| Message ID | 20191025120832.27667-6-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Y2038 preparation: use clock_[gs]ettime to implement the other time-getting and -setting functions. | expand |
On Fri, 25 Oct 2019 09:08:26 -0300 Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote: > Use clock_gettime to implement time. > > Changes from previous version: > > - Do not remove Linux arch-specific implementations. > > - Use CLOCK_REALTIME_COARSE for Linux. > > -- > > Change the default implementation of time to call clock_gettime, > to align with new Linux ports that are expected to only implement > __NR_clock_gettime. Arch-specific implementation that either call > the time vDSO or route to gettimeofday vDSO are not removed. > > Also for Linux, CLOCK_REALTIME_COARSE is used instead of generic > CLOCK_REALTIME clockid. This takes less CPU time and its behavior > better matches what the current glibc does. > > Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, > powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu. > > Co-authored-by: Zack Weinberg <zackw@panix.com> > --- > sysdeps/unix/sysv/linux/powerpc/time.c | 2 +- > .../sysv/linux/{time.c => time-internal.h} | 31 > ++++--------------- sysdeps/posix/time.c => time/time-internal.h | > 28 +++-------------- time/time.c | > 13 ++++---- 4 files changed, 17 insertions(+), 57 deletions(-) > rename sysdeps/unix/sysv/linux/{time.c => time-internal.h} (64%) > rename sysdeps/posix/time.c => time/time-internal.h (57%) > > diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c > b/sysdeps/unix/sysv/linux/powerpc/time.c index c35b80fad1..e957b81751 > 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c > +++ b/sysdeps/unix/sysv/linux/powerpc/time.c > @@ -78,6 +78,6 @@ libc_hidden_def (time) > > #else > > -#include <sysdeps/posix/time.c> > +#include <time/time.c> > > #endif /* !SHARED */ > diff --git a/sysdeps/unix/sysv/linux/time.c > b/sysdeps/unix/sysv/linux/time-internal.h similarity index 64% > rename from sysdeps/unix/sysv/linux/time.c > rename to sysdeps/unix/sysv/linux/time-internal.h > index f461733678..c4c5f6b643 100644 > --- a/sysdeps/unix/sysv/linux/time.c > +++ b/sysdeps/unix/sysv/linux/time-internal.h > @@ -1,4 +1,5 @@ > -/* Copyright (C) 2005-2019 Free Software Foundation, Inc. > +/* Internals of time and related functions. Linux version. > + Copyright 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 +16,7 @@ > License along with the GNU C Library; if not, see > <https://www.gnu.org/licenses/>. */ > > -#include <stddef.h> > -#include <time.h> > - > -#include <sysdep.h> > - > -#ifdef __NR_time > - > -time_t > -time (time_t *t) > -{ > - INTERNAL_SYSCALL_DECL (err); > - time_t res = INTERNAL_SYSCALL (time, err, 1, NULL); > - /* There cannot be any error. */ > - if (t != NULL) > - *t = res; > - return res; > -} > -libc_hidden_def (time) > - > -#else > - > -# include <sysdeps/posix/time.c> > - > -#endif > +/* Timer used on clock_gettime for time implementation. For Linux > + it uses the coarse version which returns the time at the last tick > + and mimic what time as syscall should return. */ > +#define TIME_CLOCK_GETTIME_CLOCKID CLOCK_REALTIME_COARSE > diff --git a/sysdeps/posix/time.c b/time/time-internal.h > similarity index 57% > rename from sysdeps/posix/time.c > rename to time/time-internal.h > index 0ab31bd7b6..f448f64191 100644 > --- a/sysdeps/posix/time.c > +++ b/time/time-internal.h > @@ -1,4 +1,5 @@ > -/* Copyright (C) 1991-2019 Free Software Foundation, Inc. > +/* Internals of time and related functions. > + Copyright 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 > @@ -15,26 +16,5 @@ > License along with the GNU C Library; if not, see > <https://www.gnu.org/licenses/>. */ > > -#include <stddef.h> /* For NULL. */ > -#include <time.h> > -#include <sys/time.h> > - > - > -/* Return the current time as a `time_t' and also put it in *T if T > is > - not NULL. Time is represented as seconds from Jan 1 00:00:00 > 1970. */ -time_t > -time (time_t *t) > -{ > - struct timeval tv; > - time_t result; > - > - if (__gettimeofday (&tv, (struct timezone *) NULL)) > - result = (time_t) -1; > - else > - result = (time_t) tv.tv_sec; > - > - if (t != NULL) > - *t = result; > - return result; > -} > -libc_hidden_def (time) > +/* Timer used on clock_gettime for time implementation. */ > +#define TIME_CLOCK_GETTIME_CLOCKID CLOCK_REALTIME > diff --git a/time/time.c b/time/time.c > index b53a06e29c..09a2b4fc88 100644 > --- a/time/time.c > +++ b/time/time.c > @@ -15,19 +15,18 @@ > License along with the GNU C Library; if not, see > <https://www.gnu.org/licenses/>. */ > > -#include <errno.h> > #include <time.h> > +#include <time-internal.h> > > /* Return the time now, and store it in *TIMER if not NULL. */ > time_t > time (time_t *timer) > { > - __set_errno (ENOSYS); > + struct timespec ts; > + __clock_gettime (TIME_CLOCK_GETTIME_CLOCKID, &ts); > > - if (timer != NULL) > - *timer = (time_t) -1; > - return (time_t) -1; > + if (timer) > + *timer = ts.tv_sec; > + return ts.tv_sec; > } > libc_hidden_def (time) > - > -stub_warning (time) 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
diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index c35b80fad1..e957b81751 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -78,6 +78,6 @@ libc_hidden_def (time) #else -#include <sysdeps/posix/time.c> +#include <time/time.c> #endif /* !SHARED */ diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time-internal.h similarity index 64% rename from sysdeps/unix/sysv/linux/time.c rename to sysdeps/unix/sysv/linux/time-internal.h index f461733678..c4c5f6b643 100644 --- a/sysdeps/unix/sysv/linux/time.c +++ b/sysdeps/unix/sysv/linux/time-internal.h @@ -1,4 +1,5 @@ -/* Copyright (C) 2005-2019 Free Software Foundation, Inc. +/* Internals of time and related functions. Linux version. + Copyright 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 +16,7 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <stddef.h> -#include <time.h> - -#include <sysdep.h> - -#ifdef __NR_time - -time_t -time (time_t *t) -{ - INTERNAL_SYSCALL_DECL (err); - time_t res = INTERNAL_SYSCALL (time, err, 1, NULL); - /* There cannot be any error. */ - if (t != NULL) - *t = res; - return res; -} -libc_hidden_def (time) - -#else - -# include <sysdeps/posix/time.c> - -#endif +/* Timer used on clock_gettime for time implementation. For Linux + it uses the coarse version which returns the time at the last tick + and mimic what time as syscall should return. */ +#define TIME_CLOCK_GETTIME_CLOCKID CLOCK_REALTIME_COARSE diff --git a/sysdeps/posix/time.c b/time/time-internal.h similarity index 57% rename from sysdeps/posix/time.c rename to time/time-internal.h index 0ab31bd7b6..f448f64191 100644 --- a/sysdeps/posix/time.c +++ b/time/time-internal.h @@ -1,4 +1,5 @@ -/* Copyright (C) 1991-2019 Free Software Foundation, Inc. +/* Internals of time and related functions. + Copyright 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 @@ -15,26 +16,5 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <stddef.h> /* For NULL. */ -#include <time.h> -#include <sys/time.h> - - -/* Return the current time as a `time_t' and also put it in *T if T is - not NULL. Time is represented as seconds from Jan 1 00:00:00 1970. */ -time_t -time (time_t *t) -{ - struct timeval tv; - time_t result; - - if (__gettimeofday (&tv, (struct timezone *) NULL)) - result = (time_t) -1; - else - result = (time_t) tv.tv_sec; - - if (t != NULL) - *t = result; - return result; -} -libc_hidden_def (time) +/* Timer used on clock_gettime for time implementation. */ +#define TIME_CLOCK_GETTIME_CLOCKID CLOCK_REALTIME diff --git a/time/time.c b/time/time.c index b53a06e29c..09a2b4fc88 100644 --- a/time/time.c +++ b/time/time.c @@ -15,19 +15,18 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <errno.h> #include <time.h> +#include <time-internal.h> /* Return the time now, and store it in *TIMER if not NULL. */ time_t time (time_t *timer) { - __set_errno (ENOSYS); + struct timespec ts; + __clock_gettime (TIME_CLOCK_GETTIME_CLOCKID, &ts); - if (timer != NULL) - *timer = (time_t) -1; - return (time_t) -1; + if (timer) + *timer = ts.tv_sec; + return ts.tv_sec; } libc_hidden_def (time) - -stub_warning (time)
Use clock_gettime to implement time. Changes from previous version: - Do not remove Linux arch-specific implementations. - Use CLOCK_REALTIME_COARSE for Linux. -- Change the default implementation of time to call clock_gettime, to align with new Linux ports that are expected to only implement __NR_clock_gettime. Arch-specific implementation that either call the time vDSO or route to gettimeofday vDSO are not removed. Also for Linux, CLOCK_REALTIME_COARSE is used instead of generic CLOCK_REALTIME clockid. This takes less CPU time and its behavior better matches what the current glibc does. Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu. Co-authored-by: Zack Weinberg <zackw@panix.com> --- sysdeps/unix/sysv/linux/powerpc/time.c | 2 +- .../sysv/linux/{time.c => time-internal.h} | 31 ++++--------------- sysdeps/posix/time.c => time/time-internal.h | 28 +++-------------- time/time.c | 13 ++++---- 4 files changed, 17 insertions(+), 57 deletions(-) rename sysdeps/unix/sysv/linux/{time.c => time-internal.h} (64%) rename sysdeps/posix/time.c => time/time-internal.h (57%) -- 2.17.1