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/**
* @file
*
* @ingroup libcsupport
*
* @brief POSIX 1003.1b 6.3.1 - Close a File
*/
/*
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/libio_.h>
int close(
int fd
)
{
rtems_libio_t *iop;
unsigned int flags;
int rc;
if ( (uint32_t) fd >= rtems_libio_number_iops ) {
rtems_set_errno_and_return_minus_one( EBADF );
}
iop = rtems_libio_iop( fd );
flags = rtems_libio_iop_flags( iop );
while ( true ) {
unsigned int desired;
bool success;
if ( ( flags & LIBIO_FLAGS_OPEN ) == 0 ) {
rtems_set_errno_and_return_minus_one( EBADF );
}
/* The expected flags */
flags &= LIBIO_FLAGS_REFERENCE_INC - 1U;
desired = flags & ~LIBIO_FLAGS_OPEN;
success = _Atomic_Compare_exchange_uint(
&iop->flags,
&flags,
desired,
ATOMIC_ORDER_ACQ_REL,
ATOMIC_ORDER_RELAXED
);
if ( success ) {
break;
}
if ( ( flags & ~( LIBIO_FLAGS_REFERENCE_INC - 1U ) ) != 0 ) {
rtems_set_errno_and_return_minus_one( EBUSY );
}
}
rc = (*iop->pathinfo.handlers->close_h)( iop );
rtems_libio_free( iop );
return rc;
}
/*
* _close_r
*
* This is the Newlib dependent reentrant version of close().
*/
#if defined(RTEMS_NEWLIB) && !defined(HAVE__CLOSE_R)
#include <reent.h>
int _close_r(
struct _reent *ptr RTEMS_UNUSED,
int fd
)
{
return close( fd );
}
#endif
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