VLSI DV Interview Puzzles · All levels
Handle and Copy Puzzles
These puzzles test whether you can reason about handle identity, aliasing, and object lifetime under real UVM copy/clone flows. Most failures happen when code looks correct at the top level but a nested handle remains shared, so later mutations silently corrupt expected data.
About this puzzle set
These puzzles test whether you can reason about handle identity, aliasing, and object lifetime under real UVM copy/clone flows. Most failures happen when code looks correct at the top level but a nested handle remains shared, so later mutations silently corrupt expected data.
Puzzles in this topic
diagram
1. Shallow Copy in Nested Payload [Easy]
2. Queue of Handle Cells Still Aliases [Medium]
3. Analysis Port Lifetime Reuse [Medium]
4. Null Handle During Partial Deep Copy [Hard]
5. Handle Equality vs Content Equality [Easy]
6. Clone Without Overridden do_copy [Hard]Work each puzzle before reading the solution: predict the exact output or answer, name the rule that governs it, then check yourself.
fork/join variants and completion semantics
diagram
FORK/JOIN INTERVIEW CHEAT MAP
fork
task_a(); // 3 cycles
task_b(); // 1 cycle
join
--> parent waits for all children
fork ... join_any
--> parent continues after first child completes
fork ... join_none
--> parent continues immediately; children run detached
Use wait fork; later to synchronize detached threads.