This moves locking to the inodes themselves which allows reducing lock
times significantly. Main inodes (ext2 and tmpfs) still do contain a
single big mutex that gets locked during operations but now we have the
architecture to optimize these.
Enter key now produces expected \r which gets converted to \n by default
by the ICRNL input flag.
Also input flags are now handled always, not just when ICANON is set.
I don't know why I though ICANON should disable input handling
Kernel can just use raw threads, pretty muchs the only thing that
process provides is syscalls which kernel threads of course don't
need.
Also this makes init process have pid 1 :D
Userspace can freely set terminal size, kernel just updates it when for
example new font is loaded. Also SIGWINCH is now sent by kernel instead
of userspace.
All block functions now take an optional mutex parameter that is
atomically unlocked instead of having the user unlock it before hand.
This prevents a ton of race conditions everywhere in the code!
This implementation is on top of inodes instead of fds as linux does it.
If I start finding ports/software that relies on epoll allowing
duplicate inodes, I will do what linux does.
I'm probably missing multiple epoll_notify's which may cause hangs but
the system seems to work fine :dd:
If pseudo terminal buffer was filled, old implementation would overwrite
old data. This is bad if producer is capable of producing more data than
consumer can handle.
kernel now passes the name of default console to init process so init
knows which file to open as stdio. before /dev/tty was referencing the
system wide current terminal which was inherited from cmdline. This
doesn't work anymore as we have pseudo terminals implemented that can
chage the current terminal during runtime :D
This patch implements posix_openpt() and ptsname()
grantpt() and unlockpt() are left in LibC as stubs, as posix_openpt
currently does all of the needed work.
Change Semaphore -> ThreadBlocker
This was not a semaphore, I just named it one because I didn't know
what semaphore was. I have meant to change this sooner, but it was in
no way urgent :D
Implement SMP events. Processors can now be sent SMP events through
IPIs. SMP events can be sent either to a single processor or broadcasted
to every processor.
PageTable::{map_page,map_range,unmap_page,unmap_range}() now send SMP
event to invalidate TLB caches for the changed pages.
Scheduler no longer uses a global run queue. Each processor has its own
scheduler that keeps track of the load on the processor. Once every
second schedulers do load balancing. Schedulers have no access to other
processors' schedulers, they just see approximate loads. If scheduler
decides that it has too much load, it will send a thread to another
processor through a SMP event.
Schedulers are currently run using the timer interrupt on BSB. This
should be not the case, and each processor should use its LAPIC timer
for interrupts. There is no reason to broadcast SMP event to all
processors when BSB gets timer interrupt.
Old scheduler only achieved 20% idle load on qemu. That was probably a
very inefficient implementation. This new scheduler seems to average
around 1% idle load. This is much closer to what I would expect. On my
own laptop idle load seems to be only around 0.5% on each processor.
/dev/keyboard and /dev/mouse can be read for events from any attached
keyboard or mouse respectively. This makes device hot-plugging support
pretty much automatic for TTY, GUI, and whatever takes input.
PS/2 code is now kind of messed up, but it works. Keyboards and mice are
now an abstract class that is automatically exposed to userspace. This
will make adding USB input much nicer.
Keycodes are easier to handle as you need only one keyboard layout
for keycodes. Otherwise you would need to implement keyboard layout
for every keyboard driver in every language.
Signal handling code was way too complex. Now everything is
simplified and there is no need for ThreadBlockers.
Only complication that this patch includes is that blocking syscalls
have to manually be made interruptable by signal. There might be some
clever solution to combat this is make this happen automatically.
