Retro68/gcc/newlib/libc/stdio/getc_u.c

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/*
* 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
<<getc_unlocked>>---non-thread-safe version of getc (macro)
INDEX
getc_unlocked
INDEX
_getc_unlocked_r
SYNOPSIS
#include <stdio.h>
int getc_unlocked(FILE *<[fp]>);
#include <stdio.h>
int _getc_unlocked_r(FILE *<[fp]>);
DESCRIPTION
<<getc_unlocked>> is a non-thread-safe version of <<getc>> declared in
<<stdio.h>>. <<getc_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
<<getc_unlocked>> is equivalent to <<getc>>.
The <<_getc_unlocked_r>> function is simply the reentrant version of
<<get_unlocked>> which passes an additional reentrancy structure pointer
argument: <[ptr]>.
RETURNS
See <<getc>>.
PORTABILITY
POSIX 1003.1 requires <<getc_unlocked>>. <<getc_unlocked>> may be
implemented as a macro, so arguments should not have side-effects.
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 */
#include <_ansi.h>
#include <stdio.h>
/*
* A subroutine version of the macro getc_unlocked.
*/
#undef getc_unlocked
int
_DEFUN(_getc_unlocked_r, (ptr, fp),
struct _reent *ptr _AND
register FILE *fp)
{
/* CHECK_INIT is called (eventually) by __srefill_r. */
return __sgetc_r (ptr, fp);
}
#ifndef _REENT_ONLY
int
_DEFUN(getc_unlocked, (fp),
register FILE *fp)
{
return __sgetc_r (_REENT, fp);
}
#endif /* !_REENT_ONLY */