Now EMPER builds using the liburing wrap succeed because they no longer
include liburing/src which contains a custom syscall header.

[Makefile] Make static-analysis depend on iwyu

See merge request !240

[build] Emit a message if liburing subproject is used

See merge request !239

The ninja 'iwyu' target does not depend nor generates
compile_commands_wo_subprojects/compile_commands.json. Hence iwyu
would fail if the database is not yet generated or run with an
outdated compile_commands.json.

Instead of iwyu being added to STATIC_ANALYSIS_NINJA_TARGETS, we now
have the static-analysis make target depend on iwyu. This ensures that
compile_commands_wo_subprojects/compile_commands.json is generated or
updated (if required) before iwyu is run.p

[IO] add shutdown(3) support

See merge request !190

Consume liburing as meson wrap if native is not recent enough

See merge request !238

[Future] Also log 'res' in LOGD of setCompletion(int32_t res)

See merge request !237

[GlobalIoContext] Add CompleterSchedParam option

See merge request !236

Generate a new compile_commands database in compile_commands_wo_subprojects/
without the files in subprojects/.
This new compile_commands database is than consumed by iwyu and clang-tidy.

Co-Authored-By: Florian Schmaus <schmaus@cs.fau.de>
Suggested--By: Florian Schmaus <schmaus@cs.fau.de>

It can't hurt to provide more information in log messages, especially
'res' is a good candidate in this case.

[IoContext] Add missing error handling in submitPreparedSqesAndWait()

See merge request !235

[IoContext] Remove duplicate CQE_BATCH_COUNT delcaration and definition

See merge request !233

This adds an option to make the scheduling parameters of the completer
thread configurable via a meson option.

Within the

do { reapAndScheduleCompletions() } while (io_uring_submit() == -EBUSY)

loop, the return value of io_uring_submit could be a negative value other
than EBUSY. In that case, we did not DIE.

Looking at the SubmitActor, where we have a very similar loop, the
error handling is correct. This changes the error handling in
IoContext to match the one of SubmitActor, even though it has a little
bit more overhead.

[IO] Implement configurable "simple architecture"

See merge request !230

Introduce a new meson option io_single_uring which causes EMPER
to only use the GlobalIoContexts for all IO.

To submit SQEs to the io_uring SQ SubmitActor is used.

Futures can be in a new state where they are submitted to the SubmitActor
but not to the io_uring yet.
In this state isSubmitted && !isPrepared th Future must not be destroyed
to ensure this we yield when forgetting a Future until it is prepared
and thus it is safe to destroy it.

This commit contains no optimizations (no batching, no try non blocking
syscall first, ...)

Refacter GlobalIoContext.cpp:

* rename globalCompleter to completer
* make the completer loop non-static

Move all definitions from emper.hpp in compilation unit

See merge request !232

Move emper::sleep() implemention from header in compilation unit

See merge request !231

[AbstractWorkStealingScheduler] Get rid of "rand() % workerCount"

See merge request !229

The "rand() % workerCount" constructed used in the work-stealing
scheduler is flawed. It has a bias toward lower worker IDs due the
modulo operation. This is something I always wanted to get rid of, but
never found the time to do it. Until know.

Get rid of it and replace it with
std::uniform_int_distribution<workerid_t> (as field the Worker
instance).

The main changes in AbstractWorkStealingScheduler are
- use currentWorker->nextRandomWorkerId() (instead of the flawed construct)
- currentWorker->getWorkerId() (instead of Runtime::getWorkerId())

[stats] blocked contexts

See merge request !224

Support distributing multiple echoclient over the network

See merge request !228

The Coordinator is used for our echo evaluation and implements
a barrier style synchronization mechanism for processes spread across the network.

[meson] allow building EMPER on systems whithout <filesystem>

See merge request !221

Add meson option for "check anywhere queue while stealing"

See merge request !207