Messages in this thread |  | | Date | Wed, 1 Feb 2017 10:25:21 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 01/14] locking/atomic: import atomic_dec_not_zero() |
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On Tue, Jan 31, 2017 at 09:55:08PM +0100, Fabian Frederick wrote: > Once again it's just about readability:
I feel APIs should be about common use-cases, not about sporadic weird cases.
> "add -1 unless value is zero" looks more complex in code than "dec not zero" > but maybe it's just a matter of taste :) It it's not the case why would there be > more sense about having > atomic_inc_not_zero() globally ?
inc_not_zero() has a very strong use-case, its for lockless refcount increment. Incrementing a 0 reference count is bad because the object will be freed and you'll have a use-after-free.
Arguably, once we move reference counting over to its own type, it would make sense to remove it from atomic, specifically to discourage that use case.
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