projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| b8f253e8 KM |
1 | /* |
| 2 | * Copyright (c) 1985 Regents of the University of California. | |
| cecf1c1c KB |
3 | * All rights reserved. |
| 4 | * | |
| 269a7923 | 5 | * %sccs.include.redist.c% |
| b8f253e8 KM |
6 | */ |
| 7 | ||
| 2ce81398 | 8 | #if defined(LIBC_SCCS) && !defined(lint) |
| 269a7923 | 9 | static char sccsid[] = "@(#)ualarm.c 5.4 (Berkeley) %G%"; |
| cecf1c1c | 10 | #endif /* LIBC_SCCS and not lint */ |
| 63dcf418 S |
11 | |
| 12 | #include <sys/time.h> | |
| 13 | ||
| 14 | #define USPS 1000000 /* # of microseconds in a second */ | |
| 15 | ||
| 16 | /* | |
| 17 | * Generate a SIGALRM signal in ``usecs'' microseconds. | |
| 18 | * If ``reload'' is non-zero, keep generating SIGALRM | |
| 19 | * every ``reload'' microseconds after the first signal. | |
| 20 | */ | |
| 21 | unsigned | |
| 22 | ualarm(usecs, reload) | |
| 23 | register unsigned usecs; | |
| 24 | register unsigned reload; | |
| 25 | { | |
| 26 | struct itimerval new, old; | |
| 27 | ||
| 28 | new.it_interval.tv_usec = reload % USPS; | |
| 29 | new.it_interval.tv_sec = reload / USPS; | |
| 30 | ||
| 31 | new.it_value.tv_usec = usecs % USPS; | |
| 32 | new.it_value.tv_sec = usecs / USPS; | |
| 33 | ||
| 34 | if (setitimer(ITIMER_REAL, &new, &old) == 0) | |
| 35 | return (old.it_value.tv_sec * USPS + old.it_value.tv_usec); | |
| 36 | /* else */ | |
| 37 | return (-1); | |
| 38 | } |