newlib-cygwin/newlib/libc/stdio/getchar_u.c

89 lines
2.5 KiB
C

/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
FUNCTION
<<getchar_unlocked>>---non-thread-safe version of getchar (macro)
INDEX
getchar_unlocked
INDEX
_getchar_unlocked_r
SYNOPSIS
#include <stdio.h>
int getchar_unlocked(void);
#include <stdio.h>
int _getchar_unlocked_r(struct _reent *<[ptr]>);
DESCRIPTION
<<getchar_unlocked>> is a non-thread-safe version of <<getchar>>
declared in <<stdio.h>>. <<getchar_unlocked>> may only safely be used
within a scope protected by flockfile() (or ftrylockfile()) and
funlockfile(). These functions may safely be used in a multi-threaded
program if and only if they are called while the invoking thread owns
the ( FILE *) object, as is the case after a successful call to the
flockfile() or ftrylockfile() functions. If threads are disabled,
then <<getchar_unlocked>> is equivalent to <<getchar>>.
The <<_getchar_unlocked_r>> function is simply the reentrant version of
<<getchar_unlocked>> which passes an addtional reentrancy structure pointer
argument: <[ptr]>.
RETURNS
See <<getchar>>.
PORTABILITY
POSIX 1003.1 requires <<getchar_unlocked>>. <<getchar_unlocked>> may
be implemented as a macro.
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek>>, <<read>>, <<sbrk>>, <<write>>. */
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
/*
* A subroutine version of the macro getchar_unlocked.
*/
#include <_ansi.h>
#include <reent.h>
#include <stdio.h>
#undef getchar_unlocked
int
_getchar_unlocked_r (struct _reent *ptr)
{
return _getc_unlocked_r (ptr, _stdin_r (ptr));
}
#ifndef _REENT_ONLY
int
getchar_unlocked (void)
{
/* CHECK_INIT is called (eventually) by __srefill_r. */
return _getc_unlocked_r (_REENT, _stdin_r (_REENT));
}
#endif