1 /* pselect - synchronous I/O multiplexing
3 Copyright 2011 Free Software Foundation, Inc.
5 This file is part of gnulib.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
21 /* written by Paul Eggert */
25 #include <sys/select.h>
30 /* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
31 to see whether some of their descriptors are ready for reading,
32 ready for writing, or have exceptions pending. Wait for at most
33 TIMEOUT seconds, and use signal mask SIGMASK while waiting. A null
34 pointer parameter stands for no descriptors, an infinite timeout,
35 or an unaffected signal mask. */
38 pselect (int nfds, fd_set *restrict rfds,
39 fd_set *restrict wfds, fd_set *restrict xfds,
40 struct timespec const *restrict timeout,
41 sigset_t const *restrict sigmask)
45 struct timeval tv, *tvp;
49 if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
55 tv.tv_sec = timeout->tv_sec;
56 tv.tv_usec = (timeout->tv_nsec + 999) / 1000;
62 /* Signal mask munging should be atomic, but this is the best we can
63 do in this emulation. */
65 pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
67 select_result = select (nfds, rfds, wfds, xfds, tvp);
71 int select_errno = errno;
72 pthread_sigmask (SIG_SETMASK, &origmask, NULL);