#include <latch.h>

#include <chrono>
#include <thread>
#include <vector>

#include <cassert>
#include <cstdio>

constexpr unsigned kNumThreads = 16;

int main() {
  latch gate(kNumThreads);

  std::vector<std::thread> threads;
  threads.reserve(kNumThreads);

  for (unsigned t = 0; t < kNumThreads; ++t) {
    threads.emplace_back([&gate, t]() {
      if (t % 2 == 0) {
        unsigned sec = t / 2;
        std::printf("th%02u sleep %us\n", t, sec);
        std::this_thread::sleep_for(std::chrono::seconds(sec));
      }

      std::printf("th%02u at gate\n", t);
      gate.arrive_and_wait();
      std::printf("th%02u finished\n", t);
    });
  }

  for (auto& th : threads) {
    th.join();
  }

  return 0;
}