text: // Copyright (c) 2018 The Libra Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <boost/test/unit_test.hpp>
  
  #include <chainparams.h>
  #include <consensus/merkle.h>
  #include <consensus/validation.h>
  #include <miner.h>
  #include <pow.h>
  #include <random.h>
  #include <test/test_libra.h>
  #include <validation.h>
  #include <validationinterface.h>
  
  struct RegtestingSetup : public TestingSetup {
      RegtestingSetup() : TestingSetup(CBaseChainParams::REGTEST) {}
  };
  
  BOOST_FIXTURE_TEST_SUITE(validation_block_tests, RegtestingSetup)
  
  struct TestSubscriber : public CValidationInterface {
      uint256 m_expected_tip;
  
      TestSubscriber(uint256 tip) : m_expected_tip(tip) {}
  
      void UpdatedBlockTip(const CBlockIndex* pindexNew, const CBlockIndex* pindexFork, bool fInitialDownload) override
      {
          BOOST_CHECK_EQUAL(m_expected_tip, pindexNew->GetBlockHash());
      }
  
      void BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex, const std::vector<CTransactionRef>& txnConflicted) override
      {
          BOOST_CHECK_EQUAL(m_expected_tip, block->hashPrevBlock);
          BOOST_CHECK_EQUAL(m_expected_tip, pindex->pprev->GetBlockHash());
  
          m_expected_tip = block->GetHash();
      }
  
      void BlockDisconnected(const std::shared_ptr<const CBlock>& block) override
      {
          BOOST_CHECK_EQUAL(m_expected_tip, block->GetHash());
  
          m_expected_tip = block->hashPrevBlock;
      }
  };
  
  std::shared_ptr<CBlock> Block(const uint256& prev_hash)
  {
      static int i = 0;
      static uint64_t time = Params().GenesisBlock().nTime;
  
      CScript pubKey;
      pubKey << i++ << OP_TRUE;
  
      auto ptemplate = BlockAssembler(Params()).CreateNewBlock(pubKey, false);
      auto pblock = std::make_shared<CBlock>(ptemplate->block);
      pblock->hashPrevBlock = prev_hash;
      pblock->nTime = ++time;
  
      CMutableTransaction txCoinbase(*pblock->vtx[0]);
      txCoinbase.vout.resize(1);
      txCoinbase.vin[0].scriptWitness.SetNull();
      pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
  
      return pblock;
  }
  
  std::shared_ptr<CBlock> FinalizeBlock(std::shared_ptr<CBlock> pblock)
  {
      pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
  
      while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
          ++(pblock->nNonce);
      }
  
      return pblock;
  }
  
  // construct a valid block
  const std::shared_ptr<const CBlock> GoodBlock(const uint256& prev_hash)
  {
      return FinalizeBlock(Block(prev_hash));
  }
  
  // construct an invalid block (but with a valid header)
  const std::shared_ptr<const CBlock> BadBlock(const uint256& prev_hash)
  {
      auto pblock = Block(prev_hash);
  
      CMutableTransaction coinbase_spend;
      coinbase_spend.vin.push_back(CTxIn(COutPoint(pblock->vtx[0]->GetHash(), 0), CScript(), 0));
      coinbase_spend.vout.push_back(pblock->vtx[0]->vout[0]);
  
      CTransactionRef tx = MakeTransactionRef(coinbase_spend);
      pblock->vtx.push_back(tx);
  
      auto ret = FinalizeBlock(pblock);
      return ret;
  }
  
  void BuildChain(const uint256& root, int height, const unsigned int invalid_rate, const unsigned int branch_rate, const unsigned int max_size, std::vector<std::shared_ptr<const CBlock>>& blocks)
  {
      if (height <= 0 || blocks.size() >= max_size) return;
  
      bool gen_invalid = GetRand(100) < invalid_rate;
      bool gen_fork = GetRand(100) < branch_rate;
  
      const std::shared_ptr<const CBlock> pblock = gen_invalid ? BadBlock(root) : GoodBlock(root);
      blocks.push_back(pblock);
      if (!gen_invalid) {
          BuildChain(pblock->GetHash(), height - 1, invalid_rate, branch_rate, max_size, blocks);
      }
  
      if (gen_fork) {
          blocks.push_back(GoodBlock(root));
          BuildChain(blocks.back()->GetHash(), height - 1, invalid_rate, branch_rate, max_size, blocks);
      }
  }
  
  BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering)
  {
      // build a large-ish chain that's likely to have some forks
      std::vector<std::shared_ptr<const CBlock>> blocks;
      while (blocks.size() < 50) {
          blocks.clear();
          BuildChain(Params().GenesisBlock().GetHash(), 100, 15, 10, 500, blocks);
      }
  
      bool ignored;
      CValidationState state;
      std::vector<CBlockHeader> headers;
      std::transform(blocks.begin(), blocks.end(), std::back_inserter(headers), [](std::shared_ptr<const CBlock> b) { return b->GetBlockHeader(); });
  
      // Process all the headers so we understand the toplogy of the chain
      BOOST_CHECK(ProcessNewBlockHeaders(headers, state, Params()));
  
      // Connect the genesis block and drain any outstanding events
      ProcessNewBlock(Params(), std::make_shared<CBlock>(Params().GenesisBlock()), true, &ignored);
      SyncWithValidationInterfaceQueue();
  
      // subscribe to events (this subscriber will validate event ordering)
      const CBlockIndex* initial_tip = nullptr;
      {
          LOCK(cs_main);
          initial_tip = chainActive.Tip();
      }
      TestSubscriber sub(initial_tip->GetBlockHash());
      RegisterValidationInterface(&sub);
  
      // create a bunch of threads that repeatedly process a block generated above at random
      // this will create parallelism and randomness inside validation - the ValidationInterface
      // will subscribe to events generated during block validation and assert on ordering invariance
      boost::thread_group threads;
      for (int i = 0; i < 10; i++) {
          threads.create_thread([&blocks]() {
              bool ignored;
              for (int i = 0; i < 1000; i++) {
                  auto block = blocks[GetRand(blocks.size() - 1)];
                  ProcessNewBlock(Params(), block, true, &ignored);
              }
  
              // to make sure that eventually we process the full chain - do it here
              for (auto block : blocks) {
                  if (block->vtx.size() == 1) {
                      bool processed = ProcessNewBlock(Params(), block, true, &ignored);
                      assert(processed);
                  }
              }
          });
      }
  
      threads.join_all();
      while (GetMainSignals().CallbacksPending() > 0) {
          MilliSleep(100);
      }
  
      UnregisterValidationInterface(&sub);
  
      BOOST_CHECK_EQUAL(sub.m_expected_tip, chainActive.Tip()->GetBlockHash());
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  