[Qt-interest] Segment fault when updating OpenGL QGLWidget from thread ?

[Ed Sutton]

How can I synchronize thread access to my GUI window?

1 - I have a thread receiving video data over the network.
2 - When a frame is complete it makes a callback to my QGLWidget derived class's frame handler  - a static method that gets passed the instance of the class.
3 - The segment fault appears to be triggered when calling glClearColor(),before it gets to the end and calls QWidget::update()
4 - The segment fault occurs after I select a new video channel in my GUI and the changedChannel slot handler has been called.

My figure I need a mutex in my frame handler.  However, according to my debug print statements the main window's changedChannel slot handler appears to have already completed before the segment fault occurs.  I am a Qt / Linux newbie and realize I may be doing this all wrong.

Thanks in advance for sharing your experience and any tips or direction.

-Ed


PS: Using Red Hat Enterprise Linux 5.2.  I did not know I had a problem until I tested on a multi-core machine.  ( I must figure out how get my Red Hat development VM working under 2 cores. )
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