Execution — bi-02-architecture-process-model
Steps extracted from CONCEPTS.md. Read the concepts first; this file is the doing.
Record results in observation.md; tick checkpoints in verification.md.
Lab — the process/thread lab, process and thread archaeology
See bi-02-architecture-process-model/docs/execution.md.
Debugging Exercise
On your local content_shell build:
- Launch it, then enumerate the actual processes and their types on your machine. Which process types appear for a trivial page? Which appear only after you load something that paints, or something cross-origin?
- Attach lldb to a renderer and run
thread backtrace all. Identify main, compositor, raster, and IO threads by name. Write the names down — you will grep for them in traces for the rest of the track. - Load a page with a cross-site iframe. Confirm from process inspection that a second renderer exists. Then confirm the same-site iframe case does not create one.
- Block the main thread with a long synchronous loop, and scroll. Explain what still works and why, in terms of threads rather than in terms of "the compositor is fast."