TYPE ID CLOCK                  NAME
sys   0 CLOCK_REALTIME         realtime
sys   1 CLOCK_MONOTONIC        monotonic
sys   4 CLOCK_MONOTONIC_RAW    monotonic-raw
sys   5 CLOCK_REALTIME_COARSE  realtime-coarse
sys   6 CLOCK_MONOTONIC_COARSE monotonic-coarse
sys   7 CLOCK_BOOTTIME         boottime
sys   8 CLOCK_REALTIME_ALARM   realtime-alarm
sys   9 CLOCK_BOOTTIME_ALARM   boottime-alarm
sys  11 CLOCK_TAI              tai