Structure - Specifies the format the kernel uses to maintain a mapped clock's time.
struct mapped_tvalspec
{
       tvalspec_t          mtv_time;
       unsigned int        mtv_csec;
};
typedef struct mapped_tvalspec mapped_tvalspec_t;
The mapped_tvalspec structure defines the format of the current-time structure maintained by the kernel and visible through a mapped clock (clock_map_time). The data in this structure is updated at the clock's current resolution and contains the same tvalspec value that would be returned by clock_get_time.
Because of the race between the referencing of the multiple fields in the clock value and the kernel's setting them, they should be referenced as follows:
   tvalspec_t* ts;
   do
   {
              ts-> tv_sec = mtime -> mtv_time.tv_sec;
              ts  -> tv_nsec = mtime -> mtv_time.tv_nsec;
   } while (ts  -> tv_sec != mtime -> mtv_csec);
Functions: clock_map_time, clock_get_time.
Data Structures: tvalspec.