Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtksh/ksh93/src/lib/libast/sfio/sfexcept.c

@@ -0,0 +1,125 @@
+/* $XConsortium: sfexcept.c /main/3 1995/11/01 18:28:25 rswiston $ */
+/***************************************************************
+*                                                              *
+*                      AT&T - PROPRIETARY                      *
+*                                                              *
+*         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
+*                          AT&T CORP.                          *
+*                                                              *
+*                Copyright (c) 1995 AT&T Corp.                 *
+*                     All Rights Reserved                      *
+*                                                              *
+*           This software is licensed by AT&T Corp.            *
+*       under the terms and conditions of the license in       *
+*       http://www.research.att.com/orgs/ssr/book/reuse        *
+*                                                              *
+*               This software was created by the               *
+*           Software Engineering Research Department           *
+*                    AT&T Bell Laboratories                    *
+*                                                              *
+*               For further information contact                *
+*                     gsf@research.att.com                     *
+*                                                              *
+***************************************************************/
+#include	"sfhdr.h"
+
+/*	Function to handle io exceptions.
+**	Written by Kiem-Phong Vo (8/18/90)
+*/
+#if __STD_C
+_sfexcept(reg Sfio_t* f, reg int type, reg int io, reg Sfdisc_t* disc)
+#else
+_sfexcept(f,type,io,disc)
+reg Sfio_t	*f;	/* stream where the exception happened */
+reg int		type;	/* io type that was performed */
+reg int		io;	/* the io return value that indicated exception */
+reg Sfdisc_t	*disc;	/* discipline in use */
+#endif
+{
+	reg int		d, local, lock;
+	reg uchar	*data;
+
+	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 = io;
+		d = (*(disc->exceptf))(f,type,disc);
+
+		/* relock if necessary */
+		if(local && lock)
+			SFLOCK(f,0);
+
+		if(io > 0 && !(f->flags&SF_STRING) )
+			return d;
+		else if(d < 0)
+			return SF_EDONE;
+		else if(d > 0)
+			return SF_EDISC;
+	}
+
+	if(f->flags&SF_STRING)
+	{	if(type == SF_READ)
+			goto chk_stack;
+		else if(type != SF_WRITE && type != SF_SEEK)
+			return SF_EDONE;
+		if(local && io >= 0)
+		{	if(f->size >= 0 && !(f->flags&SF_MALLOC))
+				goto chk_stack;
+			/* extend buffer */
+			if((d = f->size) < 0)
+				d = 0;
+			if((io -= d) <= 0)
+				io = SF_GRAIN;
+			d = ((d+io+SF_GRAIN-1)/SF_GRAIN)*SF_GRAIN;
+			if(f->size > 0)
+				data = (uchar*)realloc((char*)f->data,d);
+			else	data = (uchar*)malloc(d);
+			if(!data)
+				goto chk_stack;
+			f->endb = data + d;
+			f->next = data + (f->next - f->data);
+			f->endr = f->endw = f->data = data;
+			f->size = d;
+		}
+		return SF_EDISC;
+	}
+
+	if(errno == EINTR)
+	{	/* if just an interrupt, we can continue */
+		errno = 0;
+		f->flags &= ~(SF_EOF|SF_ERROR);
+		return 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((d = sfclose(pf)) < 0) /* can't close, restack */
+			(*_Sfstack)(f,pf);
+
+		if(lock)
+			SFLOCK(f,0);
+
+		return d < 0 ? SF_EDONE : SF_ESTACK;
+	}
+
+	return SF_EDONE;
+}