| sx.9 (167371) | sx.9 (167387) |
|---|---|
| 1.\" 2.\" Copyright (C) 2001 Jason Evans <jasone@FreeBSD.org>. 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 --- 10 unchanged lines hidden (view full) --- 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" | 1.\" 2.\" Copyright (C) 2001 Jason Evans <jasone@FreeBSD.org>. 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 --- 10 unchanged lines hidden (view full) --- 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" |
| 27.\" $FreeBSD: head/share/man/man9/sx.9 167371 2007-03-09 16:52:26Z jhb $ | 27.\" $FreeBSD: head/share/man/man9/sx.9 167387 2007-03-09 22:41:01Z jhb $ |
| 28.\" 29.Dd February 1, 2006 30.Dt SX 9 31.Os 32.Sh NAME 33.Nm sx , 34.Nm sx_init , 35.Nm sx_destroy , 36.Nm sx_slock , 37.Nm sx_xlock , 38.Nm sx_try_slock , 39.Nm sx_try_xlock , 40.Nm sx_sunlock , 41.Nm sx_xunlock , 42.Nm sx_unlock , 43.Nm sx_try_upgrade , 44.Nm sx_downgrade , | 28.\" 29.Dd February 1, 2006 30.Dt SX 9 31.Os 32.Sh NAME 33.Nm sx , 34.Nm sx_init , 35.Nm sx_destroy , 36.Nm sx_slock , 37.Nm sx_xlock , 38.Nm sx_try_slock , 39.Nm sx_try_xlock , 40.Nm sx_sunlock , 41.Nm sx_xunlock , 42.Nm sx_unlock , 43.Nm sx_try_upgrade , 44.Nm sx_downgrade , |
| 45.Nm sx_sleep , |
|
| 45.Nm sx_xlocked , 46.Nm sx_assert , 47.Nm SX_SYSINIT 48.Nd kernel shared/exclusive lock 49.Sh SYNOPSIS 50.In sys/param.h 51.In sys/lock.h 52.In sys/sx.h --- 15 unchanged lines hidden (view full) --- 68.Fn sx_xunlock "struct sx *sx" 69.Ft void 70.Fn sx_unlock "struct sx *sx" 71.Ft int 72.Fn sx_try_upgrade "struct sx *sx" 73.Ft void 74.Fn sx_downgrade "struct sx *sx" 75.Ft int | 46.Nm sx_xlocked , 47.Nm sx_assert , 48.Nm SX_SYSINIT 49.Nd kernel shared/exclusive lock 50.Sh SYNOPSIS 51.In sys/param.h 52.In sys/lock.h 53.In sys/sx.h --- 15 unchanged lines hidden (view full) --- 69.Fn sx_xunlock "struct sx *sx" 70.Ft void 71.Fn sx_unlock "struct sx *sx" 72.Ft int 73.Fn sx_try_upgrade "struct sx *sx" 74.Ft void 75.Fn sx_downgrade "struct sx *sx" 76.Ft int |
| 77.Fn sx_sleep "void *chan" "struct sx *sx" "int priority" "const char *wmesg" "int timo" 78.Ft int |
|
| 76.Fn sx_xlocked "struct sx *sx" 77.Pp 78.Cd "options INVARIANTS" 79.Cd "options INVARIANT_SUPPORT" 80.Ft void 81.Fn sx_assert "struct sx *sx" "int what" 82.In sys/kernel.h 83.Fn SX_SYSINIT "name" "struct sx *sx" "const char *description" --- 45 unchanged lines hidden (view full) --- 129otherwise the shared/exclusive lock will be acquired and a non-zero value will 130be returned. 131.Pp 132.Fn sx_try_upgrade 133will return 0 if the shared lock cannot be upgraded to an exclusive lock 134immediately; otherwise the exclusive lock will be acquired and a non-zero value 135will be returned. 136.Pp | 79.Fn sx_xlocked "struct sx *sx" 80.Pp 81.Cd "options INVARIANTS" 82.Cd "options INVARIANT_SUPPORT" 83.Ft void 84.Fn sx_assert "struct sx *sx" "int what" 85.In sys/kernel.h 86.Fn SX_SYSINIT "name" "struct sx *sx" "const char *description" --- 45 unchanged lines hidden (view full) --- 132otherwise the shared/exclusive lock will be acquired and a non-zero value will 133be returned. 134.Pp 135.Fn sx_try_upgrade 136will return 0 if the shared lock cannot be upgraded to an exclusive lock 137immediately; otherwise the exclusive lock will be acquired and a non-zero value 138will be returned. 139.Pp |
| 140A thread can atomically release a shared/exclusive lock while waiting for an 141event by calling 142.Fn sx_sleep . 143For more details on the parameters to this function, 144see 145.Xr sleep 9 . 146.Pp |
|
| 137When compiled with 138.Cd "options INVARIANTS" 139and 140.Cd "options INVARIANT_SUPPORT" , 141the 142.Fn sx_assert 143function tests 144.Fa sx --- 19 unchanged lines hidden (view full) --- 164.It Dv SX_UNLOCKED 165Assert that the current thread has no lock on the 166.Vt sx 167lock pointed to 168by the first argument. 169.El 170.Pp 171.Fn sx_xlocked | 147When compiled with 148.Cd "options INVARIANTS" 149and 150.Cd "options INVARIANT_SUPPORT" , 151the 152.Fn sx_assert 153function tests 154.Fa sx --- 19 unchanged lines hidden (view full) --- 174.It Dv SX_UNLOCKED 175Assert that the current thread has no lock on the 176.Vt sx 177lock pointed to 178by the first argument. 179.El 180.Pp 181.Fn sx_xlocked |
| 172will return non-zero if the current process holds the exclusive lock; | 182will return non-zero if the current thread holds the exclusive lock; |
| 173otherwise, it will return zero. 174.Pp 175For ease of programming, 176.Fn sx_unlock 177is provided as a macro frontend to the respective functions, 178.Fn sx_sunlock 179and 180.Fn sx_xunlock . --- 52 unchanged lines hidden --- | 183otherwise, it will return zero. 184.Pp 185For ease of programming, 186.Fn sx_unlock 187is provided as a macro frontend to the respective functions, 188.Fn sx_sunlock 189and 190.Fn sx_xunlock . --- 52 unchanged lines hidden --- |