Merge #17564: rpc: Use mempool from node context instead of global

fa8e650b525e9493bdfa393c0c3e34cb22c78c08 rest: Use mempool from node context instead of global (MarcoFalke)
fa660d65d7cc401ad5bbfdc076a074de19a79329 node: Use mempool from node context instead of global (MarcoFalke)
facbaf092f1ab298943206603cff6e6e3d30d452 rpc: Use mempool from node context instead of global (MarcoFalke)

Pull request description:

  Currently they are identical, but in the future we might want to turn
  the mempool into a unique_ptr. Replacing the global with the mempool
  pointer from the node context simplifies this step.

ACKs for top commit:
  jnewbery:
    Code review ACK fa8e650b5
  ryanofsky:
    Code review ACK fa8e650b525e9493bdfa393c0c3e34cb22c78c08, Only the discussed REST server changes since the last review.

Tree-SHA512: 0836f3f39cf90306455962918446e5f8612e88c32072b92afc30929aea1f17430bbda0e2b3668d36c9d6b97d63a93cf4903185194571108642b7bf5a39b89125

11 files changed, 68 insertions, 30 deletions

diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 26856a00d3..ac640aa35a 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -263,7 +263,7 @@ public:
         }
         return true;
     }
-    void findCoins(std::map<COutPoint, Coin>& coins) override { return FindCoins(coins); }
+    void findCoins(std::map<COutPoint, Coin>& coins) override { return FindCoins(m_node, coins); }
     double guessVerificationProgress(const uint256& block_hash) override
     {
         LOCK(cs_main);
diff --git a/src/interfaces/node.cpp b/src/interfaces/node.cpp
index 1877c92178..24695c1afc 100644
--- a/src/interfaces/node.cpp
+++ b/src/interfaces/node.cpp
@@ -167,8 +167,8 @@ public:
     }
     int64_t getTotalBytesRecv() override { return m_context.connman ? m_context.connman->GetTotalBytesRecv() : 0; }
     int64_t getTotalBytesSent() override { return m_context.connman ? m_context.connman->GetTotalBytesSent() : 0; }
-    size_t getMempoolSize() override { return ::mempool.size(); }
-    size_t getMempoolDynamicUsage() override { return ::mempool.DynamicMemoryUsage(); }
+    size_t getMempoolSize() override { return m_context.mempool ? m_context.mempool->size() : 0; }
+    size_t getMempoolDynamicUsage() override { return m_context.mempool ? m_context.mempool->DynamicMemoryUsage() : 0; }
     bool getHeaderTip(int& height, int64_t& block_time) override
     {
         LOCK(::cs_main);
diff --git a/src/node/coin.cpp b/src/node/coin.cpp
index ad8d1d3af4..f4f86cdbe9 100644
--- a/src/node/coin.cpp
+++ b/src/node/coin.cpp
@@ -4,14 +4,16 @@
 
 #include <node/coin.h>
 
+#include <node/context.h>
 #include <txmempool.h>
 #include <validation.h>
 
-void FindCoins(std::map<COutPoint, Coin>& coins)
+void FindCoins(const NodeContext& node, std::map<COutPoint, Coin>& coins)
 {
-    LOCK2(cs_main, ::mempool.cs);
+    assert(node.mempool);
+    LOCK2(cs_main, node.mempool->cs);
     CCoinsViewCache& chain_view = ::ChainstateActive().CoinsTip();
-    CCoinsViewMemPool mempool_view(&chain_view, ::mempool);
+    CCoinsViewMemPool mempool_view(&chain_view, *node.mempool);
     for (auto& coin : coins) {
         if (!mempool_view.GetCoin(coin.first, coin.second)) {
             // Either the coin is not in the CCoinsViewCache or is spent. Clear it.
diff --git a/src/node/coin.h b/src/node/coin.h
index eb95b75cfb..908850e2a5 100644
--- a/src/node/coin.h
+++ b/src/node/coin.h
@@ -9,14 +9,16 @@
 
 class COutPoint;
 class Coin;
+struct NodeContext;
 
 /**
  * Look up unspent output information. Returns coins in the mempool and in the
  * current chain UTXO set. Iterates through all the keys in the map and
  * populates the values.
  *
+ * @param[in] node The node context to use for lookup
  * @param[in,out] coins map to fill
  */
-void FindCoins(std::map<COutPoint, Coin>& coins);
+void FindCoins(const NodeContext& node, std::map<COutPoint, Coin>& coins);
 
