+ CLOCK_MONOTONIC = 0x4
+ CLOCK_MONOTONIC_FAST = 0xc
+ CLOCK_MONOTONIC_PRECISE = 0xb
+ CLOCK_PROCESS_CPUTIME_ID = 0xf
+ CLOCK_PROF = 0x2
+ CLOCK_REALTIME = 0x0
+ CLOCK_REALTIME_FAST = 0xa
+ CLOCK_REALTIME_PRECISE = 0x9
+ CLOCK_SECOND = 0xd
+ CLOCK_THREAD_CPUTIME_ID = 0xe
+ CLOCK_UPTIME = 0x5
+ CLOCK_UPTIME_FAST = 0x8
+ CLOCK_UPTIME_PRECISE = 0x7
+ CLOCK_VIRTUAL = 0x1