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Diffstat (limited to 'lib/libc/gen/usleep.3')
-rw-r--r-- | lib/libc/gen/usleep.3 | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/lib/libc/gen/usleep.3 b/lib/libc/gen/usleep.3 new file mode 100644 index 0000000..a17468b --- /dev/null +++ b/lib/libc/gen/usleep.3 @@ -0,0 +1,80 @@ +.\" Copyright (c) 1986, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)usleep.3 8.1 (Berkeley) 6/4/93 +.\" $FreeBSD$ +.\" +.Dd February 13, 1998 +.Dt USLEEP 3 +.Os +.Sh NAME +.Nm usleep +.Nd suspend process execution for an interval measured in microseconds +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In unistd.h +.Ft int +.Fn usleep "useconds_t microseconds" +.Sh DESCRIPTION +The +.Fn usleep +function suspends execution of the calling process until either +.Fa microseconds +microseconds have elapsed or a signal is delivered to the process and its +action is to invoke a signal-catching function or to terminate the +process. +System activity may lengthen the sleep by an indeterminate amount. +.Pp +This function is implemented using +.Xr nanosleep 2 +by pausing for +.Fa microseconds +microseconds or until a signal occurs. +Consequently, in this implementation, +sleeping has no effect on the state of process timers, +and there is no special handling for SIGALRM. +.Sh RETURN VALUES +.Rv -std usleep +.Sh ERRORS +The +.Fn usleep +function +will fail if: +.Bl -tag -width Er +.It Bq Er EINTR +A signal was delivered to the process and its +action was to invoke a signal-catching function. +.El +.Sh SEE ALSO +.Xr nanosleep 2 , +.Xr sleep 3 +.Sh HISTORY +The +.Fn usleep +function appeared in +.Bx 4.3 . |