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] |
Hi Alistair, Joseph, > The nanosleep syscall is not supported on newer 32-bit platforms (such > as RV32). To fix this issue let's use clock_nanosleep_time64 if it is > avaliable. > > Let's use CLOCK_REALTIME when calling clock_nanosleep_time64 as the > Linux specification says: > "POSIX.1 specifies that nanosleep() should measure time against the > CLOCK_REALTIME clock. However, Linux measures the time using the > CLOCK_MONOTONIC clock. This probably does not matter, since the > POSIX.1 specification for clock_settime(2) says that discontinuous > changes in CLOCK_REALTIME should not affect nanosleep()" > > Let's also expose __clock_nanosleep internally to avoid code > duplication. > --- > This was patch was runtime tested with RV32 and RV64 > It was build tested using the ./scripts/build-many-glibcs.py script. > > I am currently running: > $ make ; make install ; make check > tests on native ARM (32-bit) with the following three confiugrations: > - 4.19 Kernel and 4.19 Headers > - 5.2 Kernel and 4.19 Headers > - 5.2 Kernel and 5.2 Headers > I should have the results tomorrow. > > v4: > - Rebase on master > - Use __clock_nanosleep to avoid duplicate implementations > - Fix the error handling when a syscall fails > v2: > - Explicitly include `#include <kernel-features.h>` > > include/time.h | 23 ++++++++ > nptl/thrd_sleep.c | 25 ++++----- > sysdeps/unix/sysv/linux/Versions | 1 + > sysdeps/unix/sysv/linux/clock_nanosleep.c | 68 > +++++++++++++++++++++-- sysdeps/unix/sysv/linux/nanosleep.c | > 13 +++-- 5 files changed, 106 insertions(+), 24 deletions(-) > > diff --git a/include/time.h b/include/time.h > index 8ac58e891b5..e0974309726 100644 > --- a/include/time.h > +++ b/include/time.h > @@ -184,6 +184,9 @@ extern struct tm *__tz_convert (__time64_t timer, > int use_localtime, extern int __nanosleep (const struct timespec > *__requested_time, struct timespec *__remaining); > hidden_proto (__nanosleep) > +extern int __clock_nanosleep (clockid_t clock_id, int flags, > + const struct timespec *req, struct > timespec *rem); +libc_hidden_proto (__clock_nanosleep) > extern int __getdate_r (const char *__string, struct tm *__resbufp) > attribute_hidden; > > @@ -206,6 +209,26 @@ libc_hidden_proto (__difftime64) > > extern double __difftime (time_t time1, time_t time0); > > +#if __TIMESIZE == 64 > +# define __thrd_sleep_time64 thrd_sleep > +# define __clock_nanosleep_time64 __clock_nanosleep > +# define __nanosleep_time64 __nanosleep > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel > +#else > +extern int __thrd_sleep_time64 (const struct __timespec64* > time_point, > + struct __timespec64* remaining); > +libc_hidden_proto (__thrd_sleep_time64) > +extern int __clock_nanosleep_time64 (clockid_t clock_id, > + int flags, const struct > __timespec64 *req, > + struct __timespec64 *rem); > +libc_hidden_proto (__clock_nanosleep_time64) > +extern int __nanosleep_time64 (const struct __timespec64 > *requested_time, > + struct __timespec64 *remaining); > +libc_hidden_proto (__nanosleep_time64) > +extern int __nanosleep_nocancel_time64 (const struct __timespec64 > *requested_time, > + struct __timespec64 > *remaining); +libc_hidden_proto (__nanosleep_nocancel_time64) > +#endif > > /* Use in the clock_* functions. Size of the field representing the > actual clock ID. */ > diff --git a/nptl/thrd_sleep.c b/nptl/thrd_sleep.c > index 2e185dd748e..c865f815eea 100644 > --- a/nptl/thrd_sleep.c > +++ b/nptl/thrd_sleep.c > @@ -17,23 +17,18 @@ > <https://www.gnu.org/licenses/>. */ > > #include <time.h> > -#include <sysdep-cancel.h> > - > -#include "thrd_priv.h" > +#include <errno.h> > > int > thrd_sleep (const struct timespec* time_point, struct timespec* > remaining) { > - INTERNAL_SYSCALL_DECL (err); > - int ret = INTERNAL_SYSCALL_CANCEL (nanosleep, err, time_point, > remaining); > - if (INTERNAL_SYSCALL_ERROR_P (ret, err)) > - { > - /* C11 states thrd_sleep function returns -1 if it has been > interrupted > - by a signal, or a negative value if it fails. */ > - ret = INTERNAL_SYSCALL_ERRNO (ret, err); > - if (ret == EINTR) > - return -1; > - return -2; > - } > - return 0; > + int ret = __clock_nanosleep (CLOCK_REALTIME, 0, time_point, > remaining); Maybe this is a bit off topic (generic question to 64 bit time support) - but I'm wondering if we shall not use __clock_nanosleep_time64 here just from the outset? With using __clock_nanosleep() as the internal function, the architectures with __TIMESIZE != 64 (e.g. ARM32 bit) will not benefit from having internal glibc support for 64 bit time representation (as their __clock_nanosleep version uses 32 bit to represent time). Of course we can stick to __clock_nanosleep, but then those functions would need to be aliased or (better) renamed in the code before Y2038. The same situation is with e.g. internal usage of __clock_settime. > + /* C11 states thrd_sleep function returns -1 if it has been > interrupted > + by a signal, or a negative value if it fails. */ > + switch (ret) > + { > + case 0: return 0; > + case EINTR: return -1; > + default: