StdLib/LibC/Stdio/findfp.c

   1 /*  $NetBSD: findfp.c,v 1.23 2006/10/07 21:40:46 thorpej 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 #include  <LibConfig.h>
  35 #include  <sys/EfiCdefs.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 1.23 2006/10/07 21:40:46 thorpej Exp $");
  41 #endif
  42 #endif /* LIBC_SCCS and not lint */
  43
  44 #include  "namespace.h"
  45 #include  <sys/param.h>
  46 #include  <sys/EfiSysCall.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 #include  <MainData.h>
  55
  56 int __sdidinit;
  57
  58 #define NDYNAMIC 10   /* add ten more whenever necessary */
  59
  60 #define std(flags, file) \
  61 /*    p     r  w  flags  file  bf     lfbsize  cookie       close */ \
  62   { NULL, 0, 0, flags, file, { NULL, 0 }, 0, __sF + file, __sclose, \
  63 /*    read      seek     write     ext                              up */ \
  64     __sread,  __sseek, __swrite, { (void *)(__sFext + file), 0 }, NULL, \
  65 /*    ur ubuf,                 nbuf      lb     blksize  offset */ \
  66     0, { '\0', '\0', '\0' }, { '\0' }, { NULL, 0 }, 0, (fpos_t)0 }
  67
  68         /* the usual - (stdin + stdout + stderr) */
  69 static FILE usual[FOPEN_MAX - 3];
  70 static struct __sfileext usualext[FOPEN_MAX - 3];
  71 static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
  72
  73 #if defined(_REENTRANT) && !defined(__lint__) /* XXX lint is busted */
  74 #define STDEXT { ._lock = MUTEX_INITIALIZER, ._lockcond = COND_INITIALIZER }
  75 struct __sfileext __sFext[3] = { STDEXT,
  76          STDEXT,
  77          STDEXT};
  78 #else
  79 struct __sfileext __sFext[3];
  80 #endif
  81
  82 FILE __sF[3] = {
  83   std(__SRD, STDIN_FILENO),   /* stdin */
  84   std(__SWR, STDOUT_FILENO),    /* stdout */
  85   std(__SWR|__SNBF, STDERR_FILENO)  /* stderr */
  86 };
  87 struct glue __sglue = { &uglue, 3, __sF };
  88
  89 static struct glue *moreglue(int);
  90 void f_prealloc(void);
  91
  92 #ifdef _REENTRANT
  93 rwlock_t __sfp_lock = RWLOCK_INITIALIZER;
  94 #endif
  95
  96 static struct glue *
  97 moreglue(int n)
  98 {
  99   struct glue *g;
 100   FILE *p;
 101   struct __sfileext *pext;
 102   static FILE empty;
 103
 104   g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE)
 105     + n * sizeof(struct __sfileext));
 106   if (g == NULL)
 107     return (NULL);
 108   p = (FILE *)ALIGN((g + 1));
 109   g->next = NULL;
 110   g->niobs = n;
 111   g->iobs = p;
 112   pext = (void *)(p + n);
 113   while (--n >= 0) {
 114     *p = empty;
 115     _FILEEXT_SETUP(p, pext);
 116     p++;
 117     pext++;
 118   }
 119   return (g);
 120 }
 121
 122 /*
 123  * Find a free FILE for fopen et al.
 124  */
 125 FILE *
 126 __sfp()
 127 {
 128   FILE *fp;
 129   int n;
 130   struct glue *g;
 131
 132   if (!__sdidinit)
 133     __sinit();
 134
 135   rwlock_wrlock(&__sfp_lock);
 136   for (g = &__sglue;; g = g->next) {
 137     for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
 138       if (fp->_flags == 0)
 139         goto found;
 140     if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
 141       break;
 142   }
 143   rwlock_unlock(&__sfp_lock);
 144   return (NULL);
 145 found:
 146   fp->_flags = 1;   /* reserve this slot; caller sets real flags */
 147   fp->_p = NULL;    /* no current pointer */
 148   fp->_w = 0;   /* nothing to read or write */
 149   fp->_r = 0;
 150   fp->_bf._base = NULL; /* no buffer */
 151   fp->_bf._size = 0;
 152   fp->_lbfsize = 0; /* not line buffered */
 153   fp->_file = -1;   /* no file */
 154 /*  fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
 155   _UB(fp)._base = NULL; /* no ungetc buffer */
 156   _UB(fp)._size = 0;
 157   fp->_lb._base = NULL; /* no line buffer */
 158   fp->_lb._size = 0;
 159   memset(WCIO_GET(fp), 0, sizeof(struct wchar_io_data));
 160   rwlock_unlock(&__sfp_lock);
 161   return (fp);
 162 }
 163
 164 #if 0
 165 /*
 166  * XXX.  Force immediate allocation of internal memory.  Not used by stdio,
 167  * but documented historically for certain applications.  Bad applications.
 168  */
 169 void
 170 f_prealloc()
 171 {
 172   struct glue *g;
 173   int n;
 174
 175   n = (int)sysconf(_SC_OPEN_MAX) - FOPEN_MAX + 20; /* 20 for slop. */
 176   for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
 177     /* void */;
 178   if (n > 0)
 179     g->next = moreglue(n);
 180 }
 181 #endif
 182
 183 /*
 184  * exit() calls _cleanup() through *gMD->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   gMD->cleanup = _cleanup;   /* conservative */
 210   __sdidinit = 1;
 211 }