LC

Benchmark Lock-Free vs Mutex-Based Queue Under High Contention

easy6/8

Implement SPSC Lock-Free Queue (Single Producer Single Consumer)Implement Epoch-Based Memory Reclamation for Lock-Free Data Structures

Language

Compiler

2.0s Limit 256MB

Implementation

Benchmark lock-free queue against mutex-based queue.

Requirements:

Implement simple mutex-based queue
Use lock-free queue from earlier task
Benchmark with varying thread counts (1, 2, 4, 8)
Measure throughput and latency
Show crossover point (where lock-free wins)
Print comparison table
Explain trade-offs
Recommend when to use each

Why This Matters

This is the exact tradeoff the Linux kernel scheduler and glibc's malloc arenas navigate constantly: futex-based mutexes are simpler and often faster under light load, while high-contention hot paths (like the kernel's per-CPU run queues) switch to lock-free or RCU techniques because blocking under contention creates convoying that a CAS retry loop avoids. Measuring your own crossover point here is the practical skill that keeps engineers from reaching for lock-free code where a plain mutex would have been faster and safer.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0