.\" SPDX-License-Identifier: BSD-2-Clause .\" .\" Copyright 2024 The FreeBSD Foundation .\" .\" This documentation was written by .\" Konstantin Belousov 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(s), this list of conditions and the following disclaimer as .\" the first lines of this file unmodified other than the possible .\" addition of one or more copyright notices. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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 April 21, 2024 .Dt PTHREAD_SIGQUEUE 3 .Os .Sh NAME .Nm pthread_sigqueue .Nd queue a signal to a specified thread .Sh LIBRARY .Lb libpthread .Sh SYNOPSIS .In pthread.h .In signal.h .Ft int .Fn pthread_sigqueue "pthread_t thread" "int sig" "const union sigval value" .Sh DESCRIPTION The .Fn pthread_queue function queues a signal, specified by .Fa sig , to a thread, specified by .Fa thread . If .Fa sig is 0, error checking is performed, but no signal is actually sent. The .Fa value is queued together with the signal, and becomes available in .Vt siginfo_t data passed to the signal handler. .Pp The .Nm function is similar to .Xr sigqueue 2 , but targets a thread in the current process instead of a process. See .Xr sigqueue 2 for details about signal queueing and delivery selection. .Sh RETURN VALUES If successful, .Fn pthread_sigqueue returns 0. Otherwise, an error number is returned. .Sh ERRORS The .Fn pthread_sigqueue function will fail if: .Bl -tag -width Er .It Bq Er EAGAIN No resources are available to queue the signal. The current process has already queued .Brq Dv SIGQUEUE_MAX signals that are still pending, or a system-wide resource limit has been exceeded. .It Bq Er ESRCH .Fa thread is an invalid thread ID. .It Bq Er EINVAL .Fa sig is an invalid or unsupported signal number. .El .Sh SEE ALSO .Xr sigqueue 2 .Sh STANDARDS The .Fn pthread_sigqueue function is a .Fx extension. An identical function with the same semantic is available in other operating systems.