1.\" 2.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.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 July 19, 2003 29.Dt VM_MAP_LOCK 9 30.Os 31.Sh NAME 32.Nm vm_map_lock , 33.Nm vm_map_unlock , 34.Nm vm_map_lock_read , 35.Nm vm_map_unlock_read , 36.Nm vm_map_trylock , 37.Nm vm_map_trylock_read , 38.Nm vm_map_lock_upgrade , 39.Nm vm_map_lock_downgrade 40.Nd vm_map locking macros 41.Sh SYNOPSIS 42.In sys/param.h 43.In vm/vm.h 44.In vm/vm_map.h 45.Ft void 46.Fn vm_map_lock "vm_map_t map" 47.Ft void 48.Fn vm_map_unlock "vm_map_t map" 49.Ft void 50.Fn vm_map_lock_read "vm_map_t map" 51.Ft void 52.Fn vm_map_unlock_read "vm_map_t map" 53.Ft int 54.Fn vm_map_trylock "vm_map_t map" 55.Ft int 56.Fn vm_map_trylock_read "vm_map_t map" 57.Ft int 58.Fn vm_map_lock_upgrade "vm_map_t map" 59.Ft int 60.Fn vm_map_lock_downgrade "vm_map_t map" 61.Sh DESCRIPTION 62The 63.Fn vm_map_lock 64macro obtains an exclusive lock on 65.Fa map . 66.Pp 67The 68.Fn vm_map_unlock 69macro releases an exclusive lock on 70.Fa map . 71.Pp 72The 73.Fn vm_map_lock_read 74macro obtains a read-lock on 75.Fa map . 76Currently this is implemented as an exclusive lock. 77.Pp 78The 79.Fn vm_map_unlock_read 80macro releases a read-lock on 81.Fa map . 82.Pp 83The 84.Fn vm_map_trylock 85macro attempts to obtain an exclusive lock on 86.Fa map . 87It returns FALSE if the lock cannot be immediately acquired; 88otherwise return TRUE with the lock acquired. 89.Pp 90The 91.Fn vm_map_trylock_read 92macro attempts to obtain a read-lock on 93.Fa map . 94It returns FALSE if the lock cannot be immediately acquired; 95otherwise return TRUE with the lock acquired. 96Currently this is implemented as an exclusive lock. 97.Pp 98The 99.Fn vm_map_lock_upgrade 100macro attempts to atomically upgrade a read-lock on 101.Fa map 102to an exclusive lock. 103As read-locks are currently implemented as exclusive locks, 104this macro is a no-op. 105.Pp 106The 107.Fn vm_map_lock_downgrade 108macro attempts to downgrade an exclusive lock on 109.Fa map 110to a read-lock. 111As read-locks are currently implemented as exclusive locks, 112this macro is a no-op. 113.Sh IMPLEMENTATION NOTES 114Currently, all of the locking macros implement their locks as sleep locks. 115.Sh SEE ALSO 116.Xr vm_map 9 117.Sh AUTHORS 118This manual page was written by 119.An Bruce M Simpson Aq bms@spc.org . 120