check_c_source_compiles (
                                 "#include <pthread.h>

                                 int main () {
                                        pthread_rwlock_t rwl;

                                        pthread_rwlock_init (&rwl, 0);
                                        pthread_rwlock_destroy (&rwl);
                                        return 0;
                                 }"
                                 PLIBSYS_HAS_POSIX_RWLOCK
                                )