Error "Invalid number!" for very large thread IDs

[oliver]

When loading a JSON file in Trace Event Format where the tid (thread id) values are very large (larger than 42,949,672,959, i.e. (2**32)*10 ?), Spall shows an error message ("Oof. We're dead!"), and the JS console shows the error messages "Invalid number!" and "RuntimeError: unreachable executed". If I replace the tid values in the JSON file with smaller values, the file is loaded correctly.

Attached are two files (in ZIP files, since Github does not allow JSONs) which demonstrate the problem:

• trace-very-large-thread-ids.json.zip triggers the error in Spall
• trace-small-thread-ids.json.zip can be loaded successfully in Spall

I tried this with the current version of https://gravitymoth.com/spall/spall-web.html .

In the chrome://tracing/ viewer in Chromium, both files are displayed correctly.

I encountered this problem when viewing trace files created by an in-house C++ tool. The tid values come from std::this_thread::get_id() and have values like 140339968804608 .

Btw. for the record, I had encountered problems with large thread IDs (larger than 2**32 ?) also in Perfetto (see google/perfetto#522), but they didn't want to fix that problem.