qt event loop freezes on mac

our program is similar to a video player.

we have a QGLWidget to display the video. a QTimer will call updateGL() periodically to update the opengl scene.

however, this doesn't work on Mac sometimes, because for some reason, Qt doesn't trigger the timer's timeout event. it looks like the eventloop is frozen.

This issue is intermittent, the reproduction rate is about 50%.

the program is too large to attach, please download here

https://s3-us-west-1.amazonaws.com/qatest01/GRID+Workspace.zip

double click and then just click connect. after at least 5 seconds, if you don't see an animation, that means the window is frozen.

when the issue happens, only switching to another running application window could trigger our program to update. the Qt eventloop seems to be frozen.

thanks