[PATCH v2 07/11] Consolidate and deprecate ftime
Lukasz Majewski
lukma@denx.de
Mon Oct 28 13:23:00 GMT 2019
Hi Adhemerval,
> From: Zack Weinberg <zackw@panix.com>
>
> Consolidate and deprecate ftime
>
> Changes from previous version:
>
> - Do not remove sys/timeb.h, instead mark ftime as deprecated. The
> idea is still to remove it eventually on a future release.
>
> --
>
> ftime is an obsolete variation on gettimeofday, offering only
> millisecond time resolution; it was probably a system call in ooold
> versions of BSD Unix. For historic reasons, we had three
> implementations of it. These are all consolidated into time/ftime.c,
> and then the function is deprecated.
>
> For some reason, the implementation of ftime in terms of gettimeofday
> was rounding rather than truncating microseconds to milliseconds. In
> all the other places where we use a higher-resolution time function to
> implement a lower-resolution one, we truncate. ftime is changed to
> match, just for tidiness' sake.
>
> Like gettimeofday, ftime tries to report the time zone, and using that
> information is always a bug. This patch dummies out the reported
> timezone information; the timezone and dstflag fields of the
> returned "struct timeb" will always be zero.
>
> Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
> powerpc64-linux-gnu, and powerpc-linux-gnu.
>
> Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> NEWS | 3 +++
> sysdeps/unix/bsd/ftime.c | 40
> --------------------------------- sysdeps/unix/sysv/linux/ftime.c |
> 3 --- time/ftime.c | 26 ++++++++-------------
> time/sys/timeb.h | 3 ++-
> time/tst-ftime.c | 7 ++++++
> 6 files changed, 21 insertions(+), 61 deletions(-)
> delete mode 100644 sysdeps/unix/bsd/ftime.c
> delete mode 100644 sysdeps/unix/sysv/linux/ftime.c
>
> diff --git a/NEWS b/NEWS
> index 0b1476e745..6d109f84f0 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -58,6 +58,9 @@ Deprecated and removed features, and other changes
> affecting compatibility: settimeofday available to newly linked
> binaries after there is a replacement for Linux’s time-zone-like
> offset API.
> +* The obsolete functions ftime has been deprecated and will be
> removed from
> + a future version of glibc. Application should use clock_gettime
> instead. +
> Changes to build and runtime requirements:
>
> [Add changes to build and runtime requirements here]
> diff --git a/sysdeps/unix/bsd/ftime.c b/sysdeps/unix/bsd/ftime.c
> deleted file mode 100644
> index e1f20bc609..0000000000
> --- a/sysdeps/unix/bsd/ftime.c
> +++ /dev/null
> @@ -1,40 +0,0 @@
> -/* Copyright (C) 1994-2019 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 <sys/timeb.h>
> -#include <sys/time.h>
> -
> -int
> -ftime (struct timeb *timebuf)
> -{
> - struct timeval tv;
> - struct timezone tz;
> -
> - if (__gettimeofday (&tv, &tz) < 0)
> - return -1;
> -
> - timebuf->time = tv.tv_sec;
> - timebuf->millitm = (tv.tv_usec + 500) / 1000;
> - if (timebuf->millitm == 1000)
> - {
> - ++timebuf->time;
> - timebuf->millitm = 0;
> - }
> - timebuf->timezone = tz.tz_minuteswest;
> - timebuf->dstflag = tz.tz_dsttime;
> - return 0;
> -}
> diff --git a/sysdeps/unix/sysv/linux/ftime.c
> b/sysdeps/unix/sysv/linux/ftime.c deleted file mode 100644
> index 5a5949f608..0000000000
> --- a/sysdeps/unix/sysv/linux/ftime.c
> +++ /dev/null
> @@ -1,3 +0,0 @@
> -/* Linux defines the ftime system call but doesn't actually implement
> - it. Use the BSD implementation. */
> -#include <sysdeps/unix/bsd/ftime.c>
> diff --git a/time/ftime.c b/time/ftime.c
> index 8bedc0d91e..b4bd58ecef 100644
> --- a/time/ftime.c
> +++ b/time/ftime.c
> @@ -1,4 +1,5 @@
> -/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
> +/* Deprecated return date and time.
> + Copyright (C) 1994-2019 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
> @@ -15,27 +16,18 @@
> License along with the GNU C Library; if not, see
> <https://www.gnu.org/licenses/>. */
>
> -#include <errno.h>
> -#include <time.h>
> #include <sys/timeb.h>
> +#include <time.h>
>
> int
> ftime (struct timeb *timebuf)
> {
> - int save = errno;
> - struct tm tp;
> -
> - __set_errno (0);
> - if (time (&timebuf->time) == (time_t) -1 && errno != 0)
> - return -1;
> - timebuf->millitm = 0;
> -
> - if (__localtime_r (&timebuf->time, &tp) == NULL)
> - return -1;
> -
> - timebuf->timezone = tp.tm_gmtoff / 60;
> - timebuf->dstflag = tp.tm_isdst;
> + struct timespec ts;
> + __clock_gettime (CLOCK_REALTIME, &ts);
>
> - __set_errno (save);
> + timebuf->time = ts.tv_sec;
> + timebuf->millitm = ts.tv_nsec / 1000000;
> + timebuf->timezone = 0;
> + timebuf->dstflag = 0;
> return 0;
> }
> diff --git a/time/sys/timeb.h b/time/sys/timeb.h
> index b958dc3e4a..5c16f79da2 100644
> --- a/time/sys/timeb.h
> +++ b/time/sys/timeb.h
> @@ -36,7 +36,8 @@ struct timeb
>
> /* Fill in TIMEBUF with information about the current time. */
>
> -extern int ftime (struct timeb *__timebuf);
> +extern int ftime (struct timeb *__timebuf)
> + __nonnull ((1)) __attribute_deprecated__;
>
> __END_DECLS
>
> diff --git a/time/tst-ftime.c b/time/tst-ftime.c
> index 4b7e90cc03..39d94a1b26 100644
> --- a/time/tst-ftime.c
> +++ b/time/tst-ftime.c
> @@ -18,6 +18,7 @@
>
> #include <sys/timeb.h>
> #include <stdio.h>
> +#include <libc-diag.h>
>
> static int
> do_test (void)
> @@ -29,12 +30,18 @@ do_test (void)
> {
> prev = curr;
>
> + /* ftime was deprecated on 2.31. */
> + DIAG_PUSH_NEEDS_COMMENT;
> + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
> +
> if (ftime (&curr))
> {
> printf ("ftime returned an error\n");
> return 1;
> }
>
> + DIAG_POP_NEEDS_COMMENT;
> +
> if (curr.time < prev.time)
> {
> printf ("ftime's time flowed backwards\n");
Reviewed-by: Lukasz Majewski <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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