_sir_msec_since   180 src/libsir/include/sir/internal.h double _sir_msec_since(const sir_time* when, sir_time* out);
_sir_msec_since   594 src/libsir/src/sirinternal.c     double msec_since_thrd_chk = _sir_msec_since(&_sir_last_thrd_chk, &thrd_chk);