Strange run-time error - CAUSE UNKNOWN

[Alain Muls]

Hi

I am writing a polotting program using Qt 4.2.3 and whenever a resize or 
change of scale is being performed, I hand of the calculations and drawing to 
a pixmap to a thread (the renderthread similar to the one in the mandelbrott 
example form Qt).

Since this thread is in there, the program hangs and I can not pinpoint the 
problem. The program will hang, that is for sure, but sometimes it as at the 
first resize/rescale, sometimes it only happens after 20 such actions. There 
is no consistency to find except for the program quitting without leaving a 
core file.

I get all sort of errors, they are related to the interaction between Qt and X 
I believe. Here is an example of such errors

: RenderThread::renderBackgroundPixmap before locker
W: X Error: RenderBadPicture (invalid Picture parameter) 180
  Extension:    156 (RENDER)
  Minor opcode: 7 (RenderFreePicture)
  Resource id:  0x380248c
W: X Error: BadPixmap (invalid Pixmap parameter) 4
  Major opcode: 54 (X_FreePixmap)
  Resource id:  0x380248b

another one after another run:

W: X Error: BadRequest (invalid request code or no such operation) 1
  Extension:    253 (Uknown extension)
  Minor opcode: 0 (Unknown request)
  Resource id:  0x4e02c5e

and yet another run:

W: X Error: BadLength (poly request too large or internal Xlib length error) 
16
  Major opcode: 56 (X_ChangeGC)
  Resource id:  0x4e02c5e
W: X Error: BadPixmap (invalid Pixmap parameter) 4
  Extension:    156 (RENDER)
  Minor opcode: 5 (RenderChangePicture)
  Resource id:  0x34002c
W: X Error: BadRequest (invalid request code or no such operation) 1
  Extension:    253 (Uknown extension)
  Minor opcode: 0 (Unknown request)
  Resource id:  0x34002c


ANY ideas are more than welcome,
Tx
-- 
______________________________________________________
Alain Muls                       alain.muls at telenet.be
RMA-CISS-ASGE                            +32.2.7426340
Renaissance Avenue 30   B1000 Brussels
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