ab099bd309
about it always returning EPERM. Document that ENFILE occurs when the limit on kernel semaphores is reached.
92 lines
2.6 KiB
Groff
92 lines
2.6 KiB
Groff
.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice(s), this list of conditions and the following disclaimer as
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.\" the first lines of this file unmodified other than the possible
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.\" addition of one or more copyright notices.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice(s), this list of conditions and the following disclaimer in
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.\" the documentation and/or other materials provided with the
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.\" distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
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.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.Dd January 14, 2003
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.Dt SEM_INIT 3
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.Os
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.Sh NAME
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.Nm sem_init
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.Nd initialize an unnamed semaphore
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.Sh LIBRARY
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.Lb libc_r
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.Sh SYNOPSIS
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.In semaphore.h
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.Ft int
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.Fn sem_init "sem_t *sem" "int pshared" "unsigned int value"
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.Sh DESCRIPTION
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The
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.Fn sem_init
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function initializes the unnamed semaphore pointed to by
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.Fa sem
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to have the value
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.Fa value .
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A non-zero value for
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.Fa pshared
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specifies a shared semaphore that can be used by any process
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that can access
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.Fa sem .
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.Pp
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Following a successful call to
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.Fn sem_init ,
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.Fa sem
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can be used as an argument in subsequent calls to
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.Fa sem_wait ,
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.Fa sem_trywait ,
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.Fa sem_post ,
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and
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.Fa sem_destroy .
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.Fa sem
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is no longer valid after a successful call to
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.Fa sem_destroy .
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.Sh RETURN VALUES
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.Rv -std sem_init
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.Sh ERRORS
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.Fn sem_init
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will fail if:
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.Bl -tag -width Er
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.It Bq Er EINVAL
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.Fa value
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exceeds SEM_VALUE_MAX.
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.It Bq Er ENOSPC
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Memory allocation error.
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.It Bq Er ENFILE
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The system limit on semaphores
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.Pq Dv SEM_NSEMS_MAX
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has been reached.
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.El
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.Sh SEE ALSO
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.Xr sem_destroy 3 ,
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.Xr sem_post 3 ,
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.Xr sem_trywait 3 ,
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.Xr sem_wait 3 ,
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.Xr sem 4
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.Sh STANDARDS
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.Fn sem_init
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conforms to
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.St -p1003.1-96 .
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