On Thu, Oct 19, 2017 at 12:07:58PM -0700, Christopher Collins wrote: > On Fri, Oct 13, 2017 at 10:18:14AM -0700, Christopher Collins wrote: > > * Because this is an API change, it would be best to introduce it > > slowly. The `BLE_GAP_CONN_CANCEL` event would be marked deprecated in > > the next release, and then removed entirely in the one after that. > > After some discussion in the pull request page > (https://github.com/apache/mynewt-core/pull/632), I'm not sure it makes > sense to try to slowly "phase out" this behavior. Since this change > represents a change in behavior, rather than the removal of > functionality, I don't think there is a good way to deprecate it. The > two basic options are: > > 1. Keep deprecated symbols in the code base, but stop using them. Apps > will continue to build without errors, but any app relying on the old > behavior will silently break. > > 2. Remove unused symbols. This may introduce build errors for some > apps, but at least there is no silent breakage. > > We could also try some hybrid approach, e.g., send both types of GAP > events when a connection is cancelled. However, I think this would do > more harm than good (and probably introduce some new bugs!). > > The release policy document's section on backwards compatibility > (https://cwiki.apache.org/confluence/display/MYNEWT/Release+and+Support+Policy#ReleaseandSupportPolicy-BackwardsCompatibility) > is pretty clear - if an API change has the potential to break builds, > deprecate the old behavior for at least six months before removing it. > I think this text needs some additional language for changes such as > this one that can't be reasonably phased in.
I propose we add the following text to the release policy: Sometimes it is impossible or impractical to retain a deprecated version of an API alongside the new one. For example, a change to a callback function's type, such as the addition of a new parameter, is difficult to introduce while still maintaining the old API. For these types of changes, the `deprecated` state can be bypassed. Such changes must be voted on by the community before they are implemented. If there are no objections, I will make this addition to the wiki. Thanks, Chris