mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-01 17:30:07 +00:00
143 lines
4.0 KiB
C
143 lines
4.0 KiB
C
/* Linux select implementation.
|
|
Copyright (C) 2017-2024 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
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library. If not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sys/time.h>
|
|
#include <sys/types.h>
|
|
#include <sys/select.h>
|
|
#include <errno.h>
|
|
#include <sysdep-cancel.h>
|
|
|
|
/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
|
|
readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
|
|
(if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
|
|
after waiting the interval specified therein. Returns the number of ready
|
|
descriptors, or -1 for errors. */
|
|
|
|
int
|
|
__select64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
|
|
struct __timeval64 *timeout)
|
|
{
|
|
__time64_t s = timeout != NULL ? timeout->tv_sec : 0;
|
|
int32_t us = timeout != NULL ? timeout->tv_usec : 0;
|
|
int32_t ns;
|
|
|
|
if (s < 0 || us < 0)
|
|
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
|
|
|
|
/* Normalize the timeout, as legacy Linux __NR_select and __NR__newselect.
|
|
Different than syscall, it also handle possible overflow. */
|
|
if (us / USEC_PER_SEC > INT64_MAX - s)
|
|
{
|
|
s = INT64_MAX;
|
|
ns = NSEC_PER_SEC - 1;
|
|
}
|
|
else
|
|
{
|
|
s += us / USEC_PER_SEC;
|
|
us = us % USEC_PER_SEC;
|
|
ns = us * NSEC_PER_USEC;
|
|
}
|
|
|
|
struct __timespec64 ts64, *pts64 = NULL;
|
|
if (timeout != NULL)
|
|
{
|
|
ts64.tv_sec = s;
|
|
ts64.tv_nsec = ns;
|
|
pts64 = &ts64;
|
|
}
|
|
|
|
#ifndef __NR_pselect6_time64
|
|
# define __NR_pselect6_time64 __NR_pselect6
|
|
#endif
|
|
|
|
#ifdef __ASSUME_TIME64_SYSCALLS
|
|
int r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
|
|
pts64, NULL);
|
|
if (timeout != NULL)
|
|
TIMESPEC_TO_TIMEVAL (timeout, pts64);
|
|
return r;
|
|
#else
|
|
bool need_time64 = timeout != NULL && !in_int32_t_range (timeout->tv_sec);
|
|
if (need_time64)
|
|
{
|
|
int r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds,
|
|
exceptfds, pts64, NULL);
|
|
if ((r >= 0 || errno != ENOSYS) && timeout != NULL)
|
|
{
|
|
TIMESPEC_TO_TIMEVAL (timeout, &ts64);
|
|
}
|
|
else
|
|
__set_errno (EOVERFLOW);
|
|
return r;
|
|
}
|
|
|
|
# ifdef __ASSUME_PSELECT
|
|
struct timespec ts32, *pts32 = NULL;
|
|
if (pts64 != NULL)
|
|
{
|
|
ts32.tv_sec = pts64->tv_sec;
|
|
ts32.tv_nsec = pts64->tv_nsec;
|
|
pts32 = &ts32;
|
|
}
|
|
|
|
int r = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, pts32,
|
|
NULL);
|
|
if (timeout != NULL)
|
|
TIMESPEC_TO_TIMEVAL (timeout, pts32);
|
|
return r;
|
|
# else
|
|
struct timeval tv32, *ptv32 = NULL;
|
|
if (pts64 != NULL)
|
|
{
|
|
tv32 = valid_timespec64_to_timeval (*pts64);
|
|
ptv32 = &tv32;
|
|
}
|
|
|
|
int r = SYSCALL_CANCEL (_newselect, nfds, readfds, writefds, exceptfds, ptv32);
|
|
if (timeout != NULL)
|
|
*timeout = valid_timeval_to_timeval64 (tv32);
|
|
return r;
|
|
# endif /* __ASSUME_PSELECT */
|
|
#endif
|
|
}
|
|
|
|
#if __TIMESIZE != 64
|
|
libc_hidden_def (__select64)
|
|
|
|
int
|
|
__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
|
|
struct timeval *timeout)
|
|
{
|
|
struct __timeval64 tv64, *ptv64 = NULL;
|
|
if (timeout != NULL)
|
|
{
|
|
tv64 = valid_timeval_to_timeval64 (*timeout);
|
|
ptv64 = &tv64;
|
|
}
|
|
int r = __select64 (nfds, readfds, writefds, exceptfds, ptv64);
|
|
if (timeout != NULL)
|
|
/* The remanining timeout will be always less the input TIMEOUT. */
|
|
*timeout = valid_timeval64_to_timeval (tv64);
|
|
return r;
|
|
}
|
|
#endif
|
|
libc_hidden_def (__select)
|
|
|
|
weak_alias (__select, select)
|
|
weak_alias (__select, __libc_select)
|