Imported Upstream version 93u+upstream

1 files changed, 133 insertions, 0 deletions

diff --git a/src/lib/libast/sfio/sfexcept.c b/src/lib/libast/sfio/sfexcept.c
new file mode 100644
index 0000000..fc08d6e
--- /dev/null
+++ b/src/lib/libast/sfio/sfexcept.c
@@ -0,0 +1,133 @@
+/***********************************************************************
+*                                                                      *
+*               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"
+
+/*	Function to handle io exceptions.
+**	Written by Kiem-Phong Vo
+*/
+
+#if __STD_C
+int _sfexcept(Sfio_t* f, int type, ssize_t io, Sfdisc_t* disc)
+#else
+int _sfexcept(f,type,io,disc)
+Sfio_t*		f;	/* stream where the exception happened */
+int		type;	/* io type that was performed */
+ssize_t		io;	/* the io return value that indicated exception */
+Sfdisc_t*	disc;	/* discipline in use */
+#endif
+{
+	reg int		ev, local, lock;
+	reg ssize_t	size;
+	reg uchar*	data;
+	SFMTXDECL(f); /* declare a local stream variable for multithreading */
+
+	SFMTXENTER(f,-1);
+
+	GETLOCAL(f,local);
+	lock = f->mode&SF_LOCK;
+
+	if(local && io <= 0)
+		f->flags |= io < 0 ? SF_ERROR : SF_EOF;
+
+	if(disc && disc->exceptf)
+	{	/* let the stream be generally accessible for this duration */
+		if(local && lock)
+			SFOPEN(f,0);
+
+		/* so that exception handler knows what we are asking for */
+		_Sfi = f->val = io;
+		ev = (*(disc->exceptf))(f,type,&io,disc);
+
+		/* relock if necessary */
+		if(local && lock)
+			SFLOCK(f,0);
+
+		if(io > 0 && !(f->flags&SF_STRING) )
+			SFMTXRETURN(f, ev);
+		if(ev < 0)
+			SFMTXRETURN(f, SF_EDONE);
+		if(ev > 0)
+			SFMTXRETURN(f, SF_EDISC);
+	}
+
+	if(f->flags&SF_STRING)
+	{	if(type == SF_READ)
+			goto chk_stack;
+		else if(type != SF_WRITE && type != SF_SEEK)
+			SFMTXRETURN(f, SF_EDONE);
+		if(local && io >= 0)
+		{	if(f->size >= 0 && !(f->flags&SF_MALLOC))
+				goto chk_stack;
+			/* extend buffer */
+			if((size = f->size) < 0)
+				size = 0;
+			if((io -= size) <= 0)
+				io = SF_GRAIN;
+			size = ((size+io+SF_GRAIN-1)/SF_GRAIN)*SF_GRAIN;
+			if(f->size > 0)
+				data = (uchar*)realloc((char*)f->data,size);
+			else	data = (uchar*)malloc(size);
+			if(!data)
+				goto chk_stack;
+			f->endb = data + size;
+			f->next = data + (f->next - f->data);
+			f->endr = f->endw = f->data = data;
+			f->size = size;
+		}
+		SFMTXRETURN(f, SF_EDISC);
+	}
+
+	if(errno == EINTR)
+	{	if(_Sfexiting || (f->bits&SF_ENDING) ||	/* stop being a hero	*/
+		   (f->flags&SF_IOINTR) ) /* application requests to return	*/
+			SFMTXRETURN(f, SF_EDONE);
+
+		/* a normal interrupt, we can continue */
+		errno = 0;
+		f->flags &= ~(SF_EOF|SF_ERROR);
+		SFMTXRETURN(f, SF_ECONT);
+	}
+
+chk_stack:
+	if(local && f->push &&
+	   ((type == SF_READ  && f->next >= f->endb) ||
+	    (type == SF_WRITE && f->next <= f->data)))
+	{	/* pop the stack */
+		reg Sfio_t	*pf;
+
+		if(lock)
+			SFOPEN(f,0);
+
+		/* pop and close */
+		pf = (*_Sfstack)(f,NIL(Sfio_t*));
+		if((ev = sfclose(pf)) < 0) /* can't close, restack */
+			(*_Sfstack)(f,pf);
+
+		if(lock)
+			SFLOCK(f,0);
+
+		ev = ev < 0 ? SF_EDONE : SF_ESTACK;
+	}
+	else	ev = SF_EDONE;
+
+	SFMTXRETURN(f, ev);
+}