1.\" Copyright (c) 2003 Alexey Zelkin <phantom@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd October 12, 2021 28.Dt PTHREAD_SWITCH_ADD_NP 3 29.Os 30.Sh NAME 31.Nm pthread_switch_add_np , 32.Nm pthread_switch_delete_np 33.Nd thread context switches debugging primitives 34.Sh LIBRARY 35.Lb libpthread 36.Sh SYNOPSIS 37.In pthread_np.h 38.Ft int 39.Fn pthread_switch_add_np "pthread_switch_routine_t routine" 40.Ft int 41.Fn pthread_switch_delete_np "pthread_switch_routine_t routine" 42.Sh DESCRIPTION 43An application is allowed to monitor the thread context switches inside 44the threading library. 45An application can install a routine that gets called every time a thread 46(explicitly created by an application with the 47.Xr pthread_create 3 48function) gets the context switched. 49The routine is passed the thread IDs of the threads that are 50being switched in and out. 51Installation and removal of these hooks may be done using the 52.Fn pthread_switch_add_np 53and 54.Fn pthread_switch_delete_np 55functions respectively. 56.Sh RETURN VALUES 57If successful, 58these functions return 0. 59Otherwise, an error number is returned to indicate the error. 60.Sh ERRORS 61The 62.Fn pthread_switch_add_np 63may fail if: 64.Bl -tag -width Er 65.It Bq Er EINVAL 66.Dv NULL 67pointer was passed in the 68.Fa routine 69argument. 70.El 71.Pp 72The 73.Fn pthread_switch_delete_np 74may fail if: 75.Bl -tag -width Er 76.It Bq Er EINVAL 77The 78.Fa routine 79argument is different from the argument previously passed to the 80.Fn pthread_switch_add_np 81function. 82.El 83.Sh SEE ALSO 84.Xr pthread_create 3 , 85.Xr pthread_np 3 86.Sh AUTHORS 87This manual page was written by 88.An Alexey Zelkin Aq Mt phantom@FreeBSD.org . 89