Merged threads on Linux

Flutter 3.39 merges the UI and platform threads by default on Linux.

Originally, Flutter had separate threads to produce UI frames and to interact with the native platform.

The split-thread design prevented Flutter apps and plugins from using Dart FFI to interoperate with native APIs that must be called on the platform thread.

Flutter version 3.39 merges the UI and platform threads by default on Linux.

This mirrors all the other platforms, whose threads were merged by default in Flutter 3.29 (iOS and Android) and 3.35 (macOS and Windows).

Merged threads shouldn't affect your app.

If you suspect merged threads have caused regressions to your app, please reach out on Issue 150525.

Landed in version: 3.39.0-0.1.pre
In stable release: Not yet

Relevant issue:

• Issue 150525

Relevant PRs:

• PR 176759