Function-local `static constexpr` variables can be `constexpr`. This
can reduce memory consumption, binary size, and offer additional
compiler optimizations.
These changes result in a stripped x86_64 kernel binary size reduction
of 592 bytes.
This is not ASCII-betical because `_` comes after all the uppercase
characters. Treating `_` as a ` ` (space character), these lists are
now alphabetical.
The global variable use in these functions is super thread-unsafe and
means that any concurrent calls to sprintf or fprintf in a process
could race with each other and end up writing unexpected results.
We can just replace the function + global variable with a lambda that
captures the relevant argument when calling printf_internal instead.
Rename the bound socket accessor from socket() to bound_socket().
Also return RefPtr<LocalSocket> instead of a raw pointer, to make it
harder for callers to mess up.
Previously we would return a bytes written value of 0 if the writing end
of the socket was full. Now we either exit with EAGAIN if the socket
description is non-blocking, or block until the description can be
written to.
This is mostly a copy of the conditions in sys$write but with the "total
nwritten" parts removed as sys$sendmsg does not have that.
1. When receiving FIN while in FinWait1, we now reply with ACK
in addition to the FinWait1->Closing transition.
2. When receiving FIN|ACK while in FinWait1, we now reply with
ACK and transition from FinWait1->TimeWait.
3. When receiving FIN while in FinWait2, we now reply with ACK.
When GraphicsManagement initializes the drivers we can disable the
bootloader framebuffer console. Right now we don't yet fully destroy
the no longer needed console as it may be in use by another CPU.
Instead of seeing a black screen until GraphicsManagement was fully
initialized, this allows us to see the console output much earlier.
So, if the bootloader provided us with a framebuffer, set up a console
as early as possible.
The GenericFramebufferConsoleImpl class implements the logic without
taking into account any other details such as synchronization. The
GenericFramebufferConsole class then is a simple wrapper around
GenericFramebufferConsoleImpl that takes care of synchronization.
This allows us to re-use this implementation with e.g. different
synchronization schemes.
As make<T> is infallible, it really should not be used anywhere in the
Kernel. Instead replace with fallible `new (nothrow)` calls, that will
eventually be error-propagated.
A mutex is useful when we need to be able to block the current thread
until it's available. This is overkill for OpenFileDescriptor.
First off, this patch wraps the main state member variables inside a
SpinlockProtected<State> to enforce synchronized access. This also
avoids "free locking" where figuring out which variables are guarded
by which lock is left as an unamusing exercise for the reader.
Then we remove mutex locking from the functions that simply call through
to the underlying File or Inode, since those fields never change anyway,
and the target objects perform their own synchronization.
Add polling support to NVMe so that it does not use interrupt to
complete a IO but instead actively polls for completion. This probably
is not very efficient in terms of CPU usage but it does not use
interrupts to complete a IO which is beneficial at the moment as there
is no MSI(X) support and it can reduce the latency of an IO in a very
fast NVMe device.
The NVMeQueue class has been made the base class for NVMeInterruptQueue
and NVMePollQueue. The factory function `NVMeQueue::try_create` will
return the appropriate queue to the controller based on the polling
boot parameter.
The polling mode can be enabled by adding an extra boot parameter:
`nvme_poll`.
There is no use in calling disable_irq function in the IRQHandler
constructor if irq was not registered before. So add a condition where
we call disable_irq only if the irq was registered before.
As we don't currently support MSI(X) interrupts, it could be an issue
to boot on some newer hardware. NVMe devices support polling mode
where the driver actively polls for completion instead of waiting for
an interrupt.
When a page fault led to the mapping of a new physical page, we were
updating the page tables for *every* region that shared the same
underlying VMObject.
Let's just not do that, avoiding a bunch of unnecessary page table
updates and TLB invalidations.
Even if the PIC was disabled it can still generate noise (spurious IRQs)
so we need to register two handlers for handling such cases.
Also, we declare interrupt service routine offset 0x20 to 0x2f as
reserved, so when the PIC is disabled, we can handle spurious IRQs from
the PIC at separate handlers.
At the end of sys$execve(), we perform a context switch from the old
executable into the new executable.
However, the Kernel::Thread object we are switching to is the *same*
thread as the one we are switching from. So we must not assume the
from_thread and to_thread are different threads.
We had a bug caused by this misconception, where the "from" thread would
always get marked as "inactive" when switching to a new thread.
This meant that threads would always get switched into "inactive" mode
on first context switch into them.
If a thread then tried blocking on a kernel mutex within its first time
slice, we'd end up in Thread::block(Mutex&) with an inactive thread.
Once a thread is inactive, the scheduler believes it's okay to
reactivate the thread (by scheduling it.) If a thread got re-scheduled
prematurely while setting up a mutex block, things would fall apart and
we'd crash in Thread::block() due to the thread state being "Runnable"
instead of the expected "Running".
Move this architecture-specific sanity check (IOPL must be 0) out of
Scheduler and into the x86 enter_thread_context(). Also do this for
every thread and not just userspace ones.
