+/* Returns whether Priority Inheritance support CLOCK_MONOTONIC.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/xthread.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+bool
+support_mutex_pi_monotonic (void)
+{
+#ifdef __linux__
+# ifndef __NR_futex
+# define __NR_futex __NR_futex_time64
+# endif
+ int r = syscall (__NR_futex, &(unsigned int){0}, 13 /* FUTEX_LOCK_PI2 */,
+ 0, NULL);
+ return r == 0;
+#else
+ return false;
+#endif
+}