From 29e983386b0aecf99cdb7d0e08ba6b450bed313e Mon Sep 17 00:00:00 2001 From: Shorya Date: Wed, 1 Sep 2021 22:00:05 +0530 Subject: [PATCH] Fixes Bug in Transaction generation in ComplexMempool benchmark Available in line 59 is made a reference , so contents of the coin can be modified While generating transactions we select ancestors from available_coins ,in case we exhaust all the outputs of an entry in available_coins then we need to remove it from available_coins before the next iteration of choosing a potential ancestor , it is now implemented with this patch by ,As the index of the entry is randomly chosen from available_coins , In order to remove it from the vector if index of the selected entry is not at the end of available_coins vector, it is swapped with the entry at the back of the vector , then the entry at the end of available_coins is popped out. Code generating outputs for the transaction is moved out of the loop, as it needs to be done only once before adding the transaction to ordered_coins --- src/bench/mempool_stress.cpp | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/src/bench/mempool_stress.cpp b/src/bench/mempool_stress.cpp index f28768efc85..653a2630fc9 100644 --- a/src/bench/mempool_stress.cpp +++ b/src/bench/mempool_stress.cpp @@ -56,7 +56,7 @@ static void ComplexMemPool(benchmark::Bench& bench) size_t n_ancestors = det_rand.randrange(10)+1; for (size_t ancestor = 0; ancestor < n_ancestors && !available_coins.empty(); ++ancestor){ size_t idx = det_rand.randrange(available_coins.size()); - Available coin = available_coins[idx]; + Available& coin = available_coins[idx]; uint256 hash = coin.ref->GetHash(); // biased towards taking just one ancestor, but maybe more size_t n_to_take = det_rand.randrange(2) == 0 ? 1 : 1+det_rand.randrange(coin.ref->vout.size() - coin.vin_left); @@ -66,15 +66,17 @@ static void ComplexMemPool(benchmark::Bench& bench) tx.vin.back().scriptSig = CScript() << coin.tx_count; tx.vin.back().scriptWitness.stack.push_back(CScriptNum(coin.tx_count).getvch()); } - if (coin.vin_left == coin.ref->vin.size()) { - coin = available_coins.back(); + if (coin.vin_left == coin.ref->vout.size()) { + if(available_coins.size()-1!=idx){ // if idx is not the last index swap it with the end index + std::swap(available_coins[idx], available_coins.back()); + } available_coins.pop_back(); } - tx.vout.resize(det_rand.randrange(10)+2); - for (auto& out : tx.vout) { - out.scriptPubKey = CScript() << CScriptNum(tx_counter) << OP_EQUAL; - out.nValue = 10 * COIN; - } + } + tx.vout.resize(det_rand.randrange(10)+2); + for (auto& out : tx.vout) { + out.scriptPubKey = CScript() << CScriptNum(tx_counter) << OP_EQUAL; + out.nValue = 10 * COIN; } ordered_coins.emplace_back(MakeTransactionRef(tx)); available_coins.emplace_back(ordered_coins.back(), tx_counter++);