1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
2  *
3  * GNU Library General Public License (LGPL) version 2 or later.
4  *
5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
6  */
7 
8 #include "_stdio.h"
9 
10 
11 #ifdef __DO_UNLOCKED
12 
13 
fread_unlocked(void * __restrict ptr,size_t size,size_t nmemb,FILE * __restrict stream)14 size_t fread_unlocked(void * __restrict ptr, size_t size, size_t nmemb,
15 						FILE * __restrict stream)
16 {
17 	__STDIO_STREAM_VALIDATE(stream);
18 	assert(stream->__filedes >= -1);
19 
20 	/* Note: If nmbem * size > SIZE_MAX then there is an application
21 	 * bug since no array can be larger than SIZE_MAX in size. */
22 
23 	if ((__STDIO_STREAM_IS_NARROW_READING(stream)
24 		 || !__STDIO_STREAM_TRANS_TO_READ(stream, __FLAG_NARROW))
25 		&& size && nmemb
26 		) {
27 
28 		if (nmemb <= (SIZE_MAX / size)) {
29 			unsigned char *buffer = (unsigned char *) ptr;
30 			size_t todo, bytes, avail;
31 
32 			todo = bytes = size * nmemb;
33 
34 			/* Check for ungots... */
35 			while (stream->__modeflags & __FLAG_UNGOT) {
36 				*buffer++ = stream->__ungot[(stream->__modeflags--) & 1];
37 				stream->__ungot[1] = 0;
38 				if (!--todo) {
39 					goto DONE;
40 				}
41 			}
42 
43 #ifdef __STDIO_BUFFERS
44 			/* Next check for available buffered... */
45 			if ((avail = stream->__bufread - stream->__bufpos) > 0) {
46 				if (avail > todo) {
47 					avail = todo;
48 				}
49 				memcpy(buffer, stream->__bufpos, avail);
50 				buffer += avail;
51 				stream->__bufpos += avail;
52 				if (!(todo -= avail)) {
53 					goto DONE;
54 				}
55 			}
56 
57 			/* We need to read from the host environment, so we must
58 			 * flush all line buffered streams if the stream is not
59 			 * fully buffered. */
60 			if (!__STDIO_STREAM_IS_FBF(stream)) {
61 				__STDIO_FLUSH_LBF_STREAMS;
62 			}
63 #endif
64 
65 #ifdef __UCLIBC_MJN3_ONLY__
66 #warning CONSIDER: should we refill and read from the buffer sometimes?
67 #endif
68 			while ((avail = __stdio_READ(stream, buffer, todo)) > 0) {
69 				buffer += avail;
70 				if (!(todo -= avail)) {
71 					break;
72 				}
73 			}
74 
75 		DONE:
76 			__STDIO_STREAM_VALIDATE(stream);
77 			return (bytes - todo) / size;
78 		}
79 
80 		__STDIO_STREAM_SET_ERROR(stream);
81 		__set_errno(EINVAL);
82 	}
83 
84 	__STDIO_STREAM_VALIDATE(stream);
85 	return 0;
86 }
87 libc_hidden_def(fread_unlocked)
88 
89 #ifndef __UCLIBC_HAS_THREADS__
90 strong_alias(fread_unlocked,fread)
91 libc_hidden_def(fread)
92 #endif
93 
94 #elif defined __UCLIBC_HAS_THREADS__
95 
96 size_t fread(void * __restrict ptr, size_t size, size_t nmemb,
97 			 register FILE * __restrict stream)
98 {
99 	size_t retval;
100 	__STDIO_AUTO_THREADLOCK_VAR;
101 
102 	__STDIO_AUTO_THREADLOCK(stream);
103 
104 	retval = fread_unlocked(ptr, size, nmemb, stream);
105 
106 	__STDIO_AUTO_THREADUNLOCK(stream);
107 
108 	return retval;
109 }
110 libc_hidden_def(fread)
111 
112 #endif
113