| 1 | /* pselect - synchronous I/O multiplexing |
| 2 | |
| 3 | Copyright 2011-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of gnulib. |
| 6 | |
| 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 3, or (at your option) |
| 10 | any later version. |
| 11 | |
| 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. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License along |
| 18 | with this program; if not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | /* written by Paul Eggert */ |
| 21 | |
| 22 | #include <config.h> |
| 23 | |
| 24 | #include <sys/select.h> |
| 25 | |
| 26 | #include <errno.h> |
| 27 | #include <signal.h> |
| 28 | |
| 29 | /* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS |
| 30 | to see whether some of their descriptors are ready for reading, |
| 31 | ready for writing, or have exceptions pending. Wait for at most |
| 32 | TIMEOUT seconds, and use signal mask SIGMASK while waiting. A null |
| 33 | pointer parameter stands for no descriptors, an infinite timeout, |
| 34 | or an unaffected signal mask. */ |
| 35 | |
| 36 | #if !HAVE_PSELECT |
| 37 | |
| 38 | int |
| 39 | pselect (int nfds, fd_set *restrict rfds, |
| 40 | fd_set *restrict wfds, fd_set *restrict xfds, |
| 41 | struct timespec const *restrict timeout, |
| 42 | sigset_t const *restrict sigmask) |
| 43 | { |
| 44 | int select_result; |
| 45 | sigset_t origmask; |
| 46 | struct timeval tv, *tvp; |
| 47 | |
| 48 | if (timeout) |
| 49 | { |
| 50 | if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000)) |
| 51 | { |
| 52 | errno = EINVAL; |
| 53 | return -1; |
| 54 | } |
| 55 | |
| 56 | tv.tv_sec = timeout->tv_sec; |
| 57 | tv.tv_usec = (timeout->tv_nsec + 999) / 1000; |
| 58 | tvp = &tv; |
| 59 | } |
| 60 | else |
| 61 | tvp = NULL; |
| 62 | |
| 63 | /* Signal mask munging should be atomic, but this is the best we can |
| 64 | do in this emulation. */ |
| 65 | if (sigmask) |
| 66 | pthread_sigmask (SIG_SETMASK, sigmask, &origmask); |
| 67 | |
| 68 | select_result = select (nfds, rfds, wfds, xfds, tvp); |
| 69 | |
| 70 | if (sigmask) |
| 71 | { |
| 72 | int select_errno = errno; |
| 73 | pthread_sigmask (SIG_SETMASK, &origmask, NULL); |
| 74 | errno = select_errno; |
| 75 | } |
| 76 | |
| 77 | return select_result; |
| 78 | } |
| 79 | |
| 80 | #else /* HAVE_PSELECT */ |
| 81 | # include <unistd.h> |
| 82 | # undef pselect |
| 83 | |
| 84 | int |
| 85 | rpl_pselect (int nfds, fd_set *restrict rfds, |
| 86 | fd_set *restrict wfds, fd_set *restrict xfds, |
| 87 | struct timespec const *restrict timeout, |
| 88 | sigset_t const *restrict sigmask) |
| 89 | { |
| 90 | int i; |
| 91 | |
| 92 | /* FreeBSD 8.2 has a bug: it does not always detect invalid fds. */ |
| 93 | if (nfds < 0 || nfds > FD_SETSIZE) |
| 94 | { |
| 95 | errno = EINVAL; |
| 96 | return -1; |
| 97 | } |
| 98 | for (i = 0; i < nfds; i++) |
| 99 | { |
| 100 | if (((rfds && FD_ISSET (i, rfds)) |
| 101 | || (wfds && FD_ISSET (i, wfds)) |
| 102 | || (xfds && FD_ISSET (i, xfds))) |
| 103 | && dup2 (i, i) != i) |
| 104 | return -1; |
| 105 | } |
| 106 | |
| 107 | return pselect (nfds, rfds, wfds, xfds, timeout, sigmask); |
| 108 | } |
| 109 | |
| 110 | #endif |