| sema.9 (130482) | sema.9 (131754) |
|---|---|
| 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/sema.9 130482 2004-06-14 18:33:21Z jdp $ | 27.\" $FreeBSD: head/share/man/man9/sema.9 131754 2004-07-07 19:57:16Z ru $ |
| 28.\" 29.Dd June 14, 2004 30.Dt SEMA 9 31.Os 32.Sh NAME 33.Nm sema , 34.Nm sema_init , 35.Nm sema_destroy , --- 59 unchanged lines hidden (view full) --- 95The 96.Fa timo 97argument to 98.Fn sema_timedwait 99specifies the minimum time in ticks to wait before returning with failure. 100.Fn sema_value 101is used to read the current value of the semaphore. 102.Sh RETURN VALUES | 28.\" 29.Dd June 14, 2004 30.Dt SEMA 9 31.Os 32.Sh NAME 33.Nm sema , 34.Nm sema_init , 35.Nm sema_destroy , --- 59 unchanged lines hidden (view full) --- 95The 96.Fa timo 97argument to 98.Fn sema_timedwait 99specifies the minimum time in ticks to wait before returning with failure. 100.Fn sema_value 101is used to read the current value of the semaphore. 102.Sh RETURN VALUES |
| 103The |
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| 103.Fn sema_value | 104.Fn sema_value |
| 105function |
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| 104returns the current value of the semaphore. 105.Pp 106If decrementing the semaphore would result in its value being negative, 107.Fn sema_trywait 108returns 0 to indicate failure. 109Otherwise, a non-zero value is returned to indicate success. 110.Pp | 106returns the current value of the semaphore. 107.Pp 108If decrementing the semaphore would result in its value being negative, 109.Fn sema_trywait 110returns 0 to indicate failure. 111Otherwise, a non-zero value is returned to indicate success. 112.Pp |
| 113The |
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| 111.Fn sema_timedwait | 114.Fn sema_timedwait |
| 115function |
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| 112returns 0 if waiting on the semaphore succeeded; otherwise a 113non-zero error code is returned. 114.Sh ERRORS | 116returns 0 if waiting on the semaphore succeeded; otherwise a 117non-zero error code is returned. 118.Sh ERRORS |
| 119The |
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| 115.Fn sema_timedwait | 120.Fn sema_timedwait |
| 116will fail if: | 121function will fail if: |
| 117.Bl -tag -width Er 118.It Bq Er EWOULDBLOCK 119Timeout expired. 120.El 121.Sh SEE ALSO 122.Xr condvar 9 , 123.Xr mtx_pool 9 , 124.Xr mutex 9 , 125.Xr sx 9 | 122.Bl -tag -width Er 123.It Bq Er EWOULDBLOCK 124Timeout expired. 125.El 126.Sh SEE ALSO 127.Xr condvar 9 , 128.Xr mtx_pool 9 , 129.Xr mutex 9 , 130.Xr sx 9 |