This documentation was written by
Konstantin Belousov <kib@FreeBSD.org> under sponsorship
from the FreeBSD Foundation.
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.
THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
.Dd May 5, 2020 .Dt THR_WAKE 2 .Os .Sh NAME .Nm thr_wake .Nd wake up the suspended thread .Sh LIBRARY .Lb libc .Sh SYNOPSIS n sys/thr.h .Ft int .Fn thr_wake "long id" .Sh DESCRIPTION f -symbolic This function is intended for implementing threading. Normal applications should use .Xr pthread_cond_timedwait 3 together with .Xr pthread_cond_broadcast 3 for typical safe suspension with cooperation of the thread being suspended, or .Xr pthread_suspend_np 3 and .Xr pthread_resume_np 3 in some specific situations, instead. .Ef
p Passing the thread identifier of the calling thread
o see .Xr thr_self 2
c to .Fn thr_wake sets a thread's flag to cause the next signal-interruptible sleep of that thread in the kernel to fail immediately with the .Er EINTR error. The flag is cleared by an interruptible sleep attempt or by a call to .Xr thr_suspend 2 . This is used by the system threading library to implement cancellation.
p If .Fa id is not equal to the current thread identifier, the specified thread is woken up if suspended by the .Xr thr_suspend 2 system call. If the thread is not suspended at the time of the .Nm call, the wake is remembered and the next attempt of the thread to suspend itself with the .Xr thr_suspend 2 results in immediate return with success. Only one wake is remembered. .Sh RETURN VALUES .Rv -std thr_wake .Sh ERRORS The .Fn thr_wake operation returns these errors: l -tag -width Er t Bq Er ESRCH The specified thread was not found or does not belong to the process of the calling thread. .El .Sh SEE ALSO .Xr ps 1 , .Xr thr_self 2 , .Xr thr_suspend 2 , .Xr pthread_cancel 3 , .Xr pthread_resume_np 3 , .Xr pthread_suspend_np 3 .Sh STANDARDS The .Fn thr_suspend system call is non-standard and is used by .Lb libthr to implement .St -p1003.1-2001 .Xr pthread 3 functionality. .Sh HISTORY The .Fn thr_suspend system call first appeared in .Fx 5.2 .