#include <errno.h>
#include <magenta/futex.h>
#include <pthread.h>

int pthread_mutex_lock(pthread_mutex_t *mut)
{
	kern_futex_t expected = 0;
	while (1) {
		expected = 0;
		if (__atomic_compare_exchange_n(
			    &mut->__v,
			    &expected,
			    1,
			    0,
			    __ATOMIC_ACQUIRE,
			    __ATOMIC_ACQUIRE)) {
			return 0;
		}

		futex_wait(&mut->__v, 1, FUTEX_PRIVATE);
	}

	return __set_errno(EAGAIN);
}