Merge pull request #16 from kevacoin-project/idb-fix

Fixed Initial block download (IDB) crash. The chainActive does not contain any blocks during IDB. We must save the block hash for these blocks that are candidates of seeds.

Fixed calling params to rx_slow_hash. Set miners to 0 to prevent incorrect results.

src/bitcoin-tx.cpp

@@ -33,6 +33,8 @@ static const int CONTINUE_EXECUTION=-1;
 
 // To fix the chainActive not defined error.
 CChain chainActive;
+typedef std::map<uint64_t, CBlockIndex*> BlockSeedHeightMap;
+BlockSeedHeightMap mapBlockSeedHeight;
 
 //
 // This function returns either one of EXIT_ codes when it's expected to stop the process or

src/cn_utils/crypto/hash-ops.h

@@ -93,5 +93,6 @@ void rx_slow_hash_allocate_state(void);
 void rx_slow_hash_free_state(void);
 uint64_t rx_seedheight(const uint64_t height);
 void rx_seedheights(const uint64_t height, uint64_t *seed_height, uint64_t *next_height);
+int is_a_seed_height(const uint64_t height);
 void rx_slow_hash(const uint64_t mainheight, const uint64_t seedheight, const char *seedhash, const void *data, size_t length, char *hash, int miners, int is_alt);
 void rx_reorg(const uint64_t split_height);

src/cn_utils/crypto/rx-slow-hash.c

@@ -139,6 +139,11 @@ void rx_seedheights(const uint64_t height, uint64_t *seedheight, uint64_t *nexth
   *nextheight = rx_seedheight(height + SEEDHASH_EPOCH_LAG);
 }
 
+int is_a_seed_height(const uint64_t height) {
+    uint64_t next_seed_hegith = rx_seedheight(height + SEEDHASH_EPOCH_LAG + 1);
+    return (height == next_seed_hegith);
+}
+
 typedef struct seedinfo {
   randomx_cache *si_cache;
   unsigned long si_start;

src/primitives/block.cpp

@@ -17,32 +17,14 @@
 extern "C" void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int prehashed, uint64_t height);
 extern "C" void cn_fast_hash(const void *data, size_t length, char *hash);
 
-namespace
-{
-    boost::mutex max_concurrency_lock;
-    unsigned max_concurrency = boost::thread::hardware_concurrency();
-}
-
-void set_max_concurrency(unsigned n)
-{
-    if (n < 1)
-        n = boost::thread::hardware_concurrency();
-    unsigned hwc = boost::thread::hardware_concurrency();
-    if (n > hwc)
-        n = hwc;
-    boost::lock_guard<boost::mutex> lock(max_concurrency_lock);
-    max_concurrency = n;
-}
-
-unsigned get_max_concurrency()
-{
-    boost::lock_guard<boost::mutex> lock(max_concurrency_lock);
-    return max_concurrency;
-}
-
 static uint256 cn_get_block_hash_by_height(uint64_t seed_height, char cnHash[32])
 {
     CBlockIndex* pblockindex = chainActive[seed_height];
+    if (pblockindex == NULL) {
+        // This will only happens during initial block download.
+        pblockindex = mapBlockSeedHeight.find(seed_height)->second;
+    }
+    assert(pblockindex != NULL);
     uint256 blockHash = pblockindex->GetBlockHash();
     const unsigned char* pHash = blockHash.begin();
     for (int j = 31; j >= 0; j--) {
@@ -91,7 +73,7 @@ uint256 CBlockHeader::GetPoWHash() const
         char cnHash[32];
         seed_height = crypto::rx_seedheight(height);
         cn_get_block_hash_by_height(seed_height, cnHash);
-        crypto::rx_slow_hash(height, seed_height, cnHash, blob.data(), blob.size(), BEGIN(thash), get_max_concurrency(), 0);
+        crypto::rx_slow_hash(height, seed_height, cnHash, blob.data(), blob.size(), BEGIN(thash), 0, 0);
     } else {
         cn_slow_hash(blob.data(), blob.size(), BEGIN(thash), cnHeader.major_version - 6, 0, height);
     }

src/validation.cpp

@@ -154,6 +154,7 @@ public:
     CChain chainActive;
     BlockMap mapBlockIndex;
     std::multimap<CBlockIndex*, CBlockIndex*> mapBlocksUnlinked;
+    BlockSeedHeightMap mapBlockSeedHeight;
     CBlockIndex *pindexBestInvalid = nullptr;
 
     bool LoadBlockIndex(const Consensus::Params& consensus_params, CBlockTreeDB& blocktree);
@@ -206,6 +207,7 @@ private:
 CCriticalSection cs_main;
 
 BlockMap& mapBlockIndex = g_chainstate.mapBlockIndex;
+BlockSeedHeightMap& mapBlockSeedHeight = g_chainstate.mapBlockSeedHeight;
 CChain& chainActive = g_chainstate.chainActive;
 CBlockIndex *pindexBestHeader = nullptr;
 CWaitableCriticalSection csBestBlock;
@@ -2880,6 +2882,10 @@ CBlockIndex* CChainState::AddToBlockIndex(const CBlockHeader& block)
     // to avoid miners withholding blocks but broadcasting headers, to get a
     // competitive advantage.
     pindexNew->nSequenceId = 0;
+    uint64_t height = block.nNonce;
+    if (crypto::is_a_seed_height(height)) {
+        mapBlockSeedHeight.insert(std::make_pair(height, pindexNew));
+    }
     BlockMap::iterator mi = mapBlockIndex.insert(std::make_pair(hash, pindexNew)).first;
     pindexNew->phashBlock = &((*mi).first);
     BlockMap::iterator miPrev = mapBlockIndex.find(block.hashPrevBlock);

src/validation.h

@@ -161,6 +161,8 @@ extern CBlockPolicyEstimator feeEstimator;
 extern CTxMemPool mempool;
 typedef std::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
 extern BlockMap& mapBlockIndex;
+typedef std::map<uint64_t, CBlockIndex*> BlockSeedHeightMap;
+extern BlockSeedHeightMap& mapBlockSeedHeight;
 extern uint64_t nLastBlockTx;
 extern uint64_t nLastBlockWeight;
 extern const std::string strMessageMagic;