.\" <http://www.gnu.org/licenses/>.
.\" %%%LICENSE_END
.\"
-.TH UALARM 3 2010-09-20 "" "Linux Programmer's Manual"
+.TH UALARM 3 2013-12-23 "" "Linux Programmer's Manual"
.SH NAME
ualarm \- schedule signal after given number of microseconds
.SH SYNOPSIS
.B EINVAL
\fIusecs\fP or \fIinterval\fP is not smaller than 1000000.
(On systems where that is considered an error.)
+.SH ATTRIBUTES
+.SS Multithreading (see pthreads(7))
+The
+.BR ualarm ()
+function is thread-safe.
.SH CONFORMING TO
4.3BSD, POSIX.1-2001.
POSIX.1-2001 marks
.BR ualarm ().
4.3BSD, SUSv2, and POSIX do not define any errors.
.SH NOTES
+POSIX.1-2001 does not specify what happens if the
+.I usecs
+argument is 0.
+.\" This case is not documented in HP-US, Solar, FreeBSD, NetBSD, or OpenBSD!
+On Linux (and probably most other systems),
+the effect is to cancel any pending alarm.
+
The type
.I useconds_t
is an unsigned integer type capable of holding integers
.BR setitimer (2),
.BR usleep (3),
.BR time (7)
+.SH COLOPHON
+This page is part of release 3.65 of the Linux
+.I man-pages
+project.
+A description of the project,
+and information about reporting bugs,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.