949107 - MetroFX should gracefully handle the case that Windows terminates our suspended process due to resource constraints

Status: RESOLVED DUPLICATE of bug 850372

(Firefox for Metro Graveyard :: General, defect)

Description

[Tim Abraldes [:TimAbraldes] [:tabraldes]]

Our metro app, once launched, will be suspended if it is not currently in the foreground. If the machine becomes resource-constrained, Windows will terminate suspended processes.

Currently, metroFx reacts to such termination as if it were a crash, but should instead be able to distinguish these cases and respond appropriately:
  1 Suspend>Terminate>Activate
  2 Suspend>Terminate>Close>Activate
  3 Suspend>Terminate>Close>Reboot>Activate
  4 Suspend>Terminate>Reboot>Activate

"Respond appropriately" probably means to restore the user's session silently in case 1, and use the value of the "When Firefox Starts" pref to determine what to do in cases 2-4.

[1] http://msdn.microsoft.com/en-us/library/windows/apps/hh464925.aspx
[2] http://msdn.microsoft.com/en-us/library/windows/apps/hh465088.aspx
[3] http://msdn.microsoft.com/en-us/library/windows/apps/windows.applicationmodel.activation.applicationexecutionstate.aspx

Comment 1

[Tim Abraldes [:TimAbraldes] [:tabraldes]]

Marking this bug as dependent on bug 850372 since fixing that bug will also fix this bug.

When metroFx gets suspended, our MetroApp::OnSuspending [1] function gets called. At this point, our process has 5s to flush its session state to disk or be terminated. Once metroFx is suspended, there is no guarantee that it will get to execute any additional code. In particular, if the user closes metroFx from the suspended state (bug 922657), or if the machine reboots (bug 850372), or if Windows terminates the process to free up resources (bug 949107), metroFx does not execute any additional code. Currently, metroFx treats any termination from a suspended state as a crash, but it needs to treat termination from a suspended state as a normal shutdown.

[1] https://mxr.mozilla.org/mozilla-central/source/widget/windows/winrt/MetroApp.cpp?rev=7c8790d032b5#137