VMS Help POSIX Threads, PTHREAD routines, pthread_setcancelstate, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 state

    State of general cancelability to set for the calling thread. The
    following are valid cancel state values:

       PTHREAD_CANCEL_ENABLE
       PTHREAD_CANCEL_DISABLE

 oldstate

    Previous cancelability state for the calling thread.