Question

I want to parallelize some file-parsing actions with network activity in powershell. Quick google for it,
start-thread looked like a solution, but:

The term ‘start-thread’ is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

The same thing happened when I tried start-job.

I also tried fiddling around with System.Threading.Thread

[System.Reflection.Assembly]::LoadWithPartialName("System.Threading")
#This next errors, something about the arguments I can't figure out from the documentation of .NET
$tstart = new-object System.Threading.ThreadStart({DoSomething}) 
$thread = new-object System.Threading.Thread($tstart) 
$thread.Start()

So, I think the best would be to know what I do wrong when I use start-thread, because it seems to work for other people. I use v2.0 and I don’t need downward compatibility.

Answer 1

Powershell does not have a built-in command named Start-Thread.

V2.0 does, however, have PowerShell jobs, which can run in the background, and can be considered the equivalent of a thread. You have the following commands at your disposal for working with jobs:

Name                              Category  Synopsis
----                              --------  --------
Start-Job                         Cmdlet    Starts a Windows PowerShell background job.
Get-Job                           Cmdlet    Gets Windows PowerShell background jobs that are running in the current ...
Receive-Job                       Cmdlet    Gets the results of the Windows PowerShell background jobs in the curren...
Stop-Job                          Cmdlet    Stops a Windows PowerShell background job.
Wait-Job                          Cmdlet    Suppresses the command prompt until one or all of the Windows PowerShell...
Remove-Job                        Cmdlet    Deletes a Windows PowerShell background job.

Here is an example on how to work with it. To start a job, use start-job and pass a script block which contains the code you want run asynchronously:

$job  = start-job { get-childitem . -recurse }

This command will start a job, that gets all children under the current directory recursively, and you will be returned to the command line immediately.

You can examine the $job variable to see if the job has finished, etc. If you want to wait for a job to finish, use:

wait-job $job

Finally, to receive the results from a job, use:

receive-job $job