Implement transaction expiry for Overwinter

src/txmempool.cpp

@@ -256,6 +256,24 @@ void CTxMemPool::removeConflicts(const CTransaction &tx, std::list<CTransaction>
     }
 }
 
+void CTxMemPool::removeExpired(unsigned int nBlockHeight)
+{
+    // Remove expired txs from the mempool
+    LOCK(cs);
+    list<CTransaction> transactionsToRemove;
+    for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++)
+    {
+        const CTransaction& tx = it->GetTx();
+        if (IsExpiredTx(tx, nBlockHeight)) {
+            transactionsToRemove.push_back(tx);
+        }
+    }
+    for (const CTransaction& tx : transactionsToRemove) {
+        list<CTransaction> removed;
+        remove(tx, removed, true);
+    }
+}
+
 /**
  * Called when a block is connected. Removes from mempool and updates the miner fee estimator.
  */