Imported Upstream version 93u+upstream

1 files changed, 172 insertions, 0 deletions

diff --git a/src/lib/libast/sfio/sfsync.c b/src/lib/libast/sfio/sfsync.c
new file mode 100644
index 0000000..4a9d16f
--- /dev/null
+++ b/src/lib/libast/sfio/sfsync.c
@@ -0,0 +1,172 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#include	"sfhdr.h"
+
+/*	Synchronize data in buffers with the file system.
+**	If f is nil, all streams are sync-ed
+**
+**	Written by Kiem-Phong Vo.
+*/
+
+#if __STD_C
+static int _sfall(void)
+#else
+static int _sfall()
+#endif
+{
+	reg Sfpool_t	*p, *next;
+	reg Sfio_t*	f;
+	reg int		n, rv;
+	reg int		nsync, count, loop;
+#define MAXLOOP 3
+
+	for(loop = 0; loop < MAXLOOP; ++loop)
+	{	rv = nsync = count = 0;
+		for(p = &_Sfpool; p; p = next)
+		{	/* find the next legitimate pool */
+			for(next = p->next; next; next = next->next)
+				if(next->n_sf > 0)
+					break;
+
+			/* walk the streams for _Sfpool only */
+			for(n = 0; n < ((p == &_Sfpool) ? p->n_sf : 1); ++n)
+			{	count += 1;
+				f = p->sf[n];
+
+				if(f->flags&SF_STRING )
+					goto did_sync;
+				if(SFFROZEN(f))
+					continue;
+				if((f->mode&SF_READ) && (f->mode&SF_SYNCED) )
+					goto did_sync;
+				if((f->mode&SF_READ) && !(f->bits&SF_MMAP) &&
+				   f->next == f->endb)
+					goto did_sync;
+				if((f->mode&SF_WRITE) && !(f->bits&SF_HOLE) &&
+				   f->next == f->data)
+					goto did_sync;
+
+				if(sfsync(f) < 0)
+					rv = -1;
+
+			did_sync:
+				nsync += 1;
+			}
+		}
+
+		if(nsync == count)
+			break;
+	}
+	return rv;
+}
+
+#if __STD_C
+int sfsync(reg Sfio_t* f)
+#else
+int sfsync(f)
+reg Sfio_t*	f;	/* stream to be synchronized */
+#endif
+{
+	int	local, rv, mode, lock;
+	Sfio_t*	origf;
+	SFMTXDECL(f);
+
+	if(!(origf = f) )
+		return _sfall();
+
+	SFMTXENTER(origf,-1);
+
+	GETLOCAL(origf,local);
+
+	if(origf->disc == _Sfudisc)	/* throw away ungetc */
+		(void)sfclose((*_Sfstack)(origf,NIL(Sfio_t*)));
+
+	rv = 0;
+
+	lock = origf->mode&SF_LOCK;
+	if(origf->mode == (SF_SYNCED|SF_READ) ) /* already synced */
+		goto done;
+
+	if((origf->mode&SF_RDWR) != SFMODE(origf,local) && _sfmode(origf,0,local) < 0)
+	{	rv = -1;
+		goto done;
+	}
+
+	for(; f; f = f->push)
+	{	
+		if((f->flags&SF_IOCHECK) && f->disc && f->disc->exceptf)
+			(void)(*f->disc->exceptf)(f,SF_SYNC,(Void_t*)((int)1),f->disc);
+
+		SFLOCK(f,local);
+
+		/* pretend that this stream is not on a stack */
+		mode = f->mode&SF_PUSH;
+		f->mode &= ~SF_PUSH;
+
+		/* these streams do not need synchronization */
+		if((f->flags&SF_STRING) || (f->mode&SF_SYNCED))
+			goto next;
+
+		if((f->mode&SF_WRITE) && (f->next > f->data || (f->bits&SF_HOLE)) )
+		{	/* sync the buffer, make sure pool don't move */
+			reg int pool = f->mode&SF_POOL;
+			f->mode &= ~SF_POOL;
+			if(f->next > f->data && (SFWRALL(f), SFFLSBUF(f,-1)) < 0)
+				rv = -1;
+			if(!SFISNULL(f) && (f->bits&SF_HOLE) )
+			{	/* realize a previously created hole of 0's */
+				if(SFSK(f,(Sfoff_t)(-1),SEEK_CUR,f->disc) >= 0)
+					(void)SFWR(f,"",1,f->disc);
+				f->bits &= ~SF_HOLE;
+			}
+			f->mode |= pool;
+		}
+
+		if((f->mode&SF_READ) && f->extent >= 0 &&
+		   ((f->bits&SF_MMAP) || f->next < f->endb) )
+		{	/* make sure the file pointer is at the right place */
+			f->here -= (f->endb-f->next);
+			f->endr = f->endw = f->data;
+			f->mode = SF_READ|SF_SYNCED|lock;
+			(void)SFSK(f,f->here,SEEK_SET,f->disc);
+
+			if((f->flags&SF_SHARE) && !(f->flags&SF_PUBLIC) &&
+			   !(f->bits&SF_MMAP) )
+			{	f->endb = f->next = f->data;
+				f->mode &= ~SF_SYNCED;
+			}
+		}
+
+	next:
+		f->mode |= mode;
+		SFOPEN(f,local);
+
+		if((f->flags&SF_IOCHECK) && f->disc && f->disc->exceptf)
+			(void)(*f->disc->exceptf)(f,SF_SYNC,(Void_t*)((int)0),f->disc);
+	}
+
+done:
+	if(!local && f && (f->mode&SF_POOL) && f->pool && f != f->pool->sf[0])
+		SFSYNC(f->pool->sf[0]);
+
+	SFMTXRETURN(origf, rv);
+}