On Fri, Sep 01, 2017 at 04:41:01PM +0100, David Howells wrote: > Implement functions that increment or decrement a refcount_t object and > return the value. The dec-and-ret function can be used to maintain a > counter in a cache where 1 means the object is unused, but available and > the garbage collector can use refcount_dec_if_one() to make the object > unavailable. Further, both functions can be used to accurately trace the > refcount (refcount_inc() followed by refcount_read() can't be considered > accurate). > > The interface is as follows: > > unsigned int refcount_dec_return(refcount_t *r); > unsigned int refcount_inc_return(refcount_t *r); > I'm not immediately seeing how wanting 1 to mean unused leads to requiring these two functions. If you'll remember, I did that for inode_count and only needed dec_unless().
