The 'must be runnable' part is what tripped me up mentally.
Clarify requirements first (single-threaded vs multi-threaded, task priorities, cancellation, persistence), then propose a design using a priority queue (min-heap) keyed by execution time, and implement a working version in a language you know well. Focus on correctness, dynamic insertion, and handling edge cases like simultaneous tasks and thread safety.
Pro tip: Mention that you would use a condition variable or a delay queue to avoid busy-waiting, and discuss how you'd test it with unit tests and a simple simulation. This shows you care about efficiency and reliability, which is critical for Tesla's real-time systems.
Ask about expected load, task priorities, cancellation, persistence, and whether tasks can be added from multiple threads. This ensures you design the right system and avoid over-engineering.
Select a min-heap (priority queue) for efficient retrieval of the next task, and decide on a threading model (e.g., single scheduler thread with a condition variable, or a thread pool). Explain trade-offs.
Write code that adds tasks to the heap, waits until the next task's time, executes it, and repeats. Handle dynamic insertion by signaling the waiting thread when a new earlier task arrives.
Address simultaneous tasks, task cancellation, and thread safety using locks and condition variables. Ensure no busy-waiting and graceful shutdown.
Write unit tests for ordering, dynamic addition, and concurrency. Run a simple demo with tasks scheduled at different times to prove it works.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.