NOTE: if you are looking to record a custom AOT profile in .NET 6 or 7, then you want this repo instead:

https://github.com/jonathanpeppers/Mono.Profiler.Android

android-profiled-aot

This is a repo for recording .NET 6 AOT profiles.

See:

• xamarin/xamarin-android#6171
• dotnet/runtime#57511
• radekdoulik/aotprofile-tool

A few pieces are needed for recording AOT profiles for .NET 6:

1. aprofutil from Mono.
2. libmono-profiler-aot.so from dotnet/runtime.
3. @radekdoulik's aotprofile-tool to strip out the project assembly, as it won't match other users' project assemblies.

You only need the last aotprofile-tool step, if you are recording a profile to be distributed with the .NET 6 Android workload or .NET MAUI. If you are recording a profile for your own app, just use the profile as-is.

How do you update files in binaries folder?

For aprofutil, you can simply copy one of:

• From your system Xamarin.Android install:
  • C:\Program Files\Microsoft Visual Studio\2022\Preview\MSBuild\Xamarin\Android\aprofutil.exe
  • C:\Program Files\Microsoft Visual Studio\2022\Preview\MSBuild\Xamarin\Android\aprofutil.pdb
  • C:\Program Files\Microsoft Visual Studio\2022\Preview\MSBuild\Xamarin\Android\Mono.Profiler.Log.dll
  • /Library/Frameworks/Xamarin.Android.framework/Versions/Current/lib/xbuild/Xamarin/Android/Darwin/aprofutil
  • /Library/Frameworks/Xamarin.Android.framework/Versions/Current/lib/xbuild/Xamarin/Android/aprofutil.exe
  • /Library/Frameworks/Xamarin.Android.framework/Versions/Current/lib/xbuild/Xamarin/Android/aprofutil.pdb
  • /Library/Frameworks/Xamarin.Android.framework/Versions/Current/lib/xbuild/Xamarin/Android/Mono.Profiler.Log.dll
• From a local Xamarin.Android build tree:
  • tools/scripts/aprofutil
  • bin/Debug/lib/xamarin.android/xbuild/Xamarin/Android/Mono.Profiler.Log.dll
  • bin/Debug/lib/xamarin.android/xbuild/Xamarin/Android/aprofutil.exe
  • bin/Debug/lib/xamarin.android/xbuild/Xamarin/Android/aprofutil.pdb

I updated the aprofutil script to use aprofutil.exe in the current directory.

For libmono-profiler-aot.so, start with dotnet/runtime#57511 and rebase it on top of the release branch of choice, such as release/6.0.

Build each architecture:

./build.sh mono -bl -c Release -os android -arch arm
./build.sh mono -bl -c Release -os android -arch arm64
./build.sh mono -bl -c Release -os android -arch x64
./build.sh mono -bl -c Release -os android -arch x86

This should produce the files:

ls -l artifacts/obj/mono/Android.*/out/lib/libmono-profiler-aot.so 
413144 Aug 31 10:46 artifacts/obj/mono/Android.arm.Release/out/lib/libmono-profiler-aot.so
702424 Aug 31 11:06 artifacts/obj/mono/Android.arm64.Release/out/lib/libmono-profiler-aot.so
702240 Aug 31 09:48 artifacts/obj/mono/Android.x64.Release/out/lib/libmono-profiler-aot.so
517276 Aug 31 09:58 artifacts/obj/mono/Android.x86.Release/out/lib/libmono-profiler-aot.so

Copy the files to:

• binaries/android-arm/
• binaries/android-arm64/
• binaries/android-x64/
• binaries/android-x86/

Recording new profiles

To update the profiles recorded:

.\record.ps1

If you need to use a local .NET 6 build of the Android workload, use:

.\record.ps1 -dotnet ~\android-toolchain\dotnet\dotnet

Updating dotnet/maui's profile

1. Build dotnet/maui from source

And you can now use: C:\src\maui\bin\dotnet\dotnet.exe

2. Update MauiApp1:

cd MauiApp1
rm -r *
C:\src\maui\bin\dotnet\dotnet.exe new maui

Remove any non-Android files, like Platforms\Windows, etc.

Use a single: <TargetFramework>net6.0-android</TargetFramework>.

Make sure to keep: <ApplicationId>com.androidaot.MauiApp1</ApplicationId>

Make sure to keep: [Register("MauiApp1.MainActivity")]

Remove: <UseInterpreter Condition="'$(Configuration)' == 'Debug'">True</UseInterpreter>

3. Attach a device, and record the profile:

.\record.ps1 -dotnet C:\src\maui\bin\dotnet\dotnet.exe -app MauiApp1

Testing the profile

Run:

.\test.ps1
# or
.\test.ps1 -dotnet ~\android-toolchain\dotnet\dotnet

This will launch the app 10 times and calculate the average startup time.