[v2,08/11] Use clock_gettime to implement timespec_get.
Commit Message
From: Zack Weinberg <zackw@panix.com>
Use clock_gettime to implement timespec_get.
Changes from previous version:
- Change commit message remove the rationale to not promote it.
--
timespec_get is the same function as clock_gettime, with an obnoxious
coating of NIH painted on it by the ISO C committee. In addition to
the rename, it takes its arguments in a different order, it returns 0
on *failure* or a positive number on *success*, and it requires that
all of its TIME_* constants be positive. This last means we cannot
directly reuse the existing CLOCK_* constants for it, because
those have been allocated starting with CLOCK_REALTIME = 0 on all
existing platforms.
This patch simply promotes the sysdeps/posix implementation to
universal, and removes the Linux-specific implementation, whose
apparent reason for existing was to cut out one function call's worth
of overhead.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
---
sysdeps/posix/timespec_get.c | 32 ------------------
sysdeps/unix/sysv/linux/timespec_get.c | 46 --------------------------
time/timespec_get.c | 14 +++-----
3 files changed, 4 insertions(+), 88 deletions(-)
delete mode 100644 sysdeps/posix/timespec_get.c
delete mode 100644 sysdeps/unix/sysv/linux/timespec_get.c
Comments
Hi Adhemerval,
> From: Zack Weinberg <zackw@panix.com>
>
> Use clock_gettime to implement timespec_get.
>
> Changes from previous version:
>
> - Change commit message remove the rationale to not promote it.
>
> --
>
> timespec_get is the same function as clock_gettime, with an obnoxious
> coating of NIH painted on it by the ISO C committee. In addition to
> the rename, it takes its arguments in a different order, it returns 0
> on *failure* or a positive number on *success*, and it requires that
> all of its TIME_* constants be positive. This last means we cannot
> directly reuse the existing CLOCK_* constants for it, because
> those have been allocated starting with CLOCK_REALTIME = 0 on all
> existing platforms.
>
> This patch simply promotes the sysdeps/posix implementation to
> universal, and removes the Linux-specific implementation, whose
> apparent reason for existing was to cut out one function call's worth
> of overhead.
>
> Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
> powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
> ---
> sysdeps/posix/timespec_get.c | 32 ------------------
> sysdeps/unix/sysv/linux/timespec_get.c | 46
> -------------------------- time/timespec_get.c |
> 14 +++----- 3 files changed, 4 insertions(+), 88 deletions(-)
> delete mode 100644 sysdeps/posix/timespec_get.c
> delete mode 100644 sysdeps/unix/sysv/linux/timespec_get.c
>
> diff --git a/sysdeps/posix/timespec_get.c
> b/sysdeps/posix/timespec_get.c deleted file mode 100644
> index e3146da2d3..0000000000
> --- a/sysdeps/posix/timespec_get.c
> +++ /dev/null
> @@ -1,32 +0,0 @@
> -/* timespec_get -- C11 interface to sample a clock. Generic POSIX.1
> version.
> - Copyright (C) 2013-2019 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 <time.h>
> -
> -
> -/* Set TS to calendar time based in time base BASE. */
> -int
> -timespec_get (struct timespec *ts, int base)
> -{
> - if (base == TIME_UTC)
> - {
> - __clock_gettime (CLOCK_REALTIME, ts);
> - return base;
> - }
> - return 0;
> -}
> diff --git a/sysdeps/unix/sysv/linux/timespec_get.c
> b/sysdeps/unix/sysv/linux/timespec_get.c deleted file mode 100644
> index 629827d0f9..0000000000
> --- a/sysdeps/unix/sysv/linux/timespec_get.c
> +++ /dev/null
> @@ -1,46 +0,0 @@
> -/* Copyright (C) 2011-2019 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.
> -
> - 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 <sysdep.h>
> -#include <errno.h>
> -
> -#ifdef HAVE_CLOCK_GETTIME_VSYSCALL
> -# define HAVE_VSYSCALL
> -#endif
> -#include <sysdep-vdso.h>
> -
> -/* Set TS to calendar time based in time base BASE. */
> -int
> -timespec_get (struct timespec *ts, int base)
> -{
> - switch (base)
> - {
> - int res;
> - INTERNAL_SYSCALL_DECL (err);
> - case TIME_UTC:
> - res = INTERNAL_VSYSCALL (clock_gettime, err, 2,
> CLOCK_REALTIME, ts);
> - if (INTERNAL_SYSCALL_ERROR_P (res, err))
> - return 0;
> - break;
> -
> - default:
> - return 0;
> - }
> -
> - return base;
> -}
> diff --git a/time/timespec_get.c b/time/timespec_get.c
> index cef9a4263c..5124c747c2 100644
> --- a/time/timespec_get.c
> +++ b/time/timespec_get.c
> @@ -22,16 +22,10 @@
> int
> timespec_get (struct timespec *ts, int base)
> {
> - switch (base)
> + if (base == TIME_UTC)
> {
> - case TIME_UTC:
> - /* Not supported. */
> - return 0;
> -
> - default:
> - return 0;
> + __clock_gettime (CLOCK_REALTIME, ts);
> + return base;
> }
> -
> - return base;
> + return 0;
> }
> -stub_warning (timespec_get)
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
deleted file mode 100644
@@ -1,32 +0,0 @@
-/* timespec_get -- C11 interface to sample a clock. Generic POSIX.1 version.
- Copyright (C) 2013-2019 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 <time.h>
-
-
-/* Set TS to calendar time based in time base BASE. */
-int
-timespec_get (struct timespec *ts, int base)
-{
- if (base == TIME_UTC)
- {
- __clock_gettime (CLOCK_REALTIME, ts);
- return base;
- }
- return 0;
-}
deleted file mode 100644
@@ -1,46 +0,0 @@
-/* Copyright (C) 2011-2019 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.
-
- 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 <sysdep.h>
-#include <errno.h>
-
-#ifdef HAVE_CLOCK_GETTIME_VSYSCALL
-# define HAVE_VSYSCALL
-#endif
-#include <sysdep-vdso.h>
-
-/* Set TS to calendar time based in time base BASE. */
-int
-timespec_get (struct timespec *ts, int base)
-{
- switch (base)
- {
- int res;
- INTERNAL_SYSCALL_DECL (err);
- case TIME_UTC:
- res = INTERNAL_VSYSCALL (clock_gettime, err, 2, CLOCK_REALTIME, ts);
- if (INTERNAL_SYSCALL_ERROR_P (res, err))
- return 0;
- break;
-
- default:
- return 0;
- }
-
- return base;
-}
@@ -22,16 +22,10 @@
int
timespec_get (struct timespec *ts, int base)
{
- switch (base)
+ if (base == TIME_UTC)
{
- case TIME_UTC:
- /* Not supported. */
- return 0;
-
- default:
- return 0;
+ __clock_gettime (CLOCK_REALTIME, ts);
+ return base;
}
-
- return base;
+ return 0;
}
-stub_warning (timespec_get)