MantidPlot hangs on shutdown after opening offline help window

[Martyn Gigg]

To reproduce (seen on Ubuntu 12.04):

• Start MantidPlot
• Type Rebin in to the algorithm box & click the question mark button
• Close the help window after it appears
• Close down MantidPlot

The process hangs and the gdb backtrace indicates it's stuck in the QProcess destructor and is waiting on an already locked mutex.

My guess here is that because the Singleton destruction is done after the Qt framework as shutdown then something isn't that happy.

I have attached a patch that seems to remedy the problem on my machine but could do with checking.

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Branch: feature/6873_hanging_helpwindow_singleton

Tester: Run the steps above and MantidPlot should no longer hang on shutdown.

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Martyn Gigg]

Release the HelpWindow QProcess while MantidPlot is shutting down.

If left until the HelpWindow::destructor then the MantidPlot process hangs on shutdown inside the QProcess destructor waiting on a mutex. It is most likely that this because the Qt framework is now too far gone at the point when the singletons are released. Refs #6873

Changeset: 4dd82c767f18ffe343b5cfedfbe5a38c16a07661

[Stuart Campbell]

This ticket has been transferred to github issue ​7719