mikkeli
fc15897541
Separation that nothing exercises is separation that quietly stops being true, so this runs a full test through Iperf3Service and Iperf3Session with WidgetsFlutterBinding but no runApp: no widget tree, no render surface. If the run path ever starts needing the UI, this stops working. An architecture test additionally forbids it importing lib/ui. It is also the accurate way to measure. A 4-stream run against a local server reports 30.2% local CPU here, against 79.9% for a comparable run with the transcript repainting alongside — the UI was costing roughly fifty points of CPU on a phone already near CPU-bound at gigabit rates. Throughput figures taken through the UI are therefore pessimistic, and this is the path to use when the number matters. Parameters come from --dart-define so a run needs no code edit: flutter run -t lib/main_headless.dart --dart-define=IPERF_SERVER=… Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
iperf3-gui
A Flutter-based Android GUI wrapper for iperf3, the popular network performance measurement tool.
Features
- Client-mode network throughput testing
- Configurable server, port, duration and parallel streams
- Live iperf3 output, streamed line by line while the test runs
- Stop a running test early
- Copy the transcript to the clipboard
- iperf3 3.19 compiled into the app as a native library — no external binary
Architecture
lib/
├── domain/
│ ├── models/ # TestConfiguration, Iperf3Result
├── data/
│ └── services/ # Iperf3Service (MethodChannel → JNI)
├── ui/
│ └── features/
│ └── test_run/ # TestRunScreen, TestRunViewModel
└── main.dart # App entry point
android/app/src/main/
├── kotlin/…/IperfRunner.kt # MethodChannel handler, runs tests off the platform thread
└── cpp/iperf_jni.c # JNI bridge into the iperf3 API
See docs/README.md for the data flow, the native API surface and the design decisions behind them.
Why JNI instead of executing a binary
Android SELinux in Enforcing mode blocks execve() from the untrusted_app
domain, so shipping an iperf3 ELF in assets and running it via Process.start()
fails with "Permission denied". iperf3 is therefore compiled as a shared library
(libiperf3jni.so) and called in-process over JNI.
assets/iperf3/ still holds the pre-compiled binaries from that earlier
approach. They are not declared in pubspec.yaml, so they are not packaged into
the APK, and nothing in the app reads them.
Building
Prerequisites:
- Flutter 3.47+
- Android SDK with platform android-36
- JDK 17
- NDK r28+ and CMake 3.22.1 (for the native build)
flutter pub get
flutter analyze
flutter test
flutter build apk --debug
adb install -r build/app/outputs/flutter-apk/app-debug.apk
Testing against a local server
iperf3 -s -p 5201 # on a machine on the same network
ip -4 addr show # note its address
Enter that address in the app, then press GO.
Dependencies
- Dart:
provider - Native: iperf3 3.19 + cJSON, built by CMake for
armeabi-v7aandarm64-v8a
License
MIT — bundled iperf3 3.19 is BSD-3-Clause licensed.