Meson does only emit a warning if unknown options are passed. In our
case, this is always something we should take care of, because an
option we assumed we configured, had no effect.

See also https://github.com/mesonbuild/meson/pull/8658

[EchClient] calculate and output experiment totals

See merge request i4/manycore/emper!171

This makes looking at individual experiment results and identifying
outliers easier.

[EchoClient] overhaul the EchoClient.cpp

See merge request i4/manycore/emper!165

Split output between two ini sections: global, clients.
The global section includes results like:
Arguments, total time spent in each phase, ...

The clients section contains a sigle key 'csv' containing the csv data
from each client inclufing the header:
iterations, latency, reconnects, unexpected echos

This leaves the post processing of the data to another program
and does not hide experiment behavior (e.g. starvation of single
clients) behind averages.

Remove support for appending to an output file, because we do not
use it in our emper-io-evaluation and it does not work anymore with the
new output format.

[Future] improve cancellation

Closes #16

See merge request i4/manycore/emper!170

* Unconditionally reconnect when the TCP connection was reset and count the reconnects
* Send Client id and iteration in each echo
* Use a Client class holding a clients state instead of a pthread style clientFunc
* Create the Client object in the client Fiber to use NUMA first-touch policy
* Reduce code duplication:
  * starting a new Client is now done with Client::startNew
  * latency measurement and error handling are moved from the clientIteration*
    functions in the Client::run function

* Improve warn message in Future::cancel()
* Don't cancel a Future in the destructor if it was already cancelled or received
* Restructure CancelFutureTest into single separate test cases

With this I can not reproduce the weird CancelFutureTest behavior anymore
neither SIGABRT nor the timeout.

Add WorkerLocalData and use it for stats

See merge request i4/manycore/emper!158

For some reason, my IWYU wants this include to be removed.

Minor fixes

See merge request i4/manycore/emper!169

[LawsScheduler] Delete stray #define EMPER_OVERFLOW_QUEUE

See merge request i4/manycore/emper!168

[check-iwyu] Do not fail right away if IWYU_TOOL fails

See merge request i4/manycore/emper!167

Since only newer versions of IWYU_TOOL fail with an exit code, we have
to disable -e around the IWYU_TOOL invocation. Otherwise we would not
print IWYU_LOG.

[gitlab-ci] Update flowdalic/debian-testing-dev to 1.8

See merge request i4/manycore/emper!162

[iwyu] Take load average into consideration on CI

See merge request i4/manycore/emper!151

[IO] fix IoCompleterBehavior::none

See merge request i4/manycore/emper!161

[gitlab-ci] Fix test-with-stats

See merge request i4/manycore/emper!159

[io/Future] take a const reference of the Future::Callback

See merge request i4/manycore/emper!163

Currently we always resubmit a possible partial completed Future in
the globalIo context.
This is not possible any more when we don't have a running completer.
Therefore we must resubmit on a worker's IoContext.

Furthermore we now select the callerEnvironment at Runtime because
I can not remember the reason why I choose to always resubmit
on the GlobalIoContext.

The EMPER option Meson option for stats is called 'stats' not
'worker_stats'.

This required that we backport iwyu_tool.py from
https://github.com/include-what-you-use/include-what-you-use/pull/891
into tools/, which supports --load.

Only create, initiateTermination and waitUntilFinished if the
completer thread is actually used.

Fix race condition in io::Stats

See merge request !160

The workerStats std::vector was modified concurrently without being
synchronized. The Stats are constructed together with IoContext and
the worker IoContexts are constructed concurrently at the beginning of
the worker loop. And in the Stats constructor the workerStats
std::vector was modified by adding the Stats instance that is
currently being constructed to it.

Turns out, we don't need the workerStats data structure at all. We
simply provide the global and worker IoContexts to
io::Stats::printStats(). This results IMHO in a cleaner design of
printStats() since there is no longer a data structure called
workerStats, that in fact, not only holds the worker's stats. And
while we at it, we rename io::Stats::printWorkerStats() to
io::Stats::printsStats(), since it does, in fact, not only print the
worker stats, but more or less all related worker stats.

[EchoClient] collect the total amount of unexpected echos

See merge request !157

My first test runs don't show unexpected echos. Therefore I think
unexpected echos are rare and their average will always be 0 even if
some sparse unexpected echos occur.

[EchoClient] changes to easier debug our IO evaluation artifact

See merge request !156