This avoids putting pressure on kmalloc() during backtrace symbolication.
Since we dump backtrace for every process that exits, this is actually a
decent performance improvement for things like GCC that chain a lot of
processes together.
If we get an NP page fault in a process, and the fault address is in the
kernel address range (anywhere above 0xc0000000), we probably just need
to copy the page table info over from the kernel page directory.
The kernel doesn't allocate address space until it's needed, and when it
does allocate some, it only puts the info in the kernel page directory,
and any *new* page directories created from that point on. Existing page
directories need to be updated, and that's what this patch fixes.
Instead of PDE's and PTE's being weird wrappers around dword*, just have
MemoryManager::ensure_pte() return a PageDirectoryEntry&, which in turn has
a PageTableEntry* entries().
I've been trying to understand how things ended up this way, and I suspect
it was because I inadvertently invoked the PageDirectoryEntry copy ctor in
the original work on this, which must have made me very confused..
Anyways, now things are a bit saner and we can move forward towards a better
future, etc. :^)
Use __builtin_bswap() intrinsics for the byte swapping. Also don't swap on
systems where BYTE_ORDER != LITTLE_ENDIAN. This doesn't really affect us
at the moment since Serenity only targets x86, but I figured it doesn't hurt
to do things right. :^)
Eventually I'd like to do some kind of bitmap layers, and we definitely want
alpha channel support then, so let's just not paint ourselves into an
uncomfortable corner early on. :^)
We'll be making a lot of trees here, so let's share code during bootstrap.
Eventually some of these classes are gonna want custom trees but for now
we can just fit them all into the same clothes.
This parser assumes that the JSON is well-formed and will choke horribly
on invalid input.
Since we're primarily interested in parsing our own output right now, this
is less of a problem. Longer-term we're gonna need something better. :^)
- Delete the default constructor instead of just making it private.
It's never valid to create an empty NonnullRefPtr.
- Add copy assignment operators. I originally omitted these to force use
of .copy_ref() at call sites, but the hassle/gain ratio is minuscule.
- Allow calling all the assignment operators in all consumable states.
This codifies that it's okay to overwrite a moved-from NonnullRefPtr.
This needs more work and polish, but it's a step in a more pleasant and
useful direction.
Also turn QuickShow into a fully-fledged "application". (By that, I really
just mean giving it its own Applications/ subdirectory.)
Painter gains the ability to draw lines with arbitrary thickness.
It's basically implemented by drawing filled rects for thickness>1.
In PaintBrush, Tool classes can now override on_contextmenu() to
provide a context menu for the toolbox button. :^)
Left mouse button selects (and copies the selection on mouse up).
The right mouse button then pastes whatever's on the clipboard. I always
liked this behavior in PuTTY, so now we have it here as well :^)
Implemented this by letting GAbstractViews provide a GModelEditingDelegate
for a given index, which then knows how to create and setup a custom widget
appropriate for the data type being edited.
When we had some data already in the CIODevice buffer, we should make sure
we always return that data, even if the attempt to ::read() even more data
fails. This was causing us to lose partial HTTP payloads.
