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by Andrew Doran.
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.Dd January 2, 2008 .Dt KPAUSE 9 .Os ------------------------------------------------------------
.Sh NAME .Nm kpause .Nd make the calling LWP sleep ------------------------------------------------------------
.Sh SYNOPSIS n sys/proc.h - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
.Ft int .Fn kpause \ "const char *wmesg" "bool intr" "int timeo" "kmutex_t *mtx" ------------------------------------------------------------
.Sh DESCRIPTION .Fn kpause makes the calling LWP sleep. It's similar to .Xr cv_timedwait_sig 9 without the corresponding .Xr cv_signal 9 .
p .Fn kpause can wake up spontaneously. Callers should prepare to handle it.
p l -tag -width wmesg t Fa wmesg Specifies a string of no more than 8 characters that describes the resource or condition associated with the call of .Fn kpause . The kernel does not use this argument directly but makes it available for utilities such as .Xr ps 1 to display. t Fa intr If true, sleep interruptably. If the LWP receives a signal, or is interrupted by another condition such as its containing process exiting, the wait is ended early and an error code returned. t Fa timeo Specify a timeout. It is an architecture and system dependent value related to the number of clock interrupts per second. See .Xr hz 9 for details. The .Xr mstohz 9 macro can be used to convert a timeout expressed in milliseconds to one suitable for .Fn kpause .
p
Zero means no timeout.
t Fa mtx Convenience and symmetry with other synchronization operations.
If not
.Dv NULL ,
.Fa mtx
will be released once the LWP has prepared to sleep, and will be reacquired
before
.Fn kpause
returns.
.El
------------------------------------------------------------
.Sh RETURN VALUES
.Fn kpause
returns 0 when waking up spontaneously.
Otherwise,
It returns an error number.
------------------------------------------------------------
.Sh ERRORS
l -tag -width Er t Bq Er EINTR .Fn kpause
returned due to other reasons.
Typically as a result of a signal without
.Dv SA_RESTART
property.
t Bq Er ERESTART .Fn kpause
returned as a result of a signal with
.Dv SA_RESTART
property.
t Bq Er EWOULDBLOCK The timeout expired.
.El
------------------------------------------------------------
.Sh SEE ALSO
.Xr sigaction 2 ,
.Xr condvar 9 ,
.Xr errno 9 ,
.Xr hz 9 ,
.Xr mstohz 9