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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2025-01-19 18:13:55 +00:00
emacs/lib/pselect.c
Paul Eggert 35e9dcab51 Update from Gnulib
This incorporates:
2018-06-29 regex: glibc does not use intprops.h
2018-06-28 regex: port to recently proposed glibc regex merge
2018-06-25 Continue to use spaces for indentation, not tabs
2018-06-25 manywarnings: Don't enable -Wjump-misses-init by default
2018-06-25 acl-internal.h: remove _GL_ATTRIBUTE_CONST on void function
2018-06-24 manywarnings: accommodate GCC 9: remove -Wchkp and -Wabi
2018-06-24 maint: clarify comments about sticky EOF
2018-06-24 af_alg: avoid hangs when reading from streams
2018-06-17 crypto: use byteswap
2018-06-17 getloadavg: Return 0 on MS-Windows without Cygwi
2018-06-17 getloadavg: Allow building on MS-Windows without Cygwin
* build-aux/config.guess, build-aux/config.sub, doc/misc/texinfo.tex:
* lib/acl-internal.c, lib/acl-internal.h, lib/get-permissions.c:
* lib/getloadavg.c, lib/gettimeofday.c, lib/md5.c, lib/pselect.c:
* lib/set-permissions.c, lib/sha1.c, lib/sha256.c, lib/sha512.c:
* lib/time.in.h, m4/getloadavg.m4, m4/gnulib-common.m4:
* m4/manywarnings.m4, m4/pthread_sigmask.m4, m4/vararrays.m4:
Copy from Gnulib.
2018-06-29 17:32:35 -07:00

111 lines
2.9 KiB
C

/* pselect - synchronous I/O multiplexing
Copyright 2011-2018 Free Software Foundation, Inc.
This file is part of gnulib.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, see <https://www.gnu.org/licenses/>. */
/* written by Paul Eggert */
#include <config.h>
#include <sys/select.h>
#include <errno.h>
#include <signal.h>
/* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
to see whether some of their descriptors are ready for reading,
ready for writing, or have exceptions pending. Wait for at most
TIMEOUT seconds, and use signal mask SIGMASK while waiting. A null
pointer parameter stands for no descriptors, an infinite timeout,
or an unaffected signal mask. */
#if !HAVE_PSELECT
int
pselect (int nfds, fd_set *restrict rfds,
fd_set *restrict wfds, fd_set *restrict xfds,
struct timespec const *restrict timeout,
sigset_t const *restrict sigmask)
{
int select_result;
sigset_t origmask;
struct timeval tv, *tvp;
if (timeout)
{
if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
{
errno = EINVAL;
return -1;
}
tv.tv_sec = timeout->tv_sec;
tv.tv_usec = (timeout->tv_nsec + 999) / 1000;
tvp = &tv;
}
else
tvp = NULL;
/* Signal mask munging should be atomic, but this is the best we can
do in this emulation. */
if (sigmask)
pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
select_result = select (nfds, rfds, wfds, xfds, tvp);
if (sigmask)
{
int select_errno = errno;
pthread_sigmask (SIG_SETMASK, &origmask, NULL);
errno = select_errno;
}
return select_result;
}
#else /* HAVE_PSELECT */
# include <unistd.h>
# undef pselect
int
rpl_pselect (int nfds, fd_set *restrict rfds,
fd_set *restrict wfds, fd_set *restrict xfds,
struct timespec const *restrict timeout,
sigset_t const *restrict sigmask)
{
int i;
/* FreeBSD 8.2 has a bug: it does not always detect invalid fds. */
if (nfds < 0 || nfds > FD_SETSIZE)
{
errno = EINVAL;
return -1;
}
for (i = 0; i < nfds; i++)
{
if (((rfds && FD_ISSET (i, rfds))
|| (wfds && FD_ISSET (i, wfds))
|| (xfds && FD_ISSET (i, xfds)))
&& dup2 (i, i) != i)
return -1;
}
return pselect (nfds, rfds, wfds, xfds, timeout, sigmask);
}
#endif