Before I start this post, I’d like to point out that I am far, far from a programmer, and have very little, if any ‘real’ knowledge on this subject, so forgive my (lack of) ‘technical’ descriptions from now on!
After my previous post on Powershell scripting, I have been honing my skills and automating everything I can think of! – Building on the earlier example script I have been playing with Primal Forms from Sapien Technologies, building a pretty sweet GUI for the aforementioned script. This, however brought a previously unknown issue to my attention – threading. Now,again, I’m no programmer, I can’t code to save my life and to be honest have no intention in learning, but I know enough to get by. Powershell, as far as I can gather from various sources (namely this expert to expert podcast) Powershell is a single threaded application, in that all the building blocks for a given script are loaded into the Powershell engine together in a single thread & executed as such.
The reason I was prompted to look into threads within Powershell is whilst building the GUI for the automation script in the earlier post I hit some issues when calling external programs into the mix. The GUI would hang when an external program was running for a certain amount of time with no noticeable outcome (ie, it was waiting for something to complete) – I believe this is a Windows form issue really, within Powershell, however I have have varying success in defining my functions outside of the runspace that the GUI uses…
See this link for a better understanding.
Using this method however slightly overcomplicates the coding and for now I have left it as it was (with the addition of a status message on the GUI stating “Window may stop responding….” 
– It does the job and its not a production release.
To clarify, I believe there has been some extensive work with this on Powershell 2.0 as far as I can see from the CTP however I am still using 1.0 with this particular project and unfortunately have no upgrade path. I will be experimenting with the CTP and threading on a forthcoming project which I will talk about shortly.
Hi. I'm Matt Newham, 23 years old. I'm a network security engineer, specializing in Intrusion Detection.
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