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/* $OpenBSD: uthread_close.c,v 1.10 2003/02/14 03:58:42 marc Exp $ */
/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: uthread_close.c,v 1.7 1999/08/28 00:03:26 peter Exp $
*/
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
int
close(int fd)
{
int flags;
int ret;
struct stat sb;
/* This is a cancelation point: */
_thread_enter_cancellation_point();
if ((fd == _thread_kern_pipe[0]) || (fd == _thread_kern_pipe[1])) {
/*
* Don't allow silly programs to close the kernel pipe.
*/
errno = EBADF;
ret = -1;
}
/*
* Lock the file descriptor while the file is closed and get
* the file descriptor status:
*/
else if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) {
/*
* Check if the file should be left as blocking.
*
* This is so that the file descriptors shared with a parent
* process aren't left set to non-blocking if the child
* closes them prior to exit. An example where this causes
* problems with /bin/sh is when a child closes stdin.
*
* Setting a file as blocking causes problems if a threaded
* parent accesses the file descriptor before the child exits.
* Once the threaded parent receives a SIGCHLD then it resets
* all of its files to non-blocking, and so it is then safe
* to access them.
*
* Pipes are not set to blocking when they are closed, as
* the parent and child will normally close the file
* descriptor of the end of the pipe that they are not
* using, which would then cause any reads to block
* indefinitely.
*
* Files that we cannot fstat are probably not regular
* so we don't bother with them.
*/
if ((_thread_sys_fstat(fd, &sb) == 0) &&
((S_ISREG(sb.st_mode) || S_ISCHR(sb.st_mode)) &&
(_thread_fd_table[fd]->flags & O_NONBLOCK) == 0))
{
/* Get the current flags: */
flags = _thread_sys_fcntl(fd, F_GETFL, NULL);
/* Clear the nonblocking file descriptor flag: */
_thread_sys_fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
}
/* XXX: Assumes well behaved threads. */
/* XXX: Defer real close to avoid race condition */
_thread_fd_table_remove(fd);
/* Close the file descriptor: */
ret = _thread_sys_close(fd);
}
/* No longer in a cancellation point: */
_thread_leave_cancellation_point();
return (ret);
}
#endif
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