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2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid
[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD: src/lib/libc/stdio/findfp.c,v 1.34 2009/12/05 19:31:38 ed Exp $");
39 #include <TargetConditionals.h>
41 #include <sys/param.h>
42 #include <machine/atomic.h>
47 #include <libkern/OSAtomic.h>
53 #include "libc_private.h"
59 #if !TARGET_OS_EMBEDDED
60 #define NDYNAMIC 10 /* add ten more whenever necessary */
62 #define NDYNAMIC 1 /* add one at a time on embedded */
65 #define std(flags, file) { \
68 ._cookie = __sF + (file), \
73 ._extra = __sFX + file, \
75 #define __sFXInit {.fl_mutex = PTHREAD_MUTEX_INITIALIZER}
77 #define __sFXInit3 {.fl_mutex = PTHREAD_MUTEX_INITIALIZER, .counted = 1}
79 static int __scounted
; /* streams counted against STREAM_MAX */
80 static int __stream_max
;
82 #if !TARGET_OS_EMBEDDED
83 /* usual and usual_extra are data pigs. See 7929728. For embedded we should
84 * always allocate dynamically, and probably should for desktop too. */
85 /* the usual - (stdin + stdout + stderr) */
86 static FILE usual
[FOPEN_MAX
- 3];
87 static struct __sFILEX usual_extra
[FOPEN_MAX
- 3];
88 static struct glue uglue
= { NULL
, FOPEN_MAX
- 3, usual
};
89 #endif /* !TARGET_OS_EMBEDDED */
91 static struct __sFILEX __sFX
[3] = {__sFXInit3
, __sFXInit3
, __sFXInit3
};
94 * We can't make this 'static' due to binary compatibility concerns.
95 * This also means we cannot change the sizeof(FILE) and must continue to
96 * use the __sFILEX stuff to add to FILE.
99 std(__SRD
, STDIN_FILENO
),
100 std(__SWR
, STDOUT_FILENO
),
101 std(__SWR
|__SNBF
, STDERR_FILENO
)
104 FILE *__stdinp
= &__sF
[0];
105 FILE *__stdoutp
= &__sF
[1];
106 FILE *__stderrp
= &__sF
[2];
108 #if !TARGET_OS_EMBEDDED
109 struct glue __sglue
= { &uglue
, 3, __sF
};
110 static struct glue
*lastglue
= &uglue
;
112 struct glue __sglue
= { NULL
, 3, __sF
};
113 static struct glue
*lastglue
= &__sglue
;
116 static struct glue
* moreglue(int);
118 static spinlock_t thread_lock
= _SPINLOCK_INITIALIZER
;
119 #define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock)
120 #define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock)
123 #define SET_GLUE_PTR(ptr, val) atomic_set_rel_ptr(&(ptr), (uintptr_t)(val))
125 #define SET_GLUE_PTR(ptr, val) ptr = val
135 static struct __sFILEX emptyx
= __sFXInit
;
138 g
= (struct glue
*)malloc(sizeof(*g
) + ALIGNBYTES
+ n
* sizeof(FILE) +
139 n
* sizeof(struct __sFILEX
));
142 p
= (FILE *)ALIGN(g
+ 1);
143 fx
= (struct __sFILEX
*)&p
[n
];
158 * Find a free FILE for fopen et al.
171 if (__scounted
>= __stream_max
) {
176 OSAtomicIncrement32(&__scounted
);
179 * The list must be locked because a FILE may be updated.
182 for (g
= &__sglue
; g
!= NULL
; g
= g
->next
) {
183 for (fp
= g
->iobs
, n
= g
->niobs
; --n
>= 0; fp
++)
187 THREAD_UNLOCK(); /* don't hold lock while malloc()ing. */
188 if ((g
= moreglue(NDYNAMIC
)) == NULL
)
190 THREAD_LOCK(); /* reacquire the lock */
191 SET_GLUE_PTR(lastglue
->next
, g
); /* atomically append glue to list */
192 lastglue
= g
; /* not atomic; only accessed when locked */
195 fp
->_flags
= 1; /* reserve this slot; caller sets real flags */
197 fp
->_p
= NULL
; /* no current pointer */
198 fp
->_w
= 0; /* nothing to read or write */
200 fp
->_bf
._base
= NULL
; /* no buffer */
202 fp
->_lbfsize
= 0; /* not line buffered */
203 fp
->_file
= -1; /* no file */
204 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
205 fp
->_ub
._base
= NULL
; /* no ungetc buffer */
207 fp
->_lb
._base
= NULL
; /* no line buffer */
209 /* fp->_lock = NULL; */ /* once set always set (reused) */
211 fp
->_extra
->counted
= count
? 1 : 0;
216 * Mark as free and update count as needed
218 __private_extern__
void
219 __sfprelease(FILE *fp
)
222 OSAtomicDecrement32(&__scounted
);
229 * XXX. Force immediate allocation of internal memory. Not used by stdio,
230 * but documented historically for certain applications. Bad applications.
232 __warn_references(f_prealloc
,
233 "warning: this program uses f_prealloc(), which is not recommended.");
241 n
= getdtablesize() - FOPEN_MAX
+ 20; /* 20 for slop. */
243 * It should be safe to walk the list without locking it;
244 * new nodes are only added to the end and none are ever
247 for (g
= &__sglue
; (n
-= g
->niobs
) > 0 && g
->next
; g
= g
->next
)
249 if ((n
> 0) && ((g
= moreglue(n
)) != NULL
)) {
251 SET_GLUE_PTR(lastglue
->next
, g
);
258 * exit() calls _cleanup() through *__cleanup, set whenever we
259 * open or buffer a file. This chicanery is done so that programs
260 * that do not use stdio need not link it all in.
262 * The name `_cleanup' is, alas, fairly well known outside stdio.
267 /* (void) _fwalk(fclose); */
268 (void) _fwalk(__sflush
); /* `cheating' */
272 * __sinit() is called whenever stdio's internal variables must be set up.
278 if (__sdidinit
== 0) {
279 #if !TARGET_OS_EMBEDDED
282 /* Make sure we clean up on exit. */
283 __cleanup
= _cleanup
; /* conservative */
284 __stream_max
= sysconf(_SC_STREAM_MAX
);
285 __scounted
= 3; /* std{in,out,err} already exists */
287 #if !TARGET_OS_EMBEDDED
288 /* Set _extra for the usual suspects. */
289 for (i
= 0; i
< FOPEN_MAX
- 3; i
++) {
290 usual
[i
]._extra
= &usual_extra
[i
];
291 INITEXTRA(&usual
[i
]);