| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Sleep for a given number of seconds. POSIX.1 version. |
| 2 | Copyright (C) 1991-2016 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 <time.h> |
| 20 | #include <unistd.h> |
| 21 | #include <errno.h> |
| 22 | #include <sys/param.h> |
| 23 | |
| 24 | |
| 25 | /* Make the process sleep for SECONDS seconds, or until a signal arrives |
| 26 | and is not ignored. The function returns the number of seconds less |
| 27 | than SECONDS which it actually slept (zero if it slept the full time). |
| 28 | If a signal handler does a `longjmp' or modifies the handling of the |
| 29 | SIGALRM signal while inside `sleep' call, the handling of the SIGALRM |
| 30 | signal afterwards is undefined. There is no return value to indicate |
| 31 | error, but if `sleep' returns SECONDS, it probably didn't work. */ |
| 32 | unsigned int |
| 33 | __sleep (unsigned int seconds) |
| 34 | { |
| 35 | int save_errno = errno; |
| 36 | |
| 37 | const unsigned int max |
| 38 | = (unsigned int) (((unsigned long int) (~((time_t) 0))) >> 1); |
| 39 | struct timespec ts = { 0, 0 }; |
| 40 | do |
| 41 | { |
| 42 | if (sizeof (ts.tv_sec) <= sizeof (seconds)) |
| 43 | { |
| 44 | /* Since SECONDS is unsigned assigning the value to .tv_sec can |
| 45 | overflow it. In this case we have to wait in steps. */ |
| 46 | ts.tv_sec += MIN (seconds, max); |
| 47 | seconds -= (unsigned int) ts.tv_sec; |
| 48 | } |
| 49 | else |
| 50 | { |
| 51 | ts.tv_sec = (time_t) seconds; |
| 52 | seconds = 0; |
| 53 | } |
| 54 | |
| 55 | if (__nanosleep (&ts, &ts) < 0) |
| 56 | /* We were interrupted. |
| 57 | Return the number of (whole) seconds we have not yet slept. */ |
| 58 | return seconds + ts.tv_sec; |
| 59 | } |
| 60 | while (seconds > 0); |
| 61 | |
| 62 | __set_errno (save_errno); |
| 63 | |
| 64 | return 0; |
| 65 | } |
| 66 | weak_alias (__sleep, sleep) |