No CLOCK_MONOTONIC in OS X?

In a David Tennant voice: Wait, what?? What?!

  ~$ grep CLOCK_MONOTONIC /usr/include -rn
  ~$

Ahh, it's in the POSIX realtime extension... Dammit.

Apparently [1] one solution would be to #IFDEF DARWIN the following, as on Darwin SYSTEM_CLOCK is supposed to be a monotonic boot clock.

  #include <mach/clock.h>
  #include <mach/mach.h>
  
     ...
  
  clock_serv_t cclock;
  mach_timespec_t mts;

  host_get_clock_service(mach_host_self(), SYSTEM_CLOCK,
  &cclock);
  clock_get_time(cclock, &mts);
  mach_port_deallocate(mach_task_self(), cclock); 

Not sure if processor affinity would affect that code (don't have time right now to do the in depth reading on it), but you could always set affinity to CPU0. Though then you'd have to make sure to run the sudo'd command as a child process and appropriately reset affinity to default before a call to exec...