+//Begin-Libc
+#ifndef LIBC_ALIAS_NANOSLEEP
+//End-Libc
+int nanosleep(const struct timespec *__rqtp, struct timespec *__rmtp) __DARWIN_ALIAS_C(nanosleep);
+//Begin-Libc
+#else /* LIBC_ALIAS_NANOSLEEP */
+int nanosleep(const struct timespec *__rqtp, struct timespec *__rmtp) LIBC_ALIAS_C(nanosleep);
+#endif /* !LIBC_ALIAS_NANOSLEEP */
+//End-Libc
+#endif
+#endif /* UNIFDEF_DRIVERKIT */
+
+#if !defined(_DARWIN_FEATURE_CLOCK_GETTIME) || _DARWIN_FEATURE_CLOCK_GETTIME != 0
+#if __DARWIN_C_LEVEL >= 199309L
+#if __has_feature(enumerator_attributes)
+#define __CLOCK_AVAILABILITY __OSX_AVAILABLE(10.12) __IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
+#else
+#define __CLOCK_AVAILABILITY
+#endif
+
+typedef enum {
+_CLOCK_REALTIME __CLOCK_AVAILABILITY = 0,
+#define CLOCK_REALTIME _CLOCK_REALTIME
+_CLOCK_MONOTONIC __CLOCK_AVAILABILITY = 6,
+#define CLOCK_MONOTONIC _CLOCK_MONOTONIC
+#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
+_CLOCK_MONOTONIC_RAW __CLOCK_AVAILABILITY = 4,
+#define CLOCK_MONOTONIC_RAW _CLOCK_MONOTONIC_RAW
+_CLOCK_MONOTONIC_RAW_APPROX __CLOCK_AVAILABILITY = 5,
+#define CLOCK_MONOTONIC_RAW_APPROX _CLOCK_MONOTONIC_RAW_APPROX
+_CLOCK_UPTIME_RAW __CLOCK_AVAILABILITY = 8,
+#define CLOCK_UPTIME_RAW _CLOCK_UPTIME_RAW
+_CLOCK_UPTIME_RAW_APPROX __CLOCK_AVAILABILITY = 9,
+#define CLOCK_UPTIME_RAW_APPROX _CLOCK_UPTIME_RAW_APPROX
+#endif
+_CLOCK_PROCESS_CPUTIME_ID __CLOCK_AVAILABILITY = 12,
+#define CLOCK_PROCESS_CPUTIME_ID _CLOCK_PROCESS_CPUTIME_ID
+_CLOCK_THREAD_CPUTIME_ID __CLOCK_AVAILABILITY = 16
+#define CLOCK_THREAD_CPUTIME_ID _CLOCK_THREAD_CPUTIME_ID
+} clockid_t;
+
+#ifndef UNIFDEF_DRIVERKIT
+__CLOCK_AVAILABILITY
+int clock_getres(clockid_t __clock_id, struct timespec *__res);
+
+__CLOCK_AVAILABILITY
+int clock_gettime(clockid_t __clock_id, struct timespec *__tp);
+
+#endif /* UNIFDEF_DRIVERKIT */
+#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
+__CLOCK_AVAILABILITY
+__uint64_t clock_gettime_nsec_np(clockid_t __clock_id);