1.\" Copyright (C) 2000 Jason Evans <jasone@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(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 20.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 26.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.Dd October 27, 2023 28.Dt PTHREAD_CONDATTR 3 29.Os 30.Sh NAME 31.Nm pthread_condattr_init , 32.Nm pthread_condattr_destroy , 33.Nm pthread_condattr_getclock , 34.Nm pthread_condattr_setclock , 35.Nm pthread_condattr_getpshared , 36.Nm pthread_condattr_setpshared 37.Nd condition attribute operations 38.Sh LIBRARY 39.Lb libpthread 40.Sh SYNOPSIS 41.In pthread.h 42.Ft int 43.Fn pthread_condattr_init "pthread_condattr_t *attr" 44.Ft int 45.Fn pthread_condattr_destroy "pthread_condattr_t *attr" 46.Ft int 47.Fo pthread_condattr_getclock 48.Fa "pthread_condattr_t * restrict attr" "clockid_t * restrict clock_id" 49.Fc 50.Ft int 51.Fn pthread_condattr_setclock "pthread_condattr_t *attr" "clockid_t clock_id" 52.Ft int 53.Fo pthread_condattr_getpshared 54.Fa "pthread_condattr_t * restrict attr" "int * restrict pshared" 55.Fc 56.Ft int 57.Fn pthread_condattr_setpshared "pthread_condattr_t *attr" "int pshared" 58.Sh DESCRIPTION 59Condition attribute objects are used to specify parameters to 60.Fn pthread_cond_init . 61.Pp 62The 63.Fn pthread_condattr_init 64function initializes a condition attribute object with the default attributes. 65.Pp 66The 67.Fn pthread_condattr_destroy 68function destroys a condition attribute object. 69.Pp 70The 71.Fn pthread_condattr_getclock 72function will put the value of the clock attribute from 73.Fa attr 74into the memory area pointed to by 75.Fa clock_id . 76The 77.Fn pthread_condattr_setclock 78function will set the clock attribute of 79.Fa attr 80to the value specified in 81.Fa clock_id . 82The clock attribute affects the interpretation of 83.Fa abstime 84in 85.Xr pthread_cond_timedwait 3 86and may be set to 87.Dv CLOCK_REALTIME 88(default) 89or 90.Dv CLOCK_MONOTONIC . 91.Pp 92The 93.Fn pthread_condattr_getpshared 94function will put the value of the process-shared attribute from 95.Fa attr 96into the memory area pointed to by 97.Fa pshared . 98The 99.Fn pthread_condattr_setpshared 100function will set the process-shared attribute of 101.Fa attr 102to the value specified in 103.Fa pshared . 104The argument 105.Fa pshared 106may have one of the following values: 107.Bl -tag -width ".Dv PTHREAD_PROCESS_PRIVATE" 108.It Dv PTHREAD_PROCESS_PRIVATE 109The condition variable it is attached to may only be accessed by 110threads in the same process as the one that created the object. 111.It Dv PTHREAD_PROCESS_SHARED 112The condition variable it is attached to may be accessed by 113threads in processes other than the one that created the object. 114.El 115See 116.Xr libthr 3 117for details of the implementation of shared condition variables, 118and their limitations. 119.Sh RETURN VALUES 120If successful, these functions return 0. 121Otherwise, an error number is returned to indicate the error. 122.Sh ERRORS 123The 124.Fn pthread_condattr_init 125function will fail if: 126.Bl -tag -width Er 127.It Bq Er ENOMEM 128Out of memory. 129.El 130.Pp 131The 132.Fn pthread_condattr_destroy 133function will fail if: 134.Bl -tag -width Er 135.It Bq Er EINVAL 136Invalid value for 137.Fa attr . 138.El 139.Pp 140The 141.Fn pthread_condattr_setclock 142function will fail if: 143.Bl -tag -width Er 144.It Bq Er EINVAL 145The value specified in 146.Fa clock_id 147is not one of the allowed values. 148.El 149.Pp 150The 151.Fn pthread_condattr_setpshared 152function will fail if: 153.Bl -tag -width Er 154.It Bq Er EINVAL 155The value specified in 156.Fa pshared 157is not one of the allowed values. 158.El 159.Sh SEE ALSO 160.Xr libthr 3 , 161.Xr pthread_cond_init 3 , 162.Xr pthread_cond_timedwait 3 163.Sh STANDARDS 164The 165.Fn pthread_condattr_init 166and 167.Fn pthread_condattr_destroy 168functions conform to 169.St -p1003.1-96 170