ubuntu-phone team mailing list archive

[Manuel de la Pena <manuel.delapena@xxxxxxxxxxxxx>]

Hello,

In the ubuntu download manager we are using the new connection style syntax
(http://qt-project.org/wiki/New_Signal_Slot_Syntax) so that if there are
errors in the signal connections we will be notified at compile time.
However, in recent versions of udm we have noticed that the udm tests that
ensure that the qt signals are emitted correctly have started failing
randomly in the build servers.

As it can be seen in the following build logs the compilation does finish
with no errors but the tests raise errors at runtime (an assert was added
for each of the connect calls in the project):

https://launchpadlibrarian.net/172280588/buildlog_ubuntu-trusty-powerpc.ubuntu-download-manager_0.3%2B14.04.20140408.1-0ubuntu1_FAILEDTOBUILD.txt.gz
https://launchpadlibrarian.net/172280333/buildlog_ubuntu-trusty-arm64.ubuntu-download-manager_0.3%2B14.04.20140408.1-0ubuntu1_FAILEDTOBUILD.txt.gz
https://launchpadlibrarian.net/172280872/buildlog_ubuntu-trusty-armhf.ubuntu-download-manager_0.3%2B14.04.20140408.1-0ubuntu1_FAILEDTOBUILD.txt.gz

Some of the errors between the diff archs are the same but this feels like
a coincidence. The unity-scope-click package project has had the same issue
and has solved it in the following way:

scope/click/download-manager.cpp (123)

 // NOTE: using SIGNAL/SLOT macros here because new-style
    // connections are flaky on ARM.
    c = connect(impl->systemDownloadManager.data(),
SIGNAL(downloadCreated(Download*)),
                this, SLOT(handleDownloadCreated(Download*)));

    if (!c) {
        qDebug() << "failed to connect to
systemDownloadManager::downloadCreated";

    }


It is very interesting that the tests have never (so far) failed in the
other 2 architectures (i386, amd64). I'm raising this issue because it
might be hitting us in some other projects. I have reported the following
bug (https://bugs.launchpad.net/ubuntu-ui-toolkit/+bug/1304709) in (very
probably) wrong project. I would really appreciate input form more
intelligent developers :)

PS: At least I know that my crazy tests that ensure that all signals are
raised correctly do make sense even when they stop me from landing udm at
the moment.