thr_fcntl.c revision 53812 
1/*
2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: head/lib/libkse/thread/thr_fcntl.c 53812 1999-11-28 05:38:13Z alfred $
33 */
34#include <stdarg.h>
35#include <unistd.h>
36#include <fcntl.h>
37#ifdef _THREAD_SAFE
38#include <pthread.h>
39#include "pthread_private.h"
40
41int
42fcntl(int fd, int cmd,...)
43{
44	int             flags = 0;
45	int		nonblock;
46	int             oldfd;
47	int             ret;
48	va_list         ap;
49
50	_thread_enter_cancellation_point();
51
52	/* Lock the file descriptor: */
53	if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) {
54		/* Initialise the variable argument list: */
55		va_start(ap, cmd);
56
57		/* Process according to file control command type: */
58		switch (cmd) {
59		/* Duplicate a file descriptor: */
60		case F_DUPFD:
61			/*
62			 * Get the file descriptor that the caller wants to
63			 * use:
64			 */
65			oldfd = va_arg(ap, int);
66
67			/* Initialise the file descriptor table entry: */
68			if ((ret = _thread_sys_fcntl(fd, cmd, oldfd)) < 0) {
69			}
70			/* Initialise the file descriptor table entry: */
71			else if (_thread_fd_table_init(ret) != 0) {
72				/* Quietly close the file: */
73				_thread_sys_close(ret);
74
75				/* Reset the file descriptor: */
76				ret = -1;
77			} else {
78				/*
79				 * Save the file open flags so that they can
80				 * be         checked later:
81				 */
82				_thread_fd_table[ret]->flags = _thread_fd_table[fd]->flags;
83			}
84			break;
85		case F_SETFD:
86			flags = va_arg(ap, int);
87			ret = _thread_sys_fcntl(fd, cmd, flags);
88			break;
89		case F_GETFD:
90			ret = _thread_sys_fcntl(fd, cmd, 0);
91			break;
92		case F_GETFL:
93			ret = _thread_fd_table[fd]->flags;
94			break;
95		case F_SETFL:
96			/*
97			 * Get the file descriptor flags passed by the
98			 * caller:
99			 */
100			flags = va_arg(ap, int);
101
102			/*
103			 * Check if the user wants a non-blocking file
104			 * descriptor:
105			 */
106			nonblock = flags & O_NONBLOCK;
107
108			/* Set the file descriptor flags: */
109			if ((ret = _thread_sys_fcntl(fd, cmd, flags | O_NONBLOCK)) != 0) {
110
111			/* Get the flags so that we behave like the kernel: */
112			} else if ((flags = _thread_sys_fcntl(fd,
113			    F_GETFL, 0)) == -1) {
114				/* Error getting flags: */
115				ret = -1;
116
117			/*
118			 * Check if the file descriptor is non-blocking
119			 * with respect to the user:
120			 */
121			} else if (nonblock)
122				/* A non-blocking descriptor: */
123				_thread_fd_table[fd]->flags = flags | O_NONBLOCK;
124			else
125				/* Save the flags: */
126				_thread_fd_table[fd]->flags = flags & ~O_NONBLOCK;
127			break;
128		default:
129			/* Might want to make va_arg use a union */
130			ret = _thread_sys_fcntl(fd, cmd, va_arg(ap, void *));
131			break;
132		}
133
134		/* Free variable arguments: */
135		va_end(ap);
136
137		/* Unlock the file descriptor: */
138		_FD_UNLOCK(fd, FD_RDWR);
139	}
140	_thread_leave_cancellation_point();
141
142	/* Return the completion status: */
143	return (ret);
144}
145#endif
146