last thread is created.
(default is 180 seconds)
.NOTES
Name: ThreadedScript
Author: Kenneth W Hightower JR (The13thDoctor)
DateCreated: 11Feb2015
DateModified: 25Feb2015
To load this function into the current shell for use, or to use this file seperate from your main script,
dot-source as follows '. .\ThreadedFunction.ps1'
.EXAMPLE
ThreadedScript -Computers 'server01', 'server02' -ScriptBlock {ping $Computer}
The command 'ping' is threaded and ran against both server01 and server02. Declaring $Computer is required as is.
.EXAMPLE
'server01', 'server02' | ThreadedScript -ScriptBlock {Get-WMIObject win32_computersystem -ComputerName $Computer}
Pipes the array as Computers and gets the Win32_ComputerSystem WMI object from server01 and server02 simultaneously.
.INPUTS
System.String. Function will accept an array of strings and assume each as a parameter for the provided scriptblock.
.OUTPUTS
System.Object. All returned data from each iteration that the scriptblock may create is returned as a single array.
#>
param(
[parameter(Mandatory=$true,ValueFromPipeline=$true)]
[string[]]$arComputers,
[parameter(Mandatory=$true,ValueFromPipeline=$false)]
[scriptblock]$ScriptBlock,
[parameter(Mandatory=$false)]
[int]$maxThreads = 30,
[parameter(Mandatory=$false)]
[int]$SleepTimer = 500,
[parameter(Mandatory=$false)]
[int]$MaxWaitAtEnd = 180
)
BEGIN{
Write-Verbose "Initializing..."
$return = @()
$StartTime= Get-Date
#Create working scriptblock
$Script = [ScriptBlock]::Create( @"
param(`$Computer)
&{ $ScriptBlock } @PSBoundParameters
"@ )
$Computers = @()
}
PROCESS{
foreach($Computer in $arComputers){
$Computers += $Computer #Yes, this will flatten multi-dimentional arrays...
}
}
#when you pipeline to this function the begin section is called once, then for each item in the pipeline the entire process block is called.
#In order to collect all items in the pipeline so that everything passed in can be threaded simultaneously as intended, we handle the threading at the end.
#Otherwise each item will get threaded and collected before the next item is threaded.
END{
#Start Making Jobs
Write-Verbose "creating threads..."
Foreach($Computer in $Computers){
#Check for running threads
while ($(Get-Job -State Running | measure-object).count -ge $maxThreads){
write-host "$((Get-Job -State Running | measure-object).count) threads running, please wait..."
start-sleep -s 3
} # End while ($(Get-Job -State Running
Write-Verbose "starting $($Computer)"
Start-Job -name $Computer -scriptblock $Script -ArgumentList $Computer
#Pretty progress indicator
$ComputersStillRunning = ""
ForEach ($System in $(Get-Job -state running)){
$ComputersStillRunning += ", $($System.name)"
}
$ComputersStillRunning = $ComputersStillRunning.TrimStart(", ")
Write-Progress -Activity "Creating Jobs" `
-Status "$($(Get-Job -State Running).count) threads running..." `
-CurrentOperation "$ComputersStillRunning" `
-PercentComplete ($(Get-Job -State Completed).count / $(Get-Job).count * 100)
#Check for completed Jobs. Depending on number of jobs, we might as well collect data as we go.
ForEach($Job in $(Get-Job -State Completed)){
If($Job.HasMoreData -eq "True"){
Write-Verbose "Job $($Job.Id) finished early"
$Data = Receive-Job $Job
$Return+=$Data
}#end if($job.hasmoredata...
}#end foreach($Job...
}#end Foreach($Computer in...
#Done creating jobs.
Write-Verbose "Waiting for final threads..."
$Complete = Get-date
#Wait for the last created jobs to finish
#Following loop gets skipped if pipeline is used to pass $Computers
While ($(Get-Job -State Running | measure-object).count -gt 0){
#random information for progress screen
$ComputersStillRunning = ""
$TimeDiff = New-TimeSpan $StartTime $(Get-Date)
[string]$strTimingStatus = "{0} minutes, {1} seconds so far" -f $TimeDiff.Minutes, $TimeDiff.Seconds
ForEach ($System in $(Get-Job -state running)){
$ComputersStillRunning += ", $($System.name)"
}
$ComputersStillRunning = $ComputersStillRunning.TrimStart(", ")
Write-Progress -Activity "Waiting for completion..." `
-Status "$($(Get-Job -State Running).count) threads remaining: $strTimingStatus" `
-CurrentOperation "$ComputersStillRunning" `
-PercentComplete ($(Get-Job -State Completed).count / $(Get-Job).count * 100)
#Collecting jobs as we wait
ForEach($Job in $(Get-Job -State Completed)){
If($Job.HasMoreData -eq "True"){
Write-Verbose "Job $($Job.Id) just completed"
$Data = Receive-Job $Job
$return+=$Data
}#end if($job.hasmoredata
}#end foreach($Job
#Done waiting. Threads most likely hung up on something, throw them away.
If ($(New-TimeSpan $Complete $(Get-Date)).totalseconds -ge $MaxWaitAtEnd){
Write-Verbose "Killing all jobs still running, tired of waiting..."
Get-Job -State Running | Remove-Job -Force
}
#Lets not bog the CPU with lightning speed looping
Start-Sleep -Milliseconds $SleepTimer
}
#Final cleaning, just in case....
ForEach($Job in $(Get-Job -State Completed)){
If($Job.HasMoreData -eq "True"){
Write-Verbose "Job $($Job.Id) completed late"
$Data = Receive-Job $Job
$return+=$Data
}#end if($job.hasmoredata
}#end foreach($Job
Write-Verbose "Cleaning up threads"
Get-Job | Remove-Job -Force | Out-Null
#All this data needs to go somewhere....
return $return
}
}#end function ThreadedScript