text: #include "catch.hpp"
  
  #include <chrono>
  #include <stdexcept>
  #include <thread>
  
  #include <osmium/thread/pool.hpp>
  #include <osmium/util/compatibility.hpp>
  
  struct test_job_with_result {
      int operator()() const {
          return 42;
      }
  };
  
  struct test_job_throw {
      OSMIUM_NORETURN void operator()() const {
          throw std::runtime_error("exception in pool thread");
      }
  };
  
  TEST_CASE("number of threads in pool") {
  
      // hardcoded setting
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 1,  0,  2) ==  1);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 4,  0,  2) ==  4);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 4,  0,  4) ==  4);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(16,  0,  4) == 16);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(16,  0, 16) == 16);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 8,  4,  2) ==  8);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 8, 16,  2) ==  8);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(-2, 16,  2) ==  1);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(-2, 16,  8) ==  6);
  
      // user decides through OSMIUM_POOL_THREADS env variable
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  0,  2) ==  1);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0, -2,  4) ==  2);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0, -1,  8) ==  7);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  0, 16) == 14);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  1, 16) ==  1);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  2, 16) ==  2);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  4, 16) ==  4);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size( 0,  8, 16) ==  8);
  
      // outliers
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(-100, 0, 16) ==   1);
      REQUIRE(osrm_osmium::thread::detail::get_pool_size(1000, 0, 16) == 256);
  
  }
  
  TEST_CASE("thread") {
  
      auto& pool = osrm_osmium::thread::Pool::instance();
  
      SECTION("can get access to thread pool") {
          REQUIRE(pool.queue_empty());
      }
  
      SECTION("can send job to thread pool") {
          auto future = pool.submit(test_job_with_result {});
  
          REQUIRE(future.get() == 42);
      }
  
      SECTION("can throw from job in thread pool") {
          auto future = pool.submit(test_job_throw {});
  
          REQUIRE_THROWS_AS(future.get(), std::runtime_error);
      }
  
  }
  
  