chenjianguang 95f2b72728
Create root isolate asynchronously (#20142)
## Description
As the related issue refer, the application may be doing too much work on its main thread even in a simple hello_world demo.
That is because the creation of `Engine` on the ui thread takes a noticeable time, and it is blocking the platform thread in order to run `Shell::Setup` synchronously.
The cost of `Engine`'s constructor is mainly about the creating of root isolate. Actually, there used to be another time-consuming process, the default font manager setup, which was resolved by https://github.com/flutter/engine/pull/18225. 
Similar to https://github.com/flutter/engine/pull/18225, this pr move the creation of root isolate out from creating `Engine`. After this action, the main thread blocking is quite an acceptable slice.

## Related Issues
https://github.com/flutter/flutter/issues/40563 could be resolved by this pr.
2020-09-01 13:31:00 -07:00
2020-07-31 16:32:58 -07:00
2020-07-07 09:05:29 -07:00
2020-06-24 11:34:18 -07:00

Flutter Engine

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