This content originally appeared on DEV Community and was authored by flfljh
Flutter applications adapted for HarmonyOS can be debugged using DevTools for Dart code.
Prerequisites
- OpenHarmony Next system
- Flutter interface running in foreground
- Analysis tools: DevEco Studio Profiler SmartPerf
Flutter Thread Architecture
Flutter utilizes multiple threads for essential operations. All Dart code executes on the UI thread, which impacts other threads:
- Platform Thread Main platform thread where plugin code runs
-
UI Thread
Executes Dart code in Dart VM. Handles:
- Developer-written code
- Framework-generated code
- Creates lightweight layer trees (device-agnostic rendering commands)
- Sends layer trees to GPU thread Critical: Never block this thread! Appears in performance overlay's bottom bar.
-
Raster Thread (GPU Thread)
Processes layer trees and sends to GPU. While you can't directly interact:
- Slowness indicates Dart code issues
- Hosts Skia graphics library
- Appears in performance overlay's top bar
- I/O Thread Handles heavy I/O operations to prevent blocking UI/raster threads. Not shown in performance overlay.
-
RenderService Thread
RS process main thread. After Flutter renders frames:
- Texture mode: Composites with main thread (affected by main thread)
- Surface mode: Direct display (unaffected by main thread)
Problem Boundary Definition
In DevEco Studio:
- Open Profiler tab
- Capture application trace
- Focus on
<x>.ui,<x>.raster, and RenderService main threads
The missing frames in the RenderService in the above image are due to the UI thread taking a longer time per frame, exceeding one frame (at a frame rate of 120, one frame is 8.33 milliseconds).
If the total duration of. ui and. master in a frame rendering process exceeds one frame time, the performance issue can be defined as Flutter problem. The positioning of the problem requires further performance analysis.
This content originally appeared on DEV Community and was authored by flfljh
flfljh | Sciencx (2025-06-26T01:15:25+00:00) Flutter Performance Tuning on HarmonyOS: Performance Analysis and Boundary Definition. Retrieved from https://www.scien.cx/2025/06/26/flutter-performance-tuning-on-harmonyos-performance-analysis-and-boundary-definition/
Please log in to upload a file.
There are no updates yet.
Click the Upload button above to add an update.