This patch adds a globally shared zero-filled PhysicalPage that will
be mapped into every slot of every zero-filled AnonymousVMObject until
that page is written to, achieving CoW-like zero-filled pages.
Initial testing show that this doesn't actually achieve any sharing yet
but it seems like a good design regardless, since it may reduce the
number of page faults taken by programs.
If you look at the refcount of MM.shared_zero_page() it will have quite
a high refcount, but that's just because everything maps it everywhere.
If you want to see the "real" refcount, you can build with the
MAP_SHARED_ZERO_PAGE_LAZILY flag, and we'll defer mapping of the shared
zero page until the first NP read fault.
I've left this behavior behind a flag for future testing of this code.
This shaves ~5 seconds off of a full build, not too bad. Also it just
seems nicer to push this logic out to classes. It could be better but
it's a start. :^)
Compiling anything that includes generated IPC messages is painfully
slow at the moment. This moves the encoding helpers out of line, which
helps a bit. Doing the same for decoding will help more.
You can now #include <AK/Forward.h> to get most of the AK types as
forward declarations.
Header dependency explosion is one of the main contributors to compile
times at the moment, so this is a step towards smaller include graphs.
This patch implements basic drag & drop file management in a narrow set
of cases. You can now drag & drop a file onto a folder in the same
directory, and the dropped file will be copied into the directory.
We'll need to support a lot more variations of this, but this is nice!
You can now drop things on an AbstractView, which will ask its model if
the drag is acceptable to drop at the index where it's dropped.
If it's accepted by the model, the view will fire the on_drop hook.
This allows windows/widgets to learn when something is being dragged
over them. They can then repaint themselves somehow to indicate that
they are willing to accept a drop.
Currently this is piggybacking somewhat on the mouse event mechanism
in WindowServer. I'm not sure that's the best design but it seemed
easier to do it this way right now.
We will now send a redirect (301) if a directory listing is requested and the
request URL doesn't end with a slash character. This makes relative file URLs
that we generate in directory listings actually work as expected.
