#include "pthread_impl.h"
+#include "syscall.h"
+
+static volatile int check_pi_result = -1;
int pthread_mutexattr_setprotocol(pthread_mutexattr_t *a, int protocol)
{
- if (protocol) return ENOTSUP;
- return 0;
+ int r;
+ switch (protocol) {
+ case PTHREAD_PRIO_NONE:
+ a->__attr &= ~8;
+ return 0;
+ case PTHREAD_PRIO_INHERIT:
+ r = check_pi_result;
+ if (r < 0) {
+ volatile int lk = 0;
+ r = -__syscall(SYS_futex, &lk, FUTEX_LOCK_PI, 0, 0);
+ a_store(&check_pi_result, r);
+ }
+ if (r) return r;
+ a->__attr |= 8;
+ return 0;
+ case PTHREAD_PRIO_PROTECT:
+ return ENOTSUP;
+ default:
+ return EINVAL;
+ }
}