| 1 | /* Returns whether Priority Inheritance support CLOCK_MONOTONIC. |
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| 2 | Copyright (C) 2021-2022 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 <support/xthread.h> |
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| 20 | #include <sys/syscall.h> |
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| 21 | #include <unistd.h> |
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| 22 | |
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| 23 | bool |
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| 24 | support_mutex_pi_monotonic (void) |
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| 25 | { |
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| 26 | #ifdef __linux__ |
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| 27 | # ifndef __NR_futex |
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| 28 | # define __NR_futex __NR_futex_time64 |
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| 29 | # endif |
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| 30 | int r = syscall (__NR_futex, &(unsigned int){0}, 13 /* FUTEX_LOCK_PI2 */, |
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| 31 | 0, NULL); |
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| 32 | return r == 0; |
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| 33 | #else |
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| 34 | return false; |
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| 35 | #endif |
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| 36 | } |
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| 37 | |
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