Persist context across threads?

I am interested in preserving the complete PHP context for a thread (globals, variables, interpreter, etc.--everything) for later access from a different thread. What would be involved in this? It seems like: 1) Avoid calling ts_free_thread 2) Call tsrm_set_interpreter_context from new thread Is it safe to assume that the context of a terminated thread will not be destroyed or overwritten as long as ts_free_thread is not called? Thanks in advance, David R.