Some of that might just be sloppy development but I have a feeling that part of it's the SDK's fault. It's a weird mix of being too abstract to let you take tight control of performance but not abstract enough that I ever felt confident it was doing a reasonable job of taking care of that for me. Though maybe I'm wrong and that part's fine, I don't think I ever benchmarked power use (another thing: the tooling is about as mediocre as you'd expect for a proprietary platform like that)
I tell you what, though: having a declarative UI where "declarative" is "now draw text at coords [some coords]. Then draw a square of dimensions [dimensions] at coords [other coords]" is a fucking refreshing break from webdev. Even more so than regular mobile dev. There's simply no room on the devices for much screwing about. You've got your lifecycle methods and some calls that draw things. You can listen for button presses. That's about it as far as the UI goes.
The operating system is working as designed. Garmin wearable device customers demand maximum battery life with minimum size and weight. Within those constraints it simply isn't feasible for the OS to provide a high level of protection.
I don't understand what power constraints have to do with the operating system providing proper process control, but I'm not an OS expert. Could you maybe add a few sentences of explanation?
The Garmin Watches don't have DRAM for power reasons. The processor is a memory constrained microcontroller without a hardware memory management unit. Without the MMU you don't get as powerful memory virtualization or process isolation.
If the cpu is doing work it’ll consume battery life. You get longer battery life from a system mostly in a low power state. An app will get the cycles it requires - it’s a trade off which usually means doing more work means less low power states. Less efficient apps will not enable low power as often. There is cooperation here and it’s why Apple didn’t originally allow background apps on the iPad.
I tell you what, though: having a declarative UI where "declarative" is "now draw text at coords [some coords]. Then draw a square of dimensions [dimensions] at coords [other coords]" is a fucking refreshing break from webdev. Even more so than regular mobile dev. There's simply no room on the devices for much screwing about. You've got your lifecycle methods and some calls that draw things. You can listen for button presses. That's about it as far as the UI goes.