Hello FAW Canada,
Well, first you would have to consider at what stage you are right now in the application process. If you anticipate that the Visa Office responsible for processing your papers would require a new set of documents to be sent, then I would suggest trying to obtain one from now. The Saudi Police Clearance usually does not have a validity date written on it unlike the ones like from the Philippines where a set validity date is shown on each PCC ('Valid for 1 year', for example). That being said, you would not have an issue with it if you try to obtain one now. It's important that you try to apply for it from now so as to be familiar with the process itself while you're there in Bahrain.
However, based from what I read previously, and I'm not sure if rules have changed as of now as they frequently do, Saudi Arabia does not issue PCC for individuals who are already not living and/or working in the Kingdom. Consequently, the Canadian Visa Offices are aware of such and according to some cases they waived the need for a Saudi PCC in such circumstances.
I will also try to ask about the application for a PCC by an individual who no longer works or lives in the Kingdom.