bool psi_plist_get(struct psi_plist *list, size_t index, void *ptr);
bool psi_plist_del(struct psi_plist *list, size_t index, void *ptr);
bool psi_plist_get(struct psi_plist *list, size_t index, void *ptr);
bool psi_plist_del(struct psi_plist *list, size_t index, void *ptr);