1 | /* Copyright (C) 2006-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <limits.h> |
20 | #include <signal.h> |
21 | #include <stddef.h> /* For NULL. */ |
22 | #include <sys/poll.h> |
23 | #include <sysdep-cancel.h> |
24 | #include <time.h> |
25 | |
26 | |
27 | int |
28 | ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout, |
29 | const sigset_t *sigmask) |
30 | { |
31 | int tval = -1; |
32 | |
33 | /* poll uses a simple millisecond value. Convert it. */ |
34 | if (timeout != NULL) |
35 | { |
36 | if (timeout->tv_sec < 0 || ! valid_nanoseconds (ns: timeout->tv_nsec)) |
37 | { |
38 | __set_errno (EINVAL); |
39 | return -1; |
40 | } |
41 | |
42 | if (timeout->tv_sec > INT_MAX / 1000 |
43 | || (timeout->tv_sec == INT_MAX / 1000 |
44 | && ((timeout->tv_nsec + 999999) / 1000000 > INT_MAX % 1000))) |
45 | /* We cannot represent the timeout in an int value. Wait |
46 | forever. */ |
47 | tval = -1; |
48 | else |
49 | tval = (timeout->tv_sec * 1000 |
50 | + (timeout->tv_nsec + 999999) / 1000000); |
51 | } |
52 | |
53 | /* The setting and restoring of the signal mask and the select call |
54 | should be an atomic operation. This can't be done without kernel |
55 | help. */ |
56 | sigset_t savemask; |
57 | if (sigmask != NULL) |
58 | __sigprocmask (SIG_SETMASK, set: sigmask, oset: &savemask); |
59 | |
60 | /* Note the ppoll() is a cancellation point. But since we call |
61 | poll() which itself is a cancellation point we do not have |
62 | to do anything here. */ |
63 | int retval = __poll (fds: fds, nfds: nfds, timeout: tval); |
64 | |
65 | if (sigmask != NULL) |
66 | __sigprocmask (SIG_SETMASK, set: &savemask, NULL); |
67 | |
68 | return retval; |
69 | } |
70 | |
71 | #ifndef ppoll |
72 | libc_hidden_def (ppoll); |
73 | #endif |
74 | |