feat: basic RwMutex implementation

mutex.go

@@ -0,0 +1,31 @@
+package custom_rwmutex
+
+import "sync"
+
+type CustomRwMutex struct {
+	mu *sync.RWMutex
+}
+
+func NewCustomRwMutex() *CustomRwMutex {
+	return &CustomRwMutex{
+		mu: &sync.RWMutex{},
+	}
+}
+
+func (rwMu *CustomRwMutex) WriteHandler(fn func() error) error {
+	rwMu.mu.Lock()
+	defer rwMu.mu.Unlock()
+	if err := fn(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (rwMu *CustomRwMutex) ReadHandler(fn func() error) error {
+	rwMu.mu.RLock()
+	defer rwMu.mu.RUnlock()
+	if err := fn(); err != nil {
+		return err
+	}
+	return nil
+}