Forum Discussion
Shimming apps that start other processes in the package.
I'm not sure if the PSF is designed to handle the need to shim child processes of the shortcut app.
For example, FileZilla.exe will start fzftp.exe as a child process. I can put PsfShimLaunche...
Hi Vlad, John,
Thanks for the quick reply.
We just used the standard documentation from .NET to launch the process, we didn't write the code specifically to call ShellExecute or CreateProcess. Actually, we left the default value (true) for the property UseShellExecute when we initially wrote the code. If we set it to false, then indeed the child process inherits the fixup.
However, the point here is that the default for this property (UseShellExecute) in .NET changed over the 1809 update and this could affect other user apps too, not just our sample. Apps for which users might not be able to change the code.
This is what we were trying to understand, if this change was intended or accidental?
Regarding your question, we are using our customer launcher because it provides additional functionality (migrating user shortcuts, pins, appdata, etc.. from the old msi version of the app) while also including the PSF support you guys published. It is something we have in Advanced Installer long before PSF was announced.
Also, as I said above, is we set UseShellExecute to false then the fixup is inherited, so there isn't a problem with our launcher, it behaves just as yours.
From our tests, if you have the x86 and x64 executables called PsfRunDll<arch>.exe xchen@lantostechnologies.com, and their corresponding dlls, next to the PSF runtimemanager then the fixups are correctly inherited by the processes, when launching a process for an app with a different bitness.
ShellExecute option is needed to launch some processes, for example, with RunAs (but there are other reasons too). As we are dealing with legacy software, much of it was written without manifests and in ways that require elevation today.
Bogdan Mitrache: So in your example, the json.conf file would also have reference to the 32 and 64 bit fixup files, but tied to the different applications? I guess that works, as long as every app has an ApplicationId (exe files without shortcuts/ftas don't by default and might be an issue). It might be better to be able to wildcard the application names (so we don't need to manually generate ApplicationIIds) in the lower section and have a 32 and 64 bit entries in the conf and have PsfRunDll figure it the bitness automatically.
"So in your example, the json.conf file would also have reference to the 32 and 64 bit fixup files, but tied to the different applications?"
TIMOTHY_MANGAN Yes, we leverage the PSF behavior Vlad explained in his last post.
Vladimir Postel Thanks, I submitted the issue on the feedback hub.
- Vladimir Postel
Microsoft
Thanks for the feedback Tim.
Do you know about specific app examples that are doing it today that you can share with us?
We do support cross-architecture launches where a 32-bit process is creating a 64-bit process or vice-versa.
You can include both arch fixups in the package and refer to them from the config.
Today this is the logic we have;
When enumerating the list of fixup dll names, PSF Runtime will make two attempts to load the dll, each made relative to the package root:
- First using the name exactly as it is given (e.g. "ContosoFixup.dll" in the example above)
- If that fails, then it appends the current architecture bitness (32 or 64) to the end of the dll name (e.g. "ContosoFixup64.dll" if the current process is a 64-bit process) and attempts to load that
This is done to support applications that contain both 32 and 64-bit executables, but need the same fixups applied to both. This is why all of the inbox fixups produce binaries named _____32.dll and _____64.dll by default. This naming convention also carries over to executables to prevent naming conflicts.
Please look here for more details - https://github.com/Microsoft/MSIX-PackageSupportFramework/tree/master/PsfRuntime
Vlad
