[Qt-interest] QT 4.6.2 hangs in processEvents()

[Tony Rietwyk]

Hi Srikanth, 

 

I have a similar problem in 4.6.0 using
QEventLoop.exec(QEventLoop::ExcludeUserInputEvents) in a QSqlDriver derived
class that sends the requests using QNAM.post.  I haven't raised the
problem, since it is very complicated to explain, but it also involves a
progress dialog which stops animating - no matter where the mouse is.  If I
debug and break during the hang, the same line of code is selected.  In my
case, the number of handles (ncount) == 0.  

 

I looked at the 4.7.2 sources and see that the block of code in
qeventdispatcher_win looks the same.  

 

In my case the problem occurs when a QListWidget has been populated, and it
executes sql whenever an item is selected.  If the user selects items
slowly, then it works no problem.  But if the user holds down an arrow key
(thereby selecting items very fast) then the problem occurs.  

 

Please let me know if you find a solution to your problem! 

 

Thanks, 

 

Tony

 

 

From: qt-interest-bounces+tony.rietwyk=rightsoft.com.au at qt.nokia.com
[mailto:qt-interest-bounces+tony.rietwyk=rightsoft.com.au at qt.nokia.com] On
Behalf Of srikanth bemineni
Sent: Thursday, 25 August 2011 12:06 PM
To: qt-interest at trolltech.com
Subject: [Qt-interest] QT 4.6.2 hangs in processEvents()

 

Hi,

I am using Qt4.6.2 and I have seen some of the behaviors that I don't have
any explanation

1. When I try to exit my application during the process when QWidgetTable is
getting populated, the application gets stuck at the below code in 
qeventdispatcher_win.cpp

emit aboutToBlock();
waitRet = MsgWaitForMultipleObjectsEx(nCount, pHandles, INFINITE,
QS_ALLINPUT, MWMO_ALERTABLE)

2. My progress bar used as busy bar stops animating until and unless mouse
is moved on the application.


Any body else have seen this behavior. The first problem is making my
application to hang indefinitely.

With regards
Srikanth Bemineni

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