| /* Copyright (C) 1991-2016 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <unistd.h> |
| #include <sys/time.h> |
| |
| /* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM. |
| If SECONDS is zero, any currently scheduled alarm will be cancelled. |
| The function returns the number of seconds remaining until the last |
| alarm scheduled would have signaled, or zero if there wasn't one. |
| There is no return value to indicate an error, but you can set `errno' |
| to 0 and check its value after calling `alarm', and this might tell you. |
| The signal may come late due to processor scheduling. */ |
| unsigned int |
| alarm (unsigned int seconds) |
| { |
| struct itimerval old, new; |
| unsigned int retval; |
| |
| new.it_interval.tv_usec = 0; |
| new.it_interval.tv_sec = 0; |
| new.it_value.tv_usec = 0; |
| new.it_value.tv_sec = (long int) seconds; |
| if (__setitimer (ITIMER_REAL, &new, &old) < 0) |
| return 0; |
| |
| retval = old.it_value.tv_sec; |
| /* Round to the nearest second, but never report zero seconds when |
| the alarm is still set. */ |
| if (old.it_value.tv_usec >= 500000 |
| || (retval == 0 && old.it_value.tv_usec > 0)) |
| ++retval; |
| return retval; |
| } |
| libc_hidden_def (alarm) |