Memory Profiling

Managed Memory profiling is available through the use of the Xamarin Profiler or mprof-report.

Memory snapshots are supported to enable memory difference analysis and find memory leaks.

Using the memory profiler

  • Add the following to your csproj 
    <PropertyGroup>
  <WasmShellEnableLogProfiler>true</WasmShellEnableLogProfiler>
</PropertyGroup>

Once the application is running:

  • Use the Shift+Alt+H (Shift+Cmd+H on macOS) hotkey to create memory snapshots
  • Use the Shift+Alt+P (Shift+Cmd+P on macOS) hotkey to save the profile to a file

With the saved mlpd file, you can either:

  • Open it with the Xamarin Profiler (which needs to be explicitly installed in the VS 2022 installer)
  • Show a memory report using mprof-report. The tool can be installed under Ubuntu WSL using sudo apt install mono-utils

Additional profiler configuration

The profiler uses the official configuration string, which can be adjusted using the following options:

<PropertyGroup>
  <WasmShellEnableLogProfiler>true</WasmShellEnableLogProfiler>
  <WasmShellLogProfilerOptions>log:alloc,output=output.mlpd</WasmShellLogProfilerOptions>
</PropertyGroup>

Note that as of .NET 6:

  • The support for any timer based profiling is not supported, because of the lack of threading support in .NET
  • The support for remote control of the profiler is not supported

CPU Profiling

To enable the profiling of the WebAssembly code, set te following parameter:

<WasmShellEnableEmccProfiling>true</WasmShellEnableEmccProfiling>

This will ensure that the toolchain keeps the function names so that the browser shows meaningful information in the Performance tab.