glibc/include/time.h
Adhemerval Zanella 9d7c5cc38e linux: Normalize and return timeout on select (BZ #27651)
The commit 2433d39b69, which added time64 support to select, changed
the function to use __NR_pselect6 (or __NR_pelect6_time64) on all
architectures.  However, on architectures where the symbol was
implemented with __NR_select the kernel normalizes the passed timeout
instead of return EINVAL.  For instance, the input timeval
{ 0, 5000000 } is interpreted as { 5, 0 }.

And as indicated by BZ #27651, this semantic seems to be expected
and changing it results in some performance issues (most likely
the program does not check the return code and keeps issuing
select with unormalized tv_usec argument).

To avoid a different semantic depending whether which syscall the
architecture used to issue, select now always normalize the timeout
input.  This is a slight change for some ABIs (for instance aarch64).

Checked on x86_64-linux-gnu and i686-linux-gnu.
2021-04-12 18:38:37 -03:00

513 lines
14 KiB
C

#ifndef _TIME_H
#include <time/time.h>
#ifndef _ISOMAC
# include <bits/types/struct_timeval.h>
# include <struct___timespec64.h>
# include <struct___timeval64.h>
# include <bits/types/locale_t.h>
# include <stdbool.h>
# include <time/mktime-internal.h>
# include <sys/time.h>
# include <time-clockid.h>
# include <sys/time.h>
extern __typeof (strftime_l) __strftime_l;
libc_hidden_proto (__strftime_l)
extern __typeof (strptime_l) __strptime_l;
libc_hidden_proto (asctime)
libc_hidden_proto (mktime)
libc_hidden_proto (timelocal)
libc_hidden_proto (localtime)
libc_hidden_proto (strftime)
libc_hidden_proto (strptime)
extern __typeof (clock_gettime) __clock_gettime;
libc_hidden_proto (__clock_gettime)
extern __typeof (clock_settime) __clock_settime;
libc_hidden_proto (__clock_settime)
extern __typeof (clock_nanosleep) __clock_nanosleep;
libc_hidden_proto (__clock_nanosleep);
#ifdef __linux__
extern __typeof (clock_adjtime) __clock_adjtime;
libc_hidden_proto (__clock_adjtime);
#endif
/* Now define the internal interfaces. */
struct tm;
/* Defined in mktime.c. */
extern const unsigned short int __mon_yday[2][13] attribute_hidden;
/* Defined in localtime.c. */
extern struct tm _tmbuf attribute_hidden;
/* Defined in tzset.c. */
extern char *__tzstring (const char *string) attribute_hidden;
extern int __use_tzfile attribute_hidden;
extern void __tzfile_read (const char *file, size_t extra,
char **extrap) attribute_hidden;
extern void __tzfile_compute (__time64_t timer, int use_localtime,
long int *leap_correct, int *leap_hit,
struct tm *tp) attribute_hidden;
extern void __tzfile_default (const char *std, const char *dst,
int stdoff, int dstoff)
attribute_hidden;
extern void __tzset_parse_tz (const char *tz) attribute_hidden;
extern void __tz_compute (__time64_t timer, struct tm *tm, int use_localtime)
__THROW attribute_hidden;
#if __TIMESIZE == 64
# define __itimerspec64 itimerspec
#else
/* The glibc's internal representation of the struct itimerspec. */
struct __itimerspec64
{
struct __timespec64 it_interval;
struct __timespec64 it_value;
};
#endif
#if __TIMESIZE == 64
# define __utimbuf64 utimbuf
# define __itimerval64 itimerval
#else
/* The glibc Y2038-proof struct __utimbuf64 structure for file's access
and modification time values. */
struct __utimbuf64
{
__time64_t actime; /* Access time. */
__time64_t modtime; /* Modification time. */
};
/* The glibc's internal representation of the struct itimerval. */
struct __itimerval64
{
struct __timeval64 it_interval;
struct __timeval64 it_value;
};
#endif
#if __TIMESIZE == 64
# define __getitimer64 __getitimer
# define __setitimer64 __setitimer
#else
extern int __getitimer64 (enum __itimer_which __which,
struct __itimerval64 *__value);
libc_hidden_proto (__getitimer64)
extern int __setitimer64 (enum __itimer_which __which,
const struct __itimerval64 *__restrict __new,
struct __itimerval64 *__restrict __old);
libc_hidden_proto (__setitimer64)
#endif
#if __TIMESIZE == 64
# define __ctime64 ctime
#else
extern char *__ctime64 (const __time64_t *__timer) __THROW;
libc_hidden_proto (__ctime64)
#endif
#if __TIMESIZE == 64
# define __ctime64_r ctime_r
#else
extern char *__ctime64_r (const __time64_t *__restrict __timer,
