1.\" SPDX-License-Identifier: BSD-2-Clause 2.\" 3.\" Copyright 2024 The FreeBSD Foundation, Inc. 4.\" 5.\" This documentation was written by 6.\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship 7.\" from the FreeBSD Foundation. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice(s), this list of conditions and the following disclaimer as 14.\" the first lines of this file unmodified other than the possible 15.\" addition of one or more copyright notices. 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice(s), this list of conditions and the following disclaimer in 18.\" the documentation and/or other materials provided with the 19.\" distribution. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 22.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 25.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 28.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 30.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 31.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32.\" 33.Dd April 21, 2024 34.Dt PTHREAD_SIGQUEUE 3 35.Os 36.Sh NAME 37.Nm pthread_sigqueue 38.Nd queue a signal to a specified thread 39.Sh LIBRARY 40.Lb libpthread 41.Sh SYNOPSIS 42.In pthread.h 43.In signal.h 44.Ft int 45.Fn pthread_sigqueue "pthread_t thread" "int sig" "const union sigval value" 46.Sh DESCRIPTION 47The 48.Fn pthread_queue 49function queues a signal, specified by 50.Fa sig , 51to a thread, specified by 52.Fa thread . 53If 54.Fa sig 55is 0, error checking is performed, but no signal is actually sent. 56The 57.Fa value 58is queued together with the signal, and becomes available in 59.Vt siginfo_t 60data passed to the signal handler. 61.Pp 62The 63.Nm 64function is similar to 65.Xr sigqueue 2 , 66but targets a thread in the current process instead of a process. 67See 68.Xr sigqueue 2 69for details about signal queueing and delivery selection. 70.Sh RETURN VALUES 71If successful, 72.Fn pthread_sigqueue 73returns 0. 74Otherwise, an error number is returned. 75.Sh ERRORS 76The 77.Fn pthread_sigqueue 78function will fail if: 79.Bl -tag -width Er 80.It Bq Er EAGAIN 81No resources are available to queue the signal. 82The current process has already queued 83.Brq Dv SIGQUEUE_MAX 84signals that are still pending, 85or a system-wide resource limit has been exceeded. 86.It Bq Er ESRCH 87.Fa thread 88is an invalid thread ID. 89.It Bq Er EINVAL 90.Fa sig 91is an invalid or unsupported signal number. 92.El 93.Sh SEE ALSO 94.Xr sigqueue 2 95.Sh STANDARDS 96The 97.Fn pthread_sigqueue 98function is a 99.Fx 100extension. 101An identical function with the same semantic is available in other 102operating systems. 103