example.go

// Before
type utxoCache struct {
	// ...
	mtx sync.Mutex
}

// After
import "github.com/gcash/bchutil"

type utxoCache struct {
	// ...
	mtx bchutil.Mutex
}

logging_mutex_disabled.go

// +build !mutex-logging
type LoggingMutex struct{
	Name string // Not used, just for type compatility
	sync.Mutex
}

logging_mutex_enabled.go

// +build mutex-logging
import "github.com/gcash/bchlog"

type LoggingMutex struct{
	Name string
	log
	sync.Mutex
}

func (m *LoggingMutex) Lock() {
	bchlog.Debug("Locking mutex:", m.Name)
	m.Mutex.Lock()
}

func (m *LoggingMutex) Unlock() {
	bchlog.Debug("Unlocking mutex:", m.Name)
	m.Mutex.Unlock()
}