static extern int swapcontext(ucontext_t *__oucp, ucontext_t *__ucp);
//extern void makecontext(IntPtr* __ucp, RunDelegate __func, int __argc, params IntPtr __rest); static extern void makecontext(ucontext_t *__ucp, RunDelegate __func, int __argc);
static extern int setcontext(ucontext_t *__ucp);