1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                  Common Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*            http://www.opensource.org/licenses/cpl1.0.txt             *
11*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#include	"sfhdr.h"
23
24/*	Function to clear a locked stream.
25**	This is useful for programs that longjmp from the mid of an sfio function.
26**	There is no guarantee on data integrity in such a case.
27**
28**	Written by Kiem-Phong Vo
29*/
30#if __STD_C
31int sfclrlock(Sfio_t* f)
32#else
33int sfclrlock(f)
34Sfio_t	*f;
35#endif
36{
37	int	rv;
38	SFMTXDECL(f);
39
40	/* already closed */
41	if(f && (f->mode&SF_AVAIL))
42		return 0;
43
44	SFMTXENTER(f,0);
45
46	/* clear error bits */
47	f->flags &= ~(SF_ERROR|SF_EOF);
48
49	/* clear peek locks */
50	if(f->mode&SF_PKRD)
51	{	f->here -= f->endb-f->next;
52		f->endb = f->next;
53	}
54
55	SFCLRBITS(f);
56
57	/* throw away all lock bits except for stacking state SF_PUSH */
58	f->mode &= (SF_RDWR|SF_INIT|SF_POOL|SF_PUSH|SF_SYNCED|SF_STDIO);
59
60	rv = (f->mode&SF_PUSH) ? 0 : (f->flags&SF_FLAGS);
61
62	SFMTXRETURN(f, rv);
63}
64