User Extensions, TCB Extension area, and TCBs in general

[Wu, Mark H.]

Thank you very much!

It looks like there is some special handling for the task switch extension (which makes sense, because you want it to be fast). But the others are executed in order of creation? In that case, I can never override the built-in fatal handler (if I ever want it enabled)?

-----Original Message-----
From: Sebastian Huber [mailto:sebastian.huber at embedded-brains.de] 
Sent: Saturday, June 13, 2015 00:01
To: Wu, Mark H.
Cc: users at rtems.org
Subject: RE: User Extensions, TCB Extension area, and TCBs in general

The extensions are added and not replaced by rtems_extension_create().  It seems we have to clarify the documentation.

----- Wu, Mark H. <Mark.H.Wu at disney.com> schrieb:
> Sorry to revive an old thread, but I have a question that may solve my confusion here. When I call rtems_extension_create(), does this add or replace the current extension set? My interpretation from the documentation was that it replaced the set, but looking through some of the source code, it appears that it might actually add to the set? So if I add stack bounds checking, I don't actually have to worry about re-adding it to any new extension sets? If that's the case, then it fully addresses all of my concerns!
> 
> It looks like the order of calling the extensions is in the order they were created. Is that correct?