xref: /titanic_41/usr/src/lib/libc/port/stdio/setvbuf.c (revision 4496171313bed39e96f21bc2f9faf2868e267ae3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 
33 #include "synonyms.h"
34 #include "file64.h"
35 #include "mtlib.h"
36 #include <sys/types.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <thread.h>
40 #include <synch.h>
41 #include "stdiom.h"
42 
43 int
44 setvbuf(FILE *iop, char *abuf, int type, size_t size)
45 {
46 
47 	Uchar	*buf = (Uchar *)abuf;
48 	Uchar *temp;
49 	int	sflag = iop->_flag & _IOMYBUF;
50 	rmutex_t *lk;
51 	int fd = GET_FD(iop);
52 
53 	FLOCKFILE(lk, iop);
54 	iop->_flag &= ~(_IOMYBUF | _IONBF | _IOLBF);
55 	switch (type) {
56 	/* note that the flags are the same as the possible values for type */
57 	case _IONBF:
58 		iop->_flag |= _IONBF;	 /* file is unbuffered */
59 #ifndef _STDIO_ALLOCATE
60 		if (fd < 2) {
61 			/* use special buffer for std{in,out} */
62 			buf = (fd == 0) ? _sibuf : _sobuf;
63 			size = BUFSIZ;
64 		} else /* needed for ifdef */
65 #endif
66 		if (fd < _NFILE) {
67 			buf = _smbuf[fd];
68 			size = _SMBFSZ - PUSHBACK;
69 		} else
70 			if ((buf = malloc(_SMBFSZ * sizeof (Uchar))) != NULL) {
71 				iop->_flag |= _IOMYBUF;
72 				size = _SMBFSZ - PUSHBACK;
73 			} else {
74 				FUNLOCKFILE(lk);
75 				return (EOF);
76 			}
77 		break;
78 	case _IOLBF:
79 	case _IOFBF:
80 		iop->_flag |= type;	/* buffer file */
81 		/*
82 		 * need at least an 8 character buffer for
83 		 * out_of_sync concerns.
84 		 */
85 		if (size <= _SMBFSZ) {
86 			size = BUFSIZ;
87 			buf = NULL;
88 		}
89 		if (buf == NULL) {
90 			if ((buf = malloc(sizeof (Uchar) *
91 			    (size + _SMBFSZ))) != NULL)
92 				iop->_flag |= _IOMYBUF;
93 			else {
94 				FUNLOCKFILE(lk);
95 				return (EOF);
96 			}
97 		}
98 		else
99 			size -= _SMBFSZ;
100 		break;
101 	default:
102 		FUNLOCKFILE(lk);
103 		return (EOF);
104 	}
105 	if (iop->_base != NULL && sflag)
106 		free((char *)iop->_base - PUSHBACK);
107 	temp = buf + PUSHBACK;
108 	iop->_base = temp;
109 	_setbufend(iop, temp + size);
110 	iop->_ptr = temp;
111 	iop->_cnt = 0;
112 	FUNLOCKFILE(lk);
113 	return (0);
114 }
115