| 1 | /* clock_getres -- Get the resolution of a POSIX clockid_t. Linux version. |
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| 2 | Copyright (C) 2003-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <sysdep.h> |
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| 20 | #include <errno.h> |
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| 21 | #include <time.h> |
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| 22 | |
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| 23 | #include <sysdep-vdso.h> |
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| 24 | #include <shlib-compat.h> |
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| 25 | #include <kernel-features.h> |
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| 26 | |
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| 27 | /* Get resolution of clock. */ |
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| 28 | int |
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| 29 | __clock_getres64 (clockid_t clock_id, struct __timespec64 *res) |
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| 30 | { |
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| 31 | int r; |
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| 32 | |
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| 33 | #ifndef __NR_clock_getres_time64 |
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| 34 | # define __NR_clock_getres_time64 __NR_clock_getres |
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| 35 | #endif |
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| 36 | |
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| 37 | #ifdef HAVE_CLOCK_GETRES64_VSYSCALL |
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| 38 | r = INLINE_VSYSCALL (clock_getres_time64, 2, clock_id, res); |
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| 39 | #else |
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| 40 | r = INLINE_SYSCALL_CALL (clock_getres_time64, clock_id, res); |
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| 41 | #endif |
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| 42 | if (r == 0 || errno != ENOSYS) |
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| 43 | return r; |
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| 44 | |
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| 45 | #ifndef __ASSUME_TIME64_SYSCALLS |
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| 46 | /* Fallback code that uses 32-bit support. */ |
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| 47 | struct timespec ts32; |
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| 48 | # ifdef HAVE_CLOCK_GETRES_VSYSCALL |
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| 49 | r = INLINE_VSYSCALL (clock_getres, 2, clock_id, &ts32); |
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| 50 | # else |
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| 51 | r = INLINE_SYSCALL_CALL (clock_getres, clock_id, &ts32); |
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| 52 | # endif |
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| 53 | if (r == 0 && res != NULL) |
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| 54 | *res = valid_timespec_to_timespec64 (ts32); |
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| 55 | #endif |
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| 56 | |
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| 57 | return r; |
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| 58 | } |
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| 59 | |
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| 60 | #if __TIMESIZE != 64 |
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| 61 | libc_hidden_def (__clock_getres64) |
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| 62 | |
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| 63 | int |
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| 64 | __clock_getres (clockid_t clock_id, struct timespec *res) |
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| 65 | { |
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| 66 | struct __timespec64 ts64; |
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| 67 | int retval; |
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| 68 | |
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| 69 | retval = __clock_getres64 (clock_id, &ts64); |
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| 70 | if (retval == 0 && res != NULL) |
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| 71 | *res = valid_timespec64_to_timespec (ts64); |
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| 72 | |
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| 73 | return retval; |
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| 74 | } |
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| 75 | #endif |
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| 76 | libc_hidden_def (__clock_getres) |
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| 77 | |
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| 78 | versioned_symbol (libc, __clock_getres, clock_getres, GLIBC_2_17); |
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| 79 | /* clock_getres moved to libc in version 2.17; |
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| 80 | old binaries may expect the symbol version it had in librt. */ |
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| 81 | #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17) |
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| 82 | strong_alias (__clock_getres, __clock_getres_2); |
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| 83 | compat_symbol (libc, __clock_getres_2, clock_getres, GLIBC_2_2); |
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| 84 | #endif |
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| 85 | |
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