1999-01-07 Ulrich Drepper <drepper@cygnus.com>
+ * sysdeps/unix/sysv/linux/Makefile [subdir=time] (sysdep_routines):
+ Add ntp_adjtime and ntp_gettime.
+ * sysdeps/unix/sysv/linux/Versions [GLIBC_2.1]: Add ntp_adjtime and
+ ntp_gettime.
+
+1998-12-29 Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
+
+ * manual/time.texi (Precision Time): Add documentation for
+ ntp_gettime and ntp_adjtime.
+
+1998-12-28 Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
+
+ * sysdeps/unix/sysv/linux/ntp_gettime.c: Created new file
+
+ * sysdeps/unix/sysv/linux/ntp_adjtime.c: Created new file
+
+ * sysdeps/unix/sysv/linux/sys/timex.h (struct ntptimeval): Added.
+ Add prototypes for ntp_adjtime and ntp_gettime.
+
+1999-01-07 Ulrich Drepper <drepper@cygnus.com>
+
* sysdeps/i386/bits/select.h (__FD_ZERO): Remove early clobbers
from c and D register output.
@menu
* Processor Time:: Measures processor time used by a program.
* Calendar Time:: Manipulation of ``real'' dates and times.
+* Precision Time:: Manipulation and monitoring of high accuracy
+ time.
* Setting an Alarm:: Sending a signal after a specified time.
* Sleeping:: Waiting for a period of time.
* Resource Usage:: Measuring various resources used.
@end smallexample
+@node Precision Time
+@section Precision Time
+
+@cindex time, high precision
+@pindex sys/timex.h
+The @code{net_gettime} and @code{ntp_adjtime} functions provide an
+interface to monitor and manipulate high precision time. These
+functions are declared in @file{sys/timex.h}.
+
+@tindex struct ntptimeval
+@deftp {Data Type} {struct ntptimeval}
+This structure is used to monitor kernel time. It contains the
+following members:
+@table @code
+@item struct timeval time
+This is the current time. The @code{struct timeval} data type is
+described in @ref{High-Resolution Calendar}.
+
+@item long int maxerror
+This is the maximum error, measured in microseconds. Unless updated
+via @code{ntp_adjtime} periodically, this value will reach some
+platform-specific maximum value.
+
+@item long int esterror
+This is the estimated error, measured in microseconds. This value can
+be set by @code{ntp_adjtime} to indicate the estimated offset of the
+local clock against the true time.
+@end table
+@end deftp
+
+@comment sys/timex,h
+@comment GNU
+@deftypefun int ntp_gettime (struct ntptimeval *@var{tptr})
+The @code{ntp_gettime} function sets the structure pointed to by
+@var{tptr} to current values. The elements of the structure afterwards
+contain the values the timer implementation in the kernel assumes. They
+might or might not be correct. If they are not a @code{ntp_adjtime}
+call is necessary.
+
+The return value is @code{0} on success and other values on failure. The
+following @code{errno} error conditions are defined for this function:
+
+@table @code
+@item TIME_ERROR
+The precision clock model is not properly set up at the moment, thus the
+clock must be considered unsynchronized, and the values should be
+treated with care.
+@end table
+@end deftypefun
+
+@tindex struct timex
+@deftp {Data Type} {struct timex}
+This structure is used to control and monitor kernel time in a greater
+level of detail. It contains the following members:
+@table @code
+@item unsigned int mode
+This variable controls whether and which values are set. Several
+symbolic constants have to be combined with @emph{binary or} to specify
+the effective mode. These constants start with @code{MOD_}.
+
+@item long int offset
+This value indicates the current offset of the local clock from the true
+time. The value is given in microseconds. If bit @code{MOD_OFFSET} is
+set in @code{mode}, the offset (and possibly other dependent values) can
+be set. The offset's absolute value must not exceed @code{MAXPHASE}.
+
+@item long int frequency
+This value indicates the difference in frequency between the true time
+and the local clock. The value is expressed as scaled PPM (parts per
+million, 0.0001%). The scaling is @code{1 << SHIFT_USEC}. The value
+can be set with bit @code{MOD_FREQUENCY}, but the absolute value must
+not exceed @code{MAXFREQ}.
+
+@item long int maxerror
+This is the maximum error, measured in microseconds. A new value can be
+set using bit @code{MOD_MAXERROR}. Unless updated via
+@code{ntp_adjtime} periodically, this value will increase steadily
+and reach some platform-specific maximum value.
+
+@item long int esterror
+This is the estimated error, measured in microseconds. This value can
+be set using bit @code{MOD_ESTERROR}.
+
+@item int status
+This valiable reflects the various states of the clock machinery. There
+are symbolic constants for the significant bits, starting with
+@code{STA_}. Some of these flags can be updated using the
+@code{MOD_STATUS} bit.
+
+@item long int constant
+This value represents the bandwidth or stiffness of the PLL (phase
+locked loop) implemented in the kernel. The value can be changed using
+bit @code{MOD_TIMECONST}.
+
+@item long int precision
+This value represents the accuracy or the maximum error when reading the
+system clock. The value is expressed in microseconds and can't be changed.
+
+@item long int tolerance
+This value represents the maximum frequency error of the system clock in
+scaled PPM. This value is used to increase the @code{maxerror} every
+second.
+
+@item long int ppsfreq
+This is the first of a few optional variables that are present only if
+the system clock can use a PPS (pulse per second) signal to discipline
+the local clock. The value is expressed in scaled PPM and it denotes
+the difference in frequency between the local clock and the PPS signal.
+
+@item long int jitter
+This value expresses a median filtered average of the PPS signal's
+dispersion in microseconds.
