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1 | /* High-resolution sleep with the specified clock. | |
2 | Copyright (C) 2000-2019 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
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 <time.h> | |
22 | #include <sysdep-cancel.h> | |
23 | #include <shlib-compat.h> | |
24 | ||
25 | /* This implementation assumes that these is only a `nanosleep' system | |
26 | call. So we have to remap all other activities. */ | |
27 | int | |
28 | __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req, | |
29 | struct timespec *rem) | |
30 | { | |
31 | struct timespec now; | |
32 | ||
33 | if (__builtin_expect (req->tv_nsec, 0) < 0 | |
34 | || __builtin_expect (req->tv_nsec, 0) >= 1000000000) | |
35 | return EINVAL; | |
36 | ||
37 | if (clock_id == CLOCK_THREAD_CPUTIME_ID) | |
38 | return EINVAL; /* POSIX specifies EINVAL for this case. */ | |
39 | ||
40 | if (clock_id < CLOCK_REALTIME || clock_id > CLOCK_THREAD_CPUTIME_ID) | |
41 | return EINVAL; | |
42 | ||
43 | /* If we got an absolute time, remap it. */ | |
44 | if (flags == TIMER_ABSTIME) | |
45 | { | |
46 | long int nsec; | |
47 | long int sec; | |
48 | ||
49 | /* Make sure we use safe data types. */ | |
50 | assert (sizeof (sec) >= sizeof (now.tv_sec)); | |
51 | ||
52 | /* Get the current time for this clock. */ | |
53 | if (__clock_gettime (clock_id, &now) != 0) | |
54 | return errno; | |
55 | ||
56 | /* Compute the difference. */ | |
57 | nsec = req->tv_nsec - now.tv_nsec; | |
58 | sec = req->tv_sec - now.tv_sec - (nsec < 0); | |
59 | if (sec < 0) | |
60 | /* The time has already elapsed. */ | |
61 | return 0; | |
62 | ||
63 | now.tv_sec = sec; | |
64 | now.tv_nsec = nsec + (nsec < 0 ? 1000000000 : 0); | |
65 | ||
66 | /* From now on this is our time. */ | |
67 | req = &now; | |
68 | ||
69 | /* Make sure we are not modifying the struct pointed to by REM. */ | |
70 | rem = NULL; | |
71 | } | |
72 | else if (flags != 0) | |
73 | return EINVAL; | |
74 | else if (clock_id != CLOCK_REALTIME) | |
75 | /* Not supported. */ | |
76 | return ENOTSUP; | |
77 | ||
78 | return __nanosleep (req, rem), 0 ? errno : 0; | |
79 | } | |
80 | ||
81 | versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17); | |
82 | /* clock_nanosleep moved to libc in version 2.17; | |
83 | old binaries may expect the symbol version it had in librt. */ | |
84 | #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17) | |
85 | strong_alias (__clock_nanosleep, __clock_nanosleep_2); | |
86 | compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2); | |
87 | #endif |