如何保护多个ASP.NET页面使用的资源？

I am working on a project that includes a parent page, This parent page includes two iframe tags that is connected to two other child asp pages. I need to protect a time instance, and it should be like this: In the first child page it should be locked, and when the other child asp page reads from it should be released. Can anyone give me an advice please? I am working on a project that includes a paren