return -2; > + } > } > diff --git a/sysdeps/unix/sysv/linux/Versions > b/sysdeps/unix/sysv/linux/Versions index d385085c611..475abb50040 > 100644 --- a/sysdeps/unix/sysv/linux/Versions > +++ b/sysdeps/unix/sysv/linux/Versions > @@ -187,5 +187,6 @@ libc { > __sigtimedwait; > # functions used by nscd > __netlink_assert_response; > + __clock_nanosleep; > } > } > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c > b/sysdeps/unix/sysv/linux/clock_nanosleep.c index > 1f240b8720a..13ea9c6f802 100644 --- > a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++ > b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -16,6 +16,7 @@ > <https://www.gnu.org/licenses/>. */ > > #include <time.h> > +#include <kernel-features.h> > #include <errno.h> > > #include <sysdep-cancel.h> > @@ -26,9 +27,11 @@ > /* We can simply use the syscall. The CPU clocks are not supported > with this function. */ > int > -__clock_nanosleep (clockid_t clock_id, int flags, const struct > timespec *req, > - struct timespec *rem) > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const ^^^^^^^^^^^^^^^^^ - just an open question - shall we have the naming convention (for this function) following the new syscalls names or use e.g. __clock_nanosleep64() ? > struct __timespec64 *req, > + struct __timespec64 *rem) > { > + int r = -1; > + > if (clock_id == CLOCK_THREAD_CPUTIME_ID) > return EINVAL; > if (clock_id == CLOCK_PROCESS_CPUTIME_ID) > @@ -37,12 +40,67 @@ __clock_nanosleep (clockid_t clock_id, int flags, > const struct timespec *req, /* If the call is interrupted by a signal > handler or encounters an error, it returns a positive value similar > to errno. */ INTERNAL_SYSCALL_DECL (err); > - int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, > flags, > - req, rem); > + > +#ifdef __ASSUME_TIME64_SYSCALLS > +# ifndef __NR_clock_nanosleep_time64 > +# define __NR_clock_nanosleep_time64 __NR_clock_nanosleep > +# endif > + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id, > + flags, req, rem); > +#else > +# ifdef __NR_clock_nanosleep_time64 > + long int ret_64; I think that 'int ret;' would be a bit better. the clock_nanosleep syscall [1] returns int. > + > + ret_64 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, > clock_id, > + flags, req, rem); > + > + if (ret_64 == 0 || errno != ENOSYS) > + { > + return (INTERNAL_SYSCALL_ERROR_P (ret_64, err) > + ? INTERNAL_SYSCALL_ERRNO (ret_64, err) : 0); > + } > +# endif /* __NR_clock_nanosleep_time64 */ > + struct timespec ts32, tr32; > + > + if (! in_time_t_range (req->tv_sec)) > + { > + __set_errno (EOVERFLOW); > + return -1; > + } > + > + ts32 = valid_timespec64_to_timespec (*req); The man pages for clock_nanosleep (e.g. [2], [3]) do not mention about the possibility to have *req equal to NULL, hence I do assume that we don't need to do it here as well... > + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, &ts32, &tr32); > + > + if ((r == 0 || errno != ENOSYS) && rem) > + *rem = valid_timespec_to_timespec64 (tr32); > +#endif /* __ASSUME_TIME64_SYSCALLS */ > + > return (INTERNAL_SYSCALL_ERROR_P (r, err) > - ? INTERNAL_SYSCALL_ERRNO (r, err) : 0); > + ? INTERNAL_SYSCALL_ERRNO (r, err) : 0); > } > > +#if __TIMESIZE != 64 > +int > +__clock_nanosleep (clockid_t clock_id, int flags, const struct > timespec *req, > + struct timespec *rem) > +{ > + int r; > + struct __timespec64 treq64, trem64; > + > + treq64 = valid_timespec_to_timespec64 (*req); > + r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64); > + > + if (r == 0 || errno != ENOSYS) > + { > + if (rem) > + *rem = valid_timespec64_to_timespec (trem64); > + } > + > + return r; > +} > +#endif > +libc_hidden_def (__clock_nanosleep) > + > versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, > GLIBC_2_17); /* clock_nanosleep moved to libc in version 2.17; > old binaries may expect the symbol version it had in librt. */ > diff --git a/sysdeps/unix/sysv/linux/nanosleep.c > b/sysdeps/unix/sysv/linux/nanosleep.c index 6787909248f..30cc26909a7 > 100644 --- a/sysdeps/unix/sysv/linux/nanosleep.c > +++ b/sysdeps/unix/sysv/linux/nanosleep.c > @@ -17,15 +17,20 @@ > <https://www.gnu.org/licenses/>. */ > > #include <time.h> > -#include <sysdep-cancel.h> > -#include <not-cancel.h> > +#include <errno.h> > > /* Pause execution for a number of nanoseconds. */ > int > __nanosleep (const struct timespec *requested_time, > - struct timespec *remaining) > + struct timespec *remaining) > { > - return SYSCALL_CANCEL (nanosleep, requested_time, remaining); > + int ret = __clock_nanosleep (CLOCK_REALTIME, 0, requested_time, > remaining); > + if (ret != 0) > + { > + __set_errno (ret); > + return -1; > + } > + return ret; > } > hidden_def (__nanosleep) > weak_alias (__nanosleep, nanosleep) Links: [1] - https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/posix-timers.c#L1230 [2] - http://man7.org/linux/man-pages/man2/nanosleep.2.html [3] - https://linux.die.net/man/3/clock_nanosleep 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
Attachment:
pgpCkwB7Zvx2C.pgp
Description: OpenPGP digital signature
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |