Auto-generate libc-modules.h
[glibc.git] / sysdeps / unix / clock_nanosleep.c
blobe99a568e56cacfe51f0914408569ea245cb206c6
1 /* High-resolution sleep with the specified clock.
2 Copyright (C) 2000-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
19 #include <assert.h>
20 #include <errno.h>
21 #include <time.h>
22 #include <hp-timing.h>
23 #include <sysdep-cancel.h>
25 #if HP_TIMING_AVAIL
26 # define CPUCLOCK_P(clock) \
27 ((clock) == CLOCK_PROCESS_CPUTIME_ID \
28 || ((clock) & ((1 << CLOCK_IDFIELD_SIZE) - 1)) == CLOCK_THREAD_CPUTIME_ID)
29 #else
30 # define CPUCLOCK_P(clock) 0
31 #endif
33 #ifndef INVALID_CLOCK_P
34 # define INVALID_CLOCK_P(cl) \
35 ((cl) < CLOCK_REALTIME || (cl) > CLOCK_THREAD_CPUTIME_ID)
36 #endif
39 /* This implementation assumes that these is only a `nanosleep' system
40 call. So we have to remap all other activities. */
41 int
42 __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
43 struct timespec *rem)
45 struct timespec now;
47 if (__builtin_expect (req->tv_nsec, 0) < 0
48 || __builtin_expect (req->tv_nsec, 0) >= 1000000000)
49 return EINVAL;
51 if (clock_id == CLOCK_THREAD_CPUTIME_ID)
52 return EINVAL; /* POSIX specifies EINVAL for this case. */
54 #ifdef SYSDEP_NANOSLEEP
55 SYSDEP_NANOSLEEP;
56 #endif
58 if (CPUCLOCK_P (clock_id))
59 return ENOTSUP;
61 if (INVALID_CLOCK_P (clock_id))
62 return EINVAL;
64 /* If we got an absolute time, remap it. */
65 if (flags == TIMER_ABSTIME)
67 long int nsec;
68 long int sec;
70 /* Make sure we use safe data types. */
71 assert (sizeof (sec) >= sizeof (now.tv_sec));
73 /* Get the current time for this clock. */
74 if (__builtin_expect (clock_gettime (clock_id, &now), 0) != 0)
75 return errno;
77 /* Compute the difference. */
78 nsec = req->tv_nsec - now.tv_nsec;
79 sec = req->tv_sec - now.tv_sec - (nsec < 0);
80 if (sec < 0)
81 /* The time has already elapsed. */
82 return 0;
84 now.tv_sec = sec;
85 now.tv_nsec = nsec + (nsec < 0 ? 1000000000 : 0);
87 /* From now on this is our time. */
88 req = &now;
90 /* Make sure we are not modifying the struct pointed to by REM. */
91 rem = NULL;
93 else if (__builtin_expect (flags, 0) != 0)
94 return EINVAL;
95 else if (clock_id != CLOCK_REALTIME)
96 /* Not supported. */
97 return ENOTSUP;
99 return __builtin_expect (nanosleep (req, rem), 0) ? errno : 0;
101 weak_alias (__clock_nanosleep, clock_nanosleep)