mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-11-25 07:28:20 +00:00
111 lines
2.9 KiB
C
111 lines
2.9 KiB
C
/* pselect - synchronous I/O multiplexing
|
|
|
|
Copyright 2011-2014 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 <http://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
|