boost_thread_overhead.cpp

#define C_AND_POSIX_SHELL_POLYGLOT /*
# This section gets interpreted by the POSIX shell.
# It is inside a C comment, so it gets ignored by the C compiler.

CFLAGS="-pthread -lboost_thread -O3"
NIXPKGS=boost172
TARGET=/tmp/a.out

exec nix-shell \
    --pure \
    --packages clang_12 ${NIXPKGS} \
    --command "echo Compiling && clang++ ${CFLAGS} ${0} -o ${TARGET} && echo Running && ${TARGET} ${@}"

# The exec ensures shell does not interpret beyond this point.
*/

#include <boost/thread.hpp>
#include <string>
#include <iostream>
#include <iomanip>

int main(int argc, const char* const* argv) {
	if (argc != 2) {
		std::cerr << "Usage: `" << argv[0] << " N`, where N is a positive integer" << std::endl;
		return 1;
	}
	uint64_t iterations = std::stoi(std::string{argv[1]});
	auto start = std::chrono::high_resolution_clock::now();
	for (volatile uint64_t i = 0; i < iterations; ++i) {
		boost::thread thread {[]{}};
		thread.join();
	}
	auto stop = std::chrono::high_resolution_clock::now();
	std::cout << std::setprecision(2) << double(std::chrono::duration_cast<std::chrono::microseconds>(stop - start).count()) / iterations << "us" << std::endl;
	return 0;
}

/*
This is a self-contained C source file.

All you need to do is run this at the shell, and it will find its own
dependencies (through Nix), compile itself, and run itself.

Usage:

    $ sudo apt install -y nix
    $ chmod +x boost_thread_overhead.cpp
    $
    $ # first argument is how many trials to do
    $ # It should take
    $ ./bost_thread_overhead.cpp 65536
    Compiling
    Runing
    25us
*/