Sync Primitives in Go
From the Go cheat sheet · Concurrency · verified Jul 2026
Sync Primitives
Mutex, WaitGroup, and Once for synchronization
go
// WaitGroup: wait for goroutines
var wg sync.WaitGroup
for i := range 5 {
wg.Add(1)
go func() {
defer wg.Done()
fmt.Println(i)
}()
}
wg.Wait()
// Mutex: protect shared state
var mu sync.Mutex
mu.Lock()
// critical section
mu.Unlock()📌 Always defer wg.Done() and mu.Unlock() to prevent deadlocks
💡 Use RWMutex when reads vastly outnumber writes
🎯 sync.Once is perfect for lazy initialization
⚡ Prefer channels for communication, mutexes for state protection