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118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
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/**
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* @file
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*
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* @ingroup libcsupport
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*
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* @brief POSIX 1003.1b 6.3.1 - Close a File
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*/
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/*
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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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, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 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 BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <rtems/libio_.h>
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int close( int fd )
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{
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rtems_libio_t *iop;
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int rc;
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if ( (uint32_t) fd >= rtems_libio_number_iops ) {
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rtems_set_errno_and_return_minus_one( EBADF );
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}
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LIBIO_GET_IOP( fd, iop );
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while ( true ) {
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unsigned int flags;
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unsigned int desired;
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bool success;
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flags = rtems_libio_iop_flags( iop );
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if ( ( flags & LIBIO_FLAGS_OPEN ) == 0 ) {
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rtems_libio_iop_drop( iop );
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rtems_set_errno_and_return_minus_one( EBADF );
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}
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/**
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* When LIBIO_FLAGS_CLOSE_BUSY is not set check that only one reference
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* is held to prevent closing while busy. Otherwise atomically check that
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* the flags match to ensure the reference count is maintained.
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*/
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if ( ( flags & LIBIO_FLAGS_CLOSE_BUSY ) == 0 ) {
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flags &= LIBIO_FLAGS_FLAGS_MASK;
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flags |= LIBIO_FLAGS_REFERENCE_INC;
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}
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desired = flags & ~LIBIO_FLAGS_OPEN;
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success = _Atomic_Compare_exchange_uint(
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&iop->flags,
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&flags,
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desired,
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ATOMIC_ORDER_ACQ_REL,
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ATOMIC_ORDER_RELAXED
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);
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if ( success ) {
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break;
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}
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if (
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( flags & LIBIO_FLAGS_REFERENCE_MASK ) != LIBIO_FLAGS_REFERENCE_INC
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) {
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rtems_libio_iop_drop( iop );
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rtems_set_errno_and_return_minus_one( EBUSY );
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}
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}
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rc = ( *iop->pathinfo.handlers->close_h )( iop );
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rtems_libio_iop_drop( iop );
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return rc;
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}
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/*
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* _close_r
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*
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* This is the Newlib dependent reentrant version of close().
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*/
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#if defined( RTEMS_NEWLIB ) && !defined( HAVE__CLOSE_R )
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#include <reent.h>
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int _close_r( struct _reent *ptr RTEMS_UNUSED, int fd )
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{
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return close( fd );
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}
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#endif
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