1.\" Copyright (c) 2016 The FreeBSD Foundation, Inc. 2.\" 3.\" This documentation was written by 4.\" Konstantin Belousov <[email protected]> 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.\" $FreeBSD$ 29.\" 30.Dd May 5, 2020 31.Dt THR_kill 2 32.Os 33.Sh NAME 34.Nm thr_kill 35.Nd send signal to thread 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/thr.h 40.Ft int 41.Fn thr_kill "long id" "int sig" 42.Ft int 43.Fn thr_kill2 "pid_t pid" "long id" "int sig" 44.Sh DESCRIPTION 45The 46.Fn thr_kill 47and 48.Fn thr_kill2 49system calls allow sending a signal, specified by the 50.Fa sig 51argument, to some threads in a process. 52For the 53.Fn thr_kill 54function, signalled threads are always limited to the current process. 55For the 56.Fn thr_kill2 57function, the 58.Fa pid 59argument specifies the process with threads to be signalled. 60.Pp 61The 62.Fa id 63argument specifies which threads get the signal. 64If 65.Fa id 66is equal to \-1, all threads in the specified process are signalled. 67Otherwise, only the thread with the thread identifier equal to the 68argument is signalled. 69.Pp 70The 71.Fa sig 72argument defines the delivered signal. 73It must be a valid signal number or zero. 74In the latter case no signal is actually sent, and the call is used to 75verify the liveness of the thread. 76.Pp 77The signal is delivered with 78.Dv siginfo 79.Dv si_code 80set to 81.Dv SI_LWP . 82.Sh RETURN VALUES 83If successful, 84.Fn thr_kill 85and 86.Fn thr_kill2 87will return zero, otherwise \-1 is returned, and 88.Va errno 89is set to indicate the error. 90.Sh ERRORS 91The 92.Fn thr_kill 93and 94.Fn thr_kill2 95operations return the following errors: 96.Bl -tag -width Er 97.It Bq Er EINVAL 98The 99.Fa sig 100argument is not zero and does not specify valid signal. 101.It Bq Er ESRCH 102The specified process or thread was not found. 103.El 104.Pp 105Additionally, the 106.Fn thr_kill2 107may return the following errors: 108.Bl -tag -width Er 109.It Bq Er EPERM 110The current process does not have sufficient privilege to check existence or 111send a signal to the specified process. 112.El 113.Sh SEE ALSO 114.Xr kill 2 , 115.Xr thr_exit 2 , 116.Xr thr_new 2 , 117.Xr thr_self 2 , 118.Xr thr_set_name 2 , 119.Xr _umtx_op 2 , 120.Xr pthread_kill 3 , 121.Xr signal 3 122.Sh STANDARDS 123The 124.Fn thr_kill 125and 126.Fn thr_kill2 127system calls are non-standard and are used by the 128.Lb libthr 129to implement 130.St -p1003.1-2001 131.Xr pthread 3 132functionality. 133.Sh HISTORY 134The 135.Fn thr_kill 136and 137.Fn thr_kill2 138system calls first appeared in 139.Fx 5.2 . 140