int omp_get_ancestor_thread_num(int level);
Summary The omp_get_ancestor_thread_num routine returns, for a given nested level of the current thread, the thread number of the ancestor of the current thread.
Binding The binding thread set for an omp_get_ancestor_thread_num region is the encountering thread. The binding region for an omp_get_ancestor_thread_num region is the innermost enclosing parallel region.
Effect The omp_get_ancestor_thread_num routine returns the thread number of the ancestor at a given nest level of the current thread or the thread number of the current thread. If the requested nest level is outside the range of 0 and the nest level of the current thread, as returned by the omp_get_level routine, the routine returns -1.
Note – When the omp_get_ancestor_thread_num routine is called with a value of level=0, the routine always returns 0. If level=omp_get_level(), the routine has the same effect as the omp_get_thread_num routine.