+
+@item int int shift
+This value is a binary exponent for the duration of the PPS calibration
+interval, ranging from @code{PPS_SHIFT} to @code{PPS_SHIFTMAX}.
+
+@item long int stabil
+This value represents the median filtered dispersion of the PPS
+frequency in scaled PPM.
+
+@item long int jitcnt
+This counter represents the numer of pulses where the jitter exceeded
+the allowed maximum @code{MAXTIME}.
+
+@item long int calcnt
+This counter reflects the number of successful calibration intervals.
+
+@item long int errcnt
+This counter represents the number of calibration errors (caused by
+large offsets or jitter).
+
+@item long int stbcnt
+This counter denotes the number of of calibrations where the stability
+exceeded the threshold.
+@end table
+@end deftp
+
+@comment sys/timex.h
+@comment GNU
+@deftypefun int ntp_adjtime (int @var{mode}, struct timex *@var{tptr})
+The @code{ntp_adjtime} function sets the structure specified by
+@var{tptr} to current values. In addition, values passed in @var{tptr}
+can be used to replace existing settings. Therefore several magic
+values can be passed in @var{mode}. Setting @var{mode} to zero only
+reads the current state.
+
+The return value is @code{0} on success and other values on failure. The
+following @code{errno} error conditions are defined for this function:
+
+@table @code
+@item TIME_ERROR
+The precision clock model is not properly set up at the moment, thus the
+clock must be considered unsynchronized, and the values should be
+treated with care. Another reason could be that the specified new values
+are not allowed.
+@end table
+
+For more details see RFC1305 (Network Time Protocol, Version 3) and
+related documents.
+@end deftypefun
+
+
@node Setting an Alarm
@section Setting an Alarm
ifeq ($(subdir),time)
sysdep_headers += sys/timex.h
+
+sysdep_routines += ntp_adjtime ntp_gettime
endif
ifeq ($(subdir),socket)
# c*
capget; capset;
+ # n*
+ ntp_adjtime; ntp_gettime;
+
# s*
sendfile;
--- /dev/null
+/* Copyright (C) 1999 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <sys/timex.h>
+
+#ifndef MOD_OFFSET
+# define modes mode
+#endif
+
+int
+ntp_adjtime (amode, tntx)
+ int amode;
+ struct timex *tntx;
+{
+ /* Relies on the fact that C lib's struct timex corresponds to kernel's
+ struct timex. Otherwise you'll need a wrapper. */
+ tntx->modes = amode;
+ return __adjtimex (tntx);
+}
--- /dev/null
+/* Copyright (C) 1999 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <sys/timex.h>
+
+#ifndef MOD_OFFSET
+# define modes mode
+#endif
+
+int
+ntp_gettime (ntv)
+ struct ntptimeval *ntv;
+{
+ struct timex tntx;
+ int result;
+
+ tntx.modes = 0;
+ result = __adjtimex (&tntx);
+ ntv->time = tntx.time;
+ ntv->maxerror = tntx.maxerror;
+ ntv->esterror = tntx.esterror;
+ return result;
+}
-/* Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
/* These definitions from linux/timex.h as of 2.1.130. */
+struct ntptimeval
+{
+ struct timeval time; /* current time (ro) */
+ long int maxerror; /* maximum error (us) (ro) */
+ long int esterror; /* estimated error (us) (ro) */
+};
+
struct timex
{
unsigned int modes; /* mode selector */
- long offset; /* time offset (usec) */
- long freq; /* frequency offset (scaled ppm) */
- long maxerror; /* maximum error (usec) */
- long esterror; /* estimated error (usec) */
+ long int offset; /* time offset (usec) */
+ long int freq; /* frequency offset (scaled ppm) */
+ long int maxerror; /* maximum error (usec) */
+ long int esterror; /* estimated error (usec) */
int status; /* clock command/status */
- long constant; /* pll time constant */
- long precision; /* clock precision (usec) (read only) */
- long tolerance; /* clock frequency tolerance (ppm) (read only) */
+ long int constant; /* pll time constant */
+ long int precision; /* clock precision (usec) (read only) */
+ long int tolerance; /* clock frequency tolerance (ppm) (read only) */
struct timeval time; /* (read only) */
- long tick; /* (modified) usecs between clock ticks */
+ long int tick; /* (modified) usecs between clock ticks */
- long ppsfreq; /* pps frequency (scaled ppm) (ro) */
- long jitter; /* pps jitter (us) (ro) */
- int shift; /* interval duration (s) (shift) (ro) */
- long stabil; /* pps stability (scaled ppm) (ro) */
- long jitcnt; /* jitter limit exceeded (ro) */
- long calcnt; /* calibration intervals (ro) */
- long errcnt; /* calibration errors (ro) */
- long stbcnt; /* stability limit exceeded (ro) */
+ long int ppsfreq; /* pps frequency (scaled ppm) (ro) */
+ long int jitter; /* pps jitter (us) (ro) */
+ int shift; /* interval duration (s) (shift) (ro) */
+ long int stabil; /* pps stability (scaled ppm) (ro) */
+ long int jitcnt; /* jitter limit exceeded (ro) */
+ long int calcnt; /* calibration intervals (ro) */
+ long int errcnt; /* calibration errors (ro) */
+ long int stbcnt; /* stability limit exceeded (ro) */
/* ??? */
int :32; int :32; int :32; int :32;
extern int __adjtimex __P ((struct timex *__ntx));
extern int adjtimex __P ((struct timex *__ntx));
+extern int ntp_gettime __P ((struct ntptimeval *__ntv));
+extern int ntp_adjtime __P ((int __amode, struct timex *__tntx));
+
__END_DECLS
#endif /* sys/timex.h */
projects / external / glibc.git / commitdiff