char *__restrict __buf) __THROW;
libc_hidden_proto (__ctime64_r)
#endif
#if __TIMESIZE == 64
# define __localtime64 localtime
#else
extern struct tm *__localtime64 (const __time64_t *__timer);
libc_hidden_proto (__localtime64)
#endif
extern struct tm *__localtime_r (const time_t *__timer,
struct tm *__tp) attribute_hidden;
#if __TIMESIZE != 64
extern struct tm *__localtime64_r (const __time64_t *__timer,
struct tm *__tp);
libc_hidden_proto (__localtime64_r)
extern __time64_t __mktime64 (struct tm *__tp) __THROW;
libc_hidden_proto (__mktime64)
#endif
extern struct tm *__gmtime_r (const time_t *__restrict __timer,
struct tm *__restrict __tp);
libc_hidden_proto (__gmtime_r)
#if __TIMESIZE == 64
# define __gmtime64 gmtime
#else
extern struct tm *__gmtime64 (const __time64_t *__timer);
libc_hidden_proto (__gmtime64)
extern struct tm *__gmtime64_r (const __time64_t *__restrict __timer,
struct tm *__restrict __tp);
libc_hidden_proto (__gmtime64_r)
extern __time64_t __timegm64 (struct tm *__tp) __THROW;
libc_hidden_proto (__timegm64)
#endif
#if __TIMESIZE == 64
# define __clock_settime64 __clock_settime
#else
extern int __clock_settime64 (clockid_t clock_id,
const struct __timespec64 *tp);
libc_hidden_proto (__clock_settime64)
#endif
#if __TIMESIZE == 64
# define __clock_getres64 __clock_getres
#else
extern int __clock_getres64 (clockid_t clock_id,
struct __timespec64 *tp);
libc_hidden_proto (__clock_getres64);
#endif
#if __TIMESIZE == 64
# define __utime64 __utime
# define __utimes64 __utimes
# define __utimensat64 __utimensat
#else
extern int __utime64 (const char *file, const struct __utimbuf64 *times);
libc_hidden_proto (__utime64)
extern int __utimes64 (const char *file, const struct __timeval64 tvp[2]);
libc_hidden_proto (__utimes64)
extern int __utimensat64 (int fd, const char *file,
const struct __timespec64 tsp[2], int flags);
libc_hidden_proto (__utimensat64);
#endif
extern int __utimensat64_helper (int fd, const char *file,
const struct __timespec64 tsp[2], int flags);
libc_hidden_proto (__utimensat64_helper);
#if __TIMESIZE == 64
# define __futimes64 __futimes
# define __futimesat64 __futimesat
# define __lutimes64 __lutimes
# define __futimens64 __futimens
#else
extern int __futimes64 (int fd, const struct __timeval64 tvp64[2]);
libc_hidden_proto (__futimes64);
extern int __futimesat64 (int fd, const char *file,
const struct __timeval64 tvp[2]);
libc_hidden_proto (__futimesat64);
extern int __lutimes64 (const char *file, const struct __timeval64 tvp64[2]);
libc_hidden_proto (__lutimes64);
extern int __futimens64 (int fd, const struct __timespec64 tsp[2]);
libc_hidden_proto (__futimens64);
#endif
#if __TIMESIZE == 64
# define __timer_gettime64 __timer_gettime
# define __timerfd_gettime64 __timerfd_gettime
#else
extern int __timer_gettime64 (timer_t timerid, struct __itimerspec64 *value);
extern int __timerfd_gettime64 (int fd, struct __itimerspec64 *value);
librt_hidden_proto (__timer_gettime64);
libc_hidden_proto (__timerfd_gettime64);
#endif
#if __TIMESIZE == 64
# define __timer_settime64 __timer_settime
# define __timerfd_settime64 __timerfd_settime
#else
extern int __timer_settime64 (timer_t timerid, int flags,
const struct __itimerspec64 *value,
struct __itimerspec64 *ovalue);
extern int __timerfd_settime64 (int fd, int flags,
const struct __itimerspec64 *value,
struct __itimerspec64 *ovalue);
librt_hidden_proto (__timer_settime64);
libc_hidden_proto (__timerfd_settime64);
#endif
#if __TIMESIZE == 64
# define __sched_rr_get_interval64 __sched_rr_get_interval
#else
extern int __sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp);
libc_hidden_proto (__sched_rr_get_interval64);
#endif
#if __TIMESIZE == 64
# define __settimeofday64 __settimeofday
# define __gettimeofday64 __gettimeofday
#else
extern int __settimeofday64 (const struct __timeval64 *tv,
const struct timezone *tz);
libc_hidden_proto (__settimeofday64)
extern int __gettimeofday64 (struct __timeval64 *restrict tv,
void *restrict tz);
libc_hidden_proto (__gettimeofday64)
#endif
/* Compute the `struct tm' representation of T,
offset OFFSET seconds east of UTC,
and store year, yday, mon, mday, wday, hour, min, sec into *TP.
