1 /* $NetBSD: findfp.c,v 1.28 2012/03/27 15:05:42 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 1.28 2012/03/27 15:05:42 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 #if !defined(_LIBMINC) && !defined(__kernel__) 60 61 #define std(flags, file) { \ 62 ._p = NULL, \ 63 ._r = 0, \ 64 ._w = 0, \ 65 ._flags = (flags), \ 66 ._file = (file), \ 67 ._bf = { ._base = NULL, ._size = 0 }, \ 68 ._lbfsize = 0, \ 69 ._cookie = __sF + (file), \ 70 ._close = __sclose, \ 71 ._read = __sread, \ 72 ._seek = __sseek, \ 73 ._write = __swrite, \ 74 ._ext = { ._base = (void *)(__sFext + (file)), ._size = 0 }, \ 75 ._up = NULL, \ 76 ._ur = 0, \ 77 ._ubuf = { [0] = '\0', [1] = '\0', [2] = '\0' }, \ 78 ._nbuf = { [0] = '\0' }, \ 79 ._flush = NULL, \ 80 ._lb_unused = { '\0' }, \ 81 ._blksize = 0, \ 82 ._offset = (off_t)0, \ 83 } 84 85 #else 86 87 #define std(flags, file) { \ 88 ._p = NULL, \ 89 ._r = 0, \ 90 ._w = 0, \ 91 ._flags = (flags), \ 92 ._file = (file), \ 93 ._bf = { ._base = NULL, ._size = 0 }, \ 94 ._lbfsize = 0, \ 95 ._cookie = __sF + (file), \ 96 ._close = NULL, \ 97 ._read = NULL, \ 98 ._seek = NULL, \ 99 ._write = NULL, \ 100 ._ext = { ._base = (void *)(__sFext + (file)), ._size = 0 }, \ 101 ._up = NULL, \ 102 ._ur = 0, \ 103 ._ubuf = { [0] = '\0', [1] = '\0', [2] = '\0' }, \ 104 ._nbuf = { [0] = '\0' }, \ 105 ._flush = NULL, \ 106 ._lb_unused = { '\0' }, \ 107 ._blksize = 0, \ 108 ._offset = (off_t)0, \ 109 } 110 111 #endif /* !defined(_LIBMINC) && !defined(__kernel__) */ 112 113 #if !defined(__kernel__) 114 /* the usual - (stdin + stdout + stderr) */ 115 static FILE usual[FOPEN_MAX - 3]; 116 static struct __sfileext usualext[FOPEN_MAX - 3]; 117 static struct glue uglue = { 0, FOPEN_MAX - 3, usual }; 118 #endif /* !defined(__kernel__) */ 119 120 #if defined(_REENTRANT) && !defined(__lint__) /* XXX lint is busted */ 121 #define STDEXT { ._lock = MUTEX_INITIALIZER, ._lockcond = COND_INITIALIZER } 122 struct __sfileext __sFext[3] = { STDEXT, 123 STDEXT, 124 STDEXT}; 125 #else 126 struct __sfileext __sFext[3]; 127 #endif 128 129 FILE __sF[3] = { 130 std(__SRD, STDIN_FILENO), /* stdin */ 131 std(__SWR, STDOUT_FILENO), /* stdout */ 132 std(__SWR|__SNBF, STDERR_FILENO) /* stderr */ 133 }; 134 135 #if !defined(__kernel__) 136 struct glue __sglue = { &uglue, 3, __sF }; 137 138 void f_prealloc(void); 139 140 #ifdef _REENTRANT 141 rwlock_t __sfp_lock = RWLOCK_INITIALIZER; 142 #endif 143 144 static struct glue * 145 moreglue(int n) 146 { 147 struct glue *g; 148 FILE *p; 149 struct __sfileext *pext; 150 static FILE empty; 151 152 g = malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) 153 + n * sizeof(struct __sfileext)); 154 if (g == NULL) 155 return NULL; 156 p = (FILE *)ALIGN((u_long)(g + 1)); 157 g->next = NULL; 158 g->niobs = n; 159 g->iobs = p; 160 pext = (void *)(p + n); 161 while (--n >= 0) { 162 *p = empty; 163 _FILEEXT_SETUP(p, pext); 164 p++; 165 pext++; 166 } 167 return g; 168 } 169 170 void 171 __sfpinit(FILE *fp) 172 { 173 fp->_flags = 1; /* reserve this slot; caller sets real flags */ 174 fp->_p = NULL; /* no current pointer */ 175 fp->_w = 0; /* nothing to read or write */ 176 fp->_r = 0; 177 fp->_bf._base = NULL; /* no buffer */ 178 fp->_bf._size = 0; 179 fp->_lbfsize = 0; /* not line buffered */ 180 fp->_file = -1; /* no file */ 181 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */ 182 fp->_flush = NULL; /* default flush */ 183 _UB(fp)._base = NULL; /* no ungetc buffer */ 184 _UB(fp)._size = 0; 185 memset(WCIO_GET(fp), 0, sizeof(struct wchar_io_data)); 186 } 187 188 /* 189 * Find a free FILE for fopen et al. 190 */ 191 FILE * 192 __sfp(void) 193 { 194 FILE *fp; 195 int n; 196 struct glue *g; 197 198 if (!__sdidinit) 199 __sinit(); 200 201 rwlock_wrlock(&__sfp_lock); 202 for (g = &__sglue;; g = g->next) { 203 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) 204 if (fp->_flags == 0) 205 goto found; 206 if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL) 207 break; 208 } 209 rwlock_unlock(&__sfp_lock); 210 return NULL; 211 found: 212 __sfpinit(fp); 213 rwlock_unlock(&__sfp_lock); 214 return fp; 215 } 216 217 /* 218 * XXX. Force immediate allocation of internal memory. Not used by stdio, 219 * but documented historically for certain applications. Bad applications. 220 */ 221 void 222 f_prealloc(void) 223 { 224 #if !defined(_LIBMINC) 225 struct glue *g; 226 int n; 227 228 n = (int)sysconf(_SC_OPEN_MAX) - FOPEN_MAX + 20; /* 20 for slop. */ 229 for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next) 230 continue; 231 if (n > 0) 232 g->next = moreglue(n); 233 #endif /* !defined(_LIBMINC) */ 234 } 235 236 /* 237 * exit() calls _cleanup() through *__cleanup, set whenever we 238 * open or buffer a file. This chicanery is done so that programs 239 * that do not use stdio need not link it all in. 240 * 241 * The name `_cleanup' is, alas, fairly well known outside stdio. 242 */ 243 void 244 _cleanup(void) 245 { 246 #if !defined(_LIBMINC) 247 /* (void) _fwalk(fclose); */ 248 (void) fflush(NULL); /* `cheating' */ 249 #endif /* !defined(_LIBMINC) */ 250 } 251 252 /* 253 * __sinit() is called whenever stdio's internal variables must be set up. 254 */ 255 void 256 __sinit(void) 257 { 258 int i; 259 260 for (i = 0; i < FOPEN_MAX - 3; i++) 261 _FILEEXT_SETUP(&usual[i], &usualext[i]); 262 263 /* make sure we clean up on exit */ 264 __cleanup = _cleanup; /* conservative */ 265 __sdidinit = 1; 266 } 267 #endif /* !defined(__kernel__) */ 268