text: // Copyright (c) 2015 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "checkqueue.h"
  #include "bench.h"
  #include "prevector.h"
  #include "random.h"
  #include "util.h"
  #include "validation.h"
  
  #include <boost/thread/thread.hpp>
  
  #include <vector>
  
  static const int MIN_CORES = 2;
  static const size_t BATCHES = 101;
  static const size_t BATCH_SIZE = 30;
  static const int PREVECTOR_SIZE = 28;
  static const size_t QUEUE_BATCH_SIZE = 128;
  
  // This Benchmark tests the CheckQueue with a slightly realistic workload, where
  // checks all contain a prevector that is indirect 50% of the time and there is
  // a little bit of work done between calls to Add.
  static void CCheckQueueSpeedPrevectorJob(benchmark::State &state) {
      struct PrevectorJob {
          prevector<PREVECTOR_SIZE, uint8_t> p;
          PrevectorJob() {}
          explicit PrevectorJob(FastRandomContext &insecure_rand) {
              p.resize(insecure_rand.randrange(PREVECTOR_SIZE * 2));
          }
          bool operator()() { return true; }
          void swap(PrevectorJob &x) { p.swap(x.p); };
      };
      CCheckQueue<PrevectorJob> queue{QUEUE_BATCH_SIZE};
      boost::thread_group tg;
      for (auto x = 0; x < std::max(MIN_CORES, GetNumCores()); ++x) {
          tg.create_thread([&] { queue.Thread(); });
      }
      while (state.KeepRunning()) {
          // Make insecure_rand here so that each iteration is identical.
          FastRandomContext insecure_rand(true);
          CCheckQueueControl<PrevectorJob> control(&queue);
          std::vector<std::vector<PrevectorJob>> vBatches(BATCHES);
          for (auto &vChecks : vBatches) {
              vChecks.reserve(BATCH_SIZE);
              for (size_t x = 0; x < BATCH_SIZE; ++x)
                  vChecks.emplace_back(insecure_rand);
              control.Add(vChecks);
          }
          // control waits for completion by RAII, but it is done explicitly here
          // for clarity
          control.Wait();
      }
      tg.interrupt_all();
      tg.join_all();
  }
  BENCHMARK(CCheckQueueSpeedPrevectorJob, 1400);
  