| 1 | /* Copyright (C) 1991-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <sys/time.h> |
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| 19 | #include <unistd.h> |
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| 20 | |
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| 21 | /* Set an alarm to go off (generating a SIGALRM signal) in VALUE microseconds. |
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| 22 | If INTERVAL is nonzero, when the alarm goes off, the timer is reset to go |
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| 23 | off every INTERVAL microseconds thereafter. |
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| 24 | |
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| 25 | Returns the number of microseconds remaining before the alarm. */ |
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| 26 | useconds_t |
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| 27 | ualarm (useconds_t value, useconds_t interval) |
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| 28 | { |
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| 29 | struct itimerval timer, otimer; |
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| 30 | |
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| 31 | timer.it_value.tv_sec = 0; |
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| 32 | timer.it_value.tv_usec = value; |
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| 33 | timer.it_interval.tv_sec = 0; |
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| 34 | timer.it_interval.tv_usec = interval; |
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| 35 | |
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| 36 | if (__setitimer (ITIMER_REAL, new: &timer, old: &otimer) < 0) |
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| 37 | return -1; |
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| 38 | |
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| 39 | return (otimer.it_value.tv_sec * 1000000) + otimer.it_value.tv_usec; |
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| 40 | } |
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| 41 | |
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