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 2008 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 #include "lint.h"
33 #include "file64.h"
34 #include "mtlib.h"
35 #include <stdio.h>
36 #include <stddef.h>
37 #include <values.h>
38 #include <memory.h>
39 #include <thread.h>
40 #include <synch.h>
41 #include <errno.h>
42 #include <sys/types.h>
43 #include "stdiom.h"
44 #include "mse.h"
45
46 size_t
fread(void * ptr,size_t size,size_t count,FILE * iop)47 fread(void *ptr, size_t size, size_t count, FILE *iop)
48 {
49 ssize_t s;
50 int c;
51 char *dptr = (char *)ptr;
52 rmutex_t *lk;
53
54 FLOCKFILE(lk, iop);
55
56 _SET_ORIENTATION_BYTE(iop);
57
58 /* is it a readable stream */
59 if (!(iop->_flag & (_IOREAD | _IORW))) {
60 iop->_flag |= _IOERR;
61 errno = EBADF;
62 FUNLOCKFILE(lk);
63 return (0);
64 }
65
66 if (iop->_flag & _IOEOF) {
67 FUNLOCKFILE(lk);
68 return (0);
69 }
70
71 /* These checks are here to avoid the multiply */
72 if (count == 1)
73 s = size;
74 else if (size == 1)
75 s = count;
76 else
77 s = size * count;
78
79 while (s > 0) {
80 if (iop->_cnt < s) {
81 if (iop->_cnt > 0) {
82 (void) memcpy((void*)dptr, iop->_ptr,
83 iop->_cnt);
84 dptr += iop->_cnt;
85 s -= iop->_cnt;
86 }
87 /*
88 * filbuf clobbers _cnt & _ptr,
89 * so don't waste time setting them.
90 */
91 if ((c = __filbuf(iop)) == EOF)
92 break;
93 *dptr++ = (char)c;
94 s--;
95 }
96 if (iop->_cnt >= s) {
97 char *tmp = (char *)iop->_ptr;
98 switch (s) {
99 case 8:
100 *dptr++ = *tmp++;
101 /*FALLTHRU*/
102 case 7:
103 *dptr++ = *tmp++;
104 /*FALLTHRU*/
105 case 6:
106 *dptr++ = *tmp++;
107 /*FALLTHRU*/
108 case 5:
109 *dptr++ = *tmp++;
110 /*FALLTHRU*/
111 case 4:
112 *dptr++ = *tmp++;
113 /*FALLTHRU*/
114 case 3:
115 *dptr++ = *tmp++;
116 /*FALLTHRU*/
117 case 2:
118 *dptr++ = *tmp++;
119 /*FALLTHRU*/
120 case 1:
121 *dptr++ = *tmp++;
122 break;
123 default:
124 (void) memcpy((void*)dptr, iop->_ptr,
125 (size_t)s);
126 }
127 iop->_ptr += s;
128 iop->_cnt -= s;
129 FUNLOCKFILE(lk);
130 return (count);
131 }
132 }
133 FUNLOCKFILE(lk);
134 return (size != 0 ? count - ((s + size - 1) / size) : 0);
135 }
136