1 /* $NetBSD: findfp.c,v 1.27 2012/03/15 18:22:30 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94"; 39 #else 40 __RCSID("$NetBSD: findfp.c,v 1.27 2012/03/15 18:22:30 christos Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/param.h> 46 #include <unistd.h> 47 #include <stdio.h> 48 #include <errno.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include "reentrant.h" 52 #include "local.h" 53 #include "glue.h" 54 55 int __sdidinit; 56 57 #define NDYNAMIC 10 /* add ten more whenever necessary */ 58 59 #define std(flags, file) \ 60 /* p r w flags file bf lfbsize cookie close */ \ 61 { NULL, 0, 0, flags, file, { NULL, 0 }, 0, __sF + file, __sclose, \ 62 /* read seek write ext up */ \ 63 __sread, __sseek, __swrite, { (void *)(__sFext + file), 0 }, NULL, \ 64 /* ur ubuf, nbuf lb blksize offset */ \ 65 0, { '\0', '\0', '\0' }, { '\0' }, { NULL, 0 }, 0, (off_t)0 } 66 67 /* the usual - (stdin + stdout + stderr) */ 68 static FILE usual[FOPEN_MAX - 3]; 69 static struct __sfileext usualext[FOPEN_MAX - 3]; 70 static struct glue uglue = { 0, FOPEN_MAX - 3, usual }; 71 72 #if defined(_REENTRANT) && !defined(__lint__) /* XXX lint is busted */ 73 #define STDEXT { ._lock = MUTEX_INITIALIZER, ._lockcond = COND_INITIALIZER } 74 struct __sfileext __sFext[3] = { STDEXT, 75 STDEXT, 76 STDEXT}; 77 #else 78 struct __sfileext __sFext[3]; 79 #endif 80 81 FILE __sF[3] = { 82 std(__SRD, STDIN_FILENO), /* stdin */ 83 std(__SWR, STDOUT_FILENO), /* stdout */ 84 std(__SWR|__SNBF, STDERR_FILENO) /* stderr */ 85 }; 86 struct glue __sglue = { &uglue, 3, __sF }; 87 88 void f_prealloc(void); 89 90 #ifdef _REENTRANT 91 rwlock_t __sfp_lock = RWLOCK_INITIALIZER; 92 #endif 93 94 static struct glue * 95 moreglue(int n) 96 { 97 struct glue *g; 98 FILE *p; 99 struct __sfileext *pext; 100 static FILE empty; 101 102 g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) 103 + n * sizeof(struct __sfileext)); 104 if (g == NULL) 105 return NULL; 106 p = (FILE *)ALIGN((u_long)(g + 1)); 107 g->next = NULL; 108 g->niobs = n; 109 g->iobs = p; 110 pext = (void *)(p + n); 111 while (--n >= 0) { 112 *p = empty; 113 _FILEEXT_SETUP(p, pext); 114 p++; 115 pext++; 116 } 117 return g; 118 } 119 120 void 121 __sfpinit(FILE *fp) 122 { 123 fp->_flags = 1; /* reserve this slot; caller sets real flags */ 124 fp->_p = NULL; /* no current pointer */ 125 fp->_w = 0; /* nothing to read or write */ 126 fp->_r = 0; 127 fp->_bf._base = NULL; /* no buffer */ 128 fp->_bf._size = 0; 129 fp->_lbfsize = 0; /* not line buffered */ 130 fp->_file = -1; /* no file */ 131 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */ 132 _UB(fp)._base = NULL; /* no ungetc buffer */ 133 _UB(fp)._size = 0; 134 memset(WCIO_GET(fp), 0, sizeof(struct wchar_io_data)); 135 } 136 137 /* 138 * Find a free FILE for fopen et al. 139 */ 140 FILE * 141 __sfp(void) 142 { 143 FILE *fp; 144 int n; 145 struct glue *g; 146 147 if (!__sdidinit) 148 __sinit(); 149 150 rwlock_wrlock(&__sfp_lock); 151 for (g = &__sglue;; g = g->next) { 152 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) 153 if (fp->_flags == 0) 154 goto found; 155 if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL) 156 break; 157 } 158 rwlock_unlock(&__sfp_lock); 159 return NULL; 160 found: 161 __sfpinit(fp); 162 rwlock_unlock(&__sfp_lock); 163 return fp; 164 } 165 166 /* 167 * XXX. Force immediate allocation of internal memory. Not used by stdio, 168 * but documented historically for certain applications. Bad applications. 169 */ 170 void 171 f_prealloc(void) 172 { 173 struct glue *g; 174 int n; 175 176 n = (int)sysconf(_SC_OPEN_MAX) - FOPEN_MAX + 20; /* 20 for slop. */ 177 for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next) 178 continue; 179 if (n > 0) 180 g->next = moreglue(n); 181 } 182 183 /* 184 * exit() calls _cleanup() through *__cleanup, set whenever we 185 * open or buffer a file. This chicanery is done so that programs 186 * that do not use stdio need not link it all in. 187 * 188 * The name `_cleanup' is, alas, fairly well known outside stdio. 189 */ 190 void 191 _cleanup(void) 192 { 193 /* (void) _fwalk(fclose); */ 194 (void) fflush(NULL); /* `cheating' */ 195 } 196 197 /* 198 * __sinit() is called whenever stdio's internal variables must be set up. 199 */ 200 void 201 __sinit(void) 202 { 203 int i; 204 205 for (i = 0; i < FOPEN_MAX - 3; i++) 206 _FILEEXT_SETUP(&usual[i], &usualext[i]); 207 208 /* make sure we clean up on exit */ 209 __cleanup = _cleanup; /* conservative */ 210 __sdidinit = 1; 211 } 212