this extraction allowed easier multiplatform implementation,
even thought other platform such as QNX are not a functional
target by Jack2, it would be beneficial to allow this abstraction
as the cost for upstream is minimal

Change-Id: I92760ed539b475e210bc877b335afdbb4a982a04
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

sample_move_d32u24_sS() converts into samples like 0x00****** but S32
format expects samples like 0x********. Therefore it will not use the
full volume range when also using sample_move_d32u24_sS() for S32.

Change-Id: I4afe9bd0c3b342975536f5f98fa4dadd2eaee02d
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

* Upgrade GitHub Actions

* https://github.com/actions/cache/releases
* https://github.com/actions/checkout/releases
* https://github.com/actions/upload-artifact/releases

* Upgrade GitHub Actions

Signed-off-by: falkTX <falktx@falktx.com>

The 'U' mode bit is removed in python 3.11. It has been
deprecated for a long time. The 'U' mode bit has no effect
so this change doesn't change any behavior.

See https://docs.python.org/3.11/whatsnew/3.11.html#changes-in-the-python-api

* fix ringbuffer thread safety on ARM. fix #715 #388

This patch addresses the thread safety problem of `jack_ringbuffer_t`
mentioned in #715 and #388. The overbound read bug caused by this problem
is impossible to reproduce on x86 due to its strong memory ordering, but
it is a problem on ARM and other weakly ordered architectures.

Basically, the main problem is that, on a weakly ordered architecture,
it is possible that the pointer increment after `memcpy` becomes visible
to the other thread before `memcpy` finishes:

	memcpy (&(rb->buf[rb->write_ptr]), src, n1);
	// vvv can be visible to reading thread before memcpy finishes
	rb->write_ptr = (rb->write_ptr + n1) & rb->size_mask;

If this happens, the other thread can read the remaining garbage values
in `rb->buf` due to be overwritten by the unfinished `memcpy`.

To fix this, an explicit pair of release/acquire memory fences [1] is
used to ensure the copy on the other thread *happens after* the `memcpy`
finishes so no garbage values can be read.

[1]: https://preshing.com/20130922/acquire-and-release-fences/

* remove volatile qualifier on ringbuf r/w pointers

The volatile constraints are excess when compiler barriers are present.
It generates unnecessary `mov` instructions when pointers aren't going
to be updated.

* simplify read/write space calculations

This optimization is possible because the buffer size is always a power
of 2. See [1] for details.

[1]: https://github.com/drobilla/zix/pull/1#issuecomment-1212687196

* move acq fences to separate lines

In principle, major FreeBSD versions should be ABI compatible.
But in this case the python3 binary would only run on 13.1, not 13.0.

Signed-off-by: falkTX <falktx@falktx.com>

Reduce the base latencies for capture and playback by half a period,
and let the update method account for the additional playback latency
introduced by OSS buffer management.
This fits actual OSS latencies better, so the same settings for the
extra input-latency and output-latency parameters should apply to
different period lengths.

Beware that this change invalidates current input-latency and
output-latency values, they have to be measured again.

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Fixes #841

dbus/jack_control:
Remove unused imports for os and traceback.print_exc.
Fix indentation, whitespace and line length issues across the entire
file.
Simplify printing in `print_help()` by calling `print()` only once.

.github/workflows/lint.yml:
Ensure that flake8 in CI is run on all wscript files and on
jack_control.

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

* jack_control: move to tools for a while

* jack_control: shell mode command

This command runs loop, which executes commands from stdin until EOF
(Ctrl+D in terminal). Command status is printed to stdout.

* jack_control: optimize some functions

* jack_control: unused function

* jack_control: more informative message about dbus typesig error

* jack_control: Fix shell mode I/O

* restore jack_control path

* Add flake8 configuration

.flake8:
Add flake8 configuration that limits the line length to 120 chars and
outputs to flake8.txt

* Add flake8.txt to gitignore

.gitignore:
Add flake8.txt (flake8 output file) to ignore.

* Syntax fixes and cleanup for top-level wscript

wscript:
Fix syntax of wscript according to pep8 (but do not break long lines).
Remove unused imports and move all module level imports to the top of
the file.
Fix broken build target of IIO driver (source argument to
`create_driver_obj()` supplied an uninitialized variable).
Break lines at 120 chars.

* Fix common/wscript syntax

common/wscript:
Fix syntax problems, unneeded imports and break lines at 120 chars.

* Fix compat/alloca/wscript syntax

compat/alloca/wscript:
Fix compat/alloca/wscript syntax

* Fix compat/wscript syntax

compat/wscript:
Fix compat/wscript syntax

* Fix dbus/wscript syntax

dbus/wscript:
Fix syntax and break lintes at 120 chars.

* Fix example-clients/wscript syntax

example-clients/wscript:
Fix syntax and remove commented code.

* Fix tests/wscript syntax

tests/wscript:
Fix syntax and commented code.

* Fix tools/wscript syntax

tools/wscript:
Fix tools/wscript syntax.

* Add github workflow for linting wscripts

.github/workflows/lint.yml:
Add github workflow for linting wscripts using findutils and flake8.

* Fix project version extraction in CI

.github/workflows/build.yml:
Adapt the project version extraction in CI to the syntax changes in
the top-level wscript.

* JackWeakAPI: fix DLL loading on Windows

LoadLibrary takes a LPCWSTR (UTF16). LoadLibraryA is needed to
work with ASCII C string literals.

* JackWeakAPI: call tryload_libjack if it hasn't been called already

On non-Windows tryload_libjack is loaded on startup with
__attribute__((constructor)) but with MSVC, Microsoft documentation
says to not load libraries in a DLL's initialization function:
https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-best-practices

* JackWeakAPI: add debugging message for Windows

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>

Signed-off-by: falkTX <falktx@falktx.com>