Go: What is the difference between mutex and RWMutex?

Mutex — exclusive. RWMutex — readers/writers.

1// Mutex
2var mu sync.Mutex
3mu.Lock()
4mu.Unlock()
5
6// RWMutex
7var rwmu sync.RWMutex
8rwmu.RLock()
9rwmu.RUnlock()

When to use RWMutex:

• Read-heavy workloads.

When to use Mutex:

• Write-heavy workloads.

Common mistakes:

• Using RWMutex for write-heavy work.
• Copying mutex.
• Forgetting defer Unlock().
• Not benchmarking.
• Using RWMutex for single-goroutine.