From 3271d1ac389d2ec93db9c5b9ce0991ce478476cf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:09:41 +0200 Subject: Adding upstream version 4.3. Signed-off-by: Daniel Baumann --- sys_null.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 sys_null.c (limited to 'sys_null.c') diff --git a/sys_null.c b/sys_null.c new file mode 100644 index 0000000..3a0d5f6 --- /dev/null +++ b/sys_null.c @@ -0,0 +1,140 @@ +/* + chronyd/chronyc - Programs for keeping computer clocks accurate. + + ********************************************************************** + * Copyright (C) Miroslav Lichvar 2017 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program 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 + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + ********************************************************************** + + ======================================================================= + + Null clock driver for operation with no clock control. + */ + +#include "config.h" + +#include "sysincl.h" + +#include "sys_null.h" + +#include "local.h" +#include "localp.h" +#include "logging.h" +#include "util.h" + +/* Current frequency offset of the system clock (in ppm) */ +static double freq; + +/* Offset of the system clock at the last update */ +static double offset_register; + +/* Time of the last update */ +static struct timespec last_update; + +/* Minimum interval between updates when frequency is constant */ +#define MIN_UPDATE_INTERVAL 1000.0 + +/* ================================================== */ + +static void +update_offset(void) +{ + struct timespec now; + double duration; + + LCL_ReadRawTime(&now); + duration = UTI_DiffTimespecsToDouble(&now, &last_update); + offset_register += 1.0e-6 * freq * duration; + last_update = now; + + DEBUG_LOG("System clock offset=%e freq=%f", offset_register, freq); +} + +/* ================================================== */ + +static double +read_frequency(void) +{ + return freq; +} + +/* ================================================== */ + +static double +set_frequency(double freq_ppm) +{ + update_offset(); + freq = freq_ppm; + + return freq; +} + +/* ================================================== */ + +static void +accrue_offset(double offset, double corr_rate) +{ + offset_register += offset; +} + +/* ================================================== */ + +static int +apply_step_offset(double offset) +{ + return 0; +} + +/* ================================================== */ + +static void +offset_convert(struct timespec *raw, double *corr, double *err) +{ + double duration; + + duration = UTI_DiffTimespecsToDouble(raw, &last_update); + + if (duration > MIN_UPDATE_INTERVAL) { + update_offset(); + duration = 0.0; + } + + *corr = -1.0e-6 * freq * duration - offset_register; + + if (err) + *err = 0.0; +} + +/* ================================================== */ + +void +SYS_Null_Initialise(void) +{ + offset_register = 0.0; + LCL_ReadRawTime(&last_update); + + lcl_RegisterSystemDrivers(read_frequency, set_frequency, accrue_offset, + apply_step_offset, offset_convert, NULL, NULL); + + LOG(LOGS_INFO, "Disabled control of system clock"); +} + +/* ================================================== */ + +void +SYS_Null_Finalise(void) +{ +} -- cgit v1.2.3