1#include "pthread_impl.h"
 2#include "syscall.h"
 3
 4static volatile int check_pi_result = -1;
 5
 6int pthread_mutexattr_setprotocol(pthread_mutexattr_t *a, int protocol)
 7{
 8	int r;
 9	switch (protocol) {
10	case PTHREAD_PRIO_NONE:
11		a->__attr &= ~8;
12		return 0;
13	case PTHREAD_PRIO_INHERIT:
14#ifdef __wasilibc_unmodified_upstream
15		r = check_pi_result;
16		if (r < 0) {
17			volatile int lk = 0;
18			r = -__syscall(SYS_futex, &lk, FUTEX_LOCK_PI, 0, 0);
19			a_store(&check_pi_result, r);
20		}
21		if (r) return r;
22		a->__attr |= 8;
23		return 0;
24#else
25		return ENOTSUP;
26#endif
27	case PTHREAD_PRIO_PROTECT:
28		return ENOTSUP;
29	default:
30		return EINVAL;
31	}
32}