when_all.cpp

Simple WhenAll examples.

Simple WhenAll examples

/**
 * \example when_all.cpp
 * Simple WhenAll examples
 */
#include <yaclib/async/run.hpp>
#include <yaclib/async/when_all.hpp>
#include <yaclib/runtime/fair_thread_pool.hpp>
#include <yaclib/util/intrusive_ptr.hpp>
#include <yaclib/util/result.hpp>
 
#include <chrono>
#include <iostream>
#include <type_traits>
#include <utility>
#include <vector>
 
#include <gtest/gtest.h>
 
namespace test {
namespace {
 
using namespace std::chrono_literals;
 
// All combinator:
// std::vector<Future<T>> -> Future<std::vector<T>>
 
TEST(Example, WhenAll) {
  yaclib::FairThreadPool tp{4};
 
  std::vector<yaclib::FutureOn<int>> futs;
 
  // Run sync computations in parallel
 
  futs.reserve(5);
  for (int i = 0; i < 5; ++i) {
    futs.push_back(yaclib::Run(tp, [i]() -> int {
      return i;
    }));
  }
 
  // Parallel composition
  // All combinator: std::vector<Future<T>> -> Future<std::vector<T>>
  // Non-blocking!
  yaclib::Future<std::vector<int>> all = WhenAll(futs.begin(), futs.size());
 
  // Blocks
  std::vector<int> ints = std::move(all).Get().Ok();
 
  std::cout << "All ints: ";
  for (auto v : ints) {
    std::cout << v << ", ";
  }
  std::cout << std::endl;
  tp.Stop();
  tp.Wait();
}
 
}  // namespace
}  // namespace test