1. A method for operating a thread across virtualization contexts, the method comprising: an act of a thread operating in a first virtualization context and thus having access to first computing resources associated with the first virtualization context; an act of the thread entering an entry point to code associated with a second virtualization context and that has access to second computing resources associated with the second virtualization context; while the thread is operating on the code, an act of detecting an event; and in response to the act of detecting, an act of associating the thread with the second virtualization context such that the thread has access to the second computing resources associated with the second virtualization context.