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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/y2038-preliminaries] Use clock_gettime to implement time. Date: Fri, 25 Oct 2019 11:25:00 -0000 [thread overview] Message-ID: <20191025112552.117593.qmail@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bfc9f6179a0fdb070428010b0c5f022cca4a8c9d commit bfc9f6179a0fdb070428010b0c5f022cca4a8c9d Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> Date: Thu Oct 24 17:52:30 2019 +0000 Use clock_gettime to implement time. 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> Diff: --- sysdeps/unix/sysv/linux/powerpc/time.c | 2 +- .../unix/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(-) diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index c35b80f..e957b81 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 f461733..c4c5f6b 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 0ab31bd..f448f64 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 b53a06e..09a2b4f 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)
next reply other threads:[~2019-10-25 11:25 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-25 11:25 Adhemerval Zanella [this message] -- strict thread matches above, loose matches on Subject: below -- 2019-09-10 17:20 Adhemerval Zanella
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