Flutter app paused for about 30 seconds to 1 minute during hot reload in IntelliJ or Android Studio

[jibbers42]

I'm using IntelliJ 2019.1.3 on Ubuntu 19.04. When I make a change then hot reload activates and the IntelliJ Console output shows "The application is paused." After a while it may be responsive again, or freeze long enough that I give up. VSCode hot reloads fine, but I'd prefer to use IntelliJ.

How can I troubleshoot this?

(I also have an SO at https://stackoverflow.com/questions/56992290/flutter-app-paused-for-about-30-seconds-to-1-minute-during-hot-reload-in-intelli)

Version info

==> flutter doctor -v
[✓] Flutter (Channel stable, v1.7.8+hotfix.3, on Linux, locale en_US.UTF-8)
    • Flutter version 1.7.8+hotfix.3 at /home/jibbers42/flutter
    • Framework revision b712a172f9 (2 days ago), 2019-07-09 13:14:38 -0700
    • Engine revision 54ad777fd2
    • Dart version 2.4.0

 
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at /home/jibbers42/bin/android-sdk/
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.3
    • ANDROID_HOME = /home/jibbers42/bin/android-sdk
    • ANDROID_SDK_ROOT = /home/jibbers42/bin/android-sdk
    • Java binary at:
      /home/jibbers42/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/183.5522156/jre/bin/jav
      a
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b16-5323222)
    • All Android licenses accepted.

[✓] Android Studio (version 3.4)
    • Android Studio at
      /home/jibbers42/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/183.5522156
    • Flutter plugin version 35.3.1
    • Dart plugin version 183.6270
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b16-5323222)

[✓] IntelliJ IDEA Community Edition (version 2019.1)
    • IntelliJ at /home/jibbers42/.local/share/JetBrains/Toolbox/apps/IDEA-C/ch-0/191.7479.19
    • Flutter plugin version 37.0.3
    • Dart plugin version 191.7830

[✓] VS Code (version 1.36.1)
    • VS Code at /usr/share/code
    • Flutter extension version 3.2.0

[✓] Connected device (1 available)
    • Pixel 3 XL • 89HY071WP • android-arm64 • Android 9 (API 28)

• No issues found!

[jacob314]

Do you have an example application can reproduce this issue? If so, we are very interested to try it out and track down what is going wrong.

[DaveShuckerow]

This may be similar to what we were seeing with Mulligan in g3.

[jibbers42]

I don't have something I can provide and I haven't found the time yet to try to isolate it. Is there any logging I can enable and capture that might be useful to you?

[pq]

@DaveShuckerow: any thoughts on what @jibbers42 can log here? Or any other context that might help?

[DaveShuckerow]

One thing you can look at is the memory consumption of the app. You can check the performance tab in IntelliJ for information about this.

[DaveShuckerow]

We've seen memory consumption go up during hot reloads started from IntelliJ

[jibbers42]

It didn't really do anything dramatic - it went from around 450MB to 500MB.