I've updated the silo to sync with another upload. I get same behavior with and without the silo:
1. On first run, edit config does not hang. 2. When pressing Fake stale lock file, the subsequent edit config selections do hang. 3. When the app does not start (after fake stale lock file), the second attempt to start the app does work. 4. Removing .config/locked-crasher.mzanetti/ restores the behavior to 1. I've pinged Michael yesterday but no comment yet. I wouldn't land the changes if there's no demonstrated improvement. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to qtbase-opensource-src in Ubuntu. https://bugs.launchpad.net/bugs/1576989 Title: stale lock files freeze apps Status in Canonical System Image: Confirmed Status in qtbase-opensource-src package in Ubuntu: Confirmed Status in qtbase-opensource-src package in Ubuntu RTM: Confirmed Bug description: Debugging why the Notes app would freeze for some people, I found there were some stale .lock files around. Those .lock files are autocreated by QSettings (with QLockFile) when this file is edited. Problem is, that it sometimes seems to happen that the app is suspended by our lifecycle and then killed (either by closing from spread or OOM killed) and those .lock files stick around. I have implemented a workaround in the notes app[1] to clear up those stale locks when the app starts app, however, today I ran twice in a row into the issue that the very same happened to music app. It would just freeze on startup and never come back. Digging around a bit I found such a stale lock file on its config file which is created with the QML Settings element. This implies that every app using QSettings or QML Settings {} are potentially affected. I suspect many more app freezes can be traced down to this. Now, there is some code in Qt to detect stale lock files [2], however, not sure why it doesn't detect those lock files as stale ones and decides to wait on them forever though. Probably a bug in the code or some of the wrong #ifdefs are triggered for our package builds. [1] https://code.launchpad.net/~mzanetti/reminders-app/remove-stale-lock-files/+merge/293355 [2] http://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/io/qlockfile_unix.cpp To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1576989/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
