This new class with an admittedly long OOP-y name provides a circular
queue in shared memory. The queue is a lock-free synchronous queue
implemented with atomics, and its implementation is significantly
simplified by only accounting for one producer (and multiple consumers).
It is intended to be used as a producer-consumer communication
datastructure across processes. The original motivation behind this
class is efficient short-period transfer of audio data in userspace.
This class includes formal proofs of several correctness properties of
the main queue operations `enqueue` and `dequeue`. These proofs are not
100% complete in their existing form as the invariants they depend on
are "handwaved". This seems fine to me right now, as any proof is better
than no proof :^). Anyways, the proofs should build confidence that the
implemented algorithms, which are only roughly based on existing work,
operate correctly in even the worst-case concurrency scenarios.
AnonymousFile always allocates in multiples of a page size when created
with anon_create. This is especially an issue if we use AnonymousFile
shared memory to store a shared data structure that isn't exactly a
multiple of a page in size. Therefore, we can just allow mmaps of
AnonymousFile to map only an initial part of the shared memory.
This makes SharedSingleProducerCircularQueue work when it's introduced
later.
SystemServer had safety fallbacks to boot into text mode if the user
errorneously specified graphical mode but no video hardware was present.
As it's now possible to do exactly this intentionally, we should allow
it. This would of course make WindowServer fall over and die if
configured improperly, but if you're messing with the kernel command
line in strange ways, you should be able to fix that.
This screen backend is just memory-backed and doesn't connect to any
screen hardware. That way, we can boot Serenity without video hardware
but in full graphical mode :^)
To create a virtual screen, put something like this in your
WindowServer.ini. There's no way yet to do this through Display
Settings, though an existing virtual screen's settings can be changed
there.
```ini
[Screen0]
Mode=Virtual
Left=1024
Top=0
Width=1920
Height=1080
ScaleFactor=1
```
This will allow us to change between a couple of properties, for now
it's only Device and Virtual. (How about Remote :^) ) These get handled
by a different screen backend in the Screen.
The ScreenBackend is a thin wrapper around the actual screen hardware
connection. It contains all the variables specific to that hardware and
abstracts away operations that deal with controlling the hardware. The
standard ScreenBackend implementor is HardwareScreenBackend, which
contains all the existing frame buffer & ioctl handling code of Screen.
I took this opportunity to introduce ErrorOr wherever sensible.
This was very badly named. All that the "FBData" struct contains is the
currently to-be-flushed rectangles plus a fullness flag, so it should
better be called FlushRectData. This rename is similarly applied to all
variable names.
Previously netstat would print the whole line of an ip address or
resolved hostname. If the hostname was longer than the address column
length, it would push following columns into disaligned output.
This sets the default behavior to truncate any IP address or symbolic
hostname that is larger than the maximum address column size to provide
cleaner output. In the event the user wishes to see the whole address
name, they can then pass the wide option that will output as wide as
necessary to print the whole name.
This allows for calling this function with any argument type for which
the appropriate traits and operators have been implemented so it can be
compared to the Vector's item type
- Don't add multiple numbers to nested steps, just the innermost one
(as rendered in the HTML document)
- "Otherwise" comments go before the else, not after it
- "FIXME:" goes before step number, not between it and the comment text
- Always add a period between number and comment text
The majority of these were introduced in #13756, but some unrelated ones
have been updated as well.
In most cases it's safe to abort the requested operation and go forward,
however, in some places it's not clear yet how to handle these failures,
therefore, we use the MUST() wrapper to force a kernel panic for now.
Currently, navigating through different years in the Year view of the
Calendar app or the taskbar is very slow.
Profiling results show that almost all the time is spent in
`Calendar::update_tiles`, and specifically, in `DateTime::create` and
`DateTime::set_time`.
Performance can improve substantially if the `TZ` environment variable
is set [0], but we can improve the current code to perform better
nevertheless :^)
This diff focuses on removing the need of the `Tile` struct to require
the instantiation of a `DateTime` object, which avoids _at least_ 365
object instantiations in the Year view, on each `update_tiles` call.
Instead, as the `date_time` isn't used often, we can instantiate it on
demand when a particular date is selected.
[0] https://blog.packagecloud.io/set-environment-variable-save-thousands-of-system-calls/
This patch changes the previously used contains method for matching the
user search term with all available commands to use the fuzzy match
algorithm, which makes it more typo tolerant.
This patch adds a header containing the fuzzy match algorithm
previously used in Assistant. The algorithm was moved to AK
since there are many places where a search may benefit from fuzzyness.
This patch makes CommandPalette be closed whenever the focus shifts from
the dialog. It is closer to other non-serenity implementations of the
CommandPalette and other modal dialogs in the system.
I believe the issue was caused by the product of two u16s being promoted
to (signed) int, which can cause unwanted overflow behaviour when
comparing to size_t. Casting each term to size_t before the
multiplication makes the comparison unsigned.
According to the spec, these calls should be identical to an invocation
of `glVertex2*`, which sets the W-coordinate to 1 by default.
This fixes the credits sequence rendering of Tux Racer.
If a triangle edge is completely horizontal and moving in a positive X
direction, we were erroneously treating it as a top edge. This adds
a better check that accounts for those edges. :^)
By setting the clip plane normals' W coordinate to 1, we can skip two
coordinate retrievals and three additions. This works because the
Vector `.dot()` operation multiplies the W coordinates of both vectors.
We sat on a throne of lies: our `edge_function()` returned positive
values for _clockwise_ vertex rotation instead of _counter-clockwise_,
which was hidden by the fact that we were forcing everything into CW
rotation by an erroneous area comparison (`> 0` instead of `< 0`).
This simplifies our culling code significantly.
