The host passes information to the runtime via a string to string mapping of properties. Adding a property represents a non-trivial cost, but is currently the only way we have to pass more information from the host to the runtime.

We should add a different mechanism for this. We can pass over a callback (similar to what we currently do BUNDLE_PROBE and PINVOKE_OVERRIDE) for getting properties. Something like:

size_t STDMETHODCALLTYPE get_runtime_property(
    const char* key,
    void* value_buffer,
    size_t value_buffer_size)

The value_buffer actual type would depend on the key, such that we could have structured information.

This would enable us to provide the information necessary to support:

• Log details of app being launched by dotnet(.exe) to ETW/LTTng #3156
• Getting command line via diagnostic pipe GetProcessInfo command during suspension only reports process name #59439
• Getting managed assembly entrypoint on diagnostic pipe GetProcessInfo2 command during suspension #56808

Runtimes need to continue to respect the existing properties, but once the callback exists, it could also be used for existing properties as appropriate. This would be a step towards:

• Support pay-for-play runtime properties/services #3673