These widgets can only display a single column from the underlying data
model, and it was previously hard-coded to use column 0. Now you can
use any column you like.
This ensures the pipe fds don't leak into child processes.
This manifested as the Shell (and all processes started
from the shell) having two mysterious FIFOs open. This
was happening because of the Terminal, which the shell
was spawned form, leaking its CEventLoop wake pipe fds.
In the userspace, this mimics the Linux pipe2() syscall;
in the kernel, the Process::sys$pipe() now always accepts
a flags argument, the no-argument pipe() syscall is now a
userspace wrapper over pipe2().
Instead of generating ByteBuffers and keeping those lying around, have
these filesystems generate KBuffers instead. These are way less spooky
to leave around for a while.
Since FileDescription will keep a generated file buffer around until
userspace has read the whole thing, this prevents trivially exhausting
the kmalloc heap by opening many files in /proc for example.
The code responsible for generating each /proc file is not perfectly
efficient and many of them still use ByteBuffers internally but they
at least go away when we return now. :^)
A KBuffer always contains a valid KBufferImpl. If you need a "null"
state buffer, use Optional<KBuffer>.
This makes KBuffer very easy to work with and pass around, just like
ByteBuffer before it.
There's no need for send_ipv4() to take a ByteBuffer&&, the data is
immediately cooked into a packet and transmitted. Instead, just pass
it the address+length of whatever buffer we've been using locally.
The more we can reduce the pressure on kmalloc the better. :^)
The situations in IPv4Socket and LocalSocket were mirrors of each other
where one had implemented read/write as wrappers and the other had
sendto/recvfrom as wrappers.
Instead of this silliness, move read and write up to the Socket base.
Then mark them final, so subclasses have no choice but to implement
sendto and recvfrom.
This has a known bug in that you can't specify a negative size value.
This bug stems from the argument parser, and once it's fixed there,
everything should work here.
This memory is not accessible to userspace and comes from the kernel
page allocator, not from the kmalloc heap. This makes it ideal for
larger allocations.
This is a very basic mbedtls port. I've disabled the networking bits,
since they want some macros that we don't have defined. We might not even
want the networking functions anyway, since they wouldn't play very nice
with CEventLoop and friends.
Keep a 256-entry string cache during parse to avoid creating some new
strings when possible. This cache is far from perfect but very cheap.
Since none of the strings are transient, this only costs us a couple of
pointers and a bit of ref-count manipulation.
The cache hit rate on 4chan_catalog.json is ~33% and the speedup on
the load_4chan_catalog benchmark is ~7%.
I was able to get parsing time down to about 1/3 of the original time
by using callgrind+kcachegrind. There's definitely more improvements
that can be made here, but I'm gonna be happy with this for now. :^)
- Return more specific types from parse_array() and parse_object().
- Don't create a throwaway String in extract_while().
- Use a StringView in parse_number() to avoid a throwaway String.
This is a shameless copy-paste of String::to_int(). We should find some
way to share this code between String and StringView instead of having
two duplicate copies like this.
