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111 lines
2.9 KiB
C
111 lines
2.9 KiB
C
/* pselect - synchronous I/O multiplexing
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Copyright 2011-2017 Free Software Foundation, Inc.
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This file is part of gnulib.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, see <http://www.gnu.org/licenses/>. */
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/* written by Paul Eggert */
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#include <config.h>
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#include <sys/select.h>
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#include <errno.h>
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#include <signal.h>
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/* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
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to see whether some of their descriptors are ready for reading,
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ready for writing, or have exceptions pending. Wait for at most
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TIMEOUT seconds, and use signal mask SIGMASK while waiting. A null
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pointer parameter stands for no descriptors, an infinite timeout,
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or an unaffected signal mask. */
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#if !HAVE_PSELECT
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int
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pselect (int nfds, fd_set *restrict rfds,
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fd_set *restrict wfds, fd_set *restrict xfds,
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struct timespec const *restrict timeout,
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sigset_t const *restrict sigmask)
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{
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int select_result;
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sigset_t origmask;
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struct timeval tv, *tvp;
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if (timeout)
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{
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if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
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{
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errno = EINVAL;
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return -1;
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}
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tv.tv_sec = timeout->tv_sec;
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tv.tv_usec = (timeout->tv_nsec + 999) / 1000;
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tvp = &tv;
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}
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else
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tvp = NULL;
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/* Signal mask munging should be atomic, but this is the best we can
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do in this emulation. */
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if (sigmask)
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pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
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select_result = select (nfds, rfds, wfds, xfds, tvp);
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if (sigmask)
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{
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int select_errno = errno;
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pthread_sigmask (SIG_SETMASK, &origmask, NULL);
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errno = select_errno;
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}
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return select_result;
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}
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#else /* HAVE_PSELECT */
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# include <unistd.h>
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# undef pselect
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int
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rpl_pselect (int nfds, fd_set *restrict rfds,
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fd_set *restrict wfds, fd_set *restrict xfds,
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struct timespec const *restrict timeout,
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sigset_t const *restrict sigmask)
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{
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int i;
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/* FreeBSD 8.2 has a bug: it does not always detect invalid fds. */
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if (nfds < 0 || nfds > FD_SETSIZE)
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{
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errno = EINVAL;
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return -1;
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}
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for (i = 0; i < nfds; i++)
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{
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if (((rfds && FD_ISSET (i, rfds))
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|| (wfds && FD_ISSET (i, wfds))
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|| (xfds && FD_ISSET (i, xfds)))
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&& dup2 (i, i) != i)
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return -1;
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}
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return pselect (nfds, rfds, wfds, xfds, timeout, sigmask);
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}
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#endif
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