WiX CloseApplication for exe and dll

Question

I've created a WiX setup project based on the article WiX 3 Tutorial: Understanding main WXS and WXI file mainly because it gives the WiX needed to do an application shutdown.

However, I'm puzzled by the outcome. Here's the situation:

We have an executable which uses a dll and create a setup which installs the executable and the dll. We execute the setup.

CASE 1: Next, we change the executable and NOT the dll and create the setup again. Then we start the installed application and make sure also the dll is loaded. If we now execute the second setup, a dialog is shown asking the user to shutdown the executable just as we expected.

CASE 2: But if we do not change the application but only the dll and then execute the setup while the application is running and the dll is loaded, no dialog is shown. At the end of the setup a dialog appears asking if we want to restart the computer.

Is this expected behaviour and how can I force the application shutdown dialog of CASE 1 also when only a dll is changed as in CASE 2? I do not want the user having to restart the computer because the application is running on a server which cannot be restarted.

Answer 1

This is all determined by Windows Installer during the costing process. The installer decides which files need to be installed / updated and calculates how much disk space is needed and if there are any file locks. If there are file locks, it attempts to resolve the lock to a process with a window handle. If it can do this, you'll get the dialog. If it can't, you won't. This doesn't mean a reboot won't be needed, it just can't give you useful information on how to avoid it.

A few additional points:

Make sure you are versioning your EXE and DLL. If the old DLL is 1.0.0.0 and the new DLL is 1.0.0.0 costing will say "Nothing to do here".

How does the EXE use the DLL at runtime? It might simply not have a lock on it during the entire life of the process.

Understand that MSI's reboot behavior can be altered through the use of properties such as REBOOT=ReallySuppress

Here's some good articles to read:

InstallValidate FileInUseDialog System Reboots

Answer 2

I haven't checked the code but I think what is happening is the CloseApplication action is not running because it sees that the exe hasn't changed. As far as I am aware you cannot target a DLL with CloseApplication. If you run your install with logging you should be able to see if the action is triggered. I am assuming you have RemoveExistingProducts schedule late in the install, if you were to move it after InstallValidate it would remove the exe every time and therefore trigger the action.