This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC v2 07/20] sysdeps/gettimeofday: Use clock_gettime64 if avaliable



On 24/06/2019 21:09, Alistair Francis wrote:
> Not all architectures support the obsolete gettimeofday so use the
> newer clock_gettime64 syscall if it is avaliable. This fixes RV32
> build issues.
> 
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  ChangeLog                              |  1 +
>  sysdeps/unix/sysv/linux/gettimeofday.c | 28 ++++++++++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/ChangeLog b/ChangeLog
> index a700783ef3..f1c7acb6ab 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -4,6 +4,7 @@
>  	* sysdeps/unix/sysv/linux/nanosleep.c: Likewise.
>  	* sysdeps/unix/sysv/linux/nanosleep_nocancel.c: Likewise.
>  	* sysdeps/unix/sysv/linux/lowlevellock-futex.h: Use __NR_futex_time64 if we don't have __NR_futex.
> +	* sysdeps/unix/sysv/linux/gettimeofday.c: Use clock_gettime64 syscall for gettimeofday.
>  
>  2019-06-20  Dmitry V. Levin  <ldv@altlinux.org>
>  	    Florian Weimer  <fweimer@redhat.com>
> diff --git a/sysdeps/unix/sysv/linux/gettimeofday.c b/sysdeps/unix/sysv/linux/gettimeofday.c
> index a74f03825a..3d2b943123 100644
> --- a/sysdeps/unix/sysv/linux/gettimeofday.c
> +++ b/sysdeps/unix/sysv/linux/gettimeofday.c
> @@ -32,7 +32,35 @@
>  int
>  __gettimeofday (struct timeval *tv, struct timezone *tz)
>  {
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +  int ret;
> +  struct timespec now;
> +
> +  ret = INLINE_VSYSCALL (clock_gettime64, 2, CLOCK_REALTIME,
> +                         &now);
> +
> +  /* Convert from timespec to timeval */
> +  tv->tv_sec = now.tv_sec;
> +  tv->tv_usec = now.tv_nsec / 1000;
> +
> +  return ret;
> +#else
> +# ifdef __NR_clock_gettime64
> +  long int ret;
> +  struct timespec now;
> +
> +  ret = INLINE_VSYSCALL (clock_gettime64, 2, CLOCK_REALTIME,
> +                         &now);
> +
> +  /* Convert from timespec to timeval */
> +  tv->tv_sec = now.tv_sec;
> +  tv->tv_usec = now.tv_nsec / 1000;
> +
> +  if (ret == 0 || errno != ENOSYS)
> +    return ret;
> +# endif
>    return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
> +#endif
>  }
>  libc_hidden_def (__gettimeofday)
>  weak_alias (__gettimeofday, gettimeofday)
> 

Wouldn't be simpler to just call __clock_gettime instead:

--
__gettimeofday (struct timeval *tv, struct timezone *tz)
{
  if (tv == NULL)
    return 0;

  struct timespec ts;
  __clock_gettime (CLOCK_REALTIME, &ts);
  tv->tv_sec = ts.tv_sec;
  tv->tv_usec = (__suseconds_t)ts.tv_nsec / 1000;
  return 0;
}
--

>From the patch 'linux: Provide __clock_settime64 implementation' internal
include/time.h will redefine __clock_gettime to __clock_gettime64 if the
case.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]