Originální popis anglicky:
ualarm - set the interval timer
Návod, kniha: POSIX Programmer's Manual
#include <unistd.h>
useconds_t ualarm(useconds_t
useconds,
useconds_t interval);
The
ualarm() function shall cause the SIGALRM signal to be generated for
the calling process after the number of realtime microseconds specified 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 terminated.
Implementations may place limitations on the granularity of timer values. For
each interval timer, if the requested timer value requires a finer granularity
than the implementation supports, the actual timer value shall be rounded up
to the next supported value.
Interactions between
ualarm() and any of the following are unspecified:
alarm()
nanosleep()
setitimer()
timer_create()
timer_delete()
timer_getoverrun()
timer_gettime()
timer_settime()
sleep()
The
ualarm() function shall return the number of microseconds remaining
from the previous
ualarm() call. If no timeouts are pending or if
ualarm() has not previously been called,
ualarm() shall return
0.
No errors are defined.
The following sections are informative.
None.
Applications are recommended to use
nanosleep() if the Timers option is
supported, or
setitimer(),
timer_create(),
timer_delete(),
timer_getoverrun(),
timer_gettime(), or
timer_settime() instead of this function.
None.
None.
alarm() ,
nanosleep() ,
setitimer() ,
sleep() ,
timer_create() ,
timer_delete() ,
timer_getoverrun() ,
the Base Definitions volume of IEEE Std 1003.1-2001,
<unistd.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
