Atomic Operations & Mutexes

Synchronization Primitives

This lesson explains the main concept clearly with beginner-friendly examples and background so you can learn why the code works.

sync.Mutex

var mu sync.Mutex
counter := 0
for i := 0; i < 100; i++ {
    go func() {
        mu.Lock()
        counter++
        mu.Unlock()
    }()
}

sync.RWMutex (read‑write lock)

var rw sync.RWMutex
// multiple readers
rw.RLock(); defer rw.RUnlock()
// exclusive writer
rw.Lock(); defer rw.Unlock()

Atomic package (sync/atomic)

var ops uint64
atomic.AddUint64(&ops, 1)
val := atomic.LoadUint64(&ops)

When to use which?

• Mutex for simple critical sections.
• RWMutex when reads dominate writes.
• Atomic for lock‑free counters and flags.