Return nonzero if successful. */
extern int __offtime (__time64_t __timer,
long int __offset,
struct tm *__tp) attribute_hidden;
extern char *__asctime_r (const struct tm *__tp, char *__buf)
attribute_hidden;
extern void __tzset (void) attribute_hidden;
/* Prototype for the internal function to get information based on TZ. */
extern struct tm *__tz_convert (__time64_t timer, int use_localtime,
struct tm *tp) attribute_hidden;
extern int __nanosleep (const struct timespec *__requested_time,
struct timespec *__remaining);
hidden_proto (__nanosleep)
#if __TIMESIZE == 64
# define __nanosleep64 __nanosleep
#else
extern int __nanosleep64 (const struct __timespec64 *__requested_time,
struct __timespec64 *__remaining);
hidden_proto (__nanosleep64)
#endif
extern int __getdate_r (const char *__string, struct tm *__resbufp)
attribute_hidden;
/* Determine CLK_TCK value. */
extern int __getclktck (void) attribute_hidden;
/* strptime support. */
extern char * __strptime_internal (const char *rp, const char *fmt,
struct tm *tm, void *statep,
locale_t locparam) attribute_hidden;
#if __TIMESIZE == 64
# define __difftime64 __difftime
#else
extern double __difftime64 (__time64_t time1, __time64_t time0);
libc_hidden_proto (__difftime64)
#endif
extern double __difftime (time_t time1, time_t time0);
#if __TIMESIZE == 64
# define __clock_nanosleep_time64 __clock_nanosleep
# define __clock_gettime64 __clock_gettime
# define __timespec_get64 __timespec_get
#else
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 __clock_gettime64 (clockid_t clock_id, struct __timespec64 *tp);
libc_hidden_proto (__clock_gettime64)
extern int __timespec_get64 (struct __timespec64 *ts, int base);
libc_hidden_proto (__timespec_get64)
#endif
#if __TIMESIZE == 64
# define __time64 __time
#else
extern __time64_t __time64 (__time64_t *timer);
libc_hidden_proto (__time64)
#endif
/* Use in the clock_* functions. Size of the field representing the
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
/* Check whether T fits in time_t. */
static inline bool
in_time_t_range (__time64_t t)
{
time_t s = t;
return s == t;
}
/* Convert a known valid struct timeval into a struct __timespec64. */
static inline struct __timespec64
valid_timeval_to_timespec64 (const struct timeval tv)
{
struct __timespec64 ts64;
ts64.tv_sec = tv.tv_sec;
ts64.tv_nsec = tv.tv_usec * 1000;
return ts64;
}
/* Convert a known valid struct timeval into a struct __timeval64. */
static inline struct __timeval64
valid_timeval_to_timeval64 (const struct timeval tv)
{
struct __timeval64 tv64;
tv64.tv_sec = tv.tv_sec;
tv64.tv_usec = tv.tv_usec;
return tv64;
}
/* Convert a valid and within range of struct timeval, struct
__timeval64 into a struct timeval. */
static inline struct timeval
valid_timeval64_to_timeval (const struct __timeval64 tv64)
{
struct timeval tv;
tv.tv_sec = (time_t) tv64.tv_sec;
tv.tv_usec = (suseconds_t) tv64.tv_usec;
return tv;
}
/* Convert a struct __timeval64 into a struct __timespec64. */
static inline struct __timespec64
timeval64_to_timespec64 (const struct __timeval64 tv64)
{
struct __timespec64 ts64;
