In article <[EMAIL PROTECTED]>, David L. Mills <[EMAIL PROTECTED]> wrote:
>If POSIX has no way to discipline the clock frequency, the clock >frequency is not disciplined and the platform not reliably >synchronized. POSIX makes no claim about whether the clock has any connection whatsoever with reality. POSIX must provide for a wide variety of environments, including non-networked machines with free-running clocks that may be set from a repair technician's wristwatch once every three years. As I said, it's only a fluke that the clock_settime() interface is even in POSIX -- prior to the Real Time Extensions work there simply was no way to set the clock at all, just as there still is no way to create a new user, reboot the system, or perform any number of other administrative operations. POSIX is just an API standard; it does not try to include every possible function an operating system needs to have. I tried to interest people in an interface which would at least allow applications to *tell* whether the clock was synchronized with anything, but unfortunately timekeeping in POSIX is a deep quagmire, and any time anyone brings up any changes to the timekeeping interfaces, they are immediately overwhelmed with demands to fix the Y2038 Problem, the Leap Second Problem, the struct timespec problem, the Time Zone Thread-Safety Problem, and innumerable other pet defects. I am certainly not going to spend all my spare time dealing with that, and I don't know anyone else with the stomach for it. -GAWollman -- Garrett A. Wollman | As the Constitution endures, persons in every [EMAIL PROTECTED] | generation can invoke its principles in their own Opinions not those | search for greater freedom. of MIT or CSAIL. | - A. Kennedy, Lawrence v. Texas, 539 U.S. 558 (2003) _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
