The
pset_bind() function can return the current processor set ID to which the target is bound, or
PS_NONE. However, for example, the process may have many threads, which could be bound to different processor sets. In such a case it is unspecified which thread will be used to return the information.
There is an alternative thread affinity interface, see
affinity(3). However, processor sets and thread affinity are mutually exclusive, hence mixing of these interfaces is prohibited.