Every goroutine you start should be managed. Avoid launching "fire-and-forget" goroutines that run indefinitely or without any synchronization. Provide a way to stop goroutines (using a cancel context or done channel) and/or track them (e.g., with sync.WaitGroup) to prevent leaks.
Uncontrolled goroutines can continue running and leak memory or other resources if the rest of the program moves on (for example, on shutdown or test completion). By managing goroutine lifecycles, you ensure they exit when expected, preventing resource leaks and unpredictable behavior.
Side-by-side examples engineers can pattern-match during review.
func StartWorker() {
go func() {
for {
doWork()
// no exit condition, no tracking
}
}()
}func StartWorker(ctx context.Context, wg *sync.WaitGroup) {
wg.Add(1)
go func() {
defer wg.Done()
for {
select {
case <-ctx.Done():
return // exit when signaled
default:
doWork()
}
}
}()
}
// Now the caller can cancel the context or wait on the WaitGroup to ensure the goroutine stops.func StartWorker() {
go func() {
for {
doWork()
// no exit condition, no tracking
}
}()
}func StartWorker(ctx context.Context, wg *sync.WaitGroup) {
wg.Add(1)
go func() {
defer wg.Done()
for {
select {
case <-ctx.Done():
return // exit when signaled
default:
doWork()
}
}
}()
}
// Now the caller can cancel the context or wait on the WaitGroup to ensure the goroutine stops.From the same buckets as this rule.