1.\" Copyright (c) 2016 The FreeBSD Foundation, Inc. 2.\" 3.\" This documentation was written by 4.\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship 5.\" from the FreeBSD Foundation. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd May 5, 2020 29.Dt THR_WAKE 2 30.Os 31.Sh NAME 32.Nm thr_wake 33.Nd wake up the suspended thread 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/thr.h 38.Ft int 39.Fn thr_wake "long id" 40.Sh DESCRIPTION 41.Bf -symbolic 42This function is intended for implementing threading. 43Normal applications should use 44.Xr pthread_cond_timedwait 3 45together with 46.Xr pthread_cond_broadcast 3 47for typical safe suspension with cooperation of the thread 48being suspended, or 49.Xr pthread_suspend_np 3 50and 51.Xr pthread_resume_np 3 52in some specific situations, instead. 53.Ef 54.Pp 55Passing the thread identifier of the calling thread 56.Po 57see 58.Xr thr_self 2 59.Pc 60to 61.Fn thr_wake 62sets a thread's flag to cause the next signal-interruptible sleep 63of that thread in the kernel to fail immediately with the 64.Er EINTR 65error. 66The flag is cleared by an interruptible sleep attempt or by a call to 67.Xr thr_suspend 2 . 68This is used by the system threading library to implement cancellation. 69.Pp 70If 71.Fa id 72is not equal to the current thread identifier, the specified thread is 73woken up if suspended by the 74.Xr thr_suspend 2 75system call. 76If the thread is not suspended at the time of the 77.Nm 78call, the wake is remembered and the next attempt of the thread to 79suspend itself with the 80.Xr thr_suspend 2 81results in immediate return with success. 82Only one wake is remembered. 83.Sh RETURN VALUES 84.Rv -std thr_wake 85.Sh ERRORS 86The 87.Fn thr_wake 88operation returns these errors: 89.Bl -tag -width Er 90.It Bq Er ESRCH 91The specified thread was not found or does not belong to the process 92of the calling thread. 93.El 94.Sh SEE ALSO 95.Xr ps 1 , 96.Xr thr_self 2 , 97.Xr thr_suspend 2 , 98.Xr pthread_cancel 3 , 99.Xr pthread_resume_np 3 , 100.Xr pthread_suspend_np 3 101.Sh STANDARDS 102The 103.Fn thr_suspend 104system call is non-standard and is used by 105.Lb libthr 106to implement 107.St -p1003.1-2001 108.Xr pthread 3 109functionality. 110.Sh HISTORY 111The 112.Fn thr_suspend 113system call first appeared in 114.Fx 5.2 . 115