thr_fcntl.c revision 38925 
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 REGENTS 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 */
33#include <stdarg.h>
34#include <unistd.h>
35#include <fcntl.h>
36#ifdef _THREAD_SAFE
37#include <pthread.h>
38#include "pthread_private.h"
39
40int
41fcntl(int fd, int cmd,...)
42{
43	int             flags = 0;
44	int		nonblock;
45	int             oldfd;
46	int             ret;
47	va_list         ap;
48
49	/* Lock the file descriptor: */
50	if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) {
51		/* Initialise the variable argument list: */
52		va_start(ap, cmd);
53
54		/* Process according to file control command type: */
55		switch (cmd) {
56		/* Duplicate a file descriptor: */
57		case F_DUPFD:
58			/*
59			 * Get the file descriptor that the caller wants to
60			 * use:
61			 */
62			oldfd = va_arg(ap, int);
63
64			/* Initialise the file descriptor table entry: */
65			if ((ret = _thread_sys_fcntl(fd, cmd, oldfd)) < 0) {
66			}
67			/* Initialise the file descriptor table entry: */
68			else if (_thread_fd_table_init(ret) != 0) {
69				/* Quietly close the file: */
70				_thread_sys_close(ret);
71
72				/* Reset the file descriptor: */
73				ret = -1;
74			} else {
75				/*
76				 * Save the file open flags so that they can
77				 * be         checked later:
78				 */
79				_thread_fd_table[ret]->flags = _thread_fd_table[fd]->flags;
80			}
81			break;
82		case F_SETFD:
83			flags = va_arg(ap, int);
84			ret = _thread_sys_fcntl(fd, cmd, flags);
85			break;
86		case F_GETFD:
87			ret = _thread_sys_fcntl(fd, cmd, 0);
88			break;
89		case F_GETFL:
90			ret = _thread_fd_table[fd]->flags;
91			break;
92		case F_SETFL:
93			/*
94			 * Get the file descriptor flags passed by the
95			 * caller:
96			 */
97			flags = va_arg(ap, int);
98
99			/*
100			 * Check if the user wants a non-blocking file
101			 * descriptor:
102			 */
103			nonblock = flags & O_NONBLOCK;
104
105			/* Set the file descriptor flags: */
106			if ((ret = _thread_sys_fcntl(fd, cmd, flags | O_NONBLOCK)) != 0) {
107
108			/* Get the flags so that we behave like the kernel: */
109			} else if ((flags = _thread_sys_fcntl(fd,
110			    F_GETFL, 0)) == -1) {
111				/* Error getting flags: */
112				ret = -1;
113
114			/*
115			 * Check if the file descriptor is non-blocking
116			 * with respect to the user:
117			 */
118			} else if (nonblock)
119				/* A non-blocking descriptor: */
120				_thread_fd_table[fd]->flags = flags | O_NONBLOCK;
121			else
122				/* Save the flags: */
123				_thread_fd_table[fd]->flags = flags & ~O_NONBLOCK;
124			break;
125		default:
126			/* Might want to make va_arg use a union */
127			ret = _thread_sys_fcntl(fd, cmd, va_arg(ap, void *));
128			break;
129		}
130
131		/* Free variable arguments: */
132		va_end(ap);
133
134		/* Unlock the file descriptor: */
135		_FD_UNLOCK(fd, FD_RDWR);
136	}
137
138	/* Return the completion status: */
139	return (ret);
140}
141#endif
142