2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #include "pthread_private.h"
39 __weak_reference(__close, close);
47 struct fd_table_entry *entry;
49 if ((fd < 0) || (fd >= _thread_dtablesize) ||
50 (fd == _thread_kern_pipe[0]) || (fd == _thread_kern_pipe[1]) ||
51 (_thread_fd_table[fd] == NULL)) {
53 * Don't allow silly programs to close the kernel pipe
54 * and non-active descriptors.
60 * Lock the file descriptor while the file is closed and get
61 * the file descriptor status:
63 else if (((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) &&
64 ((ret = __sys_fstat(fd, &sb)) == 0)) {
66 * Check if the file should be left as blocking.
68 * This is so that the file descriptors shared with a parent
69 * process aren't left set to non-blocking if the child
70 * closes them prior to exit. An example where this causes
71 * problems with /bin/sh is when a child closes stdin.
73 * Setting a file as blocking causes problems if a threaded
74 * parent accesses the file descriptor before the child exits.
75 * Once the threaded parent receives a SIGCHLD then it resets
76 * all of its files to non-blocking, and so it is then safe
79 * Pipes are not set to blocking when they are closed, as
80 * the parent and child will normally close the file
81 * descriptor of the end of the pipe that they are not
82 * using, which would then cause any reads to block
85 if ((S_ISREG(sb.st_mode) || S_ISCHR(sb.st_mode))
86 && (_thread_fd_getflags(fd) & O_NONBLOCK) == 0) {
87 /* Get the current flags: */
88 flags = __sys_fcntl(fd, F_GETFL, NULL);
89 /* Clear the nonblocking file descriptor flag: */
90 __sys_fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
93 /* XXX: Assumes well behaved threads. */
94 /* XXX: Defer real close to avoid race condition */
95 entry = _thread_fd_table[fd];
96 _thread_fd_table[fd] = NULL;
99 /* Drop stale pthread stdio descriptor flags. */
101 _pthread_stdio_flags[fd] = -1;
103 /* Close the file descriptor: */
104 ret = __sys_close(fd);
114 _thread_enter_cancellation_point();
116 _thread_leave_cancellation_point();