Problems with Xdriver

ronald at ronald at
Tue Feb 9 16:23:44 EST 1993


We are running GRASS on a concurrent mc6450, and we have two small problems
concerning the Xdriver (latest version).
The first problem has to deal with using the mouse for zooming in.
When defining a new region with the mouse, the rubberbandbox is not always
visible. When the background is black the rubberbandbox is also black. Note
that I have changed gcValues.line_width in Get_location_with_box 
(in Get_w_box.c) to zero to make redrawing of the box faster. 
What can I do about this?

The second problem has to do with the communication between the Xdriver and
GRASS - display applications. When e.g. d.vect receives an "EOF from graphics
monitor" it takes about 30 seconds before the Xdriver kills itself, giving the
message "/usr/grass4.0/masscomp/dev/fifo.1b: Too many open files "

I have found out from the file /XDRIVER/SWITCHER.c that both fifo's are closed
when this happens and succesively are opened for further reading/writing
It seems that the fifo's that are opened at this stage do not have the same 
filedesciptors as the previous ones. So initially filedescriptor _rfd == 5, 
and _wfd == 6, after EOF, _rfd = 6 and _wfd = 7. After this has occurred,
this process repeates itself untill all filedesciptors are used (max 40).
The funny thing is that this happens without sending anything to the XDRIVER, so
no display program is running at the time. What can be the cause of this

Ronald Wiemer
Archis, The Netherlands

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