Move UI dispatcher to common Dispatchers.Main #641
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…discoverable via ServiceLoader * Dispatchers.Main can be consistently used and easily discovered, its implementation is discovered with ServiceLoader * It allows us to add iOS Dispatchers.Main implementation in the future thus opening the door for multiplatform UI-dispatched code * Workaround for #626, now Android users can start migration to RC coroutines Fixed #626
| public abstract override val immediate: HandlerDispatcher | ||
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| internal class AndroidDispatcherFactory : MainDispatcherFactory { |
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This class needs annotated with @Keep or it will be removed automatically as being unused for all R8/ProGuard users requiring manual configuration.
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Good catch, thank you.
I suspect this might cause start performance regression for all Android users based on putting ServiceLoader usage on the critical path
mainDispatcher is initialized only once when Dispatchers object is instantiated, it is not on the critical path.
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I suspect most Android apps will launch something during startup which requires a Dispatchers.Main reference and will force initialization.
Perhaps we can get R8 to rewrite any ServiceLoader usage with a constant array determined at compile-time. This could avoid the need for @Keep on the implementations as well.
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I get your point. Is an access to ServiceLoader a regression significant enough to postpone this change?
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I don't know what the impact is off-hand. Android definitely isn't optimized for this case though which is why it has its own resource and asset system. I can measure, but it won't be until Friday at the earliest.
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We will merge it then, mostly to stabilize our API.
If you (or anyone else) report a significant regression, we will rework this part without changing the API (e.g. with Class.forName or any other hack like this)
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How will this work in hybrid Swing-JavaFX apps? |
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@kirill-grouchnikov JavaFx will win as a main dispatcher. |
Main thread dispatchers are grouped under Dispatchers object and are discoverable via ServiceLoader
Fixed #626