m_yield

This call causes voluntary suspension of an application. When called, the application is placed at the end of the application stack, and the active state reverts to the next application. Control will not return to the caller of m_yield until some external action causes it to be made active again (generally, the user pressing a hotkey, which restarts the application).

Instead of calling this function, you should use m_action with the do_event = DO_YIELD which provides the identical service.