Switch pblock in ProcessNewBlock to a shared_ptr

This (finally) fixes a performance regression in
b3b3c2a

Author: TheBlueMatt

src/net_processing.cpp

@@ -1895,7 +1895,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         BlockTransactions resp;
         vRecv >> resp;
 
-        CBlock block;
+        std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockRead = false;
         {
             LOCK(cs_main);
@@ -1908,7 +1908,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             }
 
             PartiallyDownloadedBlock& partialBlock = *it->second.second->partialBlock;
-            ReadStatus status = partialBlock.FillBlock(block, resp.txn);
+            ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
             if (status == READ_STATUS_INVALID) {
                 MarkBlockAsReceived(resp.blockhash); // Reset in-flight state in case of whitelist
                 Misbehaving(pfrom->GetId(), 100);
@@ -1951,7 +1951,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             bool fNewBlock = false;
             // Since we requested this block (it was in mapBlocksInFlight), force it to be processed,
             // even if it would not be a candidate for new tip (missing previous block, chain not long enough, etc)
-            ProcessNewBlock(chainparams, &block, true, NULL, &fNewBlock);
+            ProcessNewBlock(chainparams, pblock, true, NULL, &fNewBlock);
             if (fNewBlock)
                 pfrom->nLastBlockTime = GetTime();
         }
@@ -2112,17 +2112,17 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
 
     else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing
     {
-        CBlock block;
-        vRecv >> block;
+        std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
+        vRecv >> *pblock;
 
-        LogPrint("net", "received block %s peer=%d\n", block.GetHash().ToString(), pfrom->id);
+        LogPrint("net", "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom->id);
 
         // Process all blocks from whitelisted peers, even if not requested,
         // unless we're still syncing with the network.
         // Such an unrequested block may still be processed, subject to the
         // conditions in AcceptBlock().
         bool forceProcessing = pfrom->fWhitelisted && !IsInitialBlockDownload();
-        const uint256 hash(block.GetHash());
+        const uint256 hash(pblock->GetHash());
         {
             LOCK(cs_main);
             // Also always process if we requested the block explicitly, as we may
@@ -2133,7 +2133,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
             mapBlockSource.emplace(hash, std::make_pair(pfrom->GetId(), true));
         }
         bool fNewBlock = false;
-        ProcessNewBlock(chainparams, &block, forceProcessing, NULL, &fNewBlock);
+        ProcessNewBlock(chainparams, pblock, forceProcessing, NULL, &fNewBlock);
         if (fNewBlock)
             pfrom->nLastBlockTime = GetTime();
     }

src/rpc/mining.cpp

@@ -131,7 +131,8 @@ UniValue generateBlocks(boost::shared_ptr<CReserveScript> coinbaseScript, int nG
         if (pblock->nNonce == nInnerLoopCount) {
             continue;
         }
-        if (!ProcessNewBlock(Params(), pblock, true, NULL, NULL))
+        std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
+        if (!ProcessNewBlock(Params(), shared_pblock, true, NULL, NULL))
             throw JSONRPCError(RPC_INTERNAL_ERROR, "ProcessNewBlock, block not accepted");
         ++nHeight;
         blockHashes.push_back(pblock->GetHash().GetHex());
@@ -728,7 +729,8 @@ UniValue submitblock(const JSONRPCRequest& request)
             + HelpExampleRpc("submitblock", "\"mydata\"")
         );
 
-    CBlock block;
+    std::shared_ptr<CBlock> blockptr = std::make_shared<CBlock>();
+    CBlock& block = *blockptr;
     if (!DecodeHexBlk(block, request.params[0].get_str()))
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");
 
@@ -758,7 +760,7 @@ UniValue submitblock(const JSONRPCRequest& request)
 
     submitblock_StateCatcher sc(block.GetHash());
     RegisterValidationInterface(&sc);
-    bool fAccepted = ProcessNewBlock(Params(), &block, true, NULL, NULL);
+    bool fAccepted = ProcessNewBlock(Params(), blockptr, true, NULL, NULL);
     UnregisterValidationInterface(&sc);
     if (fBlockPresent)
     {

src/test/miner_tests.cpp

@@ -223,7 +223,8 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
             txFirst.push_back(pblock->vtx[0]);
         pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
         pblock->nNonce = blockinfo[i].nonce;
-        BOOST_CHECK(ProcessNewBlock(chainparams, pblock, true, NULL, NULL));
+        std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
+        BOOST_CHECK(ProcessNewBlock(chainparams, shared_pblock, true, NULL, NULL));
         pblock->hashPrevBlock = pblock->GetHash();
     }
 

src/test/test_bitcoin.cpp

@@ -127,7 +127,8 @@ TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>&
 
     while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;
 
-    ProcessNewBlock(chainparams, &block, true, NULL, NULL);
+    std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
+    ProcessNewBlock(chainparams, shared_pblock, true, NULL, NULL);
 
     CBlock result = block;
     return result;

src/validation.cpp

@@ -3123,7 +3123,7 @@ static bool AcceptBlock(const CBlock& block, CValidationState& state, const CCha
     return true;
 }
 
-bool ProcessNewBlock(const CChainParams& chainparams, const CBlock* pblock, bool fForceProcessing, const CDiskBlockPos* dbp, bool *fNewBlock)
+bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<const CBlock> pblock, bool fForceProcessing, const CDiskBlockPos* dbp, bool *fNewBlock)
 {
     {
         LOCK(cs_main);
@@ -3142,13 +3142,8 @@ bool ProcessNewBlock(const CChainParams& chainparams, const CBlock* pblock, bool
 
     NotifyHeaderTip();
 
-    //TODO: This copy is a major performance regression, but callers need updated to fix this
-    std::shared_ptr<const CBlock> block_ptr;
-    if (pblock)
-        block_ptr.reset(new CBlock(*pblock));
-
     CValidationState state; // Only used to report errors, not invalidity - ignore it
-    if (!ActivateBestChain(state, chainparams, block_ptr))
+    if (!ActivateBestChain(state, chainparams, pblock))
         return error("%s: ActivateBestChain failed", __func__);
 
     return true;

src/validation.h

@@ -233,7 +233,7 @@ static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;
  * @param[out]  fNewBlock A boolean which is set to indicate if the block was first received via this call
  * @return True if state.IsValid()
  */
-bool ProcessNewBlock(const CChainParams& chainparams, const CBlock* pblock, bool fForceProcessing, const CDiskBlockPos* dbp, bool* fNewBlock);
+bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<const CBlock> pblock, bool fForceProcessing, const CDiskBlockPos* dbp, bool* fNewBlock);
 
 /**
  * Process incoming block headers.