1 /* Copyright (C) 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <assert.h>
20 #include <errno.h>
21 #include <stdbool.h>
22 #include <time.h>
23 #include <sysdep.h>
24 #include "pthreadP.h"
25 #include <bits/kernel-features.h>
26
27
28 int
pthread_condattr_setclock(pthread_condattr_t * attr,clockid_t clock_id)29 pthread_condattr_setclock (
30 pthread_condattr_t *attr,
31 clockid_t clock_id)
32 {
33 /* Only a few clocks are allowed. CLOCK_REALTIME is always allowed.
34 CLOCK_MONOTONIC only if the kernel has the necessary support. */
35 if (clock_id == CLOCK_MONOTONIC)
36 {
37 #ifndef __ASSUME_POSIX_TIMERS
38 # if defined(__NR_clock_getres) || defined(__NR_clock_getres_time64)
39 /* Check whether the clock is available. */
40 static int avail;
41
42 if (avail == 0)
43 {
44 struct timespec ts;
45
46 INTERNAL_SYSCALL_DECL (err);
47 int val;
48 #if defined(__UCLIBC_USE_TIME64__) && defined(__NR_clock_getres_time64)
49 val = INTERNAL_SYSCALL (clock_getres_time64, err, 2, CLOCK_MONOTONIC, &ts);
50 #else
51 val = INTERNAL_SYSCALL (clock_getres, err, 2, CLOCK_MONOTONIC, &ts);
52 #endif
53 avail = INTERNAL_SYSCALL_ERROR_P (val, err) ? -1 : 1;
54 }
55
56 if (avail < 0)
57 # endif
58 /* Not available. */
59 return EINVAL;
60 #endif
61 }
62 else if (clock_id != CLOCK_REALTIME)
63 /* If more clocks are allowed some day the storing of the clock ID
64 in the pthread_cond_t structure needs to be adjusted. */
65 return EINVAL;
66
67 /* Make sure the value fits in the bits we reserved. */
68 assert (clock_id < (1 << COND_NWAITERS_SHIFT));
69
70 int *valuep = &((struct pthread_condattr *) attr)->value;
71
72 *valuep = ((*valuep & ~(((1 << COND_NWAITERS_SHIFT) - 1) << 1))
73 | (clock_id << 1));
74
75 return 0;
76 }
77