toolchain/gcc/newlib/libc/stdio/getchar_u.c

   1 /*
   2  * Copyright (c) 1990 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * advertising materials, and other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Berkeley.  The name of the
  11  * University may not be used to endorse or promote products derived
  12  * from this software without specific prior written permission.
  13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16  */
  17
  18 /*
  19 FUNCTION
  20 <<getchar_unlocked>>---non-thread-safe version of getchar (macro)
  21
  22 INDEX
  23         getchar_unlocked
  24
  25 POSIX_SYNOPSIS
  26         #include <stdio.h>
  27         int getchar_unlocked();
  28
  29 DESCRIPTION
  30 <<getchar_unlocked>> is a non-thread-safe version of <<getchar>>
  31 declared in <<stdio.h>>.  <<getchar_unlocked>> may only safely be used
  32 within a scope protected by flockfile() (or ftrylockfile()) and
  33 funlockfile().  These functions may safely be used in a multi-threaded
  34 program if and only if they are called while the invoking thread owns
  35 the ( FILE *) object, as is the case after a successful call to the
  36 flockfile() or ftrylockfile() functions.  If threads are disabled,
  37 then <<getchar_unlocked>> is equivalent to <<getchar>>.
  38
  39 RETURNS
  40 See <<getchar>>.
  41
  42 PORTABILITY
  43 POSIX 1003.1 requires <<getchar_unlocked>>.  <<getchar_unlocked>> may
  44 be implemented as a macro.
  45
  46 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
  47 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.  */
  48
  49 #if defined(LIBC_SCCS) && !defined(lint)
  50 static char sccsid[] = "%W% (Berkeley) %G%";
  51 #endif /* LIBC_SCCS and not lint */
  52
  53 /*
  54  * A subroutine version of the macro getchar_unlocked.
  55  */
  56
  57 #include <stdio.h>
  58 #include <reent.h>
  59
  60 #undef getchar_unlocked
  61
  62 int
  63 _getchar_unlocked_r (f)
  64      struct _reent *f;
  65 {
  66   return getc_unlocked (_stdin_r (f));
  67 }
  68
  69 #ifndef _REENT_ONLY
  70
  71 int
  72 getchar_unlocked ()
  73 {
  74   /* CHECK_INIT is called (eventually) by __srefill.  */
  75
  76   return _getchar_unlocked_r (_REENT);
  77 }
  78
  79 #endif