Re: [Libguestfs] [libnbd PATCH] lib: Consolidate free callbacks to just happen at retire time

On Wed, Aug 14, 2019 at 05:38:31PM -0500, Eric Blake wrote: > When we introduced valid_flags, there was an incentive to do as few > callbacks as possible, favoring cb(VALID|FREE) calls over the sequence > cb(VALID);cb(FREE). To make it work, we set .callback=NULL after an > early free, so that the later check during retirement didn't free > again. > > But now that our .free callback is distinct from our other callbacks, > there is no longer an advantage to bundling things, and a significant > reduction in lines of code by just doing it in one place. This > basically reverts 9c8fccdf (which had slightly-questionable C > type-punning anyway) and 57150880. I didn't see this one before implementing an alternate version here: https://www.redhat.com/archives/libguestfs/2019-August/msg00251.html https://www.redhat.com/archives/libguestfs/2019-August/msg00253.html They're fairly similar, but I didn't get rid of the FREE_CALLBACK macro for reasons which are clearer later in the series.