3237222b62
Original issue: https://github.com/flutter/flutter/issues/150525 This PR lets the macOS embedder run both with and without UI and platform thread merged. Thread merging is controlled through `FLTEnableMergedPlatformUIThread` `info.plist` option similar to iOS embedder, though the default value is currently `false`. Changes in the resize / vsync synchronization: - Added `FlutterRunLoop` class to schedule Flutter tasks on main thread in a way where it is possible to only process these (Flutter posted) tasks while waiting for correct frame size during resizing. This significantly simplifies the resize synchronization and makes the same code work both with separate UI thread and with UI and platform thread merged. - `FlutterThreadSynchronizer` has been renamed to `FlutterResizeSynchronizer` vastly simplified, mutex and conditions are removed and the blocking is now done by only processing Flutter messages while waiting for resizing. It is now per view (instead of storing a viewId->Size map internally) and owned by the view itself, instead of engine. - This approach to resize synchronization will work for Windows and Linux as well. This will allow us to conceptually consolidate the way we do threading and resize synchronization on all three desktop embedders. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
Flutter Engine
Setting up the Engine development environment
See here
gclient bootstrap
Flutter engine uses gclient to manage dependencies.
If you've already cloned the flutter repository: