(foreign-declare "#include <time.h>")

(define realtime-microsecs (foreign-lambda* double ()
  "struct timespec ts;
   if( clock_gettime( CLOCK_MONOTONIC, &ts ) < 0 )
     return( -1.0 );
   return( ((double) ts.tv_sec) * 1000000.0 + ((double) ts.tv_nsec) / 1000.0 );"))