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 #define std(flags, file) { \ 60 ._p = NULL, \ 61 ._r = 0, \ 62 ._w = 0, \ 63 ._flags = (flags), \ 64 ._file = (file), \ 65 ._bf = { ._base = NULL, ._size = 0 }, \ 66 ._lbfsize = 0, \ 67 ._cookie = __sF + (file), \ 68 ._close = __sclose, \ 69 ._read = __sread, \ 70 ._seek = __sseek, \ 71 ._write = __swrite, \ 72 ._ext = { ._base = (void *)(__sFext + (file)), ._size = 0 }, \ 73 ._up = NULL, \ 74 ._ur = 0, \ 75 ._ubuf = { [0] = '\0', [1] = '\0', [2] = '\0' }, \ 76 ._nbuf = { [0] = '\0' }, \ 77 ._flush = NULL, \ 78 ._lb_unused = { '\0' }, \ 79 ._blksize = 0, \ 80 ._offset = (off_t)0, \ 81 } 82 83 /* the usual - (stdin + stdout + stderr) */ 84 static FILE usual[FOPEN_MAX - 3]; 85 static struct __sfileext usualext[FOPEN_MAX - 3]; 86 static struct glue uglue = { 0, FOPEN_MAX - 3, usual }; 87 88 #if defined(_REENTRANT) && !defined(__lint__) /* XXX lint is busted */ 89 #define STDEXT { ._lock = MUTEX_INITIALIZER, ._lockcond = COND_INITIALIZER } 90 struct __sfileext __sFext[3] = { STDEXT, 91 STDEXT, 92 STDEXT}; 93 #else 94 struct __sfileext __sFext[3]; 95 #endif 96 97 FILE __sF[3] = { 98 std(__SRD, STDIN_FILENO), /* stdin */ 99 std(__SWR, STDOUT_FILENO), /* stdout */ 100 std(__SWR|__SNBF, STDERR_FILENO) /* stderr */ 101 }; 102 struct glue __sglue = { &uglue, 3, __sF }; 103 104 void f_prealloc(void); 105 106 #ifdef _REENTRANT 107 rwlock_t __sfp_lock = RWLOCK_INITIALIZER; 108 #endif 109 110 static struct glue * 111 moreglue(int n) 112 { 113 struct glue *g; 114 FILE *p; 115 struct __sfileext *pext; 116 static FILE empty; 117 118 g = malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) 119 + n * sizeof(struct __sfileext)); 120 if (g == NULL) 121 return NULL; 122 p = (FILE *)ALIGN((u_long)(g + 1)); 123 g->next = NULL; 124 g->niobs = n; 125 g->iobs = p; 126 pext = (void *)(p + n); 127 while (--n >= 0) { 128 *p = empty; 129 _FILEEXT_SETUP(p, pext); 130 p++; 131 pext++; 132 } 133 return g; 134 } 135 136 void 137 __sfpinit(FILE *fp) 138 { 139 fp->_flags = 1; /* reserve this slot; caller sets real flags */ 140 fp->_p = NULL; /* no current pointer */ 141 fp->_w = 0; /* nothing to read or write */ 142 fp->_r = 0; 143 fp->_bf._base = NULL; /* no buffer */ 144 fp->_bf._size = 0; 145 fp->_lbfsize = 0; /* not line buffered */ 146 fp->_file = -1; /* no file */ 147 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */ 148 fp->_flush = NULL; /* default flush */ 149 _UB(fp)._base = NULL; /* no ungetc buffer */ 150 _UB(fp)._size = 0; 151 memset(WCIO_GET(fp), 0, sizeof(struct wchar_io_data)); 152 } 153 154 /* 155 * Find a free FILE for fopen et al. 156 */ 157 FILE * 158 __sfp(void) 159 { 160 FILE *fp; 161 int n; 162 struct glue *g; 163 164 if (!__sdidinit) 165 __sinit(); 166 167 rwlock_wrlock(&__sfp_lock); 168 for (g = &__sglue;; g = g->next) { 169 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) 170 if (fp->_flags == 0) 171 goto found; 172 if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL) 173 break; 174 } 175 rwlock_unlock(&__sfp_lock); 176 return NULL; 177 found: 178 __sfpinit(fp); 179 rwlock_unlock(&__sfp_lock); 180 return fp; 181 } 182 183 /* 184 * XXX. Force immediate allocation of internal memory. Not used by stdio, 185 * but documented historically for certain applications. Bad applications. 186 */ 187 void 188 f_prealloc(void) 189 { 190 struct glue *g; 191 int n; 192 193 n = (int)sysconf(_SC_OPEN_MAX) - FOPEN_MAX + 20; /* 20 for slop. */ 194 for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next) 195 continue; 196 if (n > 0) 197 g->next = moreglue(n); 198 } 199 200 /* 201 * exit() calls _cleanup() through *__cleanup, set whenever we 202 * open or buffer a file. This chicanery is done so that programs 203 * that do not use stdio need not link it all in. 204 * 205 * The name `_cleanup' is, alas, fairly well known outside stdio. 206 */ 207 void 208 _cleanup(void) 209 { 210 /* (void) _fwalk(fclose); */ 211 (void) fflush(NULL); /* `cheating' */ 212 } 213 214 /* 215 * __sinit() is called whenever stdio's internal variables must be set up. 216 */ 217 void 218 __sinit(void) 219 { 220 int i; 221 222 for (i = 0; i < FOPEN_MAX - 3; i++) 223 _FILEEXT_SETUP(&usual[i], &usualext[i]); 224 225 /* make sure we clean up on exit */ 226 __cleanup = _cleanup; /* conservative */ 227 __sdidinit = 1; 228 } 229
Indexes created Sat Sep 20 22:09:52 GMT 2025