StdLib/LibC/Stdio/refill.c

   1 /*  $NetBSD: refill.c,v 1.13 2003/08/07 16:43:30 agc 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 <Uefi.h>               // REMOVE, For DEBUG only
  35 #include <Library/UefiLib.h>    // REMOVE, For DEBUG only
  36
  37 #include  <LibConfig.h>
  38 #include <sys/EfiCdefs.h>
  39 #if defined(LIBC_SCCS) && !defined(lint)
  40 #if 0
  41 static char sccsid[] = "@(#)refill.c  8.1 (Berkeley) 6/4/93";
  42 #else
  43 __RCSID("$NetBSD: refill.c,v 1.13 2003/08/07 16:43:30 agc Exp $");
  44 #endif
  45 #endif /* LIBC_SCCS and not lint */
  46
  47 #include <assert.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include "reentrant.h"
  52 #include "local.h"
  53
  54 #ifdef _REENTRANT
  55 extern rwlock_t __sfp_lock;
  56 #endif
  57
  58 static int lflush(FILE *);
  59
  60 static int
  61 lflush(FILE *fp)
  62 {
  63
  64   //_DIAGASSERT(fp != NULL);
  65
  66   if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
  67     return (__sflush(fp));
  68   return (0);
  69 }
  70
  71 /*
  72  * Refill a stdio buffer.
  73  * Return EOF on eof or error, 0 otherwise.
  74  */
  75 int
  76 __srefill(FILE *fp)
  77 {
  78
  79   //_DIAGASSERT(fp != NULL);
  80
  81   /* make sure stdio is set up */
  82   if (!__sdidinit)
  83     __sinit();
  84
  85 //Print(L"%a( %d)\n", __func__, fp->_file);
  86   fp->_r = 0;   /* largely a convenience for callers */
  87
  88   /* SysV does not make this test; take it out for compatibility */
  89   if (fp->_flags & __SEOF) {
  90 //Print(L"%a: %d\n", __func__, __LINE__);
  91     return (EOF);
  92   }
  93
  94   /* if not already reading, have to be reading and writing */
  95   if ((fp->_flags & __SRD) == 0) {
  96 //Print(L"%a: %d\n", __func__, __LINE__);
  97     if ((fp->_flags & __SRW) == 0) {
  98       errno = EBADF;
  99       fp->_flags |= __SERR;   //<dvm> Allows differentiation between errors and EOF
 100 //Print(L"%a: %d\n", __func__, __LINE__);
 101       return (EOF);
 102     }
 103     /* switch to reading */
 104     if (fp->_flags & __SWR) {
 105       if (__sflush(fp)) {
 106 //Print(L"%a: %d\n", __func__, __LINE__);
 107         return (EOF);
 108       }
 109       fp->_flags &= ~__SWR;
 110       fp->_w = 0;
 111       fp->_lbfsize = 0;
 112     }
 113     fp->_flags |= __SRD;
 114   } else {
 115 //Print(L"%a: %d\n", __func__, __LINE__);
 116     /*
 117      * We were reading.  If there is an ungetc buffer,
 118      * we must have been reading from that.  Drop it,
 119      * restoring the previous buffer (if any).  If there
 120      * is anything in that buffer, return.
 121      */
 122     if (HASUB(fp)) {
 123       FREEUB(fp);
 124       if ((fp->_r = fp->_ur) != 0) {
 125         fp->_p = fp->_up;
 126 //Print(L"%a: %d\n", __func__, __LINE__);
 127         return (0);
 128       }
 129     }
 130   }
 131
 132   if (fp->_bf._base == NULL)
 133     __smakebuf(fp);
 134
 135 //Print(L"%a: %d\n", __func__, __LINE__);
 136   /*
 137    * Before reading from a line buffered or unbuffered file,
 138    * flush all line buffered output files, per the ANSI C
 139    * standard.
 140    */
 141   if (fp->_flags & (__SLBF|__SNBF)) {
 142     rwlock_rdlock(&__sfp_lock);
 143     (void) _fwalk(lflush);
 144     rwlock_unlock(&__sfp_lock);
 145 //Print(L"%a: %d\n", __func__, __LINE__);
 146   }
 147   fp->_p = fp->_bf._base;
 148   fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size);
 149   fp->_flags &= ~__SMOD;  /* buffer contents are again pristine */
 150   if (fp->_r <= 0) {
 151     if (fp->_r == 0)
 152       fp->_flags |= __SEOF;
 153     else {
 154       fp->_r = 0;
 155       fp->_flags |= __SERR;
 156     }
 157 //Print(L"%a: %d\n", __func__, __LINE__);
 158     return (EOF);
 159   }
 160 //Print(L"%a: %d\n", __func__, __LINE__);
 161   return (0);
 162 }