1 files changed, 32 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/thread/pthread_mutexattr_setprotocol.c b/libc-top-half/musl/src/thread/pthread_mutexattr_setprotocol.c
new file mode 100644
index 0000000..84b02ba
--- /dev/null
+++ b/libc-top-half/musl/src/thread/pthread_mutexattr_setprotocol.c
@@ -0,0 +1,32 @@
+#include "pthread_impl.h"
+#include "syscall.h"
+
+static volatile int check_pi_result = -1;
+
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t *a, int protocol)
+{
+	int r;
+	switch (protocol) {
+	case PTHREAD_PRIO_NONE:
+		a->__attr &= ~8;
+		return 0;
+	case PTHREAD_PRIO_INHERIT:
+#ifdef __wasilibc_unmodified_upstream
+		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;
+#else
+		return ENOTSUP;
+#endif
+	case PTHREAD_PRIO_PROTECT:
+		return ENOTSUP;
+	default:
+		return EINVAL;
+	}
+}