[PATCH v2] tst: Add test for adjtime
Lukasz Majewski
lukma@denx.de
Tue Apr 13 08:28:59 GMT 2021
Dear Community,
> Dear Community,
>
> > This code provides test to check if time on target machine is
> > properly adjusted.
> > The time is altered only when cross-test-ssh.sh is executed with
> > --allow-time-setting flag.
> >
> > As the delta added to clock is only 1 sec the original time is not
> > restored and further tests are executed with this bias.
> >
> > It is important to note that adjtime() adjusts the system time with
> > small amounts in each second (it is in fact a wrapper on
> > clock_adjtime with modes = ADJ_OFFSET_SINGLESHOT). In other words
> > some seconds (may be a random value) needs to elapse until the
> > required time offset is added to the clock. It may take
> > considerable time (in minutes) to adjust clock by e.g. 1 second.
> >
> > To handle that the struct timeval odelta is passed to adjtime (NULL,
> > &odelta) to get information of the still required delta to be added
> > to clock. This is done in loop until its members are equal to 0.
> >
> > As a reference - CLOCK_MONOTONIC is used to check if CLOCK_REALTIME
> > has been adjusted. The difference between them is measured.
> >
> > ---
> > Changes for v2:
> > - Correct code indentation
> > ---
>
> Gentle ping on this patch. Is this approach acceptable for testing
> adjtime?
Gentle ping on this patch...
>
> > sysdeps/unix/sysv/linux/Makefile | 3 +-
> > sysdeps/unix/sysv/linux/tst-adjtime.c | 83
> > +++++++++++++++++++++++++++ 2 files changed, 85 insertions(+), 1
> > deletion(-) create mode 100644 sysdeps/unix/sysv/linux/tst-adjtime.c
> >
> > diff --git a/sysdeps/unix/sysv/linux/Makefile
> > b/sysdeps/unix/sysv/linux/Makefile index ddc1e748e6..30c8629386
> > 100644 --- a/sysdeps/unix/sysv/linux/Makefile
> > +++ b/sysdeps/unix/sysv/linux/Makefile
> > @@ -113,7 +113,8 @@ tests += tst-clone tst-clone2 tst-clone3
> > tst-fanotify tst-personality \ tst-tgkill tst-sysvsem-linux
> > tst-sysvmsg-linux tst-sysvshm-linux \ tst-timerfd tst-ppoll
> > tst-futimens tst-utime tst-utimes \ tst-clock_adjtime tst-adjtimex
> > tst-ntp_adjtime tst-ntp_gettime \
> > - tst-ntp_gettimex tst-sigtimedwait tst-futimes tst-lutimes
> > + tst-ntp_gettimex tst-sigtimedwait tst-futimes tst-lutimes
> > \
> > + tst-adjtime
> >
> > # Test for the symbol version of fcntl that was replaced in glibc
> > 2.28. ifeq ($(have-GLIBC_2.27)$(build-shared),yesyes)
> > diff --git a/sysdeps/unix/sysv/linux/tst-adjtime.c
> > b/sysdeps/unix/sysv/linux/tst-adjtime.c new file mode 100644
> > index 0000000000..4b24fcb890
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-adjtime.c
> > @@ -0,0 +1,83 @@
> > +/* Test for adjtime.
> > + Copyright (C) 2021 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 Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 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
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include <time.h>
> > +#include <stdlib.h>
> > +#include <sys/time.h>
> > +#include <sys/timerfd.h>
> > +#include <support/check.h>
> > +#include <support/xunistd.h>
> > +#include <support/timespec.h>
> > +
> > +#define TIMEOUT (60*10)
> > +#define ADJTIME_LOOP_SLEEP 10000
> > +
> > +static int
> > +do_test (void)
> > +{
> > + struct timespec tv_then, tv_now, tv_then_m, tv_now_m;
> > + struct timeval delta, odelta;
> > + int ret;
> > +
> > + /* Check if altering target time is allowed. */
> > + if (getenv (SETTIME_ENV_NAME) == NULL)
> > + FAIL_UNSUPPORTED ("adjtime is executed only when "\
> > + SETTIME_ENV_NAME" is set\n");
> > +
> > + tv_then = xclock_now (CLOCK_REALTIME);
> > + tv_then_m = xclock_now (CLOCK_MONOTONIC);
> > +
> > + /* Setup time value to adjust - 1 sec. */
> > + delta.tv_sec = 1;
> > + delta.tv_usec = 0;
> > +
> > + ret = adjtime (&delta, NULL);
> > + if (ret == -1)
> > + FAIL_EXIT1 ("adjtime failed: %m\n");
> > +
> > + /* As adjtime adjust clock time gradually by some small
> > percentage
> > + of delta in each second one needs to check if this process has
> > + been finished. */
> > + do
> > + {
> > + ret = adjtime (NULL, &odelta);
> > + if (ret == -1)
> > + FAIL_EXIT1 ("adjtime failed: %m\n");
> > +
> > + ret = usleep (ADJTIME_LOOP_SLEEP);
> > + if (ret != 0)
> > + FAIL_EXIT1 ("usleep failed: %m\n");
> > + }
> > + while ( ! (odelta.tv_sec == 0 && odelta.tv_usec == 0));
> > +
> > + tv_now = xclock_now (CLOCK_REALTIME);
> > + tv_now_m = xclock_now (CLOCK_MONOTONIC);
> > +
> > + /* Check if adjtime adjusted the system time. */
> > + struct timespec r = timespec_sub (tv_now, tv_then);
> > + struct timespec r_m = timespec_sub (tv_now_m, tv_then_m);
> > +
> > + struct timespec r_adjtime = timespec_sub (r, r_m);
> > +
> > + TEST_COMPARE (support_timespec_check_in_range
> > + ((struct timespec) { 1, 0 }, r_adjtime, 0.9, 1.1),
> > 1); +
> > + return 0;
> > +}
> > +
> > +#include <support/test-driver.c>
>
>
>
>
> Best regards,
>
> Lukasz Majewski
>
> --
>
> DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email:
> lukma@denx.de
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
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