how is frozen frame rate calculated?

[thinkocapo]

Problem Statement

We know

• SDK captures slow and frozen frames per span, regardless of what’s shown on screen
• Depends on what happens during the span
• If it’s a span related to Fragment creation, the problem is in the fragment
• Sentry knows that at a specific time there was a frozen frame, but we don’t know if it’s due to the Activity or Fragment, as they’re both active same time
• We don’t distinguish which is which, so instrument Fragments properly (Custom) if needed

Trace for Activity start

• Span for Fragment
• Span for Fragment

Solution Brainstorm

Frozen Frames per fragment

[markushi]

@thinkocapo do you think this is a duplicate of #3719 ?

We don’t distinguish which is which, so instrument Fragments properly (Custom) if needed

The underlying problem here is that even with custom instrumentation the slow/frozen frame numbers are provided by the system for the whole screen, so we're not able to pinpoint a specific slow/frozen frame to a certain fragment/span.