1.\" Copyright (c) 2002,2003 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_ATTR_GET_NP 3 29.Os 30.Sh NAME 31.Nm pthread_attr_get_np 32.Nd get attributes of existent thread 33.Sh LIBRARY 34.Lb libpthread 35.Sh SYNOPSIS 36.In pthread_np.h 37.Ft int 38.Fn pthread_attr_get_np "pthread_t pid" "pthread_attr_t *dst" 39.Sh DESCRIPTION 40The 41.Fn pthread_attr_get_np 42function is used to get existent thread's attributes. 43Most fields of 44.Vt pthread_attr_t 45structure are exact values of attributes provided at thread creation 46time (as parameter to 47.Xr pthread_create 3 48function), except for the stack address. 49.Pp 50Value returned as 51.Fa dst 52is supposed to be used in conjunction with 53.Fn pthread_attr_get* 54functions to retrieve individual values from 55.Vt pthread_attr_t 56structure. 57Parameter 58.Fa dst 59should point to allocated memory area big enough to fit this structure. 60.Pp 61It is HIGHLY RECOMMENDED to use 62.Xr pthread_attr_init 3 63function to allocate attribute storage. 64.Sh IMPLEMENTATION NOTES 65The 66.Fn pthread_attr_get_np 67function will always return a pointer to the thread's real stack address, 68regardless of its value in the original attributes structure. 69.Sh RETURN VALUES 70If successful, 71.Fn pthread_attr_get_np 72function returns 0. 73Otherwise, an error number is returned to indicate the error. 74.Sh EXAMPLES 75.Bd -literal 76size_t 77my_thread_stack_size(pthread_t pid) 78{ 79 pthread_attr_t attr; 80 size_t size; 81 82 pthread_attr_init(&attr); 83 pthread_attr_get_np(pid, &attr); 84 pthread_attr_getstacksize(&attr, &size); 85 pthread_attr_destroy(&attr); 86 return(size); 87} 88.Ed 89.Sh ERRORS 90The 91.Fn pthread_attr_get_np 92function will fail if: 93.Bl -tag -width Er 94.It Bq Er EINVAL 95Invalid value for one of given parameters. 96.It Bq Er ESRCH 97No thread could be found corresponding to that specified by the given 98thread ID. 99.El 100.Sh SEE ALSO 101.Xr pthread_attr_destroy 3 , 102.Xr pthread_attr_getdetachstate 3 , 103.Xr pthread_attr_getinheritsched 3 , 104.Xr pthread_attr_getschedparam 3 , 105.Xr pthread_attr_getschedpolicy 3 , 106.Xr pthread_attr_getscope 3 , 107.Xr pthread_attr_getstack 3 , 108.Xr pthread_attr_getstackaddr 3 , 109.Xr pthread_attr_getstacksize 3 , 110.Xr pthread_attr_init 3 , 111.Xr pthread_np 3 112.Sh AUTHORS 113The 114.Fn pthread_attr_get_np 115function and this manual page were written by 116.An Alexey Zelkin Aq Mt phantom@FreeBSD.org . 117