Only booleans are supported at first. More types can be added easily.
Use this to add /proc/sys/wm_flash_flush which when enabled flashes pending
screen flush rects in yellow before they happen.
Userspace programs can now open /dev/gui_events and read a stream of GUI_Event
structs one at a time.
I was stuck on a stupid problem where we'd reenter Scheduler::yield() due to
having one of the has_data_available_for_reading() implementations using locks.
This synchronous approach to inodes is silly, obviously. I need to rework
it so that the in-memory CoreInode object is the canonical inode, and then
we just need a sync() that flushes pending changes to disk.
I was surprised to find that dup()'ed fds don't share the close-on-exec flag.
That means it has to be stored separately from the FileDescriptor object.
Pass the file name in a stack-allocated buffer instead of using an AK::String
when iterating directories. This dramatically reduces the amount of cycles
spent traversing the filesystem.
This is dirty but pretty cool! If we have a pending, unmasked signal for
a process that's blocked inside the kernel, we set up alternate stacks
for that process and unblock it to execute the signal handler.
A slightly different return trampoline is used here: since we need to
get back into the kernel, a dedicated syscall is used (sys$sigreturn.)
This restores the TSS contents of the process to the state it was in
while we were originally blocking in the kernel.
NOTE: There's currently only one "kernel resume TSS" so signal nesting
definitely won't work.
