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c8fff863 PE |
1 | /* pselect - synchronous I/O multiplexing |
2 | ||
ab422c4d | 3 | Copyright 2011-2013 Free Software Foundation, Inc. |
c8fff863 PE |
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 | ||
bb1dfdad PE |
36 | #if !HAVE_PSELECT |
37 | ||
c8fff863 PE |
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 | } | |
bb1dfdad PE |
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 |