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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94";
41 static const char rcsid[] =
43 #endif /* LIBC_SCCS and not lint */
45 #include <sys/param.h>
52 #include <libc_private.h>
60 #define NDYNAMIC 10 /* add ten more whenever necessary */
62 #define std(flags, file) \
63 {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite}
64 /* p r w flags file _bf z cookie close read seek write */
66 /* the usual - (stdin + stdout + stderr) */
67 static FILE usual[FOPEN_MAX - 3];
68 static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
71 std(__SRD, STDIN_FILENO), /* stdin */
72 std(__SWR, STDOUT_FILENO), /* stdout */
73 std(__SWR|__SNBF, STDERR_FILENO) /* stderr */
75 struct glue __sglue = { &uglue, 3, __sF };
77 static struct glue * moreglue __P((int));
79 static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
80 #define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock)
81 #define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock)
87 register struct glue *g;
91 g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE));
94 p = (FILE *)ALIGN(g + 1);
104 * Find a free FILE for fopen et al.
111 register struct glue *g;
116 for (g = &__sglue;; g = g->next) {
117 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
120 if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
126 fp->_flags = 1; /* reserve this slot; caller sets real flags */
128 fp->_p = NULL; /* no current pointer */
129 fp->_w = 0; /* nothing to read or write */
131 fp->_bf._base = NULL; /* no buffer */
133 fp->_lbfsize = 0; /* not line buffered */
134 fp->_file = -1; /* no file */
135 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
136 fp->_ub._base = NULL; /* no ungetc buffer */
138 fp->_lb._base = NULL; /* no line buffer */
144 * XXX. Force immediate allocation of internal memory. Not used by stdio,
145 * but documented historically for certain applications. Bad applications.
147 __warn_references(f_prealloc,
148 "warning: this program uses f_prealloc(), which is stupid.");
153 register struct glue *g;
156 n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */
157 for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
160 g->next = moreglue(n);
164 * exit() calls _cleanup() through *__cleanup, set whenever we
165 * open or buffer a file. This chicanery is done so that programs
166 * that do not use stdio need not link it all in.
168 * The name `_cleanup' is, alas, fairly well known outside stdio.
173 /* (void) _fwalk(fclose); */
174 (void) _fwalk(__sflush); /* `cheating' */
178 * __sinit() is called whenever stdio's internal variables must be set up.
183 /* make sure we clean up on exit */
184 __cleanup = _cleanup; /* conservative */