1.\" Copyright (c) 2004 Michael Telahun Makonnen 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 January 22, 2004 28.Dt PTHREAD_SPIN_INIT 3 29.Os 30.Sh NAME 31.Nm pthread_spin_init , pthread_spin_destroy 32.Nd "initialize or destroy a spin lock" 33.Sh LIBRARY 34.Lb libpthread 35.Lb libthr 36.Sh SYNOPSIS 37.In pthread.h 38.Ft int 39.Fn pthread_spin_init "pthread_spinlock_t *lock" "int pshared" 40.Ft int 41.Fn pthread_spin_destroy "pthread_spinlock_t *lock" 42.Sh DESCRIPTION 43The 44.Fn pthread_spin_init 45function will initialize 46.Fa lock 47to an unlocked state and 48allocate any resources necessary to begin using it. 49If 50.Fa pshared 51is set to 52.Dv PTHREAD_PROCESS_SHARED , 53any thread, 54whether belonging to the process in which the spinlock was created or not, 55that has access to the memory area where 56.Fa lock 57resides, can use 58.Fa lock . 59If it is set to 60.Dv PTHREAD_PROCESS_PRIVATE , 61it can only be used by threads within the same process. 62.Pp 63The 64.Fn pthread_spin_destroy 65function will destroy 66.Fa lock 67and release any resources that may have been allocated on its behalf. 68.Sh RETURN VALUES 69If successful, 70both 71.Fn pthread_spin_init 72and 73.Fn pthread_spin_destroy 74will return zero. 75Otherwise, an error number will be returned to indicate the error. 76.Pp 77Neither of these functions will return 78.Er EINTR . 79.Sh ERRORS 80The 81.Fn pthread_spin_init 82and 83.Fn pthread_spin_destroy 84functions will fail if: 85.Bl -tag -width Er 86.It Bq Er EBUSY 87An attempt to initialize or destroy 88.Fa lock 89while it is in use. 90.It Bq Er EINVAL 91The value specified by 92.Fa lock 93is invalid. 94.El 95.Pp 96The 97.Fn pthread_spin_init 98function will fail if: 99.Bl -tag -width Er 100.It Bq Er EAGAIN 101Insufficient resources, 102other than memory, 103to initialize 104.Fa lock . 105.It Bq Er ENOMEM 106Insufficient memory to initialize 107.Fa lock . 108.El 109.Sh SEE ALSO 110.Xr pthread_spin_lock 3 , 111.Xr pthread_spin_unlock 3 112.Sh HISTORY 113The 114.Fn pthread_spin_init 115and 116.Fn pthread_spin_destroy 117functions first appeared in 118.Lb libpthread 119in 120.Fx 5.2 , 121and in 122.Lb libthr 123in 124.Fx 5.3 . 125.Sh BUGS 126The implementation of 127.Fn pthread_spin_init 128does not fully conform to 129.St -p1003.2 130because the 131.Fa pshared 132argument is ignored in 133.Lb libthr , 134and in 135.Lb libpthread 136if any value other than 137.Dv PTHREAD_PROCESSES_PRIVATE 138is specified, it returns 139.Er EINVAL . 140