Perefetto gets stuck at "PixelMemory#ShowTotalMemory already exists" and never recovers

[alecazam]

My kram-profile app is hitting this error from Perfetto. Once it occurs, I can't get another file to load. This is Perfetto running in a Swift-wrapped WKWebView. Seems to happen if I try to quickly go through the list of files. This is reusing the same webview to load various clang -ftime-trace files.

UI: https://ui.perfetto.dev/v47.0-1b4776303

RegistryError: Registrant dev.perfetto.PixelMemory#ShowTotalMemory already exists in the registry

• RegistryError (frontend_bundle.js:3416:15)
• register (frontend_bundle.js:3434:37)
• registerCommand (frontend_bundle.js:84168:75)
• (frontend_bundle.js:84667:29)
• onTraceLoad (frontend_bundle.js:84666:29)
• (frontend_bundle.js:84465:49)
• doPluginTraceLoad (frontend_bundle.js:84460:38)
• (frontend_bundle.js:84425:38)

Trace: not available (ARRAY_BUFFER). Provide repro steps.
UA: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko)
Referrer:

[LalitMaganti]

So this is clearly a race condition because it's a double registration error. The problem is that we have no other reports of this issue.

If there's a way to repro this in a bare browser I can take a look but otherwise if this is some race condition which specific to your app/your usage of WKWebView/a bug in WKWebView, we would not have the bandwidth to look into this.

[LalitMaganti]

Also all of this code has been under heavy rework recently (for example, on HEAD doPluginTraceLoad function no longer even exists) so it's very possible that there was a bug which has been fixed.

[alecazam]

Thanks, I'll keep checking if this goes away. The inability to reuse the Perfetto web view to load different data is a problem. It's already 600KB with nothing loaded. But this new issue causes the app to never recover, and post the same error when I try to load a different trace file. Something that broke in the last 2-3 months.