net_processing: Add missing erase orphan transactions when a block is connected.

furszy · furszy · commit f04886946f29 · 2021-04-15T17:38:03.000-03:00
Eliminating a leak that causes the orphan map to always grow to its maximum size.

Extra information:
I have skipped several PRs from upstream, this was first inside ConnectBlock, then was moved to ActivateBestChain and finally ended up moving it to net_processing under the SyncTransaction slot that we don't have anymore because we are much more updated.
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
@@ -632,6 +632,37 @@ PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) :
     recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
 }
 
+void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
+{
+    LOCK(cs_main);
+
+    std::vector<uint256> vOrphanErase;
+
+    for (const CTransactionRef& ptx : pblock->vtx) {
+        const CTransaction& tx = *ptx;
+
+        // Which orphan pool entries must we evict?
+        for (size_t j = 0; j < tx.vin.size(); j++) {
+            auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].prevout);
+            if (itByPrev == mapOrphanTransactionsByPrev.end()) continue;
+            for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) {
+                const CTransaction& orphanTx = *(*mi)->second.tx;
+                const uint256& orphanHash = orphanTx.GetHash();
+                vOrphanErase.emplace_back(orphanHash);
+            }
+        }
+    }
+
+    // Erase orphan transactions include or precluded by this block
+    if (!vOrphanErase.empty()) {
+        int nErased = 0;
+        for (uint256& orphanHash : vOrphanErase) {
+            nErased += EraseOrphanTx(orphanHash);
+        }
+        LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased);
+    }
+}
+
 void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex* pindexNew, const CBlockIndex* pindexFork, bool fInitialDownload)
 {
     const int nNewHeight = pindexNew->nHeight;
diff --git a/src/net_processing.h b/src/net_processing.h
@@ -45,6 +45,7 @@ class PeerLogicValidation : public CValidationInterface {
     PeerLogicValidation(CConnman* connmanIn);
     ~PeerLogicValidation() = default;
 
+    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex) override;
     void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;
     void BlockChecked(const CBlock& block, const CValidationState& state) override;
 };
