Imported Upstream version 93u+upstream

1 files changed, 69 insertions, 0 deletions

diff --git a/src/lib/libast/sfio/sfmutex.c b/src/lib/libast/sfio/sfmutex.c
new file mode 100644
index 0000000..cc3a4b7
--- /dev/null
+++ b/src/lib/libast/sfio/sfmutex.c
@@ -0,0 +1,69 @@
+/***********************************************************************
+*                                                                      *
+*               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"
+
+/*	Obtain/release exclusive use of a stream.
+**
+**	Written by Kiem-Phong Vo.
+*/
+
+/* the main locking/unlocking interface */
+#if __STD_C
+int sfmutex(Sfio_t* f, int type)
+#else
+int sfmutex(f, type)
+Sfio_t*	f;
+int	type;
+#endif
+{
+#if !vt_threaded
+	NOTUSED(f); NOTUSED(type);
+	return 0;
+#else
+
+	SFONCE();
+
+	if(!f)
+		return -1;
+
+	if(!f->mutex)
+	{	if(f->bits&SF_PRIVATE)
+			return 0;
+
+		vtmtxlock(_Sfmutex);
+		f->mutex = vtmtxopen(NIL(Vtmutex_t*), VT_INIT);
+		vtmtxunlock(_Sfmutex);
+		if(!f->mutex)
+			return -1;
+	}
+
+	if(type == SFMTX_LOCK)
+		return vtmtxlock(f->mutex);
+	else if(type == SFMTX_TRYLOCK)
+		return vtmtxtrylock(f->mutex);
+	else if(type == SFMTX_UNLOCK)
+		return vtmtxunlock(f->mutex);
+	else if(type == SFMTX_CLRLOCK)
+		return vtmtxclrlock(f->mutex);
+	else	return -1;
+#endif /*vt_threaded*/
+}