diff options
Diffstat (limited to 'lib/libc_r/uthread/uthread_close.c')
| -rw-r--r-- | lib/libc_r/uthread/uthread_close.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/lib/libc_r/uthread/uthread_close.c b/lib/libc_r/uthread/uthread_close.c new file mode 100644 index 00000000000..7e21853223e --- /dev/null +++ b/lib/libc_r/uthread/uthread_close.c @@ -0,0 +1,89 @@ +/* + * 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 REGENTS 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. + * + */ +#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; + int status; + struct stat sb; + + /* Lock the file descriptor while the file is closed: */ + if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) { + /* Get file descriptor status. */ + _thread_sys_fstat(fd, &sb); + + /* + * 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. + */ + if ((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); + } + + /* Close the file descriptor: */ + ret = _thread_sys_close(fd); + + free(_thread_fd_table[fd]); + _thread_fd_table[fd] = NULL; + } + return (ret); +} +#endif |