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ualarm(3c) [opensolaris man page]

ualarm(3C)						   Standard C Library Functions 						ualarm(3C)

NAME
ualarm - schedule signal after interval in microseconds SYNOPSIS
#include <unistd.h> useconds_t ualarm(useconds_t useconds, useconds_t interval); DESCRIPTION
The ualarm() function causes the SIGALRM signal to be generated for the calling process after the number of real-time microseconds speci- fied by the useconds argument has elapsed. When the interval argument is non-zero, repeated timeout notification occurs with a period in microseconds specified by the interval argument. If the notification signal, SIGALRM, is not caught or ignored, the calling process is ter- minated. Because of scheduling delays, resumption of execution when the signal is caught may be delayed an arbitrary amount of time. Interactions between ualarm() and either alarm(2) or sleep(3C) are unspecified. RETURN VALUES
The ualarm() function returns the number of microseconds remaining from the previous ualarm() call. If no timeouts are pending or if ualarm() has not previously been called, ualarm() returns 0. ERRORS
No errors are defined. USAGE
The ualarm() function is a simplified interface to setitimer(2), and uses the ITIMER_REAL interval timer. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
alarm(2), setitimer(2), sighold(3C), signal(3C), sleep(3C), usleep(3C), attributes(5), standards(5) SunOS 5.11 14 Aug 2002 ualarm(3C)

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UALARM(3)						     Linux Programmer's Manual							 UALARM(3)

NAME
ualarm - schedule signal after given number of microseconds SYNOPSIS
#include <unistd.h> useconds_t ualarm(useconds_t usecs, useconds_t interval); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): ualarm(): _BSD_SOURCE || _XOPEN_SOURCE >= 500 DESCRIPTION
The ualarm() function causes the signal SIGALRM to be sent to the invoking process after (not less than) usecs microseconds. The delay may be lengthened slightly by any system activity or by the time spent processing the call or by the granularity of system timers. Unless caught or ignored, the SIGALRM signal will terminate the process. If the interval argument is nonzero, further SIGALRM signals will be sent every interval microseconds after the first. RETURN VALUE
This function returns the number of microseconds remaining for any alarm that was previously set, or 0 if no alarm was pending. ERRORS
EINTR Interrupted by a signal. EINVAL usecs or interval is not smaller than 1000000. (On systems where that is considered an error.) CONFORMING TO
4.3BSD, POSIX.1-2001. POSIX.1-2001 marks ualarm() as obsolete. POSIX.1-2008 removes the specification of ualarm(). 4.3BSD, SUSv2, and POSIX do not define any errors. NOTES
The type useconds_t is an unsigned integer type capable of holding integers in the range [0,1000000]. On the original BSD implementation, and in glibc before version 2.1, the arguments to ualarm() were instead typed as unsigned int. Programs will be more portable if they never mention useconds_t explicitly. The interaction of this function with other timer functions such as alarm(2), sleep(3), nanosleep(2), setitimer(2), timer_create(2), timer_delete(2), timer_getoverrun(2), timer_gettime(2), timer_settime(2), usleep(3) is unspecified. This function is obsolete. Use setitimer(2) or POSIX interval timers (timer_create(2), etc.) instead. SEE ALSO
alarm(2), getitimer(2), nanosleep(2), select(2), setitimer(2), usleep(3), time(7) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2008-08-06 UALARM(3)
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