Nagle's algorithm which tries to prevent small TCP frames is harmful
for our throughput if we send small echos.

Arithmetic means are inaccurate if the sample has extreme outliers
therefore we record and report the total execution times.

This is useful for my evaluation. Because with an output file I
just have to check if it exists to see if an echoclient execution was
successful.

Use getaddrinfo instead to get the socket information instead of
using always ipv4 sockets.
Pass host and port as strings for use with getaddrinfo.

Start client Fibers in batches to make sure we don't exceed the server's
TCP listen backlog.

Florian Fischer authored 4 years ago and Florian Schmaus committed 4 years ago

Modified-by: Florian Schmaus <flow@cs.fau.de>

The echo client established X connections and start the
echo phase after all sockets are connected.

Each client Fiber measures the time from sending the message until
receiving the echo.

We are unable to switch to C++20 until
https://github.com/mesonbuild/meson/issues/8084 is fixed.

This also solves a dependency declaration issue in WorkerSleepExample:
Prior to this change, a clean build could potentially result in

ninja  -C build
ninja: Entering directory `build'
[13/57] Compiling C++ object apps/worker_sleep_example.p/WorkerSleepExample.cpp.o
FAILED: apps/worker_sleep_example.p/WorkerSleepExample.cpp.o
ccache c++ -Iapps/worker_sleep_example.p -Iapps -I../apps -Iemper -I../emper -Iemper/include -I../emper/include -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -Wextra -Wpedantic -Werror -std=c++17 -O2 -g -Wno-non-virtual-dtor -MD -MQ apps/worker_sleep_example.p/WorkerSleepExample.cpp.o -MF apps/worker_sleep_example.p/WorkerSleepExample.cpp.o.d -o apps/worker_sleep_example.p/WorkerSleepExample.cpp.o -c ../apps/WorkerSleepExample.cpp
../apps/WorkerSleepExample.cpp:12:10: fatal error: emper-version.h: No such file or directory
   12 | #include "emper-version.h"        // for EMPER_FULL_VERSION
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
[17/57] Generating emper-version.h with a custom command
ninja: build stopped: subcommand failed.
make: *** [Makefile:23: build] Error 1

because worker_sleep_example_exec should have also depend on
emper_version_h. However this is obviously error prone, as users
easily forget to add this dependency. Instead we add
emper::getFullVersion() which is part of the EMPER shared object (not
just of a single header).

In debug builds, the schedule() method is now guarded by an assert(),
as due to this change, the schedule() method will no longer work from
everywhere.

This also improves the worker sleep method.

build your sleezy EMPER version by using for example

cmake -DCMAKE_BUILD_TYPE=release -DEMPER_WORKER_SLEEP=ON ..