ts64.tv_sec = tv64.tv_sec;
ts64.tv_nsec = tv64.tv_usec * 1000;
return ts64;
}
/* Convert a known valid struct timespec into a struct __timespec64. */
static inline struct __timespec64
valid_timespec_to_timespec64 (const struct timespec ts)
{
struct __timespec64 ts64;
ts64.tv_sec = ts.tv_sec;
ts64.tv_nsec = ts.tv_nsec;
return ts64;
}
/* Convert a valid and within range of struct timespec, struct
__timespec64 into a struct timespec. */
static inline struct timespec
valid_timespec64_to_timespec (const struct __timespec64 ts64)
{
struct timespec ts;
ts.tv_sec = (time_t) ts64.tv_sec;
ts.tv_nsec = ts64.tv_nsec;
return ts;
}
/* Convert a valid and within range of struct timeval struct
__timespec64 into a struct timeval. */
static inline struct timeval
valid_timespec64_to_timeval (const struct __timespec64 ts64)
{
struct timeval tv;
tv.tv_sec = (time_t) ts64.tv_sec;
tv.tv_usec = ts64.tv_nsec / 1000;
return tv;
}
/* Convert a struct __timespec64 into a struct __timeval64. */
static inline struct __timeval64
timespec64_to_timeval64 (const struct __timespec64 ts64)
{
struct __timeval64 tv64;
tv64.tv_sec = ts64.tv_sec;
tv64.tv_usec = ts64.tv_nsec / 1000;
return tv64;
}
/* A version of 'struct timeval' with 32-bit time_t
and suseconds_t. */
struct __timeval32
{
__int32_t tv_sec; /* Seconds. */
__int32_t tv_usec; /* Microseconds. */
};
/* Conversion functions for converting to/from __timeval32 */
static inline struct __timeval64
valid_timeval32_to_timeval64 (const struct __timeval32 tv)
{
return (struct __timeval64) { tv.tv_sec, tv.tv_usec };
}
static inline struct __timeval32
valid_timeval64_to_timeval32 (const struct __timeval64 tv64)
{
return (struct __timeval32) { tv64.tv_sec, tv64.tv_usec };
}
static inline struct timeval
valid_timeval32_to_timeval (const struct __timeval32 tv)
{
return (struct timeval) { tv.tv_sec, tv.tv_usec };
}
static inline struct __timeval32
valid_timeval_to_timeval32 (const struct timeval tv)
{
return (struct __timeval32) { tv.tv_sec, tv.tv_usec };
}
static inline struct timespec
valid_timeval32_to_timespec (const struct __timeval32 tv)
{
return (struct timespec) { tv.tv_sec, tv.tv_usec * 1000 };
}
static inline struct __timeval32
valid_timespec_to_timeval32 (const struct timespec ts)
{
return (struct __timeval32) { (time_t) ts.tv_sec, ts.tv_nsec / 1000 };
}
static inline struct __timeval64
valid_timespec_to_timeval64 (const struct timespec ts)
{
return (struct __timeval64) { (time_t) ts.tv_sec, ts.tv_nsec / 1000 };
}
/* Check if a value is in the valid nanoseconds range. Return true if
it is, false otherwise. */
static inline bool
valid_nanoseconds (__syscall_slong_t ns)
{
return __glibc_likely (0 <= ns && ns < 1000000000);
}
/* Helper function to get time in seconds, similar to time. */
static inline time_t
time_now (void)
{
struct timespec ts;
__clock_gettime (TIME_CLOCK_GETTIME_CLOCKID, &ts);
return ts.tv_sec;
}
#define NSEC_PER_SEC 1000000000L /* Nanoseconds per second. */
#define USEC_PER_SEC 1000000L /* Microseconds per second. */
#define NSEC_PER_USEC 1000L /* Nanoseconds per microsecond. */
#endif
#endif