 #endif // BITCOIN_NODE_COIN_H
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index 3c0df2b26e..5e2e502015 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -20,6 +20,7 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
     // node.connman is assigned both before chain clients and before RPC server is accepting calls,
     // and reset after chain clients and RPC sever are stopped. node.connman should never be null here.
     assert(node.connman);
+    assert(node.mempool);
     std::promise<void> promise;
     uint256 hashTx = tx->GetHash();
     bool callback_set = false;
@@ -35,10 +36,10 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
         // So if the output does exist, then this transaction exists in the chain.
         if (!existingCoin.IsSpent()) return TransactionError::ALREADY_IN_CHAIN;
     }
-    if (!mempool.exists(hashTx)) {
+    if (!node.mempool->exists(hashTx)) {
         // Transaction is not already in the mempool. Submit it.
         TxValidationState state;
-        if (!AcceptToMemoryPool(mempool, state, std::move(tx),
+        if (!AcceptToMemoryPool(*node.mempool, state, std::move(tx),
                 nullptr /* plTxnReplaced */, false /* bypass_limits */, max_tx_fee)) {
             err_string = FormatStateMessage(state);
             if (state.IsInvalid()) {
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index dfd56511ea..f6d2816ff8 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -134,6 +134,7 @@ void TestGUI(interfaces::Node& node)
         test.CreateAndProcessBlock({}, GetScriptForRawPubKey(test.coinbaseKey.GetPubKey()));
     }
     node.context()->connman = std::move(test.m_node.connman);
+    node.context()->mempool = std::move(test.m_node.mempool);
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(node.context()->chain.get(), WalletLocation(), WalletDatabase::CreateMock());
     bool firstRun;
     wallet->LoadWallet(firstRun);
diff --git a/src/rest.cpp b/src/rest.cpp
index 228c122de3..55756ecfdf 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -8,6 +8,7 @@
 #include <core_io.h>
 #include <httpserver.h>
 #include <index/txindex.h>
+#include <node/context.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <rpc/blockchain.h>
@@ -16,6 +17,7 @@
 #include <streams.h>
 #include <sync.h>
 #include <txmempool.h>
+#include <util/check.h>
 #include <util/strencodings.h>
 #include <validation.h>
 #include <version.h>
@@ -69,6 +71,24 @@ static bool RESTERR(HTTPRequest* req, enum HTTPStatusCode status, std::string me
     return false;
 }
 
+/**
+ * Get the node context mempool.
+ *
+ * Set the HTTP error and return nullptr if node context
+ * mempool is not found.
+ *
+ * @param[in]  req the HTTP request
+ * return pointer to the mempool or nullptr if no mempool found
+ */
+static CTxMemPool* GetMemPool(HTTPRequest* req)
+{
+    if (!g_rpc_node || !g_rpc_node->mempool) {
+        RESTERR(req, HTTP_NOT_FOUND, "Mempool disabled or instance not found");
+        return nullptr;
+    }
+    return g_rpc_node->mempool;
+}
+
 static RetFormat ParseDataFormat(std::string& param, const std::string& strReq)
 {
     const std::string::size_type pos = strReq.rfind('.');
@@ -295,12 +315,14 @@ static bool rest_mempool_info(HTTPRequest* req, const std::string& strURIPart)
 {
     if (!CheckWarmup(req))
         return false;
+    const CTxMemPool* mempool = GetMemPool(req);
+    if (!mempool) return false;
     std::string param;
     const RetFormat rf = ParseDataFormat(param, strURIPart);
 
     switch (rf) {
     case RetFormat::JSON: {
-        UniValue mempoolInfoObject = MempoolInfoToJSON(::mempool);
+        UniValue mempoolInfoObject = MempoolInfoToJSON(*mempool);
 
         std::string strJSON = mempoolInfoObject.write() + "\n";
         req->WriteHeader("Content-Type", "application/json");
@@ -315,14 +337,15 @@ static bool rest_mempool_info(HTTPRequest* req, const std::string& strURIPart)
 
 static bool rest_mempool_contents(HTTPRequest* req, const std::string& strURIPart)
 {
-    if (!CheckWarmup(req))
-        return false;
+    if (!CheckWarmup(req)) return false;
+    const CTxMemPool* mempool = GetMemPool(req);
+    if (!mempool) return false;
     std::string param;
     const RetFormat rf = ParseDataFormat(param, strURIPart);
 
     switch (rf) {
     case RetFormat::JSON: {
-        UniValue mempoolObject = MempoolToJSON(::mempool, true);
+        UniValue mempoolObject = MempoolToJSON(*mempool, true);
 
         std::string strJSON = mempoolObject.write() + "\n";
         req->WriteHeader("Content-Type", "application/json");
@@ -500,11 +523,13 @@ static bool rest_getutxos(HTTPRequest* req, const std::string& strURIPart)
         };
 
         if (fCheckMemPool) {
+            const CTxMemPool* mempool = GetMemPool(req);
+            if (!mempool) return false;
             // use db+mempool as cache backend in case user likes to query mempool
-            LOCK2(cs_main, mempool.cs);
+            LOCK2(cs_main, mempool->cs);
             CCoinsViewCache& viewChain = ::ChainstateActive().CoinsTip();
-            CCoinsViewMemPool viewMempool(&viewChain, mempool);
-            process_utxos(viewMempool, mempool);
+            CCoinsViewMemPool viewMempool(&viewChain, *mempool);
+            process_utxos(viewMempool, *mempool);
         } else {
             LOCK(cs_main);  // no need to lock mempool!
             process_utxos(::ChainstateActive().CoinsTip(), CTxMemPool());
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 44f5326b3c..02f610d841 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -528,7 +528,7 @@ static UniValue getrawmempool(const JSONRPCRequest& request)
     if (!request.params[0].isNull())
         fVerbose = request.params[0].get_bool();
 
-    return MempoolToJSON(::mempool, fVerbose);
+    return MempoolToJSON(EnsureMemPool(), fVerbose);
 }
 
 static UniValue getmempoolancestors(const JSONRPCRequest& request)
@@ -566,6 +566,7 @@ static UniValue getmempoolancestors(const JSONRPCRequest& request)
 
     uint256 hash = ParseHashV(request.params[0], "parameter 1");
 
+    const CTxMemPool& mempool = EnsureMemPool();
     LOCK(mempool.cs);
 
     CTxMemPool::txiter it = mempool.mapTx.find(hash);
@@ -591,7 +592,7 @@ static UniValue getmempoolancestors(const JSONRPCRequest& request)
             const CTxMemPoolEntry &e = *ancestorIt;
             const uint256& _hash = e.GetTx().GetHash();
             UniValue info(UniValue::VOBJ);
-            entryToJSON(::mempool, info, e);
+            entryToJSON(mempool, info, e);
             o.pushKV(_hash.ToString(), info);
         }
         return o;
@@ -633,6 +634,7 @@ static UniValue getmempooldescendants(const JSONRPCRequest& request)
 
     uint256 hash = ParseHashV(request.params[0], "parameter 1");
 
+    const CTxMemPool& mempool = EnsureMemPool();
     LOCK(mempool.cs);
 
     CTxMemPool::txiter it = mempool.mapTx.find(hash);
@@ -658,7 +660,7 @@ static UniValue getmempooldescendants(const JSONRPCRequest& request)
             const CTxMemPoolEntry &e = *descendantIt;
             const uint256& _hash = e.GetTx().GetHash();
             UniValue info(UniValue::VOBJ);
-            entryToJSON(::mempool, info, e);
+            entryToJSON(mempool, info, e);
             o.pushKV(_hash.ToString(), info);
         }
         return o;
@@ -685,6 +687,7 @@ static UniValue getmempoolentry(const JSONRPCRequest& request)
 
     uint256 hash = ParseHashV(request.params[0], "parameter 1");
 
+    const CTxMemPool& mempool = EnsureMemPool();
     LOCK(mempool.cs);
 
     CTxMemPool::txiter it = mempool.mapTx.find(hash);
@@ -694,7 +697,7 @@ static UniValue getmempoolentry(const JSONRPCRequest& request)
 
     const CTxMemPoolEntry &e = *it;
     UniValue info(UniValue::VOBJ);
-    entryToJSON(::mempool, info, e);
+    entryToJSON(mempool, info, e);
     return info;
 }
 
@@ -1070,6 +1073,7 @@ UniValue gettxout(const JSONRPCRequest& request)
     CCoinsViewCache* coins_view = &::ChainstateActive().CoinsTip();
 
     if (fMempool) {
+        const CTxMemPool& mempool = EnsureMemPool();
         LOCK(mempool.cs);
         CCoinsViewMemPool view(coins_view, mempool);
         if (!view.GetCoin(out, coin) || mempool.isSpent(out)) {
@@ -1448,7 +1452,7 @@ static UniValue getmempoolinfo(const JSONRPCRequest& request)
                 },
             }.Check(request);
 
-    return MempoolInfoToJSON(::mempool);
+    return MempoolInfoToJSON(EnsureMemPool());
 }
 
 static UniValue preciousblock(const JSONRPCRequest& request)
@@ -1964,11 +1968,13 @@ static UniValue savemempool(const JSONRPCRequest& request)
                 },
             }.Check(request);
 
-    if (!::mempool.IsLoaded()) {
+    const CTxMemPool& mempool = EnsureMemPool();
+
+    if (!mempool.IsLoaded()) {
         throw JSONRPCError(RPC_MISC_ERROR, "The mempool was not loaded yet");
     }
 
