1.\"- 2.\" Copyright (c) 2010 Xin LI <delphij@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd January 8, 2010 29.Dt PTHREAD_ATTR_AFFINITY_NP 3 30.Os 31.Sh NAME 32.Nm pthread_attr_getaffinity_np , 33.Nm pthread_attr_setaffinity_np 34.Nd manage CPU affinity in thread attribute objects 35.Sh LIBRARY 36.Lb libpthread 37.Sh SYNOPSIS 38.In pthread_np.h 39.Ft int 40.Fn pthread_attr_getaffinity_np "const pthread_attr_t *pattr" "size_t cpusetsize" "cpuset_t *cpusetp" 41.Ft int 42.Fn pthread_attr_setaffinity_np "pthread_attr_t *pattr" "size_t cpusetsize" "const cpuset_t *cpusetp" 43.Sh DESCRIPTION 44The 45.Fn pthread_attr_getaffinity_np 46and 47.Fn pthread_attr_setaffinity_np 48functions allow the manipulation of sets of CPUs available to the specified thread attribute object. 49.Pp 50Masks of type 51.Ft cpuset_t 52are composed using the 53.Xr CPU_SET 3 54macros. 55The kernel tolerates large sets as long as all CPUs specified 56in the set exist. 57Sets smaller than the kernel uses generate an error on calls to 58.Fn pthread_attr_getaffinity_np 59even if the result set would fit within the user supplied set. 60Calls to 61.Fn pthread_attr_setaffinity_np 62tolerate small sets with no restrictions. 63.Pp 64The supplied mask should have a size of 65.Fa cpusetsize 66bytes. 67This size is usually provided by calling 68.Li sizeof(cpuset_t) 69which is ultimately determined by the value of 70.Dv CPU_SETSIZE 71as defined in 72.In sys/cpuset.h . 73.Pp 74.Fn pthread_attr_getaffinity_np 75retrieves the 76mask from the thread attribute object specified by 77.Fa pattr , 78and stores it in the space provided by 79.Fa cpusetp . 80.Pp 81.Fn pthread_attr_setaffinity_np 82sets the mask for the thread attribute object specified by 83.Fa pattr 84to the value in 85.Fa cpusetp . 86.Sh RETURN VALUES 87If successful, the 88.Fn pthread_attr_getaffinity_np 89and 90.Fn pthread_attr_setaffinity_np 91functions will return zero. 92Otherwise an error number will be returned 93to indicate the error. 94.Sh ERRORS 95The 96.Fn pthread_attr_getaffinity_np 97and 98.Fn pthread_attr_setaffinity_np 99functions will fail if: 100.Bl -tag -width Er 101.It Bq Er EINVAL 102The 103.Fa pattr 104or the attribute specified by it is 105.Dv NULL . 106.El 107.Pp 108The 109.Fn pthread_attr_setaffinity_np 110function will fail if: 111.Bl -tag -width Er 112.It Bq Er EINVAL 113The 114.Fa pattr 115or the attribute specified by it is 116.Dv NULL . 117.It Bq Er ENOMEM 118Insufficient memory exists to store the cpuset mask. 119.El 120.Sh SEE ALSO 121.Xr cpuset 1 , 122.Xr cpuset 2 , 123.Xr cpuset_getid 2 , 124.Xr cpuset_setid 2 , 125.Xr CPU_SET 3 , 126.Xr pthread_get_affinity_np 3 , 127.Xr pthread_set_affinity_np 3 128.Sh STANDARDS 129The 130.Nm pthread_attr_getaffinity_np 131and 132.Nm pthread_attr_setaffinity_np 133functions are non-standard 134.Fx 135extensions and may be not available on other operating systems. 136.Sh HISTORY 137The 138.Nm pthread_attr_getaffinity_np 139and 140.Nm pthread_attr_setaffinity_np 141functions first appeared in 142.Fx 7.2 . 143.Sh AUTHORS 144.An -nosplit 145The 146.Nm pthread_attr_getaffinity_np 147and 148.Nm pthread_attr_setaffinity_np 149functions were written by 150.An David Xu Aq davidxu@FreeBSD.org , 151and this manpage was written by 152.An Xin LI Aq delphij@FreeBSD.org . 153