feat: transaction implement

internal/processlock/lock.go

@@ -0,0 +1,10 @@
+package processlock
+
+import "errors"
+
+var (
+	// ErrAlreadyLocked 表示另一个 serve 进程已经持有内核锁。
+	ErrAlreadyLocked = errors.New("process lock is already held")
+	// ErrUnsupported 表示当前操作系统不能运行服务端进程锁。
+	ErrUnsupported = errors.New("process lock is not supported on this operating system")
+)