StdLib/LibC/Stdio/refill.c

   1 /*
   2     Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
   3     This program and the accompanying materials are licensed and made available
   4     under the terms and conditions of the BSD License that accompanies this
   5     distribution.  The full text of the license may be found at
   6     http://opensource.org/licenses/bsd-license.
   7
   8     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   9     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  10
  11  * Copyright (c) 1990, 1993
  12  *  The Regents of the University of California.  All rights reserved.
  13  *
  14  * This code is derived from software contributed to Berkeley by
  15  * Chris Torek.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  * 3. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40
  41     NetBSD: refill.c,v 1.13 2003/08/07 16:43:30 agc Exp
  42     refill.c  8.1 (Berkeley) 6/4/93
  43 */
  44 #include <Uefi.h>               // REMOVE, For DEBUG only
  45 #include <Library/UefiLib.h>    // REMOVE, For DEBUG only
  46
  47 #include  <LibConfig.h>
  48 #include <sys/EfiCdefs.h>
  49
  50 #include <assert.h>
  51 #include <errno.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include "reentrant.h"
  55 #include "local.h"
  56
  57 #ifdef _REENTRANT
  58 extern rwlock_t __sfp_lock;
  59 #endif
  60
  61 static int lflush(FILE *);
  62
  63 static int
  64 lflush(FILE *fp)
  65 {
  66
  67   _DIAGASSERT(fp != NULL);
  68   if(fp == NULL) {
  69     errno = EINVAL;
  70     return (EOF);
  71   }
  72
  73   if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
  74     return (__sflush(fp));
  75   return (0);
  76 }
  77
  78 /*
  79  * Refill a stdio buffer.
  80  * Return EOF on eof or error, 0 otherwise.
  81  */
  82 int
  83 __srefill(FILE *fp)
  84 {
  85
  86   _DIAGASSERT(fp != NULL);
  87   if(fp == NULL) {
  88     errno = EINVAL;
  89     return (EOF);
  90   }
  91
  92   /* make sure stdio is set up */
  93   if (!__sdidinit)
  94     __sinit();
  95
  96 //Print(L"%a( %d)\n", __func__, fp->_file);
  97   fp->_r = 0;   /* largely a convenience for callers */
  98
  99   /* SysV does not make this test; take it out for compatibility */
 100   if (fp->_flags & __SEOF) {
 101 //Print(L"%a: %d\n", __func__, __LINE__);
 102     return (EOF);
 103   }
 104
 105   /* if not already reading, have to be reading and writing */
 106   if ((fp->_flags & __SRD) == 0) {
 107 //Print(L"%a: %d\n", __func__, __LINE__);
 108     if ((fp->_flags & __SRW) == 0) {
 109       errno = EBADF;
 110       fp->_flags |= __SERR;   //<dvm> Allows differentiation between errors and EOF
 111 //Print(L"%a: %d\n", __func__, __LINE__);
 112       return (EOF);
 113     }
 114     /* switch to reading */
 115     if (fp->_flags & __SWR) {
 116       if (__sflush(fp)) {
 117 //Print(L"%a: %d\n", __func__, __LINE__);
 118         return (EOF);
 119       }
 120       fp->_flags &= ~__SWR;
 121       fp->_w = 0;
 122       fp->_lbfsize = 0;
 123     }
 124     fp->_flags |= __SRD;
 125   } else {
 126 //Print(L"%a: %d\n", __func__, __LINE__);
 127     /*
 128      * We were reading.  If there is an ungetc buffer,
 129      * we must have been reading from that.  Drop it,
 130      * restoring the previous buffer (if any).  If there
 131      * is anything in that buffer, return.
 132      */
 133     if (HASUB(fp)) {
 134       FREEUB(fp);
 135       if ((fp->_r = fp->_ur) != 0) {
 136         fp->_p = fp->_up;
 137 //Print(L"%a: %d\n", __func__, __LINE__);
 138         return (0);
 139       }
 140     }
 141   }
 142
 143   if (fp->_bf._base == NULL)
 144     __smakebuf(fp);
 145
 146 //Print(L"%a: %d\n", __func__, __LINE__);
 147   /*
 148    * Before reading from a line buffered or unbuffered file,
 149    * flush all line buffered output files, per the ANSI C
 150    * standard.
 151    */
 152   if (fp->_flags & (__SLBF|__SNBF)) {
 153     rwlock_rdlock(&__sfp_lock);
 154     (void) _fwalk(lflush);
 155     rwlock_unlock(&__sfp_lock);
 156 //Print(L"%a: %d\n", __func__, __LINE__);
 157   }
 158   fp->_p = fp->_bf._base;
 159   fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size);
 160   fp->_flags &= ~__SMOD;  /* buffer contents are again pristine */
 161   if (fp->_r <= 0) {
 162     if (fp->_r == 0)
 163       fp->_flags |= __SEOF;
 164     else {
 165       fp->_r = 0;
 166       fp->_flags |= __SERR;
 167     }
 168 //Print(L"%a: %d\n", __func__, __LINE__);
 169     return (EOF);
 170   }
 171 //Print(L"%a: %d\n", __func__, __LINE__);
 172   return (0);
 173 }