diff options
| -rw-r--r-- | ChangeLog | 21 | ||||
| -rw-r--r-- | manual/time.texi | 165 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/Makefile | 2 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/Versions | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/ntp_adjtime.c | 34 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/ntp_gettime.c | 38 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/sys/timex.h | 44 |
7 files changed, 290 insertions, 17 deletions
diff --git a/ChangeLog b/ChangeLog index eef1b4c6e1..110585b448 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,26 @@ 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. diff --git a/manual/time.texi b/manual/time.texi index 7b6c4b3a13..7084e7f110 100644 --- a/manual/time.texi +++ b/manual/time.texi @@ -25,6 +25,8 @@ an Alarm}. @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. @@ -1801,6 +1803,169 @@ The time is 01:02 PM. @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 diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index ac99436a8d..64baeb10d6 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -53,6 +53,8 @@ endif ifeq ($(subdir),time) sysdep_headers += sys/timex.h + +sysdep_routines += ntp_adjtime ntp_gettime endif ifeq ($(subdir),socket) diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions index eeaed93fc3..6210830cce 100644 --- a/sysdeps/unix/sysv/linux/Versions +++ b/sysdeps/unix/sysv/linux/Versions @@ -73,6 +73,9 @@ libc { # c* capget; capset; + # n* + ntp_adjtime; ntp_gettime; + # s* sendfile; diff --git a/sysdeps/unix/sysv/linux/ntp_adjtime.c b/sysdeps/unix/sysv/linux/ntp_adjtime.c new file mode 100644 index 0000000000..d9f3ca7b9c --- /dev/null +++ b/sysdeps/unix/sysv/linux/ntp_adjtime.c @@ -0,0 +1,34 @@ +/* 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); +} diff --git a/sysdeps/unix/sysv/linux/ntp_gettime.c b/sysdeps/unix/sysv/linux/ntp_gettime.c new file mode 100644 index 0000000000..664d85f92f --- /dev/null +++ b/sysdeps/unix/sysv/linux/ntp_gettime.c @@ -0,0 +1,38 @@ +/* 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; +} diff --git a/sysdeps/unix/sysv/linux/sys/timex.h b/sysdeps/unix/sysv/linux/sys/timex.h index aa3ee39d22..da1e33e85a 100644 --- a/sysdeps/unix/sysv/linux/sys/timex.h +++ b/sysdeps/unix/sysv/linux/sys/timex.h @@ -1,4 +1,4 @@ -/* 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 @@ -24,28 +24,35 @@ /* 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; @@ -109,6 +116,9 @@ __BEGIN_DECLS 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 */ |