1/* Timed low level locking for pthread library. Generic futex-using version.
2 Copyright (C) 2003-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <atomic.h>
21#include <errno.h>
22#include <lowlevellock.h>
23#include <sys/time.h>
24#include <time.h>
25
26
27int
28__lll_clocklock_wait (int *futex, int val, clockid_t clockid,
29 const struct timespec *abstime, int private)
30{
31 struct timespec ts, *tsp = NULL;
32
33 if (abstime != NULL)
34 {
35 /* Reject invalid timeouts. */
36 if (! valid_nanoseconds (abstime->tv_nsec))
37 return EINVAL;
38
39 /* Get the current time. This can only fail if clockid is not valid. */
40 if (__glibc_unlikely (__clock_gettime (clockid, &ts) != 0))
41 return EINVAL;
42
43 /* Compute relative timeout. */
44 ts.tv_sec = abstime->tv_sec - ts.tv_sec;
45 ts.tv_nsec = abstime->tv_nsec - ts.tv_nsec;
46 if (ts.tv_nsec < 0)
47 {
48 ts.tv_nsec += 1000000000;
49 --ts.tv_sec;
50 }
51
52 if (ts.tv_sec < 0)
53 return ETIMEDOUT;
54
55 tsp = &ts;
56 }
57
58 /* If *futex == val, wait until woken or timeout. */
59 lll_futex_timed_wait (futex, val, tsp, private);
60
61 return 0;
62}
63