📜 WAYPOINT LESSON
Checkpoint: concurrency
⭐⭐⭐ advanced⏳ 12 min read📍 Lesson 201 of 265
Synthesis: fix a live race with atomics and reason about a real deadlock.
Checkpoint: concurrency
The graded task proves two skills at once: exact counting under parallel attack (no lost updates) and exactly-once compute publication under race. The practice set adds a live visibility bug (JIT-cached flag) and the ABBA-deadlock triage with the consistent-order fix.