Previously, we were sending Buffers to the server whenever we had new
audio data for it. This meant that for every audio enqueue action, we
needed to create a new shared memory anonymous buffer, send that
buffer's file descriptor over IPC (+recfd on the other side) and then
map the buffer into the audio server's memory to be able to play it.
This was fine for sending large chunks of audio data, like when playing
existing audio files. However, in the future we want to move to
real-time audio in some applications like Piano. This means that the
size of buffers that are sent need to be very small, as just the size of
a buffer itself is part of the audio latency. If we were to try
real-time audio with the existing system, we would run into problems
really quickly. Dealing with a continuous stream of new anonymous files
like the current audio system is rather expensive, as we need Kernel
help in multiple places. Additionally, every enqueue incurs an IPC call,
which are not optimized for >1000 calls/second (which would be needed
for real-time audio with buffer sizes of ~40 samples). So a fundamental
change in how we handle audio sending in userspace is necessary.
This commit moves the audio sending system onto a shared single producer
circular queue (SSPCQ) (introduced with one of the previous commits).
This queue is intended to live in shared memory and be accessed by
multiple processes at the same time. It was specifically written to
support the audio sending case, so e.g. it only supports a single
producer (the audio client). Now, audio sending follows these general
steps:
- The audio client connects to the audio server.
- The audio client creates a SSPCQ in shared memory.
- The audio client sends the SSPCQ's file descriptor to the audio server
with the set_buffer() IPC call.
- The audio server receives the SSPCQ and maps it.
- The audio client signals start of playback with start_playback().
- At the same time:
- The audio client writes its audio data into the shared-memory queue.
- The audio server reads audio data from the shared-memory queue(s).
Both sides have additional before-queue/after-queue buffers, depending
on the exact application.
- Pausing playback is just an IPC call, nothing happens to the buffer
except that the server stops reading from it until playback is
resumed.
- Muting has nothing to do with whether audio data is read or not.
- When the connection closes, the queues are unmapped on both sides.
This should already improve audio playback performance in a bunch of
places.
Implementation & commit notes:
- Audio loaders don't create LegacyBuffers anymore. LegacyBuffer is kept
for WavLoader, see previous commit message.
- Most intra-process audio data passing is done with FixedArray<Sample>
or Vector<Sample>.
- Improvements to most audio-enqueuing applications. (If necessary I can
try to extract some of the aplay improvements.)
- New APIs on LibAudio/ClientConnection which allows non-realtime
applications to enqueue audio in big chunks like before.
- Removal of status APIs from the audio server connection for
information that can be directly obtained from the shared queue.
- Split the pause playback API into two APIs with more intuitive names.
I know this is a large commit, and you can kinda tell from the commit
message. It's basically impossible to break this up without hacks, so
please forgive me. These are some of the best changes to the audio
subsystem and I hope that that makes up for this :yaktangle: commit.
:yakring:
With the following change in how we send audio, the old Buffer type is
not really needed anymore. However, moving WavLoader to the new system
is a bit more involved and out of the scope of this PR. Therefore, we
need to keep Buffer around, but to make it clear that it's the old
buffer type which will be removed soon, we rename it to LegacyBuffer.
Most of the users will be gone after the next commit anyways.
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.
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 is to simplify the code, as Color, Alignment, Flag, Metric and Path
RoleModel classes looked exactly the same.
Additionally, I've added a try_create() function for error propagation.
:^)
Similar reasoning to making Core::Stream::read() return Bytes, except
that every user of read_line() creates a StringView from the result, so
let's just return one right away.
Instead of having the undo operation only be able to undo one cell
for a given undo, make it able to handle multiple cells at a time.
Please enter the commit message for your changes. Lines starting
This adds a value inspector window to the Hex Editor. This window shows
the data at the current cursor position (or selection start if a range
is selected) interpreted as a variety of data types.
Currently supported values include 8, 16, 32, and 64 bit signed and
unsigned values as well as float and double.
The inspector can operate in both little endian and big endian modes.
This is switched between by options in the View menu.
Having bogus values here when we just initialize the thread state with a
process can lead to all sorts of bad things down the line, like infinite
draws.
In the process model we check the thread with tid=pid to figure out the
main thread of a process. This is used to construct the process view
tree with non-main threads listed as children of the process row.
However, there are sometimes circumstances where there is no main
thread, even though the process should have been removed from the
internal list by then. As a safe fallback, let's default to an invalid
model index if we can't figure out what the main thread of a process is.
This was a mixin class that allowed sharing a set of hooks between
InProcessWebView and OutOfProcessWebView. Now that there is only OOPWV,
we don't need the mixin.
Previously, the paste action was always enabled and always assumed that
anything was selected, which led to a crash by clicking the paste action
right after the application startup.
This patch will automatically enable/disable the paste action depending
on whether a selection exists (it usually does, except on the app launch
and after adding a new tab) and if the clipboard mime type is a text/
group.
So no, you can't paste an image into the app anymore, even though this
mostly froze the app before...
This shows all non-main threads as children of the process they belong
to. We also show the TID as that is important to distinguish the
different threads in one process.
Fixes#65
:skeleyak:
When resizing the application, the pages are expected to grow or shrink
proportionally. This means that after a resize, we need to rerender
every page.
