>Could you expand on why caching per display was not robust?
I agree with Didier that caching per display is not robust, since differently configured X servers can potentially occupy the same display over time. However, the current implementation is simply broken - this really needs to be fixed.
I also did some (very) quick tests on cached vs uncached runs of unity_support_test, and the difference was extremely negligable. Unless I'm missing something, removing the cache completely should be very little work, and also fix the fallback behaviour.
>Could you expand on why caching per display was not robust?
I agree with Didier that caching per display is not robust, since differently configured X servers can potentially occupy the same display over time. However, the current implementation is simply broken - this really needs to be fixed.
I also did some (very) quick tests on cached vs uncached runs of unity_support_test, and the difference was extremely negligable. Unless I'm missing something, removing the cache completely should be very little work, and also fix the fallback behaviour.