After reading a bunch of POSIX specs, I've learned that a file descriptor
is the number that refers to a file description, not the description itself.
So this patch renames FileDescriptor to FileDescription, and Process now has
FileDescription* file_description(int fd).
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 doesn't mean we get any line editing just yet. But the keyboard device
now recognizes the backspace key, and the console device knows what to do
with the backspace characters.
The SpinLock was all backwards and didn't actually work. Fixing it exposed
how wrong most of the locking here is.
I need to come up with a better granularity here.
FileHandle gets a hasDataAvailableForRead() getter.
If this returns true in sys$read(), the task will block(BlockedRead) + yield.
The fd blocked on is stored in Task::m_fdBlockedOnRead.
The scheduler then looks at the state of that fd during the unblock phase.
This makes "sh" restful. :^)
There's still some problem with the kernel not surviving the colonel task
getting scheduled. I need to figure that out and fix it.
- More work on funneling console output through Console.
- init() now breaks off into a separate task ASAP.
- ..this leaves the "colonel" task as a simple hlt idle loop.
- Mask all IRQs on startup (except IRQ2 for slave passthru)
- Fix underallocation bug in Task::allocateRegion().
- Remember how many times each Task has been scheduled.
The panel and scheduling banner are disabled until I get things
working nicely in the (brave) new Console world.
