Before, if we couldn't read enough data out of the buffer, we would re-
fill the buffer and recursively call read(), which in turn reads data
from the buffer into the resliced target span. This incurs very
intensive superflous memmove's when large chunks of data are read from
a buffered stream.
This commit changes the behavior so that when we exhaust the buffer, we
first read any necessary additional data directly into the target, then
fill up the buffer again. Effectively, this results in drastically
reduced overhead from Buffered when reading large contiguous chunks.
Of course, Buffered is designed to speed up data access patterns with
small frequent reads, but it's nice to be able to combine both access
patterns on one stream without penalties either way.
The final performance gain is about an additional 80% of abench decoding
speed.
This unbreaks the /var/run/utmp system which starts out as an empty
string, and is then turned into an object by the first update.
This isn't necessarily the best way for this to work, but it's how
it used to work, so this just fixes the regression for now.
This abstracts a vector of Cell* with a strongly typed span() accessor
that gives you Span<T*> instead of Span<Cell*>.
It is intended to replace MarkedValueList in situations where you only
need to store pointers to Cell (or an even more specific type of Cell).
The API can definitely be improved, it's just the bare basics for now.
We used to build with -Os in order to fit within a certain size, but
there isn't really a good reason for that kind of restriction.
Switching to -O2 yields a significant improvement in throughput,
for example `test-js` is roughly 20% faster on my machine. :^)
If we pass `-lgcc_s` explicitly to the linker, it will be added as a
dependency even if no functions are used from it. This behavior is not
consistent with other systems. GCC can already handle passing the
correct flags, so let's rely on that instead.
As an added benefit, we now get support for the `-static-libgcc` flag;
and `-static-pie` will no longer mistakenly link us against the dynamic
version of libgcc.
No toolchain rebuild is required.
The Serenity Stream API is the name for the new set of classes intended
to replace IODevice and its descendants. It provides more flexibility
for subclasses by allowing each subclass to override all the possible
functionalities according to their wishes.
Stream is the base class which implements majority of the functionality
expected from a readable and writable stream. SeekableStream adds
seeking on top, and provides a couple utility methods which derive from
seek. Socket adds a couple of BSD socket utility functions such as
checking whether there is data available to read and checking the
pending bytes on the socket.
As for the concrete classes, there is File which is a SeekableStream and
is intended to operate on file-like objects; and TCPSocket, UDPSocket
and LocalSocket, which handle TCP, UDP and UNIX sockets respectively.
The concrete classes do not do buffering by default. For buffering
functionality, a set of augmentative classes named BufferedSeekable and
BufferedSocket have been implemented, intended to wrap a SeekableStream
and a Socket, respectively.
This fixes at least half of our LibC includes in the kernel. The source
of truth for errno codes and their description strings now lives in
Kernel/API/POSIX/errno.h as an enumeration, which LibC includes.
Before this commit, we only checked the receive buffer on the socket,
which is unused on datagram streams. Now we return the actual size of
the datagram without the protocol headers, which required the protocol
to tell us what the size of the payload is.
This syscall is very much similar to open(2), with the difference of
accepting a string and a length, instead of requiring a null-terminated
string. This way, if the string passed is not null-terminated, we can
still perform the syscall.