-    if (!DumpMempool(::mempool)) {
+    if (!DumpMempool(mempool)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Unable to dump mempool to disk");
     }
 
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index fc16a31423..5017e5b9d9 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -244,6 +244,7 @@ static UniValue getmininginfo(const JSONRPCRequest& request)
             }.Check(request);
 
     LOCK(cs_main);
+    const CTxMemPool& mempool = EnsureMemPool();
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("blocks",           (int)::ChainActive().Height());
@@ -290,7 +291,7 @@ static UniValue prioritisetransaction(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Priority is no longer supported, dummy argument to prioritisetransaction must be 0.");
     }
 
-    mempool.PrioritiseTransaction(hash, nAmount);
+    EnsureMemPool().PrioritiseTransaction(hash, nAmount);
     return true;
 }
 
@@ -476,6 +477,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, PACKAGE_NAME " is in initial sync and waiting for blocks...");
 
     static unsigned int nTransactionsUpdatedLast;
+    const CTxMemPool& mempool = EnsureMemPool();
 
     if (!lpval.isNull())
     {
@@ -510,7 +512,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
                 if (g_best_block_cv.wait_until(lock, checktxtime) == std::cv_status::timeout)
                 {
                     // Timeout: Check transactions for update
-                    // without holding ::mempool.cs to avoid deadlocks
+                    // without holding the mempool lock to avoid deadlocks
                     if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLastLP)
                         break;
                     checktxtime += std::chrono::seconds(10);
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index b816a54d2f..5be7acce1c 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -636,6 +636,7 @@ static UniValue combinerawtransaction(const JSONRPCRequest& request)
     CCoinsView viewDummy;
     CCoinsViewCache view(&viewDummy);
     {
+        const CTxMemPool& mempool = EnsureMemPool();
         LOCK(cs_main);
         LOCK(mempool.cs);
         CCoinsViewCache &viewChain = ::ChainstateActive().CoinsTip();
@@ -758,7 +759,7 @@ static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
     for (const CTxIn& txin : mtx.vin) {
         coins[txin.prevout]; // Create empty map entry keyed by prevout.
     }
-    FindCoins(coins);
+    FindCoins(*g_rpc_node, coins);
 
     // Parse the prevtxs array
     ParsePrevouts(request.params[2], &keystore, coins);
@@ -890,6 +891,7 @@ static UniValue testmempoolaccept(const JSONRPCRequest& request)
         max_raw_tx_fee_rate = CFeeRate(AmountFromValue(request.params[1]));
     }
 
+    CTxMemPool& mempool = EnsureMemPool();
     int64_t virtual_size = GetVirtualTransactionSize(*tx);
     CAmount max_raw_tx_fee = max_raw_tx_fee_rate.GetFee(virtual_size);
 
@@ -1508,6 +1510,7 @@ UniValue utxoupdatepsbt(const JSONRPCRequest& request)
     CCoinsView viewDummy;
     CCoinsViewCache view(&viewDummy);
     {
+        const CTxMemPool& mempool = EnsureMemPool();
         LOCK2(cs_main, mempool.cs);
         CCoinsViewCache &viewChain = ::ChainstateActive().CoinsTip();
         CCoinsViewMemPool viewMempool(&viewChain, mempool);
diff --git a/src/test/rpc_tests.cpp b/src/test/rpc_tests.cpp
index 52dd22de7e..84a3980b19 100644
--- a/src/test/rpc_tests.cpp
+++ b/src/test/rpc_tests.cpp
@@ -112,14 +112,10 @@ BOOST_AUTO_TEST_CASE(rpc_rawsign)
     std::string notsigned = r.get_str();
     std::string privkey1 = "\"KzsXybp9jX64P5ekX1KUxRQ79Jht9uzW7LorgwE65i5rWACL6LQe\"";
     std::string privkey2 = "\"Kyhdf5LuKTRx4ge69ybABsiUAWjVRK4XGxAKk2FQLp2HjGMy87Z4\"";
-    NodeContext node;
-    node.chain = interfaces::MakeChain(node);
-    g_rpc_node = &node;
     r = CallRPC(std::string("signrawtransactionwithkey ")+notsigned+" [] "+prevout);
     BOOST_CHECK(find_value(r.get_obj(), "complete").get_bool() == false);
     r = CallRPC(std::string("signrawtransactionwithkey ")+notsigned+" ["+privkey1+","+privkey2+"] "+prevout);
     BOOST_CHECK(find_value(r.get_obj(), "complete").get_bool() == true);
-    g_rpc_node = nullptr;
 }
 
 BOOST_AUTO_TEST_CASE(rpc_createraw_op_return)