re entrancy of xlib functions known problem i ve found a problem in the use of xlib functions regarding re entrancy i decided to implement an animated cursor using created cursors by calling xdefinecursor from a sig alrm signal handler this is used to indicate we are waiting for a operator request to complete on a production control system i was redrawing the screen underneath the animated cursor and then restoring the standard cursor when complete i found dumped core and upon analysis it was when the sig alrm handler was called during a xdrawstring call xdrawstring was doing a bcopy presumably an internal structure when the xdefinecursor was called presumably the internal structure that xdrawstring was manipulating was not in a stable state and sent xdefinecursor to where it shouldn t have been has anyone else experienced this is there any official documentation that says you should ensure this doesn t happen or should bcopy be atomic we are running on sgi irix with x r regards martin martin visser electrical software engineer engineering technology department bhp steel slab and plate products division p o box wollongong nsw australia phone ext fax e mail visser itwol bhp com au
