Current context saving was very hacky and dependant on compiler
behaviour that was not consistent. Now we always use iret for
context saving. This makes everything more clean.
Scheduler now has its own data SchedulerQueue which holds active nad
blocking thread lists. This removes need for BAN/Errors.h and making
current thread separate element instead of iterator into linked list.
This makes it possible to have current_thread on each processor
instead of a global one in Scheduler.
This function was used when processes could die at any point in time.
Now that processes can only die in known spots, we can be sure they
are not holding any locks. This allows much more performant locking.
When we want to kill a process, we mark its threads as Terminating
or Terminated. If the thread is in critical section that has to be
finished, it will be in Terminating state until done. Once Scheduler
is trying to execute Terminated thread it will instead delete it.
Once processes last thread is marked Terminated, the processes will
turn it into a cleanup thread, that will allow blocks and memory
cleanup to be done.
This can be called from anywhere and just causes the scheduler to
schedule the next thread. This is more efficient and verbose version
of Scheduler::set_current_thread_sleeping(0), since we don't have
to wake other threads or do other verifications.
MMU is can now be locked with RecursiveSpinLock.
Scheduler now has get_current_tid() that works before the Scheduler
is initialized. This allows RecursiveSpinLock usage early on.
Also only process can now add threads to scheduler. Nobody should
have raw access to scheduler and everything should be through
Process::current() or irqs (reschedules)
Now after each interrupt we will ask the scheduler to reschedule
if the current thread is the idle thread. This allows semaphore
unblocking to be practically instant when there is only one thread
executing.
Now disk reading is back to ~3 MB/s for single threaded process
We can now use arbitary BAN::function<void(...)> as the Thread.
I also implemented multithreading for i386 since it was not done
on the initial multithreading commit.
This still uses only a single cpu, but we can now have 'parallelization'
This seems to work fine in qemu and bochs, but my own computer did not
like this when I last tried.
I have absolutely no idea how multithreading should actually be
implmemented and I just thought and implemented the most simple one I
could think of. This might not be in any way correct :D
Bananymous